[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO2024192546A1 - 一种探测方法以及相关装置 - Google Patents

一种探测方法以及相关装置 Download PDF

Info

Publication number
WO2024192546A1
WO2024192546A1 PCT/CN2023/082046 CN2023082046W WO2024192546A1 WO 2024192546 A1 WO2024192546 A1 WO 2024192546A1 CN 2023082046 W CN2023082046 W CN 2023082046W WO 2024192546 A1 WO2024192546 A1 WO 2024192546A1
Authority
WO
WIPO (PCT)
Prior art keywords
sub
echo
histogram
optical signal
compensation
Prior art date
Application number
PCT/CN2023/082046
Other languages
English (en)
French (fr)
Inventor
韩二江
石现领
曹国亮
于众
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to PCT/CN2023/082046 priority Critical patent/WO2024192546A1/zh
Publication of WO2024192546A1 publication Critical patent/WO2024192546A1/zh

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/4865—Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak

Definitions

  • the present application relates to the field of optoelectronic technology, and more specifically, to a detection method and related devices.
  • Laser radar light detection and ranging, Lidar
  • Lidar has the characteristics of high resolution and strong anti-active interference ability, so it is widely used in various technical fields.
  • Lidar emits a laser beam to the target object to be detected. After the laser beam contacts the target object, it will be reflected and received by the signal detector in the form of an echo beam.
  • the echo beam hits the pixel array of the signal detector to form a light spot, and the pixel array converts the echo beam from an optical signal to an electrical signal.
  • some parameters are determined, and then the target parameters such as the distance between the current Lidar and the target object and the reflectivity of the target object can be solved to achieve functions such as target ranging and target recognition.
  • the target parameters are solved based on the echo signal of the specified spot distribution, which usually contains errors. Therefore, the target parameters corresponding to the above spot distribution can be compensated for errors based on the error compensation table.
  • the spot distribution usually changes. Therefore, if the target parameters are compensated through the above error compensation table, the accuracy of the compensation for the target parameters cannot be guaranteed.
  • the embodiments of the present application provide a detection method and related devices, which can avoid the situation where the light spot distribution is changed when the light spot is offset due to the uneven distribution of the light spot formed by the echo light beam on the detector, and thus cause inaccurate error compensation of the target parameters calculated by the lidar system, thereby helping to increase the accuracy of error compensation.
  • a detection method which is applied to a detector, and the method includes: receiving an echo light beam, which hits a first pixel of the detector; the first pixel includes N sub-pixels, and N first sub-light signals are determined based on the N sub-pixels, wherein N is a positive integer; based on the N first sub-light signals, N first echo parameters are determined, and the first echo parameters are used to characterize the signal strength of the first sub-light signal; and a first light signal is determined based on the N first echo parameters, and the first light signal corresponds to the echo light beam.
  • the echo light beam is finally presented in the form of a light spot on the pixel array of the detector. Therefore, when the light spot occupies multiple pixels, the light signal determined based on the echo light beam corresponds to a part of the light spot; when the light spot only occupies the first pixel, the light signal determined based on the echo light beam corresponds to the entire light spot.
  • the first pixel can be divided into N sub-pixels with the same geometric parameters, and the embodiment of the present application does not limit the specific geometric parameters.
  • the first pixel can also be divided into N sub-pixels with different geometric parameters, and the first pixel can also be divided into a part of sub-pixels with the first geometric parameter and another part of sub-pixels with the second geometric parameter, etc.
  • the pixel array can adjust the division mode of each pixel on the pixel array in real time according to the current light spot distribution, so that the light spot distribution in each sub-pixel is uniform, so as to further increase the accuracy of subsequent error compensation.
  • the first optical signal is an optical signal compensated based on the first echo parameter corresponding to each first sub-optical signal, and the target parameter carried by the first optical signal can be accurately compensated.
  • the first pixel is divided into N sub-pixels. Since the sub-pixels are very small, the spot distribution in the sub-pixels is uniform or approximately uniform. When detecting the distance of the target object or the reflectivity of the target object, no matter how factors such as the distance of the target object and the temperature of the laser change, the spot distribution in the sub-pixel remains unchanged. Therefore, based on this method, it helps to avoid the problem that the error cannot be accurately compensated based on a compensation table due to changes in the spot distribution. That is, this method can achieve the premise that the geometric parameters of the N sub-pixels are the same, and the accurate compensation amount can be obtained through a compensation table, which improves the accuracy of error compensation and is easy to implement.
  • a first sub-histogram is determined based on the first sub-optical signal, the first sub-histogram including a signal intensity change trend of the first sub-optical signal in multiple unit time periods; and a first echo parameter is determined based on the first sub-histogram.
  • the first echo parameter characterizing the signal strength of the first sub-light signal is calculated by the first sub-histogram, and the method is easy to implement.
  • N first sub-compensation amounts are determined based on N first echo parameters; and a first compensation amount is determined based on the N first sub-compensation amounts, and the first compensation amount is used to determine the compensation amount of the above-mentioned first optical signal.
  • the first sub-compensation amount can be determined by looking up a compensation table.
  • the compensation table can be determined in advance through experiments. Different sub-pixel geometric parameters correspond to different compensation tables. Based on this, when the N sub-pixel geometric parameters are the same, the first compensation amount can be determined through one compensation table.
  • the method of determining the above-mentioned first compensation amount is also different: the N first sub-compensation amounts can be weighted accumulated, and the weighted accumulation can include two cases, one case is that the weight is 1, and the weighted accumulation process is actually a direct accumulation process, and the other case is that the weight is not 1; in addition, the N first sub-compensation amounts can also be accumulated to obtain the average value.
  • the N first echo parameters are determined based on the N first sub-light signals received by the N sub-pixels, and since the sub-pixels are very small, even if the light spot corresponding to the echo light beam is offset, for the N sub-pixels, when N is large enough, the distribution of some light spots on the sub-pixels is approximately uniform, so regardless of whether the light spot is offset, the distribution of some light spots corresponding to the N sub-pixels is maintained as uniform, therefore, the N first sub-compensation amounts determined based on the N first echo parameters are accurate, and thus the first compensation amount is accurate, thereby increasing the accuracy of error compensation.
  • a corresponding first compensation table is screened out based on the geometric parameters of the sub-pixel; the first compensation table is searched based on the first echo parameter to determine the first sub-compensation amount corresponding to the first echo parameter, and the first compensation table is determined in advance through experiments, and the first compensation table includes a mapping relationship between the first echo parameter and the first sub-compensation amount.
  • the geometric parameters of the sub-pixel include the shape and/or area of the sub-pixel.
  • the first compensation table corresponding to different sub-pixels can be reasonably determined, which helps to ensure the accuracy of error compensation.
  • the first echo parameter includes at least one of the following: an echo area, an echo peak, an echo pulse width of the first sub-optical signal, and a rising edge slope of a curve image in the first sub-histogram.
  • the first sub-compensation amount can be determined based on at least one of the echo area, echo peak value, echo pulse width of the first sub-light signal and the rising edge slope of the curve image in the first sub-histogram, which provides multiple ways to determine the compensation amount and increases the flexibility of the solution.
  • a first result value is determined based on a second optical signal, wherein the second optical signal is an original optical signal determined based on the above-mentioned echo light beam; the first result value is compensated by a first compensation amount to determine a first target parameter value, which corresponds to the above-mentioned first optical signal.
  • the first result value may be the distance of the target object, or may be the energy value of the second light signal used to calculate the reflectivity of the target object.
  • the first result value is an uncompensated result value.
  • a first histogram is determined based on the second optical signal, the first histogram including a signal strength change trend of the second optical signal in multiple unit time periods; and a first result value is determined based on the first histogram.
  • the echo area, echo pulse width, echo peak value of the second optical signal and the rising edge slope of the curve image in the first histogram can be determined according to the first histogram.
  • the echo area is the integral value of the curve image in the first histogram; the echo pulse width can be divided into the first pulse width and the second pulse width.
  • the first pulse width is also called the full pulse width, which is the difference between the horizontal coordinates of the starting point and the end point of the curve image in the first histogram;
  • the second pulse width is the pulse width corresponding to a certain proportional threshold, that is, the pulse width of the curve image in the first histogram horizontally intercepted at a preset position, wherein the preset position can be 1/2 of the curve image (in this case, the second pulse width is also called the half-height pulse width), or 1/3 and other reasonable positions.
  • the preset position is 1/2 of the curve image
  • the ordinate of the peak point of the curve image is y
  • the ordinates of the two endpoints of the half-height pulse width are y/2
  • the difference between the horizontal coordinates of the two endpoints is the half-height pulse width
  • the echo peak value is the ordinate of the peak point of the curve image in the first histogram.
  • the first echo parameter can also be determined based on the first sub-histogram, and the first echo parameter includes at least one of the echo area, echo pulse width, and echo peak value of the first sub-light signal.
  • the first histogram can be intercepted based on a first detection threshold, so that the first result value is calculated based on the portion of the image above the first detection threshold.
  • the first detection threshold is a reasonable preset value.
  • the first sub-histogram since the first sub-histogram is the first histogram compressed according to a corresponding ratio, the first sub-histogram can also correspond to a second detection threshold, which is proportionally reduced based on the first detection threshold.
  • the start time and end time of the first histogram can be determined based on the first histogram and the first detection threshold, and the start time and end time also correspond to the start time and end time of the first sub-histogram, there is no need to determine The above second detection threshold can complete the interception of the first sub-histogram.
  • the first result value can be determined relatively intuitively and simply through the first histogram corresponding to the second optical signal, which helps to improve calculation efficiency.
  • the moment when the laser beam is emitted to the target object is determined as the first moment; based on the first histogram, the second moment is determined; based on the time difference between the second moment and the first moment, the flight time corresponding to the second light signal is determined; and based on the speed of light and the flight time, the above-mentioned first result value is determined.
  • the second moment is determined by the first histogram, which makes the acquisition of the second moment relatively simple, and helps to improve the efficiency of calculating the first result value.
  • the starting moment of detecting the second optical signal is determined as the above-mentioned second moment; or, based on the first histogram, the peak moment of the first histogram is determined as the above-mentioned second moment; or, based on the first histogram, the above-mentioned second moment is determined by constant fraction timing (CFD) method; or, based on the first histogram, the echo time of the second optical signal is determined, and then the second moment is determined according to the echo time corresponding to the second optical signal through a centroid algorithm.
  • CFD constant fraction timing
  • the echo area and/or echo peak value of the second optical signal is determined according to the first histogram; the signal strength of the second optical signal is determined according to the echo area and/or echo peak value of the second optical signal; and the first result value is determined according to the signal strength of the second optical signal.
  • the signal strength of the second optical signal is determined by the first histogram. This method is relatively simple and helps to improve the efficiency of calculating the first result value.
  • a first compensation table is determined, including: obtaining a second target parameter value and a geometric parameter of a sub-pixel, the second target parameter value being an accurate target parameter value; determining a first sub-light signal obtained by the sub-pixel; determining a second result value based on the first echo parameter corresponding to the first sub-light signal, the second result value being a result value that needs to be compensated; determining a first sub-compensation amount based on the second result value and the second target parameter value; recording the first echo parameter corresponding to the first sub-light signal to determine a mapping relationship between the first echo parameter and the first sub-compensation amount; and adding the mapping relationship to the first compensation table corresponding to the geometric parameter of the sub-pixel.
  • the target object distance is an accurate distance value measured in advance
  • the second target parameter value is the energy value of the second light signal corresponding to the echo light beam reflected by the target object
  • the energy value is an accurate energy value measured in advance
  • the geometric parameters of the sub-pixel are determined in the process of determining the first pixel division method.
  • the geometric parameters of the sub-pixel can be stored in the memory.
  • the second result value when the second result value is the distance of the target object that has not been compensated, based on the description of the corresponding embodiment, it can be known that the second result value can be calculated based on the flight time of the first sub-light signal.
  • the second result value is the energy value of the first sub-light signal that has not been compensated, based on the description of the corresponding embodiment, it can be known that the second result value can be calculated based on the signal strength of the first sub-light signal.
  • the second target parameter value and the second result value may be subtracted to determine the distance sub-compensation.
  • the first sub-compensation is an energy sub-compensation of the first sub-optical signal
  • the energy quantum compensation amount may be estimated based on the second target parameter value and the second result value.
  • a corresponding first compensation table is determined for sub-pixels with different geometric parameters through a preliminary experimental method.
  • the first pixel is divided into a plurality of sub-pixels with the same geometric parameters, accurate compensation for the distance compensation amount can be achieved based on a first compensation table determined through the above experiment. Even if the geometric parameters of the plurality of sub-pixels into which the first pixel is divided are not completely the same, for example, two geometric parameters. Only two of the above first compensation tables are needed to accurately compensate for the distance compensation amount. The problem of difficulty in accurately performing error compensation in the prior art is solved.
  • the N sub-pixels are divided based on single photon avalanche diodes SPAD in the pixel array.
  • the above-mentioned SPAD includes a pixel activation area, and each pixel in the pixel activation area can be pre-set by SPAD initial parameters to divide the pixel into multiple sub-pixels.
  • the initial parameters include geometric parameters of each sub-pixel, such as the length and width of each pixel, and set a number for each sub-pixel. And it also supports numbering each pixel. In this way, it is possible to distinguish the partial light signal corresponding to each sub-pixel.
  • the above first pixel is divided by SPAD, which provides the necessary prerequisite for the subsequent sub-pixel-based compensation solution and is the basis for accurate error compensation.
  • the echo light beam hits the pixel array to form a light spot, and the distribution of part of the light spot on each sub-pixel is uniform.
  • the distribution of part of the light spot on the sub-pixel can be guaranteed to be uniform, which can further increase the accuracy of subsequent error compensation.
  • a detection device which is applied to a detector, and the device includes: a receiving unit, which is used to receive an echo light beam, and the echo light beam hits a first pixel of the detector, and the first pixel includes N sub-pixels; a determination unit, which is used to determine N first sub-light signals based on the above-mentioned N sub-pixels, wherein N is a positive integer; based on the N first sub-light signals, N first echo parameters are determined, and the first echo parameters are used to characterize the signal strength of the first sub-light signal; and a first light signal is determined based on the above-mentioned N first echo parameters, and the first light signal corresponds to the above-mentioned echo light beam.
  • the first pixel is divided into N sub-pixels. Since the sub-pixels are very small, the spot distribution in the sub-pixels is uniform or approximately uniform. When detecting the distance of the target object or the reflectivity of the target object, no matter how factors such as the distance of the target object and the temperature of the laser change, the spot distribution in the sub-pixel remains unchanged. Therefore, based on this method, it helps to avoid the problem that the error cannot be accurately compensated based on a compensation table due to changes in the spot distribution. That is, this method can achieve the premise that the geometric parameters of the N sub-pixels are the same, and the accurate compensation amount can be obtained through a compensation table, which improves the accuracy of error compensation and is easy to implement.
  • the above-mentioned determination unit is specifically used to: determine a first sub-histogram based on the first sub-light signal, the first sub-histogram including a signal intensity change trend of the first sub-light signal within multiple unit time periods; determine a first echo parameter based on the first sub-histogram.
  • the first echo parameter characterizing the signal strength of the first sub-light signal is calculated by the first sub-histogram, and the method is easy to implement.
  • the determination unit is further used to: determine N first sub-compensation amounts according to the N first echo parameters; determine a first compensation amount according to the N first sub-compensation amounts, the first compensation amount The compensation amount is used to determine the compensation amount of the first optical signal.
  • the N first echo parameters are determined based on the N first sub-light signals received by the N sub-pixels, and since the sub-pixels are very small, even if the light spot corresponding to the echo light beam is offset, for the N sub-pixels, when N is large enough, the distribution of some light spots on the sub-pixels is approximately uniform, so regardless of whether the light spot is offset, the distribution of some light spots corresponding to the N sub-pixels is maintained as uniform, therefore, the N first sub-compensation amounts determined based on the N first echo parameters are accurate, and thus the first compensation amount is accurate, thereby increasing the accuracy of error compensation.
  • the above-mentioned determination unit is specifically used to: screen out the corresponding first compensation table according to the geometric parameters of the sub-pixel; search the first compensation table according to the first echo parameter, and determine the first sub-compensation amount corresponding to the first echo parameter, the first compensation table is determined in advance through experiments, and the first compensation table includes a mapping relationship between the first echo parameter and the first sub-compensation amount.
  • the geometric parameters of the sub-pixel include the shape and/or area of the sub-pixel.
  • the first compensation table corresponding to different sub-pixels can be reasonably determined, which helps to ensure the accuracy of error compensation.
  • the first echo parameter includes at least one of the following: an echo area, an echo peak, an echo pulse width of the first sub-light signal, and a rising edge slope of a curve image in the first sub-histogram.
  • the above-mentioned determination unit is also used to: determine a first result value based on a second optical signal, where the second optical signal is an original optical signal determined based on the above-mentioned echo light beam; compensate the first result value by a first compensation amount to determine a first target parameter value, and the first target parameter value corresponds to the above-mentioned first optical signal.
  • the above-mentioned determination unit is specifically used to: determine a first histogram based on the second optical signal, the first histogram including the signal strength change trend of the second optical signal in multiple unit time periods; determine a first result value based on the first histogram.
  • the above-mentioned determination unit when the above-mentioned first result value is the distance to the target object, is specifically used to: determine the moment when the laser beam is emitted to the target object as the first moment; determine the second moment according to the first histogram; determine the flight time corresponding to the second light signal according to the time difference between the second moment and the first moment; determine the above-mentioned first result value according to the speed of light and the flight time.
  • the second moment is determined by the first histogram, making it relatively simple to obtain the second moment. This helps improve the efficiency of calculating the first result value.
  • the above-mentioned determination unit is specifically used to: based on the first histogram, determine the starting moment of detecting the second optical signal as the second moment; or, based on the first histogram, determine the peak moment of the first histogram as the second moment; or, based on the first histogram, determine the second moment by means of a constant ratio timing CFD; or, based on the first histogram, determine the echo time corresponding to the second optical signal, and then determine the second moment according to the echo time corresponding to the second optical signal by means of a centroid algorithm.
  • the above-mentioned determination unit when the first result value is the energy value of the second optical signal, is specifically used to: determine the echo area and/or echo peak value of the second optical signal according to the first histogram; determine the signal strength of the second optical signal according to the echo area and/or echo peak value of the second optical signal; determine the first result value according to the signal strength of the second optical signal.
  • the signal strength of the second optical signal is determined by the first histogram. This method is relatively simple and helps to improve the efficiency of calculating the first result value.
  • the above-mentioned determination unit before the above-mentioned determination unit determines the first compensation amount based on N first echo parameters, the above-mentioned determination unit is also used to: determine a first compensation table, including: obtaining a second target parameter value and a geometric parameter of a sub-pixel, the second target parameter value being an accurate target parameter value; determining a first sub-light signal obtained by the sub-pixel; determining a second result value based on the first echo parameter corresponding to the first sub-light signal, the second result value being a result value that needs to be compensated; determining a first sub-compensation amount based on the second result value and the second target parameter value; recording the first echo parameter corresponding to the first sub-light signal to determine a mapping relationship between the first echo parameter and the first sub-compensation amount; and adding the mapping relationship to the first compensation table corresponding to the geometric parameter of the sub-pixel.
  • a corresponding first compensation table is determined for sub-pixels with different geometric parameters through a preliminary experimental method.
  • the first pixel is divided into a plurality of sub-pixels with the same geometric parameters, accurate compensation for the distance compensation amount can be achieved based on a first compensation table determined through the above experiment. Even if the geometric parameters of the plurality of sub-pixels into which the first pixel is divided are not completely the same, for example, two geometric parameters. Only two of the above first compensation tables are needed to accurately compensate for the distance compensation amount. This solves the problem of difficulty in accurately performing error compensation in the prior art.
  • the N sub-pixels are divided based on single photon avalanche diodes SPAD in the pixel array.
  • the above first pixel is divided by SPAD, which provides the necessary prerequisite for the subsequent sub-pixel-based compensation solution and is the basis for accurate error compensation.
  • the echo light beam hits the pixel array to form a light spot, and the distribution of part of the light spot on each sub-pixel is uniform.
  • the distribution of part of the light spot on the sub-pixel can be guaranteed to be uniform, which can further increase the accuracy of subsequent error compensation.
  • a detection device comprising a processor and a memory, wherein the processor and the memory are connected, wherein the memory is used to store program code, and the processor is used to call the program code to execute a method in any possible implementation mode of the method design of the first aspect above.
  • a chip system is provided, the chip system is applied to an electronic device; the chip system comprises one or more interface circuits and one or more processors; the interface circuit and the processor are interconnected via a line; the interface circuit is used to The memory of the electronic device receives a signal and sends a signal to the processor, the signal including computer instructions stored in the memory; when the processor executes the computer instructions, the electronic device executes a method in any possible implementation of the method design of the first aspect above.
  • a computer-readable storage medium storing a computer program or instructions, wherein the computer program or instructions are used to implement the method in any possible implementation manner in the method design of the first aspect.
  • a computer program product is provided.
  • the computer program code or instructions are executed on a computer, the computer executes a method in any possible implementation of the method design of the first aspect above.
  • FIG. 1 is a schematic diagram of a Lidar system provided in an embodiment of the present application.
  • FIG3 is a schematic flow chart of a detection method provided in an embodiment of the present application.
  • FIG. 4 is a schematic diagram of a pixel division provided in an embodiment of the present application.
  • FIG6 is a schematic diagram of a first sub-histogram provided in an embodiment of the present application.
  • FIG. 7 is a schematic diagram of a method for determining a first histogram provided in an embodiment of the present application.
  • FIG8 is a schematic flow chart of a method for determining a first result value provided in an embodiment of the present application.
  • FIG. 9 is a flowchart of another method for determining a first result value proposed in an embodiment of the present application.
  • FIG. 11 is a schematic diagram of the relationship between a first sub-compensation amount and a first echo parameter determined through experiments according to an embodiment of the present application.
  • FIG. 12 is a schematic diagram of a detection system proposed in an embodiment of the present application.
  • FIG. 13 is a schematic block diagram of a detection device 1300 provided in an embodiment of the present application.
  • prefixes such as “first” and “second” are used only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects.
  • the use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present application does not constitute a limitation on the described objects.
  • the meaning of "multiple" is two or more.
  • Lidar is an indispensable key part in the fields of autonomous driving, robotics, and drones.
  • FIG1 is a schematic diagram of a Lidar system proposed in an embodiment of the present application.
  • Lidar generally includes a controller, a Controller, signal transmitter, signal detector, processor, and memory.
  • the controller can be used to control the modulator and the signal transmitter to emit a laser beam of specified signal intensity; it can also be used to control the signal detector to receive the echo light beam; it can also be used to control the processor to process and calculate the relevant parameters carried by the echo light beam.
  • the modulator is used to modulate the laser beam so that the Lidar can emit a laser beam with a specified signal intensity.
  • the signal transmitter generally includes a light source (also called a laser) and a transmitting optical lens, which is used to transmit a laser beam to a target object.
  • the transmitting optical lens is used to refract the laser beam emitted by the light source and transmit the laser beam to the target object along a specified optical path.
  • the processor is used to process the echo beam, determine relevant parameters, perform error compensation on the relevant parameters, and finally solve the first target parameter value.
  • the first target parameter value includes: the distance from the target object, the reflectivity of the target object, etc.
  • Memory is used to store intermediate results during signal processing.
  • the Lidar based on the above architecture can detect the distance between the target object and the laser.
  • this embodiment of the application simply refers to the distance to the target object.
  • the working principle of measuring the distance to the target object is as follows:
  • the signal transmitter emits a laser beam to the target object, and the laser beam is reflected by the target object and reflected to the signal detector in the form of an echo beam.
  • a light spot is formed on one or more pixels of the pixel array of the signal detector, and the echo beam is converted from an optical signal to an electrical signal.
  • the processor can then determine the time difference between the start of the transmission of the transmission signal and the final reception based on a built-in timer (such as a system clock), and then determine the flight time of the signal.
  • the distance to the target object can be solved based on the flight time and the speed of light.
  • the Lidar based on the above architecture can detect the reflectivity of the target object, and its working principle is as follows:
  • the signal transmitter emits a laser beam to the target object.
  • the laser beam is reflected by the target object and reflected to the signal receiver in the form of an echo beam, forming a light spot on the pixel array of the signal receiver.
  • the signal detector detects the echo beam, responds to the echo beam and determines the signal strength, that is, determines the energy value corresponding to the echo beam.
  • the distance of the target object needs to be determined, and then the processor determines the reflectivity of the target object based on the energy value and the distance of the target object.
  • Target objects with different surface materials belong to different categories, so the reflectivity of the target object can be used to identify the type of target object.
  • the detection of the target parameters is based on the calculation after the light spot of the echo beam on the detector pixel array is finally converted into an electrical signal.
  • the target receiving position does not deviate, the target receiving position may be the focal plane of the receiving light spot, and the light spot does not diffuse on the pixel array, then the light spot distribution does not change.
  • the target parameters calculated based on the electrical signal corresponding to the light spot are accurate.
  • light spot offset refers to the offset of the position of the light spot on the plane of the pixel array. Since the receiving range of the pixel array is fixed, the light spot offset will cause some light signals to be unable to be received; light spot dispersion means that the imaging position of the light spot is not on the plane of the pixel array. After the light spot dispersion, there will be a deviation between the responded light signal intensity and the actual light signal intensity.
  • FIG2 shows a schematic diagram of the relationship between an off-axis Lidar spot offset and the distance to the target object proposed in an embodiment of the present application.
  • the transmit path and receive path of Lidar do not overlap. If the target object is far enough away from the Lidar, the transmit path and receive path of Lidar can be approximated into two parallel paths. At this time, the degree of dispersion and offset of the light spot imaged on the pixel array are very small, or even negligible; if the target object is close to the Lidar, the transmit path and receive path of Lidar are two non-parallel paths, causing the light spot of the pixel array to have relatively large dispersion and offset. Calculating the target parameters based on the electrical signals corresponding to the dispersed and offset light spots will introduce errors, so the calculation results also need to be compensated for errors.
  • the above calculation results can be error compensated through a specific error compensation table, for example, a distance compensation table or an energy compensation table for calculating reflectivity.
  • a specific error compensation table for example, a distance compensation table or an energy compensation table for calculating reflectivity.
  • the corresponding error compensation value is found in the error compensation table.
  • this is all based on the premise that the light spot distribution remains unchanged, and usually, the light spot imaged on the pixel array is uneven.
  • the light spot position is offset, or the light spot is diffused, which will cause the light spot distribution to change. After the light spot distribution changes, it is also inaccurate to perform error compensation based on the error compensation table corresponding to the above light spot distribution.
  • the following is an explanation through specific embodiments.
  • the compensation process based on the above method can be divided into two parts, as follows:
  • the actual target distance is 15m.
  • the overall distribution of the light spot corresponding to the echo beam is uneven, and diffusion and offset occur, resulting in changes in the distribution of the light spot.
  • the detected target distance is 14.8m.
  • the error value corresponding to the signal strength of the current echo beam is found from the distance compensation table 1, which is 0.2m. This is to achieve error correction for the detected target distance.
  • the actual target distance becomes 10m.
  • the light spot will further diffuse, causing the light spot distribution to change again, and then the detection target distance is 9.5m.
  • the distance compensation table 1 used for the last error correction is still used, the current echo is found from the distance compensation table 1
  • the error value corresponding to the signal intensity of the light beam is usually inaccurate, for example, 0.4m. If accurate compensation is required, a distance compensation table 2 for the current light spot distribution needs to be saved to ensure the accuracy of error compensation.
  • the current temperature of the laser radar is 10°C
  • the actual target distance is 200m.
  • the temperature of the laser radar will cause the light spot position to shift, which in turn causes the light spot distribution to change, and the detected target distance is 198m.
  • the system stores distance compensation table 3 and that the distance compensation table 3 can accurately compensate for the error in the current situation, find the error value corresponding to the signal strength of the current echo beam from the distance compensation table 3, 2m. This is to achieve error correction for the detected target distance.
  • the actual target distance remains unchanged, but the temperature of the laser radar becomes 25°C. Due to thermal expansion and contraction, the lens of the laser radar transmitter or receiver is offset. At this time, the spot position will be further offset, causing the spot distribution to change again, and then the detection target distance is 196m.
  • the distance compensation table 3 used for the last error correction is still used, the error value corresponding to the signal intensity of the current echo beam is usually inaccurate from the distance compensation table 3, such as 3m. If accurate compensation is required, a distance compensation table 4 for the current spot distribution needs to be saved to ensure the accuracy of error compensation, otherwise there will be problems of insufficient compensation or excessive compensation.
  • an embodiment of the present application proposes a detection method, which further splits each pixel in the pixel array that receives the light spot, and splits each pixel into multiple sub-pixels. Since the sub-pixels are very small, the light spot distribution within the sub-pixel range is uniform or approximately uniform. Then, based on the error compensation table determined by a preliminary experiment, the compensation amount corresponding to the above sub-pixels is determined, thereby ensuring that the compensation amount corresponding to each sub-pixel is accurate. Then, based on the compensation amount corresponding to each sub-pixel, the compensation amount of the entire pixel is determined. Since the compensation amount corresponding to each sub-pixel is accurate, the compensation amount of the entire pixel determined thereby is also accurate. In this way, error compensation for the target parameters calculated by the laser radar system is achieved, and the accuracy of the error compensation is also increased.
  • the compensation amount of one pixel calculated based on the above method is accurate, so the target parameter result calculated subsequently is also accurate;
  • the weighted sum is performed based on the compensation amount of each pixel, and the target parameter result is compensated based on the result, so that the target parameter result calculated subsequently is also accurate.
  • FIG3 shows a schematic flow chart of a detection method proposed in an embodiment of the present application.
  • This method is applied to a detector. Before executing the method, it is necessary to emit a laser beam to a target object and receive an echo beam (or echo signal) formed by the laser beam being reflected by the target object.
  • S310 receiving an echo light beam, where the echo light beam hits a first pixel of a detector, where the first pixel includes N sub-pixels.
  • the echo light beam may hit a pixel array of a detector.
  • the above-mentioned echo light beam is finally presented in the form of a light spot on the pixel array, when the light spot occupies multiple pixels, the light signal determined based on the echo light beam corresponds to a part of the light spot; When the first pixel is detected, the light signal determined based on the echo light beam corresponds to the entire light spot.
  • the first pixel may be pre-divided into N sub-pixels, where N is a positive integer.
  • FIG. 4 shows a schematic diagram of a pixel division proposed in an embodiment of the present application.
  • the first pixel can be divided into N sub-pixels with the same geometric parameters, and the embodiments of the present application do not limit the specific geometric parameters.
  • the first pixel can also be divided into N sub-pixels with different geometric parameters, and the first pixel can also be divided into a part of sub-pixels with the first geometric parameter and another part of sub-pixels with the second geometric parameter, etc.
  • the above-mentioned process of pixel division is also to divide the light spot, dividing a complete light spot into several parts of sub-light spots, and ensuring that each sub-light spot is evenly distributed on the pixel array. Therefore, for the uniformly distributed sub-light spots corresponding to each sub-pixel, regardless of whether the light spot on the pixel array is offset and diffused, the distribution of the sub-light spots corresponding to the sub-pixels is unchanged and remains uniformly distributed. Since the distribution of the sub-light spots is unchanged, when the geometric parameters of the sub-pixels are consistent, accurate error compensation for the target parameters solved based on the echo signals corresponding to the sub-light spots can be achieved based on an error compensation table.
  • the pixel array can adjust the division mode of each pixel on the pixel array in real time according to the current light spot distribution, so that the light spot distribution in each sub-pixel is uniform. Based on this technical solution, the accuracy of subsequent error compensation can be further increased.
  • the first pixel can be divided by SPAD in the pixel array, and the SPAD includes a pixel activation area.
  • Each pixel in the pixel activation area can be pre-set by SPAD initial parameters to divide the pixel into multiple sub-pixels.
  • the initial parameters include geometric parameters of each sub-pixel, such as the length and width of each pixel, and set a number for each sub-pixel. And it also supports numbering each pixel. In this way, it is possible to distinguish the partial light signal corresponding to each sub-pixel.
  • the shape geometric parameter of the first pixel may be a 1*1 pixel square, and the relevant information of each sub-pixel may be described in the following manner.
  • Pixel 01:Son-Pixel 01 ⁇ "Length":"0.5Pixel”,”Width”:"0.5Pixel” ⁇ ;
  • Pixel 01:Son-Pixel 01 ⁇ "Length":"0.5Pixel”,”Width”:"0.5Pixel” ⁇ ;
  • Pixel 01:Son-Pixel 01 ⁇ "Length":"0.5Pixel”,”Width”:"0.5Pixel” ⁇ ;
  • Pixel 01:Son-Pixel 01 ⁇ "Length":"0.5Pixel”,”Width”:"0.5Pixel” ⁇ ;
  • the first pixel is divided into four sub-pixels of the same shape, and the shape geometric parameter of each sub-pixel is a square of 0.5*0.5 pixels.
  • S320 Determine N first sub-light signals according to the N sub-pixels.
  • S330 Determine N first echo parameters according to the N first optical sub-signals, where the first echo parameters are used to characterize signal strengths of the first optical sub-signals.
  • the first echo parameter includes at least one of the following: an echo area, an echo peak value, an echo pulse width, and a rising edge slope of a curve image in the first sub-histogram of the first light sub-signal.
  • the first echo parameter may be determined based on a first sub-histogram corresponding to the first sub-light signal.
  • S340 Determine a first optical signal according to the N first echo parameters, where the first optical signal corresponds to the echo light beam.
  • the first optical signal is determined based on the first echo parameters corresponding to each first sub-optical signal, and the target parameters corresponding to the first optical signal are compensated accordingly.
  • the first pixel is divided into N sub-pixels. Since the sub-pixels are very small, the spot distribution in the sub-pixels is uniform or approximately uniform. When detecting the distance of the target object or the reflectivity of the target object, no matter how factors such as the distance of the target object and the temperature of the laser change, the spot distribution in the sub-pixel remains unchanged. Therefore, based on this method, it helps to avoid the problem that the error cannot be accurately compensated based on a compensation table due to changes in the spot distribution. That is, this method can achieve the premise that the geometric parameters of the N sub-pixels are the same, and the accurate compensation amount can be obtained through a compensation table, which improves the accuracy of error compensation and is easy to implement.
  • the embodiment of the present application proposes a compensation scheme based on the first sub-light signal.
  • a prerequisite is provided for determining the spot parameters corresponding to the first pixel for accurate compensation.
  • the detection method provided in the embodiment of the present application can also perform the following steps: determine N first sub-compensation amounts based on the above N first echo parameters, and determine the first compensation amount based on the N first sub-compensation amounts, and the first compensation amount is used to determine the compensation amount of the above first light signal.
  • the first sub-compensation amount can be determined by looking up a compensation table.
  • the compensation table can be determined in advance through experiments, and the compensation table records the mapping relationship between the first echo parameter and the first sub-compensation amount. For example, the mapping relationship between the echo area of the first sub-light signal and the first sub-compensation amount, or the mapping relationship between the echo pulse width of the first sub-light signal and the first sub-compensation amount, or the mapping relationship between the echo peak value of the first sub-light signal and the first sub-compensation amount, and then the weighted sum of the N first sub-compensation amounts determined by the table lookup can determine the first compensation amount.
  • the first compensation amount can be determined through a compensation table, which improves the accuracy of error compensation and is easy to implement.
  • the specific method for determining the above-mentioned first compensation amount is different for different compensation amounts: for example, the N first sub-compensation amounts can be weighted accumulated, and the weighted accumulation can include two cases, one case is that the weight is 1, and the weighted accumulation process is actually a direct accumulation process, and the other case is that the weight is not 1; in addition, the N first sub-compensation amounts can also be accumulated to obtain the average value.
  • the N first echo parameters are determined based on the N first sub-light signals received by the N sub-pixels, and since the sub-pixels are very small, even if the light spot corresponding to the echo light beam is offset, for the N sub-pixels, when N is large enough, the distribution of some light spots on the sub-pixels is approximately uniform, so regardless of whether the light spot is offset, the distribution of some light spots corresponding to the N sub-pixels is maintained as uniform, therefore, the N first sub-compensation amounts determined based on the N first echo parameters are accurate, and thus the first compensation amount is accurate, thereby increasing the accuracy of error compensation.
  • the first result value can be determined based on the second optical signal, the second optical signal being the original optical signal determined based on the echo light beam, the first result value can be the target object distance, or the energy value of the second optical signal used to calculate the reflectivity of the target object.
  • the first result value is an uncompensated result value, so the first compensation amount can be determined based on the method proposed in the above embodiment, and then the first result value can be compensated by the first compensation amount, thereby determining the first target parameter value, the first target parameter value corresponding to the first optical signal. Signal.
  • the first result value may be determined based on a first histogram corresponding to the second optical signal, the first histogram including a signal intensity variation trend of the first pixel responding to the second optical signal in a plurality of unit time periods. Further, the echo area, echo pulse width, echo peak value of the second optical signal and the rising edge slope of the curve image in the first histogram may be determined based on the first histogram. The first histogram is shown in FIG5 below.
  • FIG5 shows a schematic diagram of a first histogram proposed in an embodiment of the present application.
  • the horizontal axis of the first histogram is the above-mentioned multiple unit time periods, and the vertical axis is the signal intensity of the first pixel responding to the second light signal in the unit time period. Therefore, the first histogram intuitively presents the trend of the signal intensity of the second light signal changing over time.
  • the echo area is the integral value of the curve image in the first histogram; the echo pulse width can be divided into a first pulse width and a second pulse width.
  • the first pulse width is also called the full pulse width, which is the difference between the horizontal coordinates of the starting point and the end point of the curve image in the first histogram;
  • the second pulse width is the pulse width corresponding to a certain proportional threshold, that is, the pulse width of the curve image in the first histogram horizontally intercepted at a preset position, wherein the preset position can be 1/2 of the curve image (in this case, the second pulse width is also called the half-height pulse width), or 1/3 or other reasonable positions.
  • the preset position is 1/2 of the curve image
  • the ordinate of the peak point of the curve image is y
  • the ordinates of the two endpoints of the half-height pulse width are y/2
  • the difference between the horizontal coordinates of the two endpoints is the half-height pulse width
  • the echo peak value is the ordinate of the peak point of the curve image in the first histogram.
  • the first echo parameter can be determined based on the first sub-histogram corresponding to the first sub-light signal.
  • the first sub-histogram can be determined based on the first sub-light signal, and the first sub-histogram includes the signal intensity variation trend of the sub-pixel response of the first sub-light signal to the first sub-light signal within the above multiple unit time periods.
  • the echo area, echo pulse width, echo peak value of the first sub-light signal and the rising edge slope of the curve image in the corresponding first sub-histogram can also be determined based on the first sub-histogram, and these parameters all belong to the first echo parameter.
  • the first sub-histogram is shown in FIG6 .
  • FIG6 shows a schematic diagram of a first sub-histogram proposed in an embodiment of the present application.
  • the meanings of the abscissa and ordinate of the first sub-histogram are the same as those of the abscissa and ordinate of the first histogram described above.
  • the first sub-histogram characterizes the trend of the signal strength of the first sub-light signal changing over time.
  • the first echo parameter can also be determined based on the first sub-histogram, and the first echo parameter includes at least one of the echo area, echo pulse width, and echo peak value of the first sub-light signal.
  • the meanings of the echo area, echo pulse width, echo peak value, etc. have been described in the above corresponding embodiments and will not be repeated here.
  • the first echo parameter characterizing the signal strength of the first sub-light signal is calculated by the first sub-histogram. This method is easy to implement and has high flexibility.
  • the signal strength of the first sub-light signal can be characterized by any parameter such as echo area, echo pulse width, and echo peak value.
  • the first histogram may be intercepted based on the first detection threshold so that The first result value is calculated based on the portion of the image above the first detection threshold, wherein the first detection threshold is a reasonable preset value.
  • the first sub-histogram since the first sub-histogram is compressed according to the corresponding ratio of the first histogram, the first sub-histogram may also correspond to a second detection threshold, which is proportionally reduced based on the first detection threshold.
  • the start time and the end time of the first histogram can be determined according to the first histogram and the first detection threshold, and the start time and the end time also correspond to the start time and the end time of the first sub-histogram, there is no need to determine the second detection threshold, and the first sub-histogram can be intercepted.
  • the corresponding first histogram may also be determined by using the N first sub-histograms.
  • Fig. 7 shows a schematic diagram of a method for determining a first histogram proposed in an embodiment of the present application.
  • the first pixel is divided into 4 sub-pixels with the same shape and geometric parameters.
  • each sub-pixel will receive the first sub-light signal, and then the 4 first sub-light signals are detected respectively, and then 4 first sub-histograms are determined, namely, the first sub-histogram 1, the first sub-histogram 2, the first sub-histogram 3, and the first sub-histogram 4.
  • the memory is used to store the parameters required to generate the first sub-histogram and store the data of the determined first sub-histogram. Then, multiple first sub-histograms are accumulated through the accumulator to determine the first histogram.
  • the process of determining the first sub-histogram may be completed in the detector or in the signal processing module, which is not limited in the embodiments of the present application.
  • the first result value being the distance of the target object as an example, the first result value may be determined in the following manner.
  • FIG8 shows a schematic flow chart of a method for determining a first result value proposed in an embodiment of the present application.
  • S810 Determine the moment of emitting a laser beam to the target object as the first moment.
  • S820 Determine a second moment according to the first histogram.
  • the start time of detecting the second optical signal can be used as the second time based on the first histogram; the peak time of the first histogram can be used as the second time directly; the second time can also be determined by CFD based on the first histogram; the second time can also be determined by the centroid algorithm based on the first histogram and the following formula (1), where formula (1) is used to calculate the echo time corresponding to the second optical signal.
  • the formula (1) is specifically as follows:
  • t represents the echo time
  • a represents the starting position of the first histogram
  • b represents the ending position of the first histogram
  • bin represents the abscissa of each point in the first histogram
  • A(bin) represents the ordinate of each point in the first histogram.
  • S830 Determine the flight time corresponding to the second optical signal according to the time difference between the second moment and the first moment.
  • S840 Determine a first result value according to the speed of light and the above-mentioned flight time.
  • the distance to the target object is obtained by multiplying the speed of light and the flight time and dividing by 2, i.e., the first result value mentioned above.
  • the signal strength of the second light signal also changes during the change of the distance to the target object, the corresponding light spot will also shift and/or diffuse, so it can be seen that the first result value is inaccurate. Therefore, after determining the first result value, it is necessary to determine the first compensation amount based on the first sub-light signal corresponding to each sub-pixel.
  • the first echo parameter of the first sub-light signal includes the echo area of the first sub-light signal.
  • the first compensation amount can be determined by the following method:
  • the first compensation table may be searched according to the echo areas of the N first sub-optical signals to determine N first sub-compensation amounts corresponding to the echo areas of the N first sub-optical signals, wherein the N first sub-compensation amounts are distance compensation amounts calculated based on the processing of the N first sub-optical signals.
  • the first compensation table may be a table determined in advance through experiments to record the mapping relationship between the echo areas of different first sub-optical signals and the first sub-compensation amounts. Then, the N first sub-compensation amounts are weighted and accumulated to determine the first compensation amount.
  • the first result value being the energy value of the second optical signal as an example
  • the first result value may be determined in the following manner.
  • FIG. 9 shows a schematic flow chart of another method for determining a first result value proposed in an embodiment of the present application.
  • S910 Determine the echo area and/or peak value of the second optical signal according to the first histogram.
  • S920 Determine the signal strength of the second optical signal according to the echo area and/or peak value of the second optical signal.
  • S930 Determine a first result value according to the signal strength of the second optical signal.
  • the corresponding light spot is also offset and/or diffused, so it can be seen that the first result value is inaccurate. Therefore, after determining the first result value, it is necessary to determine the first compensation amount based on the first sub-light signal corresponding to each sub-pixel.
  • the first echo parameter of the first sub-light signal includes the echo area of the first sub-light signal.
  • the first compensation amount can be determined by the following method:
  • the first compensation table may be searched according to the echo areas of the N first light sub-signals to determine N first sub-compensation amounts corresponding to the echo areas of the N first light sub-signals, wherein the N first sub-compensation amounts are energy compensation amounts calculated based on the N first light sub-signals.
  • the first compensation table may be a table determined in advance through experiments to record the mapping relationship between the echo areas of different first light sub-signals and the first sub-compensation amounts. Then, the first compensation amount is determined according to the N first sub-compensation amounts.
  • the table is defined as the first compensation table.
  • FIG. 10 shows a schematic flow chart of a method for determining a first compensation table proposed in an embodiment of the present application.
  • the first compensation table may be determined by the following experimental method:
  • S1010 Acquire a second target parameter value and a geometric parameter of a sub-pixel, where the second target parameter value is an accurate target parameter value.
  • the target object distance is an accurate distance value measured in advance; when the second target parameter value is the energy value of the second light signal reflected by the target object, the energy value is an accurate energy value measured in advance.
  • the geometric parameters of the sub-pixels are determined in the process of determining the first pixel division method.
  • the geometric parameters of the sub-pixels may be stored in the memory.
  • the geometric parameters of the sub-pixel include the shape and/or area of the sub-pixel.
  • different first compensation tables need to be determined correspondingly for sub-pixels with different geometric parameters.
  • S1020 Determine a first sub-light signal acquired through a sub-pixel.
  • the first sub-light signal is a portion of the second light signal that is reflected back from the target object after the laser beam is emitted to the target object.
  • S1030 Determine a second result value based on the first sub-light signal, where the second result value is a result value that needs to be compensated.
  • the second result value when the second result value is the target object distance that has not been compensated, based on the description of the corresponding embodiment, the second result value can be calculated based on the flight time of the first sub-light signal.
  • the second result value when the second result value is the energy value of the first sub-light signal that has not been compensated, based on the description of the corresponding embodiment, the second result value can be calculated based on the signal strength of the first sub-light signal.
  • S1040 Determine a first sub-compensation amount according to the second target parameter value and the second result value.
  • the distance sub-compensation amount when the first sub-compensation amount is a distance sub-compensation amount, the distance sub-compensation amount may be determined by subtracting the second target parameter value from the second result value.
  • the energy sub-compensation amount when the first sub-compensation amount is an energy sub-compensation amount of the first sub-optical signal, the energy sub-compensation amount may be estimated based on the second target parameter value and the second result value.
  • S1050 Record the first echo parameter corresponding to the first sub-optical signal at this time to determine a mapping relationship between the first echo parameter and the first sub-compensation amount.
  • the second target parameter value is modified, and based on the above method, the experiment is repeated, and the determined multiple mapping relationships are added to the first compensation table, and the first compensation table is continuously expanded to continuously improve it.
  • a corresponding first compensation table is determined for sub-pixels with different geometric parameters through a preliminary experimental method.
  • the first pixel is divided into a plurality of sub-pixels with the same geometric parameters, accurate compensation for the distance compensation amount can be achieved based on a first compensation table determined through the above experiment. Even if the geometric parameters of the plurality of sub-pixels into which the first pixel is divided are not completely the same, for example, two geometric parameters. Only two of the above first compensation tables are needed to accurately compensate for the distance compensation amount. This solves the problem of difficulty in accurately performing error compensation in the prior art.
  • the first compensation amount is the distance compensation amount
  • the first sub-compensation amount can be found and the compensated first result value can be determined in the following manner:
  • the geometric parameters of the sub-pixel are determined to select the corresponding first compensation table.
  • the first echo parameter acquired by the sub-pixel is determined.
  • the corresponding first sub-compensation amount is searched in the first compensation table.
  • the first compensation amount is determined, and the compensated target object distance is calculated according to the first result value and the first compensation amount.
  • the first compensation amount when the first compensation amount is a distance compensation amount, the first compensation amount can be determined by the following formula (2).
  • ⁇ x represents the first compensation amount, which is the distance compensation amount in this embodiment
  • N represents the first image
  • the number of sub-pixels into which the pixel is divided corresponds to N first sub-histograms
  • area n represents the echo area of the nth first sub-histogram in the N first sub-histograms
  • ⁇ x n represents the first sub-compensation amount corresponding to the echo area of the nth first sub-histogram in the N first sub-histograms obtained by looking up the first compensation table.
  • the first sub-compensation amount is also called the distance sub-compensation amount.
  • the echo area of the echo signal may be determined by the following formula (3):
  • area is the echo area of the echo signal
  • ⁇ t is the time length of a unit time period for the first pixel to respond to the echo signal
  • the echo signal may be the above-mentioned second light signal or the first sub-light signal.
  • the distance compensation amount can be replaced by the delay compensation amount; correspondingly, the distance sub-compensation amount can be replaced by the delay sub-compensation amount. After determining the delay compensation amount, multiply it by the speed of light to determine the distance compensation amount.
  • the distance compensation amount may be calculated based on the echo areas of the N first light sub-signals, and specifically applied to the above formulas (1) to (3). In addition, the distance compensation amount may also be calculated based on the echo peak values or echo pulse widths of the N first light sub-signals. Although the specific formula used may be different from the above formulas (1) to (3), the principle is the same and will not be described in detail here.
  • the first compensation table when the first result value is the energy value of the second optical signal, correspondingly, the first compensation amount is the energy compensation amount, and the first sub-compensation amount can be found and the compensated first result value can be determined in the following manner:
  • the target object distance may be the target object distance obtained after compensation based on the corresponding method proposed in the above embodiments.
  • the geometric parameters of the sub-pixels are determined to select the corresponding first compensation table.
  • the corresponding first sub-compensation amount is searched in the first compensation table.
  • the above-mentioned first compensation amount is determined. Since the first result value and the first compensation amount are energy values, when determining the first result value and the first compensation amount, it is also necessary to combine the target object distance to solve the compensated target object reflectivity.
  • the mapping relationship between the echo area of the above-mentioned first sub-light signal and the above-mentioned distance compensation amount and the mapping relationship between the echo area and the above-mentioned energy compensation amount can be recorded in different compensation tables respectively, or can be recorded in one compensation table, for example, both can be recorded in the first compensation table, and the embodiments of the present application are not limited to this.
  • the first compensation amount is the energy compensation amount
  • the first compensation amount can be determined by the following formula (4).
  • peakest n represents the first sub-compensation amount corresponding to the echo area of the nth first sub-histogram obtained by looking up the first compensation table.
  • the first sub-compensation amount is also called energy sub-compensation amount; peakest represents the first compensation amount.
  • the first compensation amount is also called energy compensation amount.
  • the first compensation table may further include a mapping relationship between the echo pulse width or echo peak value of different first sub-light signals and the first sub-compensation amount, wherein the echo pulse width or echo peak value of the first sub-light signal The value belongs to the above-mentioned first echo parameter. Based on this, the first compensation table can also be searched according to the echo pulse width or echo peak value of the first sub-light signal to determine the first sub-compensation amount.
  • the experimental method for determining the mapping relationship between the echo pulse width or echo peak value of different first sub-light signals and the above-mentioned first sub-compensation amount is the same as the experimental method of the above-mentioned corresponding embodiment, and no further description is given here.
  • the above distance compensation amount can be accurately compensated based on a first compensation table determined by the above experiment. Even if the geometric parameters of the plurality of sub-pixels into which the first pixel is divided are not completely the same, for example, two geometric parameters. Only two of the above first compensation tables are needed to accurately compensate the above distance compensation amount. This solves the problem that it is difficult to accurately compensate for errors in the prior art.
  • FIG11 shows a schematic diagram of the relationship between the first sub-compensation amount and the first echo parameter determined by experiment in an embodiment of the present application.
  • FIG11 (a) specifically shows the schematic diagram of the relationship between the distance quantum compensation amount corresponding to the first sub-light signal and the echo area
  • FIG11 (b) specifically shows the schematic diagram of the relationship between the energy quantum compensation amount corresponding to the first sub-light signal and the echo area
  • FIG11 (c) specifically shows the schematic diagram of the relationship between the energy quantum compensation amount corresponding to the first sub-light signal and the echo pulse width
  • FIG11 (d) specifically shows the schematic diagram of the relationship between the energy quantum compensation amount corresponding to the first sub-light signal and the echo peak value.
  • the efficiency of determining the first sub-compensation amount can be further improved, and the problems of low efficiency of table lookup operation and high resource overhead can be effectively avoided.
  • Fig. 12 shows a schematic diagram of a detection system proposed in an embodiment of the present application.
  • the system includes a controller, a modulator, a signal transmitter, a signal detector, and a signal processor.
  • controller and the modulator are the same as those of the controller and the modulator in the embodiment corresponding to FIG. 1 , and the corresponding contents in the aforementioned embodiment may be referred to and will not be repeated here.
  • the signal transmitter also includes a scanning mirror, which is used to reflect the laser beam emitted by the laser and scan the laser beam onto the target object, so that the echo light beam reflected by the target object can carry the overall relevant information of the target object.
  • a scanning mirror which is used to reflect the laser beam emitted by the laser and scan the laser beam onto the target object, so that the echo light beam reflected by the target object can carry the overall relevant information of the target object.
  • the target parameter values such as the reflectivity of the target object can be determined through the detection method proposed in the above embodiment.
  • the signal detector includes a pixel array, and each pixel in the pixel array is divided into a plurality of sub-pixels based on SPAD. Taking the first pixel as an example, it can be divided into N sub-pixels.
  • the signal detector can perform signal preprocessing on the light signal received through the pixel array.
  • the first pixel determines the second light signal, and then generates a first histogram based on the second light signal, and filters the first histogram through a finite impulse response (FIR) filter, and performs echo detection on the second light signal to obtain the above-mentioned first result value.
  • FIR finite impulse response
  • N first sub-histograms can be generated respectively based on the N first sub-light signals received by the N sub-pixels, and the N first sub-histograms can be filtered accordingly, and the N first sub-histograms can be filtered accordingly, and the N first sub-light signals can be echo detected respectively to obtain the above-mentioned N first echo parameters.
  • the signal processor may be used to determine N first sub-compensation amounts based on the first compensation table according to the first echo parameters corresponding to the N sub-pixels.
  • the N first echo parameters are respectively input into the first function to determine the N first sub-compensation amounts.
  • the N first sub-compensation amounts are weighted and accumulated to determine the first compensation amount corresponding to the first pixel as a whole. Then, the first compensation amount is used to perform error compensation on the first amount to be compensated to determine the target result value.
  • the signal detector and the signal processor may also be integrated into one device, which is not limited in the embodiments of the present application.
  • the first pixel is divided into N sub-pixels. Since the sub-pixels are very small, the spot distribution in the sub-pixels is uniform or approximately uniform. When detecting the distance of the target object or the reflectivity of the target object, no matter how the factors such as the distance of the target object, the laser temperature, and the detector temperature change, the spot distribution in the sub-pixel remains unchanged. This can effectively avoid the problem that the error cannot be accurately compensated based on a compensation table due to changes in the spot distribution. When the geometric parameters of the N sub-pixels are the same, this method can determine the first compensation amount through a compensation table, which improves the accuracy of error compensation and is easy to implement.
  • the laser beam in order to prevent the jitter of the optical signal from affecting the detection of the target object, during the detection of the target object, the laser beam may be emitted to the target object multiple times, and echo detection may be performed multiple times based on the reflected echo beam, thereby obtaining multiple sets of first echo parameters.
  • the multiple sets of first echo parameters are then accumulated to determine a set of second echo parameters, and then the target object detection parameters may be solved based on the second echo parameters.
  • the laser beam in order to avoid the influence of the jitter of the optical signal on the detection of the target object, during the detection of the target object, the laser beam can be emitted to the target object multiple times, and multiple first histograms can be determined based on the reflected echo beams. Then, the multiple first histograms are superimposed to determine the second histogram, and then the corresponding parameters can be determined based on the second histogram to solve the target object detection parameters.
  • the first sub-histogram can also adopt this histogram superposition method to process the determined multiple first sub-histograms.
  • an embodiment of the present application also provides a device for implementing any of the above methods.
  • a detection device is provided, which includes a unit (or means) for implementing any of the above detection methods.
  • FIG13 shows a schematic block diagram of a detection device 1300 provided in an embodiment of the present application. As shown in FIG13 , the device 1300 includes:
  • a receiving unit 1310 is used to receive an echo light beam, where the echo light beam hits a first pixel of the detector, where the first pixel includes N sub-pixels;
  • the determination unit 1320 is used to determine N first sub-light signals based on the above-mentioned N sub-pixels, where N is a positive integer; determine N first echo parameters based on the N first sub-light signals, and the first echo parameters are used to characterize the signal strength of the first sub-light signal; determine the first light signal based on the above-mentioned N first echo parameters, and the first light signal corresponds to the echo light beam.
  • the determination unit 1320 is specifically configured to: determine a first sub-histogram according to the first sub-optical signal, wherein the first sub-histogram includes a signal intensity variation trend of the first sub-optical signal in multiple unit time periods; and determine a first echo parameter according to the first sub-histogram.
  • the determination unit 1320 is specifically used to: determine N first sub-compensation amounts according to N first echo parameters; determine a first compensation amount according to the N first sub-compensation amounts, where the first compensation amount is used to determine the compensation amount of the first optical signal.
  • the above-mentioned determination unit 1320 is specifically used to: screen out the corresponding first compensation table according to the geometric parameters of the sub-pixel; search the first compensation table according to the first echo parameter, and determine the first sub-compensation amount corresponding to the first echo parameter, the first compensation table is determined in advance through experiments, and the first compensation table includes a mapping relationship between the first echo parameter and the first sub-compensation amount.
  • the geometric parameters of the sub-pixel include the shape and/or area of the sub-pixel.
  • the first echo parameter includes at least one of the following: an echo area, an echo peak value, an echo pulse width of the first sub-light signal, and a rising edge slope of a curve image in the first sub-histogram.
  • the determination unit 1320 is further used to: determine a first result value based on a second optical signal, where the second optical signal is an original optical signal determined based on the echo light beam; compensate the first result value by a first compensation amount to determine a first target parameter value, where the first target parameter value corresponds to the first optical signal.
  • the determination unit 1320 is specifically configured to: determine a first histogram according to the second optical signal, the first histogram including a signal strength variation trend of the second optical signal in a plurality of unit time periods; and determine a first result value according to the first histogram.
  • the above-mentioned determination unit 1320 is specifically used to: determine the moment of emitting a laser beam to the target object as the first moment; determine the second moment according to the first histogram; determine the flight time corresponding to the second light signal according to the time difference between the second moment and the first moment; determine the above-mentioned first result value according to the speed of light and the flight time.
  • the determination unit 1320 is specifically used to: based on the first histogram, determine the start time of detecting the second optical signal as the second time; or, based on the first histogram, determine the peak time of the first histogram as the second time; or, based on the first histogram, determine the second time by means of constant ratio timing CFD; or, based on the first histogram, determine the echo time corresponding to the second optical signal, and then determine the second time according to the echo time of the second optical signal by means of a centroid algorithm.
  • the above-mentioned determination unit 1320 is specifically used to: determine the echo area and/or echo peak value of the second optical signal according to the first histogram; determine the signal strength of the second optical signal according to the echo area and/or echo peak value of the second optical signal; determine the first result value according to the signal strength of the second optical signal.
  • the determination unit 1320 before the determination unit determines the first compensation amount based on N first echo parameters, the determination unit 1320 is also used to: determine a first compensation table, including: obtaining a second target parameter value and a geometric parameter of a sub-pixel, the second target parameter value being an accurate target parameter value; determining a first sub-light signal obtained by the sub-pixel; determining a second result value based on the first echo parameter corresponding to the first sub-light signal, the second result value being a result value that needs to be compensated; determining a first sub-compensation amount based on the second result value and the second target parameter value; recording the first echo parameter corresponding to the first sub-light signal to determine a mapping relationship between the first echo parameter and the first sub-compensation amount; and adding the mapping relationship to the first compensation table corresponding to the geometric parameter of the sub-pixel.
  • the N sub-pixels are divided based on single photon avalanche diodes (SPADs) in a pixel array.
  • SPADs single photon avalanche diodes
  • the echo light beam hits the pixel array to form a light spot, and the distribution of a portion of the light spot on each sub-pixel is uniform.
  • an embodiment of the present application also proposes a vehicle, which includes the above-mentioned device 1300.
  • the disclosed systems, devices and methods can be implemented in other ways.
  • the device embodiments described above are only schematic.
  • the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.
  • Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
  • the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.
  • the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art.
  • the computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application.
  • the aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

本申请提供了一种探测方法以及相关装置，涉及光电技术领域，该方法包括：接收回波光束，该回波光束打在探测器的第一像素上；该第一像素包括N个子像素，根据该N个子像素，确定N个第一子光信号，其中，N为正整数；根据该N个第一子光信号，确定N个第一回波参数，该第一回波参数用于表征第一子光信号的信号强度；根据该N个第一回波参数确定第一光信号，该第一光信号与回波光束对应。基于该方案，能够避免因回波光束在探测器上形成的光斑分布不均匀，使光斑发生偏移时，造成光斑分布发生改变，进而造成对激光雷达系统计算的目标参数误差补偿不准的情况，有助于增加误差补偿的准确性。

Description

一种探测方法以及相关装置 技术领域
本申请涉及光电技术领域，并且更具体地，涉及一种探测方法以及相关装置。
背景技术
激光雷达(light detection and ranging，Lidar)具有分辨率高、抗有源干扰能力强的特点，因此广泛应用于各个技术领域。在Lidar系统中，Lidar向待检测的目标物体发射激光束，激光束接触到目标物体后会进行反射，以回波光束的形式再由信号探测器接收。回波光束打在信号探测器的像素阵列上形成光斑，像素阵列将回波光束由光信号转化为电信号。然后基于该电信号确定一些参数，进而能够求解出当前Lidar与目标物体之间的距离、目标物体的反射率等目标参数，以实现目标测距、目标识别等功能。
在Lidar系统中，基于响应到的指定光斑分布的回波信号求解目标参数，通常是存在误差的。所以可以基于误差补偿表，对上述光斑分布对应的目标参数进行误差补偿。但是，由于系统设备老化、系统设备温度变化以及目标物体与激光器之间的距离变化，通常会造成光斑分布发生变化。因此，若还通过上述误差补偿表对目标参数进行补偿，则无法保障针对目标参数进行补偿的准确性。
因此，如何对激光雷达系统计算的目标参数进行误差补偿，并且尽可能地增加误差补偿的准确性，是一项亟需解决的问题。
发明内容
本申请实施例提供了一种探测方法以及相关装置，能够避免因回波光束在探测器上形成的光斑分布不均匀，使光斑发生偏移时，造成光斑分布发生改变，进而造成对激光雷达系统计算的目标参数误差补偿不准的情况，有助于增加误差补偿的准确性。
第一方面，提供了一种探测方法，应用于探测器，该方法包括：接收回波光束，该回波光束打在探测器的第一像素上；该第一像素包括N个子像素，根据该N个子像素，确定N个第一子光信号，其中，N为正整数；根据该N个第一子光信号，确定N个第一回波参数，该第一回波参数用于表征第一子光信号的信号强度；根据该N个第一回波参数确定第一光信号，该第一光信号与回波光束对应。
示例地，回波光束最终在探测器的像素阵列上以光斑的形式呈现。所以在光斑占据多个像素时，基于回波光束确定的光信号对应于光斑的一部分；在光斑仅占据上述第一像素时，基于回波光束确定的光信号则对应于光斑的全部。
示例地，以第一像素为例，可以将第一像素划分为N个几何参数相同的子像素，本申请实施例对具体几何参数不做限定。此外，也可以将第一像素划分为N个不同几何参数的子像素，还可以将第一像素划分为一部分是第一几何参数的子像素，另一部分是第二几何参数的子像素等。
示例地，像素阵列可以根据当前的光斑分布，实时地调整像素阵列上各个像素的划分方式，以使得各个子像素中的光斑分布都是均匀的，以进一步增加后续误差补偿的准确性。
应理解，第一光信号是基于每个第一子光信号对应的第一回波参数进行补偿后的光信号，该第一光信号所携带的目标参数是能够被准确补偿的。
基于上述技术方案，将第一像素划分为N个子像素，由于子像素很小，所以子像素中的光斑分布是均匀的或者近似于均匀的。检测目标物体距离或者目标物体反射率时，无论目标物体距离以及激光器温度等因素如何变化，子像素中的光斑分布都是不变的。因此，基于该方法，有助于避免因光斑分布变化，导致基于一张补偿表无法准确补偿误差的问题。即该方法可以实现在N个子像素的几何参数相同的前提下，能够通过一张补偿表即可获得准确的补偿量，提升了误差补偿的准确性，且易于实现。
结合第一方面，在第一方面的某些实现方式中，根据第一子光信号，确定第一子直方图，第一子直方图包括多个单位时段内第一子光信号的信号强度变化趋势；根据第一子直方图，确定第一回波参数。
基于上述技术方案，通过第一子直方图来计算表征第一子光信号的信号强度的第一回波参数，该方法易于实现。
结合第一方面，在第一方面的某些实现方式中，根据N个第一回波参数，确定N个第一子补偿量；根据N个第一子补偿量，确定第一补偿量，该第一补偿量为用于确定上述第一光信号的补偿量。
示例地，上述第一子补偿量可以通过查找补偿表的方式确定。该补偿表可以是预先通过实验确定的。不同的子像素几何参数对应着不同的补偿表。基于此，在N个子像素几何参数相同时，通过一张补偿表即可实现第一补偿量的确定。
示例地，针对于不同的补偿量，确定上述第一补偿量的方法也有所不同：可以将N个第一子补偿量进行加权累加，该加权累加可以包括两种情况，一种情况是权数为1，此时加权累加的过程其实就是直接累加的过程，另一种情况是权数不为1；此外，也可以将N个第一子补偿量进行累加求平均值。
基于上述技术方案，由于上述N个第一回波参数是基于N个子像素接收到的N个第一子光信号确定的，由于子像素很小，即便与回波光束对应的光斑发生了偏移，对于N个子像素来说，在N足够大的情况下，子像素上的部分光斑的分布是近似于均匀分布的，所以无论光斑是否发生偏移，N个子像素对应的部分光斑分布是保持为均匀分布的，因此，基于N个第一回波参数确定的N个第一子补偿量是准确的，进而第一补偿量是准确的，增加了误差补偿的准确性。
结合第一方面，在第一方面的某些实现方式中，根据子像素的几何参数，筛选出对应的第一补偿表；根据第一回波参数，查找第一补偿表，确定第一回波参数对应的第一子补偿量，第一补偿表是预先通过实验确定的，第一补偿表包括第一回波参数与第一子补偿量之间的映射关系。
基于上述技术方案，可以实现在N个子像素的几何参数相同的前提下，能够通过一张补偿表确定第一补偿量，提升了误差补偿的准确性，且易于实现。
结合第一方面，在第一方面的某些实现方式中，子像素的几何参数包括子像素的形状和/或面积。
基于上述技术方案，通过子像素的形状和/或面积作为其几何参数，能够合理地确定不同子像素对应的第一补偿表，有助于保障误差补偿的准确性。
结合第一方面，在第一方面的某些实现方式中，第一回波参数包括以下至少一种：第一子光信号的回波面积、回波峰值、回波脉宽以及第一子直方图中曲线图像的上升沿斜率。
基于上述技术方案，基于第一子光信号的回波面积、回波峰值、回波脉宽以及第一子直方图中曲线图像的上升沿斜率中的至少一种，即可确定第一子补偿量，为确定补偿量提供了多种途径，增加了方案的灵活性。
结合第一方面，在第一方面的某些实现方式中，根据第二光信号，确定第一结果值，其中，第二光信号是基于上述回波光束确定的原始的光信号；通过第一补偿量对第一结果值进行补偿，确定第一目标参数值，该第一目标参数值对应于上述第一光信号。
示例地，上述第一结果值可以是目标物体距离，也可以是用于计算目标物体反射率的第二光信号的能量值。但是，上述第一结果值是没有经过补偿的结果值。
基于上述技术方案，基于上述方法确定的第一补偿量对第一结果值进行补偿，有助于提升第一目标参数值的准确性。
结合第一方面，在第一方面的某些实现方式中，根据第二光信号，确定第一直方图，第一直方图包括多个单位时段内第二光信号的信号强度变化趋势；根据第一直方图，确定第一结果值。
示例地，根据第一直方图可以确定第二光信号的回波面积、回波脉宽、回波峰值以及第一直方图中曲线图像的上升沿斜率。
示例地，上述回波面积是第一直方图中的曲线图像的积分值；上述回波脉宽可以分为第一脉宽和第二脉宽。其中，第一脉宽也称脉冲全宽，是第一直方图中的曲线图像起始点到终止点的横坐标之差；第二脉宽是一定比例门限对应的脉宽，即第一直方图中的曲线图像于预设位置横向截取的脉宽，其中，预设位置可以是曲线图像的1/2处(该情况下上述第二脉宽也称半高脉宽)，或者1/3处等合理位置。示例地，在预设位置是曲线图像的1/2处时，假设曲线图像的峰值点的纵坐标为y，那么半高脉宽的两个端点的纵坐标就是y/2，那么这两个端点的横坐标之差就是半高脉宽；上述回波峰值则是上述第一直方图中的曲线图像的峰值点的纵坐标。而基于上述第二光信号的回波面积、回波脉宽以及回波峰值中的任一项，都可以表征第二光信号的信号强度。
示例地，为了更准确地确定第二光信号的信号强度，还需要确定当前环境的背景光值，并将背景光值对于第二光信号的信号强度的误差剔除。
应理解，由于第一子光信号是第二光信号的一部分，所以第一子直方图的曲线趋势和第一直方图的曲线趋势基本是一致的。所以基于第一子直方图也可以确定第一回波参数，该第一回波参数包括第一子光信号的回波面积、回波脉宽、回波峰值中的至少一种。
示例地，可以基于第一检测门限，对上述第一直方图进行截取，使得上述第一结果值基于第一检测门限之上的部分图像进行计算。其中，第一检测门限是一个合理的预设值。对应地，由于第一子直方图是上述第一直方图按照对应的比例压缩的，所以第一子直方图也可以对应着一个第二检测门限，该第二检测门限是基于第一检测门限成比例缩小的。或者，由于根据第一直方图和第一检测门限，能够确定第一直方图的起始时刻和终止时刻，而该起始时刻和终止时刻也对应于第一子直方图的起始时刻和终止时刻，从而无需再确定 上述第二检测门限，即可完成对第一子直方图的截取。
基于上述技术方案，通过第二光信号对应的第一直方图，能够相对直观简单地确定第一结果值，有助于提升计算效率。
结合第一方面，在第一方面的某些实现方式中，在第一结果值是与目标物体之间的距离时，确定向目标物体发射激光束的时刻为第一时刻；根据第一直方图，确定第二时刻；根据第二时刻与第一时刻之间的时间差，确定第二光信号对应的飞行时间；根据光速和飞行时间，确定上述第一结果值。
基于上述技术方案，通过第一直方图来确定第二时刻，使第二时刻的获取相对简单，有助于提升计算第一结果值的效率。
结合第一方面，在第一方面的某些实现方式中，基于第一直方图，将确定探测到第二光信号的起始时刻作为上述第二时刻；或者，基于第一直方图，将第一直方图的峰值时刻作为上述第二时刻；或者，基于第一直方图通过恒比定时(constant fraction timing,CFD)的方式，确定上述第二时刻；或者，基于第一直方图，确定第二光信号的回波时间，再通过质心算法，根据第二光信号对应的回波时间，确定上述第二时刻。
基于上述技术方案，提供了多种获得第二时刻的途径，增加了方法的灵活性。
结合第一方面，在第一方面的某些实现方式中，在第一结果值是第二光信号的能量值时，根据第一直方图，确定第二光信号的回波面积和/或回波峰值；根据第二光信号的回波面积和/或回波峰值，确定第二光信号的信号强度；根据第二光信号的信号强度，确定第一结果值。
基于上述技术方案，通过第一直方图来确定第二光信号的信号强度，该方法相对简单，有助于提升计算第一结果值的效率。
结合第一方面，在第一方面的某些实现方式中，在根据N个第一回波参数，确定第一补偿量之前，确定第一补偿表，包括：获取第二目标参数值和子像素的几何参数，第二目标参数值是准确的目标参数值；确定通过子像素获取的第一子光信号；基于第一子光信号对应的第一回波参数，确定第二结果值，该第二结果值是需要补偿的结果值；根据第二结果值和第二目标参数值，确定第一子补偿量；记录第一子光信号对应的第一回波参数，以确定第一回波参数与第一子补偿量之间的映射关系；将映射关系添加至与子像素的几何参数对应的第一补偿表。
示例地，当上述第二目标参数值为目标物体距离时，该目标物体距离是预先测量好的准确的距离值；当上述第二目标参数值为经由目标物体反射的回波光束对应的第二光信号的能量值时，该能量值是预先测量好的准确的能量值。
示例地，上述子像素的几何参数，在确定第一像素划分方式的过程中已经确定。该子像素的几何参数可以存储于上述存储器中。
示例地，在上述第二结果值为尚未进行补偿的目标物体距离时，基于上述对应实施例的说明可知，上述第二结果值可以是基于第一子光信号的飞行时间计算得到。在上述第二结果值为尚未进行补偿的第一子光信号的能量值时，基于上述对应实施例的说明可知，上述第二结果值可以是基于第一子光信号的信号强度计算得到的。
示例地，在第一子补偿量为距离子补偿量时，可以将上述第二目标参数值和上述第二结果值作差，确定上述距离子补偿量。在第一子补偿量为第一子光信号的能量子补偿量时， 可以基于上述第二目标参数值和上述第二结果值，估算出上述能量子补偿量。
示例地，通过修改上述第二目标参数值，重复上述方法提到的实验，将确定的多个映射关系添加至第一补偿表，不断扩充第一补偿表，使之不断完善。
基于上述技术方案，通过预先实验的方法，针对不同几何参数的子像素，确定相应的第一补偿表。以使得在第一像素被划分为几何参数相同的多个子像素时，基于一张通过上述实验确定的第一补偿表，即可实现对上述距离补偿量的准确补偿。即便第一像素被划分为的多个子像素的几何参数不完全相同，例如，两种几何参数。也只需要两张上述第一补偿表，即可实现对上述距离补偿量的准确补偿。解决了现有技术中难以准确进行误差补偿的问题。
结合第一方面，在第一方面的某些实现方式中，上述N个子像素是基于像素阵列中的单光子雪崩二极管SPAD划分的。
示例地，上述SPAD包括像素激活区，像素激活区中的每个像素可以预先通过SPAD初始参数设置，将像素划分为多个子像素，该初始参数包括每个子像素的几何参数，例如每个像素的长度宽度，并为每个子像素设置编号。并且也支持对每个像素进行编号。以此实现分辨每个子像素对应的部分光信号。
基于上述技术方案，通过SPAD对上述第一像素进行划分，为后续基于子像素进行补偿的方案提供必要的前提条件，是准确进行误差补偿的基础。
结合第一方面，在第一方面的某些实现方式中，上述回波光束打在像素阵列上形成光斑，每个子像素上部分光斑的分布是均匀的。
基于上述技术方案，使得无论光斑是否发生偏移或者弥散，子像素上部分光斑的分布都能够保障是均匀分布，能够进一步增加后续误差补偿的准确性。
第二方面，提供了一种探测装置，应用于探测器，该装置包括：接收单元，用于接收回波光束，该回波光束打在探测器的第一像素上，该第一像素包括N个子像素；确定单元，用于根据上述N个子像素，确定N个第一子光信号，其中，N为正整数；根据该N个第一子光信号，确定N个第一回波参数，该第一回波参数用于表征第一子光信号的信号强度；根据上述N个第一回波参数确定第一光信号，该第一光信号与上述回波光束对应。
基于上述技术方案，将第一像素划分为N个子像素，由于子像素很小，所以子像素中的光斑分布是均匀的或者近似于均匀的。检测目标物体距离或者目标物体反射率时，无论目标物体距离以及激光器温度等因素如何变化，子像素中的光斑分布都是不变的。因此，基于该方法，有助于避免因光斑分布变化，导致基于一张补偿表无法准确补偿误差的问题。即该方法可以实现在N个子像素的几何参数相同的前提下，能够通过一张补偿表即可获得准确的补偿量，提升了误差补偿的准确性，且易于实现。
结合第二方面，在第二方面的某些实现方式中，上述确定单元具体用于：根据第一子光信号，确定第一子直方图，第一子直方图包括多个单位时段内第一子光信号的信号强度变化趋势；根据第一子直方图，确定第一回波参数。
基于上述技术方案，通过第一子直方图来计算表征第一子光信号的信号强度的第一回波参数，该方法易于实现。
结合第二方面，在第二方面的某些实现方式中，上述确定单元还用于：根据N个第一回波参数，确定N个第一子补偿量；根据N个第一子补偿量，确定第一补偿量，该第一 补偿量为用于确定上述第一光信号的补偿量。
基于上述技术方案，由于上述N个第一回波参数是基于N个子像素接收到的N个第一子光信号确定的，由于子像素很小，即便与回波光束对应的光斑发生了偏移，对于N个子像素来说，在N足够大的情况下，子像素上的部分光斑的分布是近似于均匀分布的，所以无论光斑是否发生偏移，N个子像素对应的部分光斑分布是保持为均匀分布的，因此，基于N个第一回波参数确定的N个第一子补偿量是准确的，进而第一补偿量是准确的，增加了误差补偿的准确性。
结合第二方面，在第二方面的某些实现方式中，上述确定单元具体用于：根据子像素的几何参数，筛选出对应的第一补偿表；根据第一回波参数，查找第一补偿表，确定第一回波参数对应的第一子补偿量，第一补偿表是预先通过实验确定的，第一补偿表包括第一回波参数与第一子补偿量之间的映射关系。
基于上述技术方案，可以实现在N个子像素的几何参数相同的前提下，能够通过一张补偿表确定第一补偿量，提升了误差补偿的准确性，且易于实现。
结合第二方面，在第二方面的某些实现方式中，上述子像素的几何参数包括子像素的形状和/或面积。
基于上述技术方案，通过子像素的形状和/或面积作为其几何参数，能够合理地确定不同子像素对应的第一补偿表，有助于保障误差补偿的准确性。
结合第二方面，在第二方面的某些实现方式中，上述第一回波参数包括以下至少一种：第一子光信号的回波面积、回波峰值、回波脉宽以及第一子直方图中曲线图像的上升沿斜率。
基于上述技术方案，基于第一子光信号的回波面积、回波峰值、回波脉宽以及第一子直方图中曲线图像的上升沿斜率中的至少一种，即可确定第一子补偿量，为确定补偿量提供了多种途径，增加了方案的灵活性。
结合第二方面，在第二方面的某些实现方式中，上述确定单元还用于：根据第二光信号，确定第一结果值，该第二光信号是基于上述回波光束确定的原始的光信号；通过第一补偿量对第一结果值进行补偿，确定第一目标参数值，该第一目标参数值对应于上述第一光信号。
基于上述技术方案，基于上述方法确定的第一补偿量对第一结果值进行补偿，有助于提升第一目标参数值的准确性。
结合第二方面，在第二方面的某些实现方式中，上述确定单元具体用于：根据第二光信号，确定第一直方图，第一直方图包括多个单位时段内第二光信号的信号强度变化趋势；根据第一直方图，确定第一结果值。
基于上述技术方案，通过第二光信号对应的第一直方图，能够相对直观简单地确定第一结果值，有助于提升计算效率。
结合第二方面，在第二方面的某些实现方式中，在上述第一结果值是与目标物体之间的距离时，上述确定单元具体用于：确定向目标物体发射激光束的时刻为第一时刻；根据第一直方图，确定第二时刻；根据第二时刻与第一时刻之间的时间差，确定第二光信号对应的飞行时间；根据光速和飞行时间，确定上述第一结果值。
基于上述技术方案，通过第一直方图来确定第二时刻，使第二时刻的获取相对简单， 有助于提升计算第一结果值的效率。
结合第二方面，在第二方面的某些实现方式中，上述确定单元具体用于：基于第一直方图，将确定探测到第二光信号的起始时刻作为第二时刻；或者，基于第一直方图，将第一直方图的峰值时刻作为第二时刻；或者，基于第一直方图通过恒比定时CFD的方式，确定第二时刻；或者，基于第一直方图，确定第二光信号对应的回波时间，再通过质心算法，根据第二光信号对应的回波时间，确定第二时刻。
基于上述技术方案，提供了多种获得第二时刻的途径，增加了方法的灵活性。
结合第二方面，在第二方面的某些实现方式中，在第一结果值是第二光信号的能量值时，上述确定单元具体用于：根据第一直方图，确定第二光信号的回波面积和/或回波峰值；根据第二光信号的回波面积和/或回波峰值，确定第二光信号的信号强度；根据第二光信号的信号强度，确定第一结果值。
基于上述技术方案，通过第一直方图来确定第二光信号的信号强度，该方法相对简单，有助于提升计算第一结果值的效率。
结合第二方面，在第二方面的某些实现方式中，在上述确定单元根据N个第一回波参数，确定第一补偿量之前，上述确定单元还用于：确定第一补偿表，包括：获取第二目标参数值和子像素的几何参数，第二目标参数值是准确的目标参数值；确定通过子像素获取的第一子光信号；基于第一子光信号对应的第一回波参数，确定第二结果值，第二结果值是需要补偿的结果值；根据第二结果值和第二目标参数值，确定第一子补偿量；记录第一子光信号对应的第一回波参数，以确定第一回波参数与第一子补偿量之间的映射关系；将映射关系添加至与子像素的几何参数对应的第一补偿表。
基于上述技术方案，通过预先实验的方法，针对不同几何参数的子像素，确定相应的第一补偿表。以使得在第一像素被划分为几何参数相同的多个子像素时，基于一张通过上述实验确定的第一补偿表，即可实现对上述距离补偿量的准确补偿。即便第一像素被划分为的多个子像素的几何参数不完全相同，例如，两种几何参数。也只需要两张上述第一补偿表，即可实现对上述距离补偿量的准确补偿。解决了现有技术中难以准确进行误差补偿的问题。
结合第二方面，在第二方面的某些实现方式中，上述N个子像素是基于像素阵列中的单光子雪崩二极管SPAD划分的。
基于上述技术方案，通过SPAD对上述第一像素进行划分，为后续基于子像素进行补偿的方案提供必要的前提条件，是准确进行误差补偿的基础。
结合第二方面，在第二方面的某些实现方式中，上述回波光束打在像素阵列上形成光斑，每个子像素上部分光斑的分布是均匀的。
基于上述技术方案，使得无论光斑是否发生偏移或者弥散，子像素上部分光斑的分布都能够保障是均匀分布，能够进一步增加后续误差补偿的准确性。
第三方面，提供了一种探测装置，包括处理器和存储器，其中，处理器和存储器相连，其中，存储器用于存储程序代码，处理器用于调用程序代码，以执行上述第一方面的方法设计中任意一种可能的实现方式中的方法。
第四方面，提供了一种芯片系统，芯片系统应用于电子设备；芯片系统包括一个或多个接口电路，以及一个或多个处理器；接口电路和处理器通过线路互联；接口电路用于从 电子设备的存储器接收信号，并向处理器发送信号，信号包括存储器中存储的计算机指令；当处理器执行计算机指令时，电子设备执行上述第一方面的方法设计中任意一种可能的实现方式中的方法。
第五方面，提供了一种计算机可读存储介质，存储有计算机程序或指令，该计算机程序或指令用于实现第一方面的方法设计中任意一种可能的实现方式中的方法。
第六方面，提供了一种计算机程序产品，该计算机程序代码或指令在计算机上执行时，使得计算机执行上述第一方面的方法设计中任意一种可能的实现方式中的方法。
第七方面，本申请实施例提供一种车辆，该车辆包括如第二方面和第三方面中任一种可能实现方式中的装置。
附图说明
图1是本申请实施例提供的一种Lidar系统的示意图。
图2是本申请实施例提供的一种光斑偏移量与目标物体距离之间的关系示意图。
图3是本申请实施例提供的一种探测方法流程示意图。
图4是本申请实施例提供的一种像素划分的示意图。
图5是本申请实施例提供的一种第一直方图的示意图。
图6是本申请实施例提供的一种第一子直方图的示意图。
图7是本申请实施例提供的一种确定第一直方图的方法示意图。
图8是本申请实施例提供的一种确定第一结果值的方法流程示意图。
图9是本申请实施例提出的又一种确定第一结果值的方法流程示意图。
图10是本申请实施例提供的又一种确定第一补偿表的方法流程示意图。
图11是本申请实施例提出的一种通过实验确定的第一子补偿量与第一回波参数之间的关系示意图。
图12是本申请实施例提出的一种探测系统的示意图。
图13是本申请实施例提供的一种探测装置1300的示意性框图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述。其中，在本申请实施例的描述中，除非另有说明，“/”表示或的意思，例如，A/B可以表示A或B；本文中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。
本申请实施例中采用诸如“第一”、“第二”的前缀词，仅仅为了区分不同的描述对象，对被描述对象的位置、顺序、优先级、数量或内容等没有限定作用。本申请实施例中对序数词等用于区分描述对象的前缀词的使用不对所描述对象构成限制，对所描述对象的陈述参见权利要求或实施例中上下文的描述，不应因为使用这种前缀词而构成多余的限制。此外，在本实施例的描述中，除非另有说明，“多个”的含义是两个或两个以上。
Lidar作为一种主动式的传感器，是自动驾驶、机器人、无人机等领域不可或缺的关键部分。
图1示出了本申请实施例提出的一种Lidar系统的示意图。Lidar一般包括控制器、调 制器、信号发射器、信号探测器、处理器、存储器。
其中，控制器可以用于控制调制器和信号发射器发射指定信号强度的激光束；也可以用于控制信号探测器接收回波光束；还可以用于控制处理器对回波光束携带的相关参数进行处理和计算。
调制器用于对激光束进行调制，以使得Lidar能够发射出指定信号强度的激光束。
信号发射器，一般包括光源(也称激光器)和发射光学透镜，用于向目标物体发射激光束。其中，发射光学透镜用于将光源发射的激光束进行折射，将激光束按照指定光路传输至目标物体之上。
信号探测器，一般包括探测器(也称接收器)和接收光学透镜，用于探测并接收回波光束，并将回波光束由光信号转化为电信号，确定各个时段内回波光束的信号强度，进而生成关于回波光束的直方图。可见，该直方图能够表示回波光束在各个时间段内的信号强度。其中，接收光学透镜用于将从目标物体反射回来的回波光束进行折射，将回波光束折射至探测器的指定位置。
在一些可能的实施例中，上述探测器可以是一种单光子雪崩二极管(single photon avalanche diode，SPAD)探测器，该SPAD包括在探测器的像素阵列中，该像素阵列用于接收上述回波光束，并且像素阵列的一个或多个像素上形成光斑，并且将回波光束由光信号转化为电信号。
处理器，用于对回波光束进行处理，确定相关参数，并对相关参数进行误差补偿，最后求解第一目标参数值。其中，第一目标参数值包括：与目标物体之间的距离，目标物体的反射率等。
存储器，用于存储信号处理过程中的中间结果。
在一些可能的实施例中，基于上述架构的Lidar，可以检测出目标物体与激光器之间的距离，为了方便描述，本申请实施例将该距离简称为目标物体距离。测量目标物体距离的工作原理如下：
信号发射器向目标物体发射激光束，该激光束经由目标物体反射，以回波光束的形式反射至信号探测器中。对应地，信号探测器的像素阵列的一个或多个像素上形成光斑，并且将回波光束由光信号转化为电信号。然后处理器可以基于内置的计时器(如系统时钟)确定发射信号开始发射与最终接收的时间差，进而确定信号的飞行时间，根据该飞行时间和光速即可求解出目标物体距离。
在一些可能的实施例中，基于上述架构的Lidar，可以检测出目标物体的反射率，其工作原理如下：
信号发射器向目标物体发射激光束，该激光束经由目标物体反射，以回波光束的形式反射至信号接收器中，并在信号接收器的像素阵列上形成光斑。然后信号探测器对回波光束进行检测，响应回波光束并确定信号强度，即确定回波光束对应的能量值。此外，还需要确定目标物体距离，然后处理器根据该能量值以及目标物体距离，进而确定目标物体的反射率。而表面材质不同的目标物体，其所属的类别也不同，因此目标物体的反射率可以应用于对目标物体的种类识别。
以目标参数是目标物体距离和反射率为例，目标参数的检测都是基于回波光束最终在探测器像素阵列上的光斑转化为电信号后进行计算的。如果光斑在像素阵列上的成像位置 位于目标接收位置不发生偏移，该目标接收位置可以是接收光斑的焦平面，且光斑在像素阵列上不发生弥散，则光斑分布不会发生变化。在满足这些前提条件时，基于光斑对应的电信号所计算的目标参数是准确的。
其中，光斑偏移指的是光斑在像素阵列的平面上发生位置的偏移，由于像素阵列的接收范围是固定的，光斑偏移后会造成部分光信号无法接收到；光斑弥散则是光斑成像位置并不在像素阵列的平面上，光斑弥散后会导致响应到的光信号强度和实际光信号强度存在偏差。
以Lidar系统为例，图2示出了本申请实施例提出的一种离轴式Lidar光斑偏移量与目标物体距离之间的关系示意图。可见，对于离轴式的Lidar，目标物体距离激光器之间的距离发生变化时，光斑在水平方向上也会发生偏移。当Lidar和目标物体之间的距离越近时，光斑偏移量越大，虽然光斑偏移量仅是微米量级的，但是微米量级的偏移也会对最终计算目标物体距离造成较大的误差。所以需要对计算结果进行误差补偿。
而对于离轴式的Lidar，Lidar的发射路径和接收路径并不重合。若目标物体距离激光雷达足够远，则Lidar的发射路径和接收路径可以是近似成两条平行的路径，此时成像在像素阵列的光斑弥散程度以及光斑偏移程度很小，甚至可以忽略不计；若目标物体距离激光雷达较近，则激光雷达的发射路径和接收路径是两条不平行的路径，造成了像素阵列的光斑产生相对较大的弥散和偏移。而基于发生弥散和偏移的光斑对应的电信号进行目标参数计算，是会引入误差的，所以也需要对计算结果进行误差补偿。
此外，Lidar内部的部件热胀冷缩或者部件老化等因素，会造成雷达的发射器镜头发生变形，也会造成光斑在像素阵列上的成像位置发生偏移。由于像素阵列的接收位置和响应范围是固定的，所以当光斑在像素阵列上接收的位置发生偏移后，会造成部分光信号无法被像素阵列接收到，可见，基于发生位置偏移的光斑进行目标参数计算，是会引入误差的，所以也需要对计算结果进行误差补偿。
在一些可能的实施例中，可以通过特定的误差补偿表对上述计算结果进行误差补偿，例如，距离补偿表或者用于计算反射率的能量补偿表。根据通过像素阵列响应到的回波信号参数，在误差补偿表中查找对应的误差补偿值。但是这都是基于光斑分布不变的前提而言的，而通常情况下，成像于像素阵列的光斑是不均匀的。在成像在像素阵列上的光斑分布不均匀时，光斑位置发生偏移，或者光斑发生弥散，都会造成光斑分布发生变化。而光斑分布发生变化后，再基于上述光斑分布对应的误差补偿表进行误差补偿，也是不准确的。以下通过具体实施例进行说明。
以测距为例，基于上述方法的补偿过程可以分为两部分，具体如下：
1)对于目标物体距离改变造成的误差进行补偿。例如，当前实际目标距离是15m，此时回波光束对应的光斑整体分布不均匀，且发生了弥散与偏移，导致光斑分布发生变化，检测得到的目标距离是14.8m。假设系统内存储着距离补偿表1且该距离补偿表1能够准确补偿当前情况下的误差，则从该距离补偿表1中查找当前回波光束的信号强度对应的误差值，0.2m。以实现对检测目标距离的误差补正。
但是第二次对目标进行检测时，实际目标距离变为了10m，此时光斑会进一步发生弥散，导致光斑分布再次发生变化，进而使检测目标距离是9.5m。而针对于此时的光斑分布，如果还沿用上一次进行误差补正的距离补偿表1，从该距离补偿表1中查找当前回波 光束的信号强度对应的误差值，通常是不准确的，例如0.4m。若要补偿准确，则需要另外保存一个针对于当前光斑分布情况的距离补偿表2，以保证误差补偿的准确性。
2)对于激光雷达温度改变造成的误差进行补偿。例如，当前激光雷达的温度是10℃，实际目标距离是200m，假设此时光斑位置没有因目标距离发生偏移，但是此时激光雷达的温度会造成光斑位置的偏移，进而导致光斑分布发生变化，检测得到的目标距离是198m。假设系统内存储着距离补偿表3且该距离补偿表3能够准确补偿当前情况下的误差，从该距离补偿表3中查找当前回波光束的信号强度对应的误差值，2m。以实现对检测目标距离的误差补正。
但是第二次对目标进行检测时，实际目标距离不变，但是激光雷达的温度变为了25℃，由于热胀冷缩，造成激光雷达的发射器或者接收器的镜头发生偏移，此时光斑位置会进一步发生偏移，导致光斑分布再次发生变化，进而使检测目标距离是196m。而针对于此时的光斑分布，如果还沿用上一次进行误差补正的距离补偿表3，从该距离补偿表3中查找当前回波光束的信号强度对应的误差值，通常是不准确的，例如3m。若要补偿准确，则需要另外保存一个针对于当前光斑分布情况的距离补偿表4，以保证误差补偿的准确性，否则存在补偿量不足或者补偿过量的问题。
基于上述方法对目标物体进行反射率检测时，同样会出现上述问题。
由此可见，基于上述说明中提到的情况，光斑分布的变化是多样的，通过一张误差补偿表是无法补偿准确的。那么需要保存大量和不同光斑分布情况对应的误差补偿表，这样造成了资源的浪费，并且在实际应用中也难以实现准确的误差补偿。
鉴于此，本申请实施例提出了一种探测方法，对接收光斑的像素阵列中的每个像素进一步拆分，将每个像素拆分为多个子像素。由于子像素很小，所以子像素范围内的光斑分布是均匀或者近似于均匀的。然后基于通过预先实验确定的误差补偿表，确定上述子像素对应的补偿量，这样确保了每个子像素对应的补偿量都是准确的。然后根据每个子像素对应的补偿量，确定整个像素的补偿量。由于每个子像素对应的补偿量是准确的，那么由此确定的整个像素的补偿量也是准确的。以此实现对激光雷达系统计算的目标参数进行误差补偿，也增加了误差补偿的准确性。
应理解，在光斑几何参数小于或者等于一个像素时，基于上述方法计算的一个像素的补偿量是准确的，那么后续计算的目标参数结果也是准确的；在光斑几何参数为多个像素时，由于基于上述方法计算的每个像素补偿量是准确的，那么根据各个像素的补偿量再进行加权求和，并基于该结果对目标参数结果进行补偿，以使得后续计算的目标参数结果也是准确的。
图3示出了本申请实施例提出的一种探测方法流程示意图。
该方法应用于探测器，在执行该方法之前，还需要向目标物体发射激光束，并接收该激光束经由目标物体反射形成的回波光束(或称回波信号)。
S310：接收回波光束，该回波光束打在探测器的第一像素上，该第一像素包括N个子像素。
在一些可能的实施例中，该回波光束可以打在探测器的像素阵列上。
在一些可能的实施例中，由于上述回波光束最终在像素阵列上以光斑的形式呈现。所以在光斑占据多个像素时，基于回波光束确定的光信号对应于光斑的一部分；在光斑仅占 据第一像素时，基于回波光束确定的光信号则对应于光斑的全部。
应理解，上述第一像素可以是被预先划分为N个子像素的，其中，N为正整数。
图4示出了本申请实施例提出的一种像素划分的示意图。
在一些可能的实施例中，以第一像素为例。可以将第一像素划分为N个几何参数相同的子像素，本申请实施例对具体几何参数不做限定。此外，也可以将第一像素划分为N个不同几何参数的子像素，还可以将第一像素划分为一部分是第一几何参数的子像素，另一部分是第二几何参数的子像素等。
应理解，上述第一像素划分的份数N越大，子像素的面积就越小，从而每个子像素对应的部分光斑(也称子光斑)的分布就约趋近于均匀。此外，上述对像素划分的过程，也是对光斑进行划分，将一个完整的光斑划分为若干部分的子光斑，而且保证针对于每个子光斑来说，其在像素阵列上分布是均匀的。因此针对每个子像素对应的分布均匀的子光斑而言，无论像素阵列上的光斑是否发生偏移以及弥散，子像素对应的子光斑的分布都是不变的，均保持为一种均匀分布。由于子光斑的分布不变，所以在子像素的几何参数都一致的情况下，基于一张误差补偿表即可实现准确对基于子光斑对应的回波信号求解的目标参数进行误差补偿。
在一些可能的实施例中，像素阵列可以根据当前的光斑分布，实时地调整像素阵列上各个像素的划分方式，以使得各个子像素中的光斑分布都是均匀的。基于该技术方案，能够进一步增加后续误差补偿的准确性。
在一些可能的实施例中，可以通过像素阵列中的SPAD对上述第一像素进行划分，该SPAD包括像素激活区，像素激活区中的每个像素可以预先通过SPAD初始参数设置，将像素划分为多个子像素，该初始参数包括每个子像素的几何参数，例如每个像素的长度宽度，并为每个子像素设置编号。并且也支持对每个像素进行编号。以此实现分辨每个子像素对应的部分光信号。
示例地，以第一像素为例，该第一像素形状几何参数可以为1*1像素的正方形，可以通过如下方式描述每个子像素的相关信息。
Pixel 01:Son-Pixel 01＝{“Length”:“0.5Pixel”,“Width”:“0.5Pixel”}；
Pixel 01:Son-Pixel 01＝{“Length”:“0.5Pixel”,“Width”:“0.5Pixel”}；
Pixel 01:Son-Pixel 01＝{“Length”:“0.5Pixel”,“Width”:“0.5Pixel”}；
Pixel 01:Son-Pixel 01＝{“Length”:“0.5Pixel”,“Width”:“0.5Pixel”}；
由此可见，第一像素被划分为4个形状相同的子像素，每个子像素的形状几何参数都是0.5*0.5像素的正方形。
S320：根据上述N个子像素，确定N个第一子光信号。
S330：根据上述N个第一子光信号，确定N个第一回波参数，该第一回波参数用于表征第一子光信号的信号强度。
在一些可能的实施例中，上述第一回波参数包括以下至少一种：上述第一子光信号的回波面积、回波峰值、回波脉宽、第一子直方图中曲线图像的上升沿斜率。
在一些可能的实施例中，上述第一回波参数可以是基于第一子光信号对应的第一子直方图确定的。
S340：根据上述N个第一回波参数确定第一光信号，该第一光信号与回波光束对应。
应理解，上述第一光信号是基于各个第一子光信号对应的第一回波参数确定的，并对第一光信号对应的目标参数进行了相应的补偿。
基于上述技术方案，将第一像素划分为N个子像素，由于子像素很小，所以子像素中的光斑分布是均匀的或者近似于均匀的。检测目标物体距离或者目标物体反射率时，无论目标物体距离以及激光器温度等因素如何变化，子像素中的光斑分布都是不变的。因此，基于该方法，有助于避免因光斑分布变化，导致基于一张补偿表无法准确补偿误差的问题。即该方法可以实现在N个子像素的几何参数相同的前提下，能够通过一张补偿表即可获得准确的补偿量，提升了误差补偿的准确性，且易于实现。
应理解，在回波光束在探测器上形成的光斑发生偏移时，若直接基于上述基于回波光束确定的光信号直接求解相应的目标参数，并对该目标参数进行补偿通常是不准确的，因为光斑发生偏移会导致光斑分布发生变化，而每种光斑分布对应于一张补偿表，而光斑分布变化往往是一个动态的过程，只基于一张补偿表对目标参数进行补偿，必然是不准确的。所以，本申请实施例提出了基于第一子光信号进行补偿的方案。
在一些可能的实施例中，在执行上述S340后，为确定第一像素对应的光斑参数进行准确补偿提供了前提条件，本申请实施例提供的探测方法还可以执行如下步骤：根据上述N个第一回波参数，确定N个第一子补偿量，并根据该N个第一子补偿量，确定第一补偿量，该第一补偿量为用于确定上述第一光信号的补偿量。
在一些可能的实施例中，上述第一子补偿量可以通过查找补偿表的方式确定。该补偿表可以是预先通过实验确定的，该补偿表记载着第一回波参数和第一子补偿量之间的映射关系。例如，第一子光信号的回波面积与第一子补偿量之间的映射关系，或者第一子光信号的回波脉宽与第一子补偿量的映射关系，或者第一子光信号的回波峰值与第一子补偿量之间的映射关系，然后将查表确定的N个第一子补偿量进行加权求和，即可确定上述第一补偿量。基于该技术方案，在N个子像素几何参数相同时，通过一张补偿表即可实现第一补偿量的确定，提升了误差补偿的准确性，且易于实现。
在一些可能的实施例中，针对于不同的补偿量，确定上述第一补偿量的具体方法也有所不同：示例地，可以将N个第一子补偿量进行加权累加，该加权累加可以包括两种情况，一种情况是权数为1，此时加权累加的过程其实就是直接累加的过程，另一种情况是权数不为1；此外，也可以将N个第一子补偿量进行累加求平均值。
基于上述技术方案，由于上述N个第一回波参数是基于N个子像素接收到的N个第一子光信号确定的，由于子像素很小，即便与回波光束对应的光斑发生了偏移，对于N个子像素来说，在N足够大的情况下，子像素上的部分光斑的分布是近似于均匀分布的，所以无论光斑是否发生偏移，N个子像素对应的部分光斑分布是保持为均匀分布的，因此，基于N个第一回波参数确定的N个第一子补偿量是准确的，进而第一补偿量是准确的，增加了误差补偿的准确性。
在一些可能的实施例中，可以根据第二光信号，确定第一结果值，该第二光信号是基于上述回波光束确定的原始的光信号，该第一结果值可以是目标物体距离，也可以是用于计算目标物体反射率的第二光信号的能量值。但是，上述第一结果值是没有经过补偿的结果值，所以可以基于上述实施例提出的方法，确定第一补偿量，然后通过第一补偿量对上述第一结果值进行补偿，进而确定第一目标参数值，该第一目标参数值对应于上述第一光 信号。
基于上述技术方案，有助于提升上述第一目标参数值的准确性。
在一些可能的实施例中，上述第一结果值可以是基于第二光信号对应的第一直方图确定的，该第一直方图包括多个单位时段内第一像素响应到第二光信号的信号强度变化趋势。进一步地，根据第一直方图可以确定第二光信号的回波面积、回波脉宽、回波峰值以及第一直方图中曲线图像的上升沿斜率。第一直方图如下图5所示。
图5示出了本申请实施例提出的一种第一直方图的示意图。该第一直方图的横坐标为上述多个单位时段，纵坐标为单位时段内第一像素响应到第二光信号的信号强度。因此，第一直方图直观地呈现了第二光信号的信号强度随着时间的变化趋势。
在一些可能的实施例中，上述回波面积是第一直方图中的曲线图像的积分值；上述回波脉宽可以分为第一脉宽和第二脉宽。其中，第一脉宽也称脉冲全宽，是第一直方图中的曲线图像起始点到终止点的横坐标之差；第二脉宽是一定比例门限对应的脉宽，即第一直方图中的曲线图像于预设位置横向截取的脉宽，其中，预设位置可以是曲线图像的1/2处(该情况下上述第二脉宽也称半高脉宽)，或者1/3处等合理位置。示例地，在预设位置是曲线图像的1/2处时，假设曲线图像的峰值点的纵坐标为y，那么半高脉宽的两个端点的纵坐标就是y/2，那么这两个端点的横坐标之差就是半高脉宽；上述回波峰值则是上述第一直方图中的曲线图像的峰值点的纵坐标。而基于上述第二光信号的回波面积、回波脉宽以及回波峰值中的任一项，都可以表征第二光信号的信号强度。
在一些可能的实施例中，为了更准确地确定第二光信号的信号强度，还需要确定当前环境的背景光值，并将背景光值对于第二光信号的信号强度的误差剔除。基于该技术方案，能够进一步提升误差补偿的准确性。
在一些可能的实施例中，上述第一回波参数可以是基于第一子光信号对应的第一子直方图确定的，基于与上述实施例确定第一直方图类似的方法，可以根据第一子光信号，确定第一子直方图，该第一子直方图包括第一子光信号在上述多个单位时段内子像素响应到第一子光信号的信号强度变化趋势。进一步地，基于第一子直方图也可以确定第一子光信号的回波面积、回波脉宽、回波峰值以及对应第一子直方图中曲线图像的上升沿斜率，而这些参数均属于上述第一回波参数。第一子直方图如图6所示。
图6示出了本申请实施例提出的一种第一子直方图的示意图。第一子直方图的横坐标和纵坐标的含义和上述第一直方图的横坐标和纵坐标的含义相同。同理，第一子直方图表征了第一子光信号的信号强度随着时间的变化趋势。
通过图6可知，由于第一子光信号是第二光信号的一部分，所以第一子直方图的曲线趋势和第一直方图的曲线趋势基本是一致的。所以基于第一子直方图也可以确定第一回波参数，该第一回波参数包括第一子光信号的回波面积、回波脉宽、回波峰值中的至少一种。其中，回波面积、回波脉宽、回波峰值等的含义在上述对应实施例中已描述，在此不再赘述。
基于上述技术方案，通过第一子直方图来计算表征第一子光信号的信号强度的第一回波参数，该方法易于实现，且灵活性高，通过回波面积、回波脉宽、回波峰值任一项参数，都可以表征第一子光信号的信号强度。
在一些可能的实施例中，可以基于第一检测门限，对上述第一直方图进行截取，使得 上述第一结果值基于第一检测门限之上的部分图像进行计算。其中，第一检测门限是一个合理的预设值。
对应地，由于第一子直方图是上述第一直方图按照对应的比例压缩的，所以第一子直方图也可以对应着一个第二检测门限，该第二检测门限是基于第一检测门限成比例缩小的。或者，由于根据第一直方图和第一检测门限，能够确定第一直方图的起始时刻和终止时刻，而该起始时刻和终止时刻也对应于第一子直方图的起始时刻和终止时刻，从而无需再确定上述第二检测门限，即可完成对第一子直方图的截取。
基于上述技术方案，可以只对大于检测门限的部分直方图数据进行分析，并且在门限值设置合理的前提下，不会影响直方图分析的准确性，并且有助于增加直方图分析的效率。
在一些可能的实施例中，还可以通过上述N个第一子直方图，确定对应的第一直方图。图7示出了本申请实施例提出的一种确定第一直方图的方法示意图。
以上述第一像素为例，该第一像素被划分为4个形状几何参数相同的子像素，对应地，每个子像素都会接收到第一子光信号，然后分别对4个第一子光信号进行检测，进而确定4个第一子直方图，即第一子直方图1、第一子直方图2、第一子直方图3、第一子直方图4。其中，存储器用于存储生成第一子直方图所需要的参数以及存储确定的第一子直方图的数据。然后通过累加器将多个第一子直方图进行累加，确定第一直方图。
在一些可能的实施例中，可以确定第一子直方图的过程可以是在探测器中完成的，也可以是在信号处理模块中完成的，本申请实施例对此不作限定。
为了方便理解，以下将对本申请实施例提出的一种探测方法进行详细说明。
以第一结果值是目标物体距离为例，该第一结果值可以通过如下方式确定。
图8示出了本申请实施例提出的一种确定第一结果值的方法流程示意图。
S810：确定向目标物体发射激光束的时刻为第一时刻。
S820：根据上述第一直方图，确定第二时刻。
在一些可能的实施例中，可以基于第一直方图，将探测到第二光信号(即回波信号)的起始时刻作为上述第二时刻；也可以直接将第一直方图的峰值时刻作为上述第二时刻；还可以基于第一直方图通过CFD的方式，确定上述第二时刻；还可以基于第一直方图和如下公式(1)，通过质心算法，确定上述第二时刻，其中公式(1)用于计算第二光信号对应的回波时间。该公式(1)具体如下：
其中，t表示回波时间，a表示第一直方图的起始位置，b表示第一直方图的终止位置，bin表示第一直方图的各个点的横坐标，A(bin)表示第一直方图中各个点的纵坐标。
S830：根据第二时刻与第一时刻之间的时间差，确定上述第二光信号对应的飞行时间。
S840：根据光速和上述飞行时间，确定第一结果值。
在一些可能的实施例中，将光速和飞行时间相乘并且除以2，即可得到目标物体距离，即上述第一结果值。但是，由于在目标物体距离变化的过程中，第二光信号的信号强度也在变化，对应地光斑也会发生偏移和/或弥散，可见第一结果值是不准确的。所以在确定上述第一结果值之后，需要基于各个子像素对应的第一子光信号，确定第一补偿量。上述 第一子光信号的第一回波参数包括第一子光信号的回波面积。可以通过如下方法确定上述第一补偿量：
在一些可能的实施例中，可以根据上述N个第一子光信号的回波面积，查找第一补偿表，确定与N个第一子光信号的回波面积相对应的N个第一子补偿量，其中，N个第一子补偿量是对基于N个第一子光信号处理计算得到的距离补偿量。基于上述实施例对应说明可知，该第一补偿表可以是预先通过实验确定的用于记载不同第一子光信号的回波面积与第一子补偿量之间映射关系的表。然后将上述N个第一子补偿量加权累加，确定第一补偿量。
以第一结果值是上述第二光信号的能量值为例，该第一结果值可以通过如下方式确定。
图9示出了本申请实施例提出的又一种确定第一结果值的方法流程示意图。
S910：根据第一直方图，确定第二光信号的回波面积和/或峰值。
S920：根据第二光信号的回波面积和/或峰值，确定第二光信号的信号强度。
S930：根据上述第二光信号的信号强度，确定第一结果值。
在一些可能的实施例中，由于在雷达的发射器镜头发生变形，或者目标物体距离发生变化时，对应地光斑也发生偏移和/或弥散，可见第一结果值是不准确的，所以在确定上述第一结果值之后，需要基于各个子像素对应的第一子光信号，确定第一补偿量。上述第一子光信号的第一回波参数包括第一子光信号的回波面积。可以通过如下方法确定上述第一补偿量：
在一些可能的实施例中，可以根据上述N个第一子光信号的回波面积，查找第一补偿表，确定与N个第一子光信号的回波面积相对应的N个第一子补偿量，其中，N个第一子补偿量是对基于N个第一子光信号处理计算得到的能量补偿量。基于上述实施例对应说明可知，该第一补偿表可以是预先通过实验确定的用于记载不同第一子光信号的回波面积与第一子补偿量之间映射关系的表。然后根据上述N个第一子补偿量，确定第一补偿量。
可见，在实际应用中，若要确定第一子光信号的第一回波参数对应的第一子补偿量，则需要预先确定好上述实施例提到的记载第一回波参数与第一子补偿量之间的映射关系的表，在本申请实施例中将该表定义为第一补偿表。
图10示出了本申请实施例提出的一种确定第一补偿表的方法流程示意图。
在一些可能的实施例中，可以通过如下实验方式确定第一补偿表：
S1010：获取第二目标参数值和子像素的几何参数，该第二目标参数值是准确的目标参数值。
在一些可能的实施例中，当上述第二目标参数值为目标物体距离时，该目标物体距离是预先测量好的准确的距离值；当上述第二目标参数值为经由目标物体反射的第二光信号的能量值时，该能量值是预先测量好的准确的能量值。
在一些可能的实施例中，上述子像素的几何参数，在确定第一像素划分方式的过程中已经确定。该子像素的几何参数可以存储于上述存储器中。
在一些可能的实施例中，上述子像素的几何参数包括子像素的形状和/或面积。
在一些可能的实施例中，对于不同几何参数的子像素，需要对应地确定不同的第一补偿表。
S1020：确定通过子像素获取的第一子光信号。
应理解，上述第一子光信号是向目标物体发射激光束后，经由目标物体反射回来的第二光信号的一部分。
S1030：基于上述第一子光信号，确定第二结果值，该第二结果值是需要补偿的结果值。
应理解，在上述第二结果值为尚未进行补偿的目标物体距离时，基于上述对应实施例的说明可知，上述第二结果值可以是基于第一子光信号的飞行时间计算得到。在上述第二结果值为尚未进行补偿的第一子光信号的能量值时，基于上述对应实施例的说明可知，上述第二结果值可以是基于第一子光信号的信号强度计算得到的。
S1040：根据上述第二目标参数值和上述第二结果值，确定第一子补偿量。
在一些可能的实施例中，在第一子补偿量为距离子补偿量时，可以将上述第二目标参数值和上述第二结果值作差，确定上述距离子补偿量。在第一子补偿量为第一子光信号的能量子补偿量时，可以基于上述第二目标参数值和上述第二结果值，估算出上述能量子补偿量。
S1050：记录此时第一子光信号对应的第一回波参数，以确定该第一回波参数与第一子补偿量之间的映射关系。
S1060：将上述映射关系添加至与上述子像素的几何参数对应的第一补偿表。
在一些可能的实施例中，修改上述第二目标参数值，基于上述方法，重复实验，将确定的多个映射关系添加至第一补偿表，不断扩充第一补偿表，使之不断完善。
基于上述技术方案，通过预先实验的方法，针对不同几何参数的子像素，确定相应的第一补偿表。以使得在第一像素被划分为几何参数相同的多个子像素时，基于一张通过上述实验确定的第一补偿表，即可实现对上述距离补偿量的准确补偿。即便第一像素被划分为的多个子像素的几何参数不完全相同，例如，两种几何参数。也只需要两张上述第一补偿表，即可实现对上述距离补偿量的准确补偿。解决了现有技术中难以准确进行误差补偿的问题。
在一些可能的实施例中，在上述第一补偿表确定后，当第一结果值为上述目标物体距离时，对应地，第一补偿量为上述距离补偿量，可以通过如下方式查找第一子补偿量，并确定补偿后的第一结果值：
首先确定子像素的几何参数，以选取对应的第一补偿表。
然后确定子像素采集到的第一回波参数。
再根据第一回波参数，在第一补偿表中查找对应的第一子补偿量。
最后基于多个第一子补偿量，确定上述第一补偿量，并根据第一结果值和第一补偿量解算出经过补偿的目标物体距离。
在一些可能的实施例中，在上述第一补偿量为距离补偿量时，可以通过如下公式(2)，确定上述第一补偿量。
其中，Δx表示第一补偿量，在本实施例中第一补偿量为距离补偿量；N表示当第一像 素被划分子像素的数量，对应着N个第一子直方图；arean表示N个第一子直方图中的第n个第一子直方图的回波面积，Δxn表示通过查找第一补偿表得到的N个第一子直方图中的第n个第一子直方图的回波面积对应的第一子补偿量，在本实施例中第一子补偿量也称距离子补偿量。
在一些可能的实施例中，回波信号的回波面积可以通过如下公式(3)确定：
其中，area为回波信号的回波面积，Δt为第一像素响应回波信号的单位时段的时间长度，该回波信号可以是上述第二光信号，也可以是第一子光信号。
在一些可能的实施例中，由于目标物体距离是基于光速和第二光信号对应的飞行时间确定的。所以，上述距离补偿量可以替换为时延补偿量；对应地，上述距离子补偿量可以替换为时延子补偿量。在确定时延补偿量之后，乘以光速，即可确定上述距离补偿量。
在一些可能的实施例中，上述距离补偿量可以基于N个第一子光信号的回波面积来计算，具体应用到了上述公式(1)至(3)。此外，上述距离补偿量还可以基于N个第一子光信号的回波峰值或者回波脉宽等来计算，虽然具体使用的公式可能不同于上述(1)至(3)，但是原理是相同的，在此不进行赘述。
在一些可能的实施例中，在上述第一补偿表确定后，当第一结果值为上述第二光信号的能量值时，对应地，第一补偿量为上述能量补偿量，可以通过如下方式查找第一子补偿量，并且确定补偿后的第一结果值：
首先确定目标物体距离。
在一些可能的实施例中，上述目标物体距离可以是基于上述实施例中提出的对应方法进行补偿后得到的目标物体距离。
然后确定子像素的几何参数，以选取对应的第一补偿表。
再确定子像素采集到的第一回波参数。
再根据第一回波参数，在第一补偿表中查找对应的第一子补偿量。
最后基于多个第一子补偿量，确定上述第一补偿量，由于第一结果值和第一补偿量为能量值，所以在确定第一结果值和第一补偿量的同时，还需要结合目标物体距离，解算出经过补偿的目标物体反射率。
在一些可能的实施例中，上述第一子光信号的回波面积与上述距离补偿量的映射关系以及与上述能量补偿量的映射关系可以分别记载于不同的补偿表中，也可以记载于一个补偿表中，例如都记载到第一补偿表中，本申请实施例对此不做限定。
第一补偿量为能量补偿量时，可以通过如下公式(4)，确定上述第一补偿量。
其中，peakestn表示通过查找第一补偿表得到的第n个第一子直方图的回波面积对应的第一子补偿量，在本实施例中第一子补偿量也称能量子补偿量；peakest表示第一补偿量，在该实施例中第一补偿量也称能量补偿量。
在一些可能的实施例中，上述第一补偿表还可以包括不同第一子光信号的回波脉宽或者回波峰值与上述第一子补偿量之间的映射关系，该第一子光信号的回波脉宽或者回波峰 值属于上述第一回波参数。基于此，还可以根据第一子光信号的回波脉宽或者回波峰值查找第一补偿表，确定第一子补偿量。而确定不同第一子光信号的回波脉宽或者回波峰值与上述第一子补偿量之间的映射关系的实验方法与上述对应实施例的实验方法相同，在此不过多赘述。
基于上述技术方案，在第一像素被划分为几何参数相同的多个子像素时，基于一张通过上述实验确定的第一补偿表，即可实现对上述距离补偿量的准确补偿。即便第一像素被划分为的多个子像素的几何参数不完全相同，例如，两种几何参数。也只需要两张上述第一补偿表，即可实现对上述距离补偿量的准确补偿。解决了现有技术中难以准确进行误差补偿的问题。
图11示出了本申请实施例提出的一种通过实验确定的第一子补偿量与第一回波参数之间的关系示意图。其中，图11中的(a)具体表示第一子光信号对应的距离子补偿量与回波面积之间的关系示意图；图11中的(b)具体表示第一子光信号对应的能量子补偿量与回波面积之间的关系示意图；图11中的(c)具体表示第一子光信号对应的能量子补偿量与回波脉宽之间的关系示意图；图11中的(d)具体表示第一子光信号对应的能量子补偿量与回波峰值之间的关系示意图。
在一些可能的实施例中，由于上述通过查找第一补偿表确定第一子补偿量的操作还是较为繁琐的，而且资源开销相对较大。而通过图11可知，第一回波参数与第一子补偿量之间的关系是存在线性趋势的。所以可以通过线性回归的方式，将上述第一补偿表记载的映射关系进行拟合，确定第一函数，当确定第一子光信号的第一回波参数时，将第一回波参数输入至第一函数中，即可确定第一子补偿量。
基于上述技术方案，能够进一步提升确定第一子补偿量的效率，并且有效避免查表操作效率低、资源开销大的问题。
图12示出了本申请实施例提出的一种探测系统的示意图。该系统包括控制器、调制器、信号发射器、信号探测器、信号处理器。
其中，控制器和调制器的功能和上述图1对应实施例中的控制器和调制器的功能相同，可以参考前述实施例中的对应内容，在此不再赘述。
信号发射器除了包括激光器和发射光学透镜，还包括一个扫描镜，该扫描镜用于将激光器发射的激光束进行反射，将激光束扫描到目标物体之上，使经由目标物体反射的回波光束能够携带目标物体的整体相关信息，例如，通过该回波光束成像在像素阵列上的光斑，经过上述实施例中提出的探测方法，即可确定目标物体反射率等目标参数值。
信号探测器包括像素阵列，并基于SPAD将像素阵列中的每个像素划分为多个子像素。以上述第一像素为例，可以划分为N个子像素。
此外，信号探测器可以对通过像素阵列接收到的光信号进行信号预处理。以第一像素为例，第一像素接收到回波光束后，确定第二光信号，然后可以基于第二光信号生成第一直方图，并且通过有限冲激响应(finite impulse response，FIR)滤波器对第一直方图进行滤波处理，以及对第二光信号进行回波检测，以获得上述第一结果值。而对于N个子像素，可以分别基于N个子像素共接收到的N个第一子光信号，对应生成N个第一子直方图，并对N个第一子直方图进行相应的滤波处理，以及对N个第一子光信号分别进行回波检测，以获得上述N个第一回波参数。
信号处理器可以用于根据上述N个子像素分别对应的第一回波参数，基于上述第一补偿表，确定N个第一子补偿量。或者，将这N个第一回波参数分别输入到第一函数，确定N个第一子补偿量。并且将这N个第一子补偿量进行加权累加等操作，确定第一像素整体对应的第一补偿量。然后通过第一补偿量，对上述第一待补偿量进行误差补偿，确定目标结果值。
在一些可能的实施例中，上述信号探测器和信号处理器也可以集成在一个设备当中。本申请实施例对此不作限定。
基于上述技术方案，将第一像素划分为N个子像素，由于子像素很小，所以子像素中的光斑分布是均匀的或者近似于均匀的。检测目标物体距离或者目标物体反射率时，无论目标物体距离、激光器温度、探测器温度等因素如何变化，子像素中的光斑分布都是不变的。这样能够有效避免因光斑分布变化，导致基于一张补偿表无法准确补偿误差的问题。该方法在N个子像素的几何参数相同时，可以实现通过一张补偿表确定第一补偿量，提升了误差补偿的准确性，且易于实现。
在一些可能的实施例中，为了避免光信号的抖动对目标物体检测产生影响，在目标物体的探测的过程中，可以对该目标物体多次发射激光束，并多次基于反射回来的回波光束进行回波检测，从而得到多组第一回波参数。然后将多组第一回波参数进行累加，确定一组第二回波参数，之后可以基于该第二回波参数来对目标物体检测参数进行解算。
在一些可能的实施例中，为了避免光信号的抖动对目标物体检测产生影响，在目标物体的探测的过程中，可以对该目标物体多次发射激光束，并多次基于反射回来的回波光束，确定多个第一直方图。然后将多个第一直方图进行叠加，确定第二直方图，之后可以基于该第二直方图确定相应的参数，来对目标物体检测参数进行解算。同理，第一子直方图也可以采取这种直方图叠加的方法，对确定的多个第一子直方图进行处理。
基于上述技术方案，有助于进一步增加对目标物体检测的准确性。
此外，本申请实施例还提供用于实现以上任一种方法的装置，例如，提供一种探测装置，该装置包括用以实现以上任一种探测方法的单元(或手段)。
图13示出了本申请实施例提供的一种探测装置1300的示意性框图。如图13所示，该装置1300包括：
接收单元1310，用于接收回波光束，该回波光束打在探测器的第一像素上，该第一像素包括N个子像素；
确定单元1320，用于根据上述N个子像素，确定N个第一子光信号，其中，N为正整数；根据该N个第一子光信号，确定N个第一回波参数，该第一回波参数用于表征第一子光信号的信号强度；根据上述N个第一回波参数确定第一光信号，该第一光信号与回波光束对应。
在一些可能的实施例中，上述确定单元1320具体用于：根据第一子光信号，确定第一子直方图，第一子直方图包括多个单位时段内第一子光信号的信号强度变化趋势；根据第一子直方图，确定第一回波参数。
在一些可能的实施例中，上述确定单元1320具体用于：根据N个第一回波参数，确定N个第一子补偿量；根据N个第一子补偿量，确定第一补偿量，该第一补偿量为用于确定上述第一光信号的补偿量。
在一些可能的实施例中，上述确定单元1320具体用于：根据子像素的几何参数，筛选出对应的第一补偿表；根据第一回波参数，查找第一补偿表，确定第一回波参数对应的第一子补偿量，第一补偿表是预先通过实验确定的，第一补偿表包括第一回波参数与第一子补偿量之间的映射关系。
在一些可能的实施例中，上述子像素的几何参数包括子像素的形状和/或面积。
在一些可能的实施例中，上述第一回波参数包括以下至少一种：第一子光信号的回波面积、回波峰值、回波脉宽以及第一子直方图中曲线图像的上升沿斜率。
在一些可能的实施例中，上述确定单元1320还用于：根据第二光信号，确定第一结果值，该第二光信号是基于上述回波光束确定的原始的光信号；通过第一补偿量对第一结果值进行补偿，确定第一目标参数值，该第一目标参数值对应于上述第一光信号。
在一些可能的实施例中，上述确定单元1320具体用于：根据第二光信号，确定第一直方图，第一直方图包括多个单位时段内第二光信号的信号强度变化趋势；根据第一直方图，确定第一结果值。
在一些可能的实施例中，在上述第一结果值是与目标物体之间的距离时，上述确定单元1320具体用于：确定向目标物体发射激光束的时刻为第一时刻；根据第一直方图，确定第二时刻；根据第二时刻与第一时刻之间的时间差，确定第二光信号对应的飞行时间；根据光速和飞行时间，确定上述第一结果值。
在一些可能的实施例中，上述确定单元1320具体用于：基于第一直方图，将确定探测到第二光信号的起始时刻作为第二时刻；或者，基于第一直方图，将第一直方图的峰值时刻作为第二时刻；或者，基于第一直方图通过恒比定时CFD的方式，确定第二时刻；或者，基于第一直方图，确定第二光信号对应的回波时间，再通过质心算法，根据第二光信号的回波时间，确定第二时刻。
在一些可能的实施例中，在第一结果值是第二光信号的能量值时，上述确定单元1320具体用于：根据第一直方图，确定第二光信号的回波面积和/或回波峰值；根据第二光信号的回波面积和/或回波峰值，确定第二光信号的信号强度；根据第二光信号的信号强度，确定第一结果值。
在一些可能的实施例中，在上述确定单元根据N个第一回波参数，确定第一补偿量之前，上述确定单元1320还用于：确定第一补偿表，包括：获取第二目标参数值和子像素的几何参数，第二目标参数值是准确的目标参数值；确定通过子像素获取的第一子光信号；基于第一子光信号对应的第一回波参数，确定第二结果值，第二结果值是需要补偿的结果值；根据第二结果值和第二目标参数值，确定第一子补偿量；记录第一子光信号对应的第一回波参数，以确定第一回波参数与第一子补偿量之间的映射关系；将映射关系添加至与子像素的几何参数对应的第一补偿表。
在一些可能的实施例中，上述N个子像素是基于像素阵列中的单光子雪崩二极管SPAD划分的。
在一些可能的实施例中，上述回波光束打在像素阵列上形成光斑，每个子像素上部分光斑的分布是均匀的。
此外，本申请实施例还提出了一种车辆，该车辆包括上述装置1300。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及 算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(Read-Only Memory，ROM)、随机存取存储器(Random Access Memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (33)

  1. 一种探测方法，应用于探测器，其特征在于，所述方法包括：
    接收回波光束，所述回波光束打在所述探测器的第一像素上；
    所述第一像素包括N个子像素，根据所述N个子像素，确定N个第一子光信号，所述N为正整数；
    根据所述N个第一子光信号，确定N个第一回波参数，所述第一回波参数用于表征所述第一子光信号的信号强度；
    根据所述N个第一回波参数确定第一光信号，所述第一光信号与所述回波光束对应。
  2. 根据权利要求1所述的方法，其特征在于，所述根据所述N个第一子光信号，确定N个第一回波参数包括：
    根据所述第一子光信号，确定第一子直方图，所述第一子直方图包括多个单位时段内所述第一子光信号的信号强度变化趋势；
    根据所述第一子直方图，确定所述第一回波参数。
  3. 根据权利要求1或2所述的方法，其特征在于，所述根据所述N个第一回波参数确定第一光信号包括：
    根据所述N个第一回波参数，确定N个第一子补偿量；
    根据所述N个第一子补偿量，确定第一补偿量，所述第一补偿量为用于确定所述第一光信号的补偿量。
  4. 根据权利要求3所述的方法，其特征在于，所述根据所述N个第一回波参数，确定N个第一子补偿量包括：
    根据所述子像素的几何参数，筛选出对应的第一补偿表；
    根据所述第一回波参数，查找所述第一补偿表，确定所述第一回波参数对应的第一子补偿量，所述第一补偿表是预先通过实验确定的，所述第一补偿表包括所述第一回波参数与所述第一子补偿量之间的映射关系。
  5. 根据权利要求4所述的方法，其特征在于，所述子像素的几何参数包括所述子像素的形状和/或面积。
  6. 根据权利要求1至5中任一项所述的方法，其特征在于，所述第一回波参数包括以下至少一种：所述第一子光信号的回波面积、回波峰值、回波脉宽以及第一子直方图中曲线图像的上升沿斜率。
  7. 根据权利要求1至6中任一项所述的方法，其特征在于，所述方法还包括：
    根据第二光信号，确定第一结果值，所述第二光信号是基于所述回波光束确定的原始的光信号；
    通过所述第一补偿量对所述第一结果值进行补偿，确定第一目标参数值，所述第一目标参数值对应于所述第一光信号。
  8. 根据权利要求7所述的方法，其特征在于，所述根据第二光信号，确定第一结果值包括：
    根据所述第二光信号，确定第一直方图，所述第一直方图包括多个单位时段内所述第 二光信号的信号强度变化趋势；
    根据所述第一直方图，确定所述第一结果值。
  9. 根据权利要求8所述的方法，其特征在于，在所述第一结果值是与所述目标物体之间的距离时，所述根据所述第一直方图，确定所述第一结果值包括：
    确定所述向目标物体发射激光束的时刻为第一时刻；
    根据所述第一直方图，确定第二时刻；
    根据所述第二时刻与所述第一时刻之间的时间差，确定所述第二光信号对应的飞行时间；
    根据光速和所述飞行时间，确定所述第一结果值。
  10. 根据权利要求9所述的方法，其特征在于，所述根据所述第一直方图，确定第二时刻包括：
    基于所述第一直方图，将确定探测到所述第二光信号的起始时刻作为所述第二时刻；或者，
    基于所述第一直方图，将所述第一直方图的峰值时刻作为所述第二时刻；或者，
    基于所述第一直方图通过恒比定时CFD的方式，确定所述第二时刻；或者，
    基于所述第一直方图，确定所述第二光信号对应的回波时间，再通过质心算法，根据所述第二光信号对应的回波时间，确定所述第二时刻。
  11. 根据权利要求8所述的方法，其特征在于，在所述第一结果值是所述第二光信号的能量值时，所述根据所述第一直方图，确定所述第一结果值包括：
    根据所述第一直方图，确定所述第二光信号的回波面积和/或回波峰值；
    根据所述第二光信号的回波面积和/或回波峰值，确定所述第二光信号的信号强度；
    根据所述第二光信号的信号强度，确定所述第一结果值。
  12. 根据权利要求1至11中任一项所述的方法，其特征在于，在所述根据所述N个第一回波参数，确定第一补偿量之前，所述方法还包括：
    确定第一补偿表，包括：
    获取第二目标参数值和所述子像素的几何参数，所述第二目标参数值是准确的目标参数值；
    确定通过所述子像素获取的第一子光信号；
    基于所述第一子光信号对应的所述第一回波参数，确定第二结果值，所述第二结果值是需要补偿的结果值；
    根据所述第二结果值和所述第二目标参数值，确定第一子补偿量；
    记录所述第一子光信号对应的所述第一回波参数，以确定所述第一回波参数与所述第一子补偿量之间的映射关系；
    将所述映射关系添加至与所述子像素的几何参数对应的所述第一补偿表。
  13. 根据权利要求1至12中任一项所述的方法，其特征在于，所述N个子像素是基于像素阵列中的单光子雪崩二极管SPAD划分的。
  14. 根据权利要求1至13中任一项所述的方法，其特征在于，所述回波光束打在所述像素阵列上形成光斑，每个所述子像素上部分光斑的分布是均匀的。
  15. 一种探测装置，应用于探测器，其特征在于，所述装置包括：
    接收单元，用于接收回波光束，所述回波光束打在所述探测器的第一像素上，所述第一像素包括N个子像素；
    确定单元，用于根据所述N个子像素，确定N个第一子光信号，所述N为正整数；根据所述N个第一子光信号，确定N个第一回波参数，所述第一回波参数用于表征所述第一子光信号的信号强度；根据所述N个第一回波参数确定第一光信号，所述第一光信号与所述回波光束对应。
  16. 根据权利要求15所述的装置，其特征在于，所述确定单元具体用于：
    根据所述第一子光信号，确定第一子直方图，所述第一子直方图包括多个单位时段内所述第一子光信号的信号强度变化趋势；
    根据所述第一子直方图，确定所述第一回波参数。
  17. 根据权利要求15或16所述的装置，其特征在于，所述确定单元具体用于：
    用于根据所述N个第一子光信号，确定N个第一回波参数，所述第一回波参数用于表征所述第一子光信号的信号强度；根据所述N个第一回波参数，确定N个第一子补偿量；根据所述N个第一子补偿量，确定第一补偿量，所述第一补偿量为用于确定所述第一光信号的补偿量。
  18. 根据权利要求17所述的装置，其特征在于，所述确定单元具体用于：
    根据所述子像素的几何参数，筛选出对应的第一补偿表；
    根据所述第一回波参数，查找所述第一补偿表，确定所述第一回波参数对应的第一子补偿量，所述第一补偿表是预先通过实验确定的，所述第一补偿表包括所述第一回波参数与所述第一子补偿量之间的映射关系。
  19. 根据权利要求18所述的装置，其特征在于，所述子像素的几何参数包括所述子像素的形状和/或面积。
  20. 根据权利要求15至19中任一项所述的装置，其特征在于，所述第一回波参数包括以下至少一种：所述第一子光信号的回波面积、回波峰值、回波脉宽以及第一子直方图中曲线图像的上升沿斜率。
  21. 根据权利要求15至20中任一项所述的装置，其特征在于，所述确定单元还用于：
    根据所述第二光信号，确定第一结果值，所述第二光信号是基于所述回波光束确定的原始的光信号；
    通过所述第一补偿量对所述第一结果值进行补偿，确定第一目标参数值，所述第一目标参数值对应于所述第一光信号。
  22. 根据权利要求21所述的装置，其特征在于，所述确定单元具体用于：
    根据所述第二光信号，确定第一直方图，所述第一直方图包括多个单位时段内所述第二光信号的信号强度变化趋势；
    根据所述第一直方图，确定所述第一结果值。
  23. 根据权利要求22所述的装置，其特征在于，在所述第一结果值是与所述目标物体之间的距离时，所述确定单元具体用于：
    确定所述向目标物体发射激光束的时刻为第一时刻；
    根据所述第一直方图，确定第二时刻；
    根据所述第二时刻与所述第一时刻之间的时间差，确定所述第二光信号对应的飞行时 间；
    根据光速和所述飞行时间，确定所述第一结果值。
  24. 根据权利要求23所述的装置，其特征在于，所述确定单元具体用于：
    基于所述第一直方图，将确定探测到所述第二光信号的起始时刻作为所述第二时刻；或者，
    基于所述第一直方图，将所述第一直方图的峰值时刻作为所述第二时刻；或者，
    基于所述第一直方图通过恒比定时CFD的方式，确定所述第二时刻；或者，
    基于所述第一直方图，确定所述第二光信号对应的回波时间，再通过质心算法，根据所述第二光信号对应的回波时间，确定所述第二时刻。
  25. 根据权利要求22所述的装置，其特征在于，在所述第一结果值是所述第二光信号的能量值时，所述确定单元具体用于：
    根据所述第一直方图，确定所述第二光信号的回波面积和/或回波峰值；
    根据所述第二光信号的回波面积和/或回波峰值，确定所述第二光信号的信号强度；
    根据所述第二光信号的信号强度，确定所述第一结果值。
  26. 根据权利要求15至25中任一项所述的装置，其特征在于，在所述确定单元根据所述N个第一回波参数，确定第一补偿量之前，所述确定单元还用于：
    确定第一补偿表，包括：
    获取第二目标参数值和所述子像素的几何参数，所述第二目标参数值是准确的目标参数值；
    确定通过所述子像素获取的第一子光信号；
    基于所述第一子光信号对应的所述第一回波参数，确定第二结果值，所述第二结果值是需要补偿的结果值；
    根据所述第二结果值和所述第二目标参数值，确定第一子补偿量；
    记录所述第一子光信号对应的所述第一回波参数，以确定所述第一回波参数与所述第一子补偿量之间的映射关系；
    将所述映射关系添加至与所述子像素的几何参数对应的所述第一补偿表。
  27. 根据权利要求15至26中任一项所述的装置，其特征在于，所述N个子像素是基于像素阵列中的单光子雪崩二极管SPAD划分的。
  28. 根据权利要求15至27中任一项所述的装置，其特征在于，所述回波光束打在所述像素阵列上形成光斑，每个所述子像素上部分光斑的分布是均匀的。
  29. 一种探测装置，其特征在于，包括处理器和存储器，其中，所述处理器和存储器相连，其中，所述存储器用于存储程序代码，所述处理器用于调用所述程序代码，以执行如权利要求1至14任一项所述的方法。
  30. 一种芯片系统，其特征在于，所述芯片系统应用于电子设备；所述芯片系统包括一个或多个接口电路，以及一个或多个处理器；所述接口电路和所述处理器通过线路互联；所述接口电路用于从所述电子设备的存储器接收信号，并向所述处理器发送所述信号，所述信号包括所述存储器中存储的计算机指令；当所述处理器执行所述计算机指令时，所述电子设备执行如权利要求1至14中任一项所述的方法。
  31. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质存储有计算机 程序，所述计算机程序被处理器执行以实现如权利要求1至14中任一项所述的方法。
  32. 一种计算机程序产品，其特征在于，所述计算机程序代码或指令在计算机上执行时，使得所述计算机执行如权利要求1至14中任一项所述的方法。
  33. 一种车辆，其特征在于，包括如权利要求15至29中任一项所述的装置。
PCT/CN2023/082046 2023-03-17 2023-03-17 一种探测方法以及相关装置 WO2024192546A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2023/082046 WO2024192546A1 (zh) 2023-03-17 2023-03-17 一种探测方法以及相关装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2023/082046 WO2024192546A1 (zh) 2023-03-17 2023-03-17 一种探测方法以及相关装置

Publications (1)

Publication Number Publication Date
WO2024192546A1 true WO2024192546A1 (zh) 2024-09-26

Family

ID=92840648

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/082046 WO2024192546A1 (zh) 2023-03-17 2023-03-17 一种探测方法以及相关装置

Country Status (1)

Country Link
WO (1) WO2024192546A1 (zh)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090202127A1 (en) * 2006-06-22 2009-08-13 Koninklijke Philips Electronics N.V. Method And System For Error Compensation
CN114236506A (zh) * 2021-12-20 2022-03-25 奥诚信息科技(上海)有限公司 一种基于DToF的标定方法、探测方法及系统
CN114442106A (zh) * 2022-01-28 2022-05-06 西安知微传感技术有限公司 激光雷达系统的校准方法及装置
CN115343693A (zh) * 2022-08-30 2022-11-15 西北工业大学宁波研究院 一种基于脉宽补偿的激光测距方法及系统

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090202127A1 (en) * 2006-06-22 2009-08-13 Koninklijke Philips Electronics N.V. Method And System For Error Compensation
CN114236506A (zh) * 2021-12-20 2022-03-25 奥诚信息科技(上海)有限公司 一种基于DToF的标定方法、探测方法及系统
CN114442106A (zh) * 2022-01-28 2022-05-06 西安知微传感技术有限公司 激光雷达系统的校准方法及装置
CN115343693A (zh) * 2022-08-30 2022-11-15 西北工业大学宁波研究院 一种基于脉宽补偿的激光测距方法及系统

Similar Documents

Publication Publication Date Title
WO2021008209A1 (zh) 深度测量装置及距离测量方法
JP6863342B2 (ja) 光測距装置
US11187804B2 (en) Time of flight range finder for a structured light system
US11693093B2 (en) Distance-measuring apparatus that outputs precision information
CN112255636A (zh) 一种距离测量方法、系统及设备
WO2022110947A1 (zh) 电子装置的控制方法、电子装置及计算机可读存储介质
US11774563B2 (en) Time-of-flight module and method to determine distance to object
KR101790864B1 (ko) 주파수 변조 방식의 라이다 센서 시스템에서 멀티패스에 의한 상호 간섭 제거 방법 및 그 장치
US20230325979A1 (en) Image correction method, and under-screen system
CN112255635B (zh) 一种距离测量方法、系统及设备
US12130382B2 (en) Lidar control method, terminal apparatus, and computer-readable storage medium
US20190162824A1 (en) Time-of-flight acquisition method and time-of-flight camera
WO2024192546A1 (zh) 一种探测方法以及相关装置
US10628951B2 (en) Distance measurement system applicable to different reflecting surfaces and computer system
WO2016002490A1 (ja) 波面計測装置及び波面計測方法
WO2022160622A1 (zh) 一种距离测量方法、装置及系统
US20210396876A1 (en) Optical distance measurement apparatus
US20230126462A1 (en) Radar data processing method, terminal device, and computer-readable storage medium
US12032065B2 (en) System and method for histogram binning for depth detection
CN113614566B (zh) 测距方法、测距装置以及程序记录介质
CN115079193A (zh) 光电检测装置、控制方法、电子设备及存储介质
WO2023181881A1 (ja) 情報処理装置、情報処理方法及びプログラム
CN115754979B (zh) 一种激光雷达控制方法、装置、控制芯片及激光雷达
WO2023176646A1 (ja) 情報処理装置、情報処理方法及びプログラム
CN112204420B (zh) 结构化光系统的飞行时间测距仪

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23927865

Country of ref document: EP

Kind code of ref document: A1