JP6747115B2 - Laser radar device - Google Patents

Description

The present invention relates to a laser radar device, and more particularly to a technique for detecting an object having a low reflectance.

The laser radar device irradiates laser light to the outside of the device and receives the reflected light generated by the laser light being reflected by an object outside the device. Based on the intensity of the reflected light, it is determined whether an object exists, and the distance to the object is calculated from the time until the reflected light is received. As described in Patent Document 1, the laser radar device scans a laser beam to detect whether or not an object exists in the surveillance area.

JP, 2008-216238, A

The laser radar device does not need to detect fog. However, the laser light is also reflected by fog. However, since fog has a space between particles, it has a low reflectance for reflecting laser light. In this specification, the reflectance is the ratio of the laser light applied to the object and the reflected light reflected in the direction of the laser radar device.

Since the fog has a low reflectance, it is conceivable to reduce the light receiving sensitivity in order to prevent the fog from being detected. When the light receiving sensitivity is lowered, the intensity of the reflected light from the object having a low reflectance is less likely to exceed the threshold value for determining that the object is detected. Therefore, it is possible to prevent the fog from being detected.

However, there are objects with low reflectance other than fog. For example, a black object has low reflectance. Also, an object having a mirror surface has a low reflectance. Therefore, an object whose color is black and whose surface is a mirror surface has a particularly low reflectance. An example of such an object is a black car.

When the laser radar device needs to detect an object that is not fog and has a low reflectance, there is a problem that if the light receiving sensitivity is lowered, it becomes difficult to detect an object having a low reflectance that should be detected.

The present invention has been made based on this situation, and an object thereof is to provide a laser radar device capable of detecting an object having a low reflectance to be detected while suppressing the detection of fog. To provide.

The above objective is achieved by a combination of features described in independent claims, and the subclaims define further advantageous embodiments of the invention. The reference numerals in parentheses in the claims indicate the correspondence with the specific means described in the embodiments described later as one aspect, and do not limit the technical scope of the present invention. ..

The present invention for achieving the above object,
A light projecting section (10) for generating and projecting laser light;
A scanning unit (50, 60) for irradiating the laser light projected by the light projecting unit to the outside of the device while changing the irradiation direction;
A light receiving unit (20, 120H, 120L) for receiving the reflected light generated by the laser light applied to the outside of the device by the scanning unit and reflected outside the device;
A laser radar device (1, 100) having a measuring unit (4, 104) including
The measuring unit sets the detection performance level, which indicates the easiness of detecting an object, which is determined by the intensity of the laser beam emitted by the light projecting unit and the light receiving sensitivity of the light receiving unit receiving the reflected light, to the preset detection level with low reflectance. Low reflection detection that is the target object High detection performance level that is the detection performance level that can be detected when the target object is at the reference angle with respect to the laser radar device at the reference distance, and reference with respect to the laser radar device at the reference distance The detection target object is detected with two types of detection performance levels of low detection performance level that does not detect the low reflection detection target object that is an angle,
A low detection performance measurement unit that performs a low detection performance measurement process in which the laser light is emitted to the outside of the device while the irradiation direction is changed by the scanning unit and the reflected light is received by the light reception unit in the measurement unit with a low detection performance level ( 83, 183),
The low detection performance measurement unit executes the low detection performance measurement process, and based on the reflected light received by the light receiving unit, the low detection performance measurement process determines whether an object exists in the direction irradiated with the laser light. A low detection performance object determination unit (85),
In the measurement unit with a high detection performance level, the low detection performance object determination unit irradiates the scanning unit with laser light in at least the direction in which the object was not determined to be present, while the light reception unit reflected light. A high detection performance measurement unit (84, 184) that executes a high detection performance measurement process of receiving light,
Low detection performance For the direction in which the object determination unit did not determine that an object exists, the high detection performance measurement unit executes the high detection performance measurement process, and the waveform width of the reflected light received by the light reception unit is the fog determination width threshold value. A high detection performance object determination unit (86) that determines that an object is present based on the fact that the object is shorter than
The high detection performance object determination unit detects the light detection unit by performing the high detection performance measurement process by the high detection performance measurement unit for a single direction in which the low detection performance object determination unit has not determined that an object exists. When there is a section in which the reflected light exceeds two object determination thresholds, it is determined that an object exists without comparing the waveform width of the reflected light with the fog determination width threshold.

According to the present invention, the measuring unit detects the detection target object with two types of detection performance levels, that is, a high detection performance level and a low detection performance level, which are detection performance levels indicating the ease of detecting the object. The high detection performance level is a detection performance level that can be detected when a low reflection detection target object which is a preset detection target object having a low reflectance has a reference angle with respect to the laser radar device at the reference distance. On the other hand, the low detection performance level is a detection performance level at which the low reflection detection target object having the reference angle with respect to the laser radar device at the reference distance is not detected.

The low detection performance measurement unit is a measurement unit having a low detection performance level, and executes a low detection performance measurement process in which the reflected light is received by the light receiving unit while changing the irradiation direction of the laser light. The low detection performance object determination unit determines whether or not an object exists in the direction in which the laser light is emitted, based on the reflected light received by the light receiving unit by executing this low detection performance measurement process. When the detection performance level is low, it is difficult to detect an object having a low reflectance. Therefore, the low detection performance object determination unit can suppress detection of fog. However, in the direction in which the low detection performance object determination unit does not determine that an object exists, there is a possibility that a detection target object with low reflectance exists.

Therefore, in the present invention, the low-detection-performance object determining unit further determines whether or not an object is present in the high-detection-performance measuring unit and the high-detection-performance object determining unit for the direction in which it was not determined that the object exists. To do.

The high detection performance measurement unit is a measurement unit having a high detection performance level, and the low detection performance object determination unit irradiates a laser beam to a direction including at least a direction in which the object is not determined to exist, and reflects light. Is received by the light receiving section. By measuring at a high detection performance level, there is a possibility that reflected light having an intensity of a level of determining an object can be detected even in a direction in which it was not determined that an object exists at a low detection performance level.

In the direction where the object was not judged to be present at the low detection performance level, when the reflected light with the level of the object detection level was detected at the high detection performance level, the object with low reflectance exists in that direction. I know what to do.

However, the low reflectance object may be fog or a detection target object. The inventor has found that if the low reflectance object is fog, the waveform width of the reflected light measured by the high detection performance measurement process is significantly wider than that when the low reflectance object is the detection target object. I found it.

A fog is composed of many water particles floating in the air in the direction of travel of a laser beam, and the laser beam emitted to the fog may pass through the water particles or be reflected by the water particles. There is also. Therefore, the laser light applied to the fog repeats transmission and reflection. It is considered that this causes the waveform width of the reflected light to become wider. On the other hand, if the object having a low reflectance is the object to be detected, the laser light is only once reflected on the surface of the object. From these, it is considered that if the low reflectance object is fog, the waveform width of the reflected light measured by the high detection performance measurement process becomes significantly wider than that in the case where the low reflectance object is the detection target object. To be

Utilizing this, the high-detection-performance object determination unit should execute the high-detection-performance measurement processing by the high-detection-performance measurement unit for the direction in which the low-detection-performance object determination unit has not determined that an object exists. It is determined that an object is present based on the waveform width of the reflected light detected by the light receiving unit being shorter than the fog determination width threshold. By doing so, it is possible to detect an object having a low reflectance to be detected while suppressing the fog from being detected.
Further, in the present invention, since it is not necessary to compare the waveform width with the fog determination width threshold, the process of determining the waveform width and the process of comparing the waveform width with the fog determination width threshold are unnecessary. Therefore, it is possible to quickly obtain the determination result that the object exists. Further, when the length of the fog in the irradiation direction of the laser light is not so long, there is a possibility that the reflected light generated by the fog does not have a wide waveform width. Even in such a case, it is possible to determine that the fog is present, and thus it is possible to further prevent the fog from being detected.

The invention according to claim 2 is provided with a detection performance level setting unit (81) that sets a high detection performance level and a low detection performance level by changing at least one of the intensity of laser light and the light reception sensitivity,
The low detection performance measurement unit (83) sets the detection performance level of the measurement unit to the low detection performance level by the detection performance level setting unit and executes the low detection performance measurement process,
The high detection performance measurement unit (84) sets the detection performance level of the measurement unit to the high detection performance level by the detection performance level setting unit and executes the high detection performance measurement process.

With this configuration, the measurement unit can realize the high detection performance level and the low detection performance level with the single light receiving unit.

In the invention according to claim 3, the detection performance level setting unit changes the intensity of the laser light projected by the light projecting unit, while the light receiving sensitivity of the light receiving unit receiving the reflected light is not changed, and the low detection performance level is set. And set the high detection performance level.

In this way, when setting the detection performance level by changing the detection performance level with the intensity of the laser light projected by the light projecting unit, compare it with the case where the same high detection performance level is set by changing the light receiving sensitivity. Thus, the light receiving sensitivity can be lowered. The lower the light receiving sensitivity, the more the influence of the ambient light can be suppressed, and thus, the influence of the ambient light can be suppressed.

In the invention according to claim 4, the light receiving portion includes a first light receiving portion (120H) and a second light receiving portion (120L) which are arranged at different positions to receive the reflected light,
The measurement unit (104) detects the reflected light at a division ratio such that the first light receiving unit detects the detection target object at the high detection performance level and the second light receiving unit detects the detection target object at the low detection performance level. A beam splitter (135) for splitting is provided.

With this configuration, the measurement at the high detection performance level and the measurement at the low detection performance level can be performed by the same scanning with the laser light. Therefore, compared to the case where the measurement at the high detection performance level and the measurement at the low detection performance level are performed by scanning different laser beams, the cycle at which the high detection performance object determination unit makes a determination, that is, the object detection cycle is shortened. can do.

Further, a high detection performance level and a low detection performance level can be realized without changing the light receiving sensitivities of the first light receiving unit and the second light receiving unit and the intensity of the laser light. Therefore, there is also an advantage that it is not necessary to provide a configuration for changing the intensity of laser light or a configuration for changing the light receiving sensitivity.

It is a figure which shows the internal structure of the laser radar apparatus 1 of 1st Embodiment. It is a figure which shows in detail the structure of the circuit part 70 of FIG. It is a figure which shows in detail the structure of the control part 80 of FIG. It is a figure which shows repetition of the low detection performance measurement process and high detection performance measurement process which the measurement process part 82 of FIG. 3 performs. It is a figure which shows the difference of the object which can be detected by a low detection performance level and a high detection performance level. FIG. 6 is a diagram illustrating processing of a low detection performance object determination unit 85, a high detection performance object determination unit 86, and a distance measurement unit 87 of FIG. 3. It is a figure explaining which low measurement performance level or high detection performance level measurement data is used in an example of a concrete situation. It is a figure explaining the structure which is different from the laser radar apparatus 1 of 1st Embodiment in the laser radar apparatus 100 of 2nd Embodiment. FIG. 9 is a block diagram showing the configuration of the circuit unit 170 of FIG. 8. 10 is a block diagram showing a configuration of a control unit 180 of FIG. 9.

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the laser radar device 1 according to the first embodiment includes a laser diode 10 that is a light projecting unit, and a photodiode 20 that is an example of a light receiving unit that receives reflected light L1 from an object outside the device. And detects the distance and direction to an object outside the device. The laser radar device 1 is installed outdoors and detects an object moving in the monitoring area of the laser radar device 1. An object to be detected (hereinafter, an object to be detected) is a moving body other than a particulate suspended matter. For example, the detection target object may be a person or a car on which a person is boarding.

In FIG. 1, a laser diode 10 projects pulsed laser light (hereinafter, irradiation light L0). The photodiode 20 detects reflected light L1 generated by the irradiation light L0 being reflected by an object outside the apparatus and converts it into an electric signal.

A collimator lens 30 and a perforated mirror 40 are provided on the optical axis of the laser diode 10. The collimator lens 30 converts the irradiation light L0 projected by the laser diode 10 into parallel light.

The perforated mirror 40 has a flat plate shape and is arranged on the optical axis of the laser diode 10 at a predetermined angle with respect to the optical axis. The lower surface of the perforated mirror 40 is a reflecting surface 41, and a through hole 42 is formed at the center of the perforated mirror 40 so as to penetrate in the vertical direction. The perforated mirror 40 is arranged so that the through hole 42 is located on the optical axis of the laser diode 10.

A rotating mirror 50 is provided on the optical axis of the irradiation light L0 passing through the perforated mirror 40. The rotating mirror 50 is disposed so as to be rotatable about a central axis extending in the optical axis direction of the laser diode 10, and the irradiation light L0 is deflected by a concave mirror 51 whose focal position is set on the central axis. The irradiation light L0 is irradiated to the outside of the device. Further, the concave mirror 51 deflects the reflected light L1 toward the perforated mirror 40.

The motor 60 rotates the rotating shaft 61, thereby rotating the rotating mirror 50 connected to the rotating shaft 61. The rotary shaft 61 is the rotary shaft of the motor 60, and also serves as the rotary shaft of the rotary mirror 50 because the rotary mirror 50 is rotated by the rotation of the rotary shaft 61. When the irradiation light L0 is sequentially incident on the concave mirror 51 while the rotating mirror 50 is being rotated by the motor 60, the irradiation light L0 is emitted to the outside of the device while the irradiation direction changes according to the rotation of the rotating mirror 50. It The rotating mirror 50 and the motor 60 correspond to a scanning unit. The measuring unit 4 includes a laser diode 10 corresponding to a light projecting unit, a rotating mirror 50 corresponding to a scanning unit, a motor 60, and a photodiode 20 corresponding to a light receiving unit.

The rotation angle position sensor 62 detects the rotation angle position of the rotation shaft 61, that is, the rotation angle position of the concave mirror 51. As the rotation angle position sensor 62, various types such as a rotary encoder can be used as long as they can detect the rotation angle position of the rotation shaft 61.

The circuit unit 70 has a configuration shown in FIG. 2 described later. These components are housed in the apparatus internal space formed by the housing 2 and the housing window 3. The housing 2 has a box shape in which a portion to which the housing window 3 is attached is open. The housing window 3 is made of a light transmissive member and is attached to the housing 2. The range around the horizontal plane to which the housing window 3 is attached is a scanning angle range or an angle range larger than the scanning angle range with the front direction of the laser radar device 1 as the center. The scanning angle range is 190 degrees, for example. The front direction of the laser radar device 1 is a direction from the inside of the laser radar device 1 toward the housing window 3 in a vertical cross section that divides the housing window 3 into two equal parts.

As shown in FIG. 2, the circuit unit 70 includes an LD drive circuit 71, an amplifier 72, a motor drive circuit 73, a storage unit 74, and a control unit 80. The LD drive circuit 71 is a circuit that drives the laser diode 10. The amplifier 72 amplifies the electric signal output from the photodiode 20 and outputs the electric signal to the control unit 80. The motor drive circuit 73 is a circuit that outputs a current to the motor 60 to rotate the motor 60. The storage unit 74 has a rewritable configuration and is used by the measurement processing unit 82, the low detection performance object determination unit 85, and the high detection performance object determination unit 86, which will be described later.

The control unit 80 includes circuits such as a CPU, ROM, RAM, ASIC, CPLD, and comparator. The control unit 80 executes various functions by using a part or all of the circuit, for example, the CPU executes the program stored in the ROM while the CPU uses the temporary storage function of the RAM.

The control unit 80 outputs a light emission command to the LD drive circuit 71, for example, to cause the laser diode 10 to generate laser light in pulses. This light emission command includes information indicating a drive voltage value, and the LD drive circuit 71 causes the laser diode 10 to generate a laser beam with a drive voltage value determined by the light emission command. The higher the drive voltage value, the more intense the laser diode 10 emits laser light. Further, the control unit 80 acquires the detection value of the rotation angle position sensor 62 and detects the rotation position and the rotation speed of the rotating mirror 50. Further, it outputs a motor drive signal instructing the motor drive circuit 73 to rotate the motor 60 at a predetermined speed.

Further, the control unit 80 also functions as each unit shown in FIG. That is, the control unit 80 also functions as the detection performance level setting unit 81, the measurement processing unit 82, the low detection performance object determination unit 85, the high detection performance object determination unit 86, and the distance measurement unit 87.

The detection performance level setting unit 81 selects and sets the detection performance level of the laser radar device 1 from a high detection performance level and a low detection performance level. The detection performance level is an index indicating the ease with which an object can be detected. The stronger the intensity of the irradiation light L0, the stronger the intensity of the reflected light L1 from the same object at the same distance, and therefore the intensity of the reflected light L1 easily exceeds the object detection threshold value for determining that the object is detected. Therefore, the stronger the intensity of the irradiation light L0, the easier it is to detect an object.

Even if the reflected light L1 having the same intensity is received, the higher the light receiving sensitivity of the photodiode 20, the more easily the intensity of the reflected light L1 exceeds the object detection threshold for determining that an object has been detected. The higher the sensitivity, the easier it is to detect an object. Therefore, the detection performance level is determined by the product of the intensity of the irradiation light L0 and the light receiving sensitivity of the photodiode 20. The light receiving sensitivity of the photodiode 20 is determined by the amplification factor of the amplifier 72.

The high detection performance level in the present embodiment is that a black, glass-coated metal flat plate (hereinafter referred to as a black flat plate) is 45 m away from the laser radar device 1 at a position 5 m away from the irradiation direction of the irradiation light L0. The detection performance level is such that the black flat plate can be detected in a state in which the black plate is inclined. The black flat plate is an object imitating a black vehicle body, and in the present embodiment, the black flat plate is a low reflection detection target object. Further, 5 m is the reference distance and 45 degrees is the reference angle, and the measurement condition with the reference angle at the reference distance is the reference measurement condition.

The low detection performance level is a detection performance level at which the black flat plate that is the standard measurement condition cannot be detected. However, this low detection performance level is a detection performance level at which fog with a predetermined visibility is not detected. The predetermined visibility is 20 m, for example. Note that the high detection performance level described above can detect a black flat plate that is in the standard measurement condition, but it will detect fog that is not detected at the low detection performance level.

In the present embodiment, the detection performance level setting unit 81 controls the drive voltage value to be output to the LD drive circuit 71, thereby changing the intensity of the irradiation light L0 output from the laser diode 10 to obtain a high detection performance level. Set a low detection performance level. For example, the intensity of the irradiation light L0 at the high detection performance level is set to 10 to 20 times the intensity of the irradiation light L0 at the low detection performance level.

The measurement processing unit 82 includes a low detection performance measurement unit 83 and a high detection performance measurement unit 84. The low detection performance measurement unit 83 executes low detection performance measurement processing. The low detection performance measurement process is a process in which the measurement unit 4 having a low detection performance level scans the monitoring area with the irradiation light L0 and receives the reflected light L1. In the first embodiment, the detection performance level setting unit 81 sets the detection performance level to the low detection performance level in order to set the measurement unit 4 to the low detection performance level.

Similar to the scanning angle range, the monitoring area is an angle range of ±95 degrees centering on the front direction of the laser radar apparatus 1 and a total of 190 degrees, and the distance from the laser radar apparatus 1 is, for example, 30 m. In order to detect the detection target object existing in this monitoring area, the rotating mirror 50 is rotated by the motor 60 to change the irradiation direction of the irradiation light L0 within the scanning angle range, and to emit the irradiation light L0. Irradiate outside. Then, the photodiode 20 receives the reflected light L1. The received reflected light L1 is input to the control unit 80 via the amplifier 72. The low detection performance measuring unit 83 compares the signal intensity of the input reflected light L1 with the object detection threshold, and when the signal intensity of the reflected light L1 exceeds the object detection threshold, the signal intensity of the reflected light L1 detects the object. The time when the value is below the threshold value is stored in the storage unit 74 in association with the irradiation direction of the irradiation light L0.

The high detection performance measurement unit 84 executes high detection performance measurement processing. The high detection performance measurement process is the same as the low detection performance measurement process, except that the measurement unit 4 having a high detection performance level measures. In the first embodiment, the detection performance level setting unit 81 sets the detection performance level to the high detection performance level in order to set the measurement unit 4 to the high detection performance level.

The measurement processing unit 82 alternately repeats the low detection performance measurement process by the low detection performance measurement unit 83 and the high detection performance measurement process by the high detection performance measurement unit 84. FIG. 4 is a diagram showing the repetition of the low detection performance measurement processing and the high detection performance measurement processing executed by the measurement processing unit 82. As shown in FIG. 4, the detection performance level is a low detection performance level in the low detection performance measurement process, and the detection performance level is a high detection performance level in the high detection performance measurement process. Further, in any of the processes, the light emission pulse, that is, the pulsed irradiation light L0 is set at constant angles (corresponding to the angle range of the monitoring area) while the rotation angle θ of the rotating mirror 50 is from −95° to 95°. For example, every 0.25 degree).

The low detection performance object determination unit 85 acquires, from the storage unit 74, the reflected light L1 received by the photodiode 20 by the low detection performance measurement unit 83 executing the low detection performance measurement process together with the irradiation direction. Regarding the irradiation direction in which the intensity of the acquired reflected light L1 exceeds the object determination threshold, it is determined that an object exists in that direction, and the object exists in the irradiation direction in which the intensity of the reflected light L1 does not exceed the object determination threshold. It is determined not to. Then, the storage unit 74 stores the direction in which it is not determined that the object exists.

The high detection performance object determination unit 86 determines whether or not an object exists in the direction stored in the storage unit 74, which the low detection performance object determination unit 85 did not determine that the object exists. The determination method is as follows. First, in the direction in which the low detection performance object determination unit 85 stored in the storage unit 74 does not determine that an object exists, the signal intensity of the reflected light L1 when the high detection performance measurement process is executed is the object detection. The time when the threshold is exceeded and the time when the threshold is less than the object detection threshold are acquired from the storage unit 74. Then, the waveform width is set from the time when the signal intensity of the reflected light L1 exceeds the object detection threshold to the time when it falls below the object detection threshold when the high detection performance measurement process is executed.

In the reflected light L1 obtained for a single irradiation direction, when there are two peaks for which the waveform width can be calculated, an object exists in the irradiation direction stored corresponding to the reflected light L1. Then determine. This is because when there are two peaks for which the waveform width can be calculated, the first peak is due to fog, but the second peak is considered to be the detection target object.

Further, in the reflected light L1 obtained for a single irradiation direction, even if there is only one peak for which the waveform width can be calculated, and the waveform width is shorter than the fog determination width threshold value, it corresponds to the reflected light L1. Then, it is determined that there is an object in the stored irradiation direction. On the other hand, if there is only one peak for which the waveform width can be calculated and the waveform width is greater than or equal to the fog determination width threshold value, it is determined that the object existing in the irradiation direction is fog.

This fog determination width threshold is a threshold set based on the knowledge that the waveform width of fog is significantly wider than the waveform width of a black flat plate that is a low reflection detection target object when measured by the high detection performance measurement process. ..

In the low detection performance measurement process, the waveform width of the reflected light L1 from the detection target object having low reflectance also becomes so wide that it is difficult to distinguish it from fog. In the low detection performance measurement process, a low detection performance level is set. The low detection performance level is low because the intensity of the irradiation light L0 is high, the light receiving sensitivity of the photodiode 20 is high, or both. The signal intensity is high even for the reflected light L1 from the reflection detection target object. As a result, the waveform width is wide even for the reflected light L1 from the low-reflection detection target object.

In the low detection performance measurement process, the waveform width of the reflected light L1 from the detection target object having a low reflectance also becomes so wide that it is difficult to distinguish it from fog. Therefore, in the present embodiment, the low detection performance object determination unit 85 determines whether or not the object exists in the high detection performance object determination unit 86 only in the direction in which it is not determined that the object exists.

FIG. 5 is a diagram summarizing the differences in detectable objects between the low detection performance level and the high detection performance level. In FIG. 5, the high reflectance detection target object is, for example, a person. As shown in FIG. 5, at the low detection performance level, the detection target object having high reflectance can be detected, but the detection target object having low reflectance cannot be detected. However, at a low detection performance level, it is possible to prevent erroneous detection of fog as a detection target object.

On the other hand, at the high detection performance level, it is possible to detect a detection target object having a low reflectance. However, fog is also detected at a high detection performance level. However, the waveform width at the high detection performance level is different in that the detection target object having low reflectance is narrow and the fog is wide. By utilizing this difference, it is determined whether it is fog or a detection target object having a low reflectance.

The description returns to FIG. The distance measuring unit 87 calculates the distance to an object existing in the surveillance area. The processing of the distance measuring unit 87 will be described with reference to FIG. In FIG. 6, steps S4 and S5 are processes of the distance measuring unit 87, step S1 is a process of the low detection performance object determination unit 85, and steps S2 and S3 are processes of the high detection performance object determination unit 86.

The process shown in FIG. 6 is a process performed after one low detection performance measurement process by the low detection performance measurement unit 83 and one subsequent high detection performance measurement process by the high detection performance measurement unit 84 are completed. Yes, the process of FIG. 6 is executed for every scanning angle within the scanning angle range.

In step S1, it is determined whether or not distance measurement is possible at a low detection performance level. In other words, this determination is to determine whether or not the low detection performance object determination unit 85 determines that an object exists. If the determination in step S1 is no, the process proceeds to step S2.

In step S2, it is determined whether or not the measurement data at the high detection performance level has two peaks exceeding the object determination threshold value. If this determination is YES, it means that there is a detection target object with low reflectance. If the determination in step S2 is YES, the process proceeds to step S5. On the other hand, if the determination in step S2 is no, the process proceeds to step S3.

In step S3, it is determined whether or not the measurement data measured at the high detection performance level includes data whose waveform width is equal to or larger than the fog determination width threshold value. If the determination in step S3 is YES, the reflected light L1 detected at the high detection performance level is considered to be the reflected light L1 generated by fog. If the determination in step S3 is yes, the process proceeds to step S4. On the other hand, if the determination in step S3 is NO, it can be estimated that fog has not been detected. If the determination in step S3 is no, the process proceeds to step S5.

In step S4, the distance to the object is calculated using the measurement data at the low detection performance level. Step S4 is executed when the determination in step S1 is YES or when the determination in step S3 is YES. If the determination in step S1 is YES, it means that it is determined that an object exists. When it is determined that the object exists, the distance to the object is calculated from the time from the irradiation of the irradiation light L0 to the reception time of the reflected light L1 that exceeds the object determination threshold. The reception time of the reflected light L1 that exceeds the object determination threshold is, for example, the time when the intensity of the reflected light L1 first exceeds the object determination threshold. Further, the intermediate time of the period in which the intensity of the reflected light L1 exceeds the object determination threshold may be set as the time at which the object determination threshold is exceeded.

If fog is generated and a detection target object (for example, a person) is present in the fog, there may be two sections in which the intensity of the reflected light L1 exceeds the object determination threshold. Part of the irradiation light L0 is reflected by the fog, the reflected light L1 generated by the reflection by the fog exceeds the object determination threshold, and the reflected light L1 that is generated by passing through the fog and reflected by the detection target object is also the object determination threshold. Because it may exceed.

When there are two sections in which the intensity of the reflected light L1 exceeds the object determination threshold, the distance to the object is calculated later using the section in which the intensity exceeds the object determination threshold. When there are two sections in which the intensity of the reflected light L1 exceeds the object determination threshold value, it is a state in which an object behind the fog can be seen through the fog. This is because the section that exceeds the front object determination threshold is considered to be the reflected light L1 due to fog, and the section that exceeds the object determination threshold later is considered to be the reflected light L1 due to the detection target object.

When the determination in step S3 is YES and step S4 is executed, it is determined that the object does not exist from the measurement data of the low detection performance level, and therefore the distance to the object is not calculated.

In step S5, the distance to the object is calculated using the measurement data at the high detection performance level. Step S5 is executed when the determination in step S2 is YES or when the determination in step S3 is YES. If the determination in step S2 is YES, it means that the high detection performance object determination unit 86 determines that the detection target object exists. In this case, the distance to the object is calculated in the same manner as step S4, which is executed when the determination in step S1 is YES. Therefore, similar to step S4, when there are two sections in which the intensity of the reflected light L1 exceeds the object determination threshold, the distance to the object is calculated later using the section in which the intensity exceeds the object determination threshold.

When the determination in step S3 is YES, the waveform width obtained at the high detection performance level does not exceed the fog determination width threshold, but a peak exceeding the object determination threshold is detected with a time width that can be distinguished from noise. In some cases, peaks exceeding the object determination threshold may not be detected. In the former case, the distance to the object is calculated as in step S4. In the latter case, since the object does not exist, the distance to the object is not calculated either.

FIG. 7 is a diagram for explaining whether measurement data with a low detection performance level is used or measurement data with a high detection performance level is used in an example of a specific situation. In FIG. 7, -95 degrees is the scanning start angle. No object exists from −95 degrees to the angle θ1. Therefore, steps S1, S2, and S3 are all NO, and the process proceeds to step S5, so that the measurement data at the high detection performance level is used. As a result, the distance to the object is not calculated.

Even during the period from the angle θ1 to the angle θ2, steps S1, S2, and S3 are all NO, and the measurement data at the high detection performance level is used. However, between the angle θ1 and the angle θ2, the distance to the black car 90 is calculated by using the measurement data obtained at the high detection performance level.

Between the angle θ2 and the angle θ3, the same as from −95 degrees to the angle θ1 is used, and the measurement data at the high detection performance level is used. Since there is no object, the distance to the object is not calculated.

During the period from the angle θ3 to the angle θ4, the determination in step S1 is YES, and the process proceeds to step S4, so that the distance to the pedestrian 92 is calculated using the measurement data of the low detection performance level.

Between the angle θ4 and the angle θ5, the same as from −95 degrees to the angle θ1 is used, and the measurement data at the high detection performance level is used. Since there is no object, the distance to the object is not calculated.

From the angle θ5 to the angle θ6, the fog 94 is present but no other object is present. Therefore, since the determinations in steps S1 and S2 are NO, the determination in step S3 is YES and the process proceeds to step S4, the measurement data of low detection performance level is used. Since the fog 94 is not detected in the measurement data of the low detection performance level, the distance to the object is not calculated.

The fog 94 is present between the angle θ6 and the angle θ7, and the pedestrian 96 is present in the fog 94. In the measurement data at the low detection performance level, the fog 94 is not detected, but the pedestrian 96 is detected. Therefore, the determination in step S1 is YES and the process proceeds to step S4, and the distance to the pedestrian 96 is calculated using the data of the low detection performance level.

The angle θ7 to the angle θ8 is the same as the angle θ5 to the angle θ6, and the measurement data of the low detection performance level is used. Therefore, since the fog 94 is not detected, the distance to the object is not calculated.

Between the angles θ8 and 95 degrees is the same as from −95 degrees to the angle θ1, and the measurement data at the high detection performance level is used. Since there is no object, the distance to the object is not calculated.

In the laser radar device 1 of the present embodiment described above, the detection performance level setting unit 81 can set the detection performance level indicating the ease of detecting an object by selecting it from the high detection performance level and the low detection performance level. .. The high detection performance level is a detection performance level at which a black flat plate can be detected under the reference measurement conditions, and the low detection performance level is a detection performance level at which a black flat plate is not detected under the reference measurement conditions.

The low detection performance measuring unit 83 sets the detection performance level to the low detection performance level and executes the low detection performance measurement process of receiving the reflected light L1 by the photodiode 20 while changing the irradiation direction of the irradiation light L0. .. The low detection performance object determination unit 85 determines the direction in which the irradiation light L0 is emitted depending on whether or not the intensity of the reflected light L1 acquired from the photodiode 20 by executing this low detection performance measurement process exceeds the object determination threshold value. It is determined whether or not an object exists in.

When the detection performance level is low, it is difficult to detect an object having a low reflectance. Therefore, as shown in FIG. 5, it is possible to prevent fog from being detected when the measurement is performed at a low detection performance level. However, in the direction in which the low detection performance object determination unit 85 does not determine that an object exists, there is a possibility that a detection target object with low reflectance exists.

Therefore, in the present embodiment, in the direction in which the low detection performance object determination unit 85 does not determine that an object exists, whether the high detection performance measurement unit 84 and the high detection performance object determination unit 86 do not have an object. Determine further.

The high detection performance measurement unit 84 performs the same processing as the low detection performance measurement processing except that the detection performance level is set to the high detection performance level. Even in the direction in which it is not determined that the object exists at the low detection performance level, when the reflected light L1 having the intensity equal to or higher than the object determination threshold value can be detected at the high detection performance level, the object having the low reflectance is detected in that direction. I know it exists. This low reflectance object may be fog or a detection target object, as shown in FIG. However, in the case of the reflected light L1 from the detection target object, the waveform width becomes narrow. Therefore, the high detection performance object determination unit 86 executes the high detection performance measurement process for the direction in which the low detection performance object determination unit 85 has not determined that the object exists, and thereby the reflected light acquired from the photodiode 20. When the waveform width of L1 is shorter than the fog determination width threshold value, it is determined that the detection target object exists. By doing so, the laser radar device 1 of the present embodiment can detect an object having a low reflectance to be detected while suppressing the detection of fog.

Further, the detection performance level setting unit 81 of the present embodiment sets the low detection performance level and the high detection performance level without changing the light receiving sensitivity of the photodiode 20 while changing the intensity of the irradiation light L0. Therefore, the light receiving sensitivity can be lowered as compared with the case where the same high detection performance level is set by changing the light receiving sensitivity. Therefore, the influence of ambient light can be suppressed.

In addition, in the present embodiment, when it is determined that the measurement data of the high detection performance level has two or more peaks (S2: YES), is the waveform width obtained at the high detection performance level equal to or larger than the fog determination width threshold value? It is determined that the detection target object exists without determining whether or not the detection target object exists. This eliminates the need for the process of determining the waveform width and the process of comparing the waveform width with the fog determination width threshold value. Therefore, it is possible to quickly obtain the determination result that the detection target object exists.

Furthermore, the fog length in the irradiation direction of the irradiation light L0 may not be so long at the beginning of fog generation, and in this case, the waveform width of the reflected light L1 reflected by the fog may not be so wide. There is also. However, even in such a case, it is possible to determine that it is fog by performing the determination in step S2, and thus it is possible to further suppress detection of fog.

<Second Embodiment>
Next, a second embodiment will be described. In the following description of the second embodiment, elements having the same reference numerals as those used so far are the same as the elements having the same reference numerals in the previous embodiments, unless otherwise specified. Further, when only a part of the configuration is described, the above-described embodiments can be applied to other parts of the configuration.

As shown in FIG. 8, the laser radar device 100 of the second embodiment includes a photodiode 120H and a beam splitter 135 between the photodiode 120H and the reflecting surface 41 of the perforated mirror 40. The laser radar device 100 of the second embodiment also includes a photodiode 120L. The photodiode 120H corresponds to the first light receiving portion, and the photodiode 120L corresponds to the second light receiving portion. The measurement unit 104 of the second embodiment includes the photodiodes 120H and 120L instead of the photodiode 20 of the first embodiment. The other configuration of the measurement unit 104 is the same as that of the measurement unit 4 of the first embodiment.

The photodiodes 120H and 120L are connected to the circuit unit 170. The configuration of the circuit unit 170 differs from that of the first embodiment. The configuration of the circuit unit 170 will be described later with reference to FIG. In the laser radar device 100 of the second embodiment, the parts not shown in FIG. 8 are the same as those of the first embodiment.

The photodiodes 120H and 120L are arranged at different positions to receive the reflected light L1 split by the beam splitter 135. The photodiode 120H is arranged at a position for receiving the reflected light L1 transmitted through the beam splitter 135. On the other hand, the photodiode 120L is arranged at a position for receiving the reflected light L1 reflected by the beam splitter 135.

The photodiodes 120H and 120L can have the same light receiving sensitivity as the photodiode 20 of the first embodiment. However, either or both of the photodiodes 120H and 120L may have a light receiving sensitivity different from that of the photodiode 20 of the first embodiment.

Regarding the light receiving sensitivity of the photodiode 120H, the detection performance level determined by the light receiving sensitivity, the amplification factor of the amplifier 172H shown in FIG. 9, and the division ratio by the beam splitter 135 may be a high detection performance level. Further, regarding the light receiving sensitivity of the photodiode 120L, the detection performance level determined by the light receiving sensitivity, the amplification factor of the amplifier 172L shown in FIG. 9, and the division ratio of the beam splitter 135 may be a low detection performance level.

The beam splitter 135 is arranged at a position where the reflected light L1 reflected by the reflecting surface 41 of the perforated mirror 40 is incident, reflects a part of the reflected light L1, and transmits the rest. As a result, the beam splitter 135 splits the reflected light L1 reflected by the reflecting surface 41 of the perforated mirror 40 into the direction in which the photodiode 120H is located and the direction in which the photodiode 120L is located. The beam splitter 135 shown in FIG. 8 is a plate type, but a beam splitter having various structures such as a cube type can be used.

The splitting ratio of the beam splitter 135 can be set variously. In this embodiment, the photodiode 120H can detect the detection target object at a high detection performance level, and the photodiode 120L detects the detection target object at a low detection performance level. Thus, the reflected light L1 is split. For example, 80% of the reflected light L1 is transmitted and guided to the photodiode 120H, and 20% is reflected and guided to the photodiode 120L.

Of course, the above numerical values are examples. The ratio of the light transmitted through the beam splitter 135 to the light reflected by the beam splitter 135 is adjusted so that the photodiode 120H functions as a photodiode for a high detection performance level and the photodiode 120L functions as a photodiode for a low detection performance level. It should be. An electric signal representing the intensity of the reflected light L1 detected by each of the photodiodes 120H and 120L is supplied to the circuit unit 170.

The circuit unit 170 has the configuration shown in FIG. In the configuration shown in FIG. 9, the difference from the circuit unit 70 of the first embodiment is that one amplifier 72 is provided in the first embodiment, whereas the circuit unit 170 of the second embodiment has two. This is the point that the amplifiers 172H and 172L are provided and the processing of the control unit 180.

The amplifier 172H is connected to the photodiode 120H, amplifies the electric signal output from the photodiode 120H, and outputs the amplified electric signal to the control unit 180. The amplifier 172L is connected to the photodiode 120L, amplifies the electric signal output from the photodiode 120L, and outputs the amplified electric signal to the control unit 180. The amplification factor of the amplifier 172H is set to a value that allows the photodiode 120H to perform measurement at a high detection performance level. On the other hand, the amplification factor of the amplifier 172L is set to an amplification factor that allows the photodiode 120L to perform measurement at a low detection performance level.

The hardware configuration of the control unit 180 is the same as that of the control unit 80 of the first embodiment, and includes circuits such as a CPU, ROM, RAM, ASIC, CPLD, and comparator. Similar to the control unit 80 of the first embodiment, the control unit 180 outputs a light emission command to the LD drive circuit 71 and outputs a motor drive signal to the motor drive circuit 73.

Further, the control unit 180 also functions as each unit shown in FIG. That is, the control unit 180 also functions as the measurement processing unit 182, the low detection performance object determination unit 85, the high detection performance object determination unit 86, and the distance measurement unit 87.

The measurement processing unit 182 includes a low detection performance measurement unit 183 and a high detection performance measurement unit 184. The low detection performance measurement unit 183 executes low detection performance measurement processing. As described in the first embodiment, the low detection performance measurement process is a process in which the measurement unit 4 having a low detection performance level scans the irradiation light L0 on the monitoring area and receives the reflected light L1. In the second embodiment, the measurement unit 4 has a low detection performance level by using the reflected light L1 received by the photodiode 120L.

Then, similar to the first embodiment, the signal intensity of the reflected light L1 input from the amplifier 172L is compared with the object detection threshold. As a result of the comparison, the time when the signal intensity of the reflected light L1 exceeds the object detection threshold and the time when the signal intensity of the reflected light L1 falls below the object detection threshold are stored in the storage unit 74 in association with the irradiation direction of the irradiation light L0. To do. It should be noted that the object detection threshold may be a value that provides a low detection performance level measurement, and may be the same value as the object detection threshold of the first embodiment, for example.

The high detection performance measurement unit 184 executes high detection performance measurement processing. The high detection performance measurement process is a process in which the measurement unit 4 having a high detection performance level scans the monitoring area with the irradiation light L0 and receives the reflected light L1. In the second embodiment, the measurement unit 4 has a high detection performance level by using the reflected light L1 received by the photodiode 120H.

Then, the signal intensity of the reflected light L1 input from the amplifier 172H is compared with the object detection threshold. As a result of the comparison, the time when the signal intensity of the reflected light L1 exceeds the object detection threshold and the time when the signal intensity of the reflected light L1 falls below the object detection threshold are stored in the storage unit 74 in association with the irradiation direction of the irradiation light L0. To do. The object detection threshold may be a value that provides a high detection performance level measurement, and may be the same value as the object detection threshold of the first embodiment, for example.

In the second embodiment, both the low detection performance measurement process by the low detection performance measurement unit 183 and the high detection performance measurement process by the high detection performance measurement unit 184 are performed by one scan of the irradiation light L0. That is, the scanning of the irradiation light L0 in the high detection performance measurement processing and the scanning of the irradiation light L0 in the low detection performance measurement processing are the same scanning. Therefore, in the second embodiment, the output intensity of the laser diode 10 is the same at the high detection performance level and the low detection performance level.

After the low detection performance measurement process by the low detection performance measurement unit 183 and the high detection performance measurement process by the high detection performance measurement unit 184 are performed, the low detection performance object determination unit 85, similar to the first embodiment, The storage unit 74 stores the direction in which it is determined that the object exists and the direction in which the object does not exist at the low detection performance level. Then, the high detection performance object determination unit 86 determines whether or not the object exists in the direction in which the low detection performance object determination unit 85 does not determine that the object exists.

In the second embodiment described above, the beam splitter 135 that includes the two photodiodes 120H and 120L and that splits the reflected light L1 into the direction of incidence on the photodiode 120H and the direction of incidence on the photodiode 120L is provided. Prepare Thereby, the reflected light L1 generated from the same irradiation light L0 can be received by the photodiode 120H and the photodiode 120L.

The division ratio of the beam splitter 135 is set so that the photodiode 120H functions as a photodiode for a high detection performance level and the photodiode 120L functions as a photodiode for a low detection performance level.

Based on this configuration, the low detection performance measurement unit 183 and the high detection performance measurement unit 184 perform the low detection performance measurement process and the high detection performance measurement process, respectively, by scanning the same irradiation light L0. Therefore, the laser radar device 100 of the second embodiment has a high detection performance object as compared with the case where the low detection performance measurement process and the high detection performance measurement process are alternately performed like the laser radar device 1 of the first embodiment. The cycle in which the determination unit 86 makes a determination, that is, the object detection cycle can be shortened.

Further, unlike the first embodiment, it is not necessary to change the output intensity of the laser diode 10 in order to achieve the high detection level and the low detection performance level, and it is also necessary to switch the light receiving sensitivity of the photodiode 120H and the photodiode 120L. There is no. Therefore, there is an advantage that it is not necessary to provide a configuration for changing the intensity of the irradiation light L0 or a configuration for changing the light receiving sensitivity.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the following modified examples are also included in the technical scope of the present invention. Various modifications can be made without departing from the scope.

<Modification 1>
For example, in the above-described embodiment, the low detection performance level and the high detection performance level are set without changing the light receiving sensitivity while changing the intensity of the irradiation light L0. However, the low detection performance level and the high detection performance level may be set by changing only the light reception sensitivity, or both the intensity of the irradiation light L0 and the light reception sensitivity may be changed to set the low detection performance level and the high detection performance level. May be set.

<Modification 2>
The laser radar device 1 of the above-described embodiment includes the perforated mirror 40 and irradiates the rotary mirror 50 with the irradiation light L0 from the through hole 42 of the perforated mirror 40, but is not limited to this. .. The positions of the laser diode 10 and the photodiode 20 may be exchanged, and the irradiation light L0 may be reflected by the reflection plate to irradiate the rotation mirror 50 with the irradiation light L0. Further, the present invention is not limited to the coaxial system in which the light emitting unit and the light receiving unit commonly use the rotating mirror 50, but the present invention can be applied to a laser radar device of another axis system using a rotating mirror in which the light emitting unit and the light receiving unit are different. ..

<Modification 3>
Further, in the above-described embodiment, the low detection performance measuring unit 83 and the high detection performance measuring unit 84 determine that the signal intensity of the reflected light L1 is below the object detection threshold at the time when the signal intensity of the reflected light L1 exceeds the object detection threshold. The stored time is stored in the storage unit 74 in association with the irradiation direction of the irradiation light L0. However, instead of this, the waveform of the reflected light L1 may be stored in the storage unit 74.

<Modification 4>
In the above-described embodiment, the irradiation light L0 is applied to the same angle range as the low detection performance measurement processing even in the high detection performance measurement processing. However, instead of this, the low detection performance object determination unit 85 may irradiate the irradiation light L0 only to the angle at which it is determined that the object does not exist.

<Modification 5>
In the second embodiment, the photodiode 120H for high detection performance level is arranged at a position for receiving the reflected light L1 transmitted through the beam splitter 135, and the beam splitter 135 reflects the photodiode 120L for low detection performance level. It is arranged at a position for receiving the reflected light L1. However, on the contrary, the photodiode 120H for high detection performance level is arranged at a position for receiving the reflected light L1 reflected by the beam splitter 135, and the photodiode 120L for low detection performance level is arranged at the beam splitter 135. It may be arranged at a position for receiving the reflected light L1 transmitted through.

1: Laser radar device 2: Housing 3: Housing window 4: Measuring part 10: Laser diode 20: Photodiode 30: Collimating lens 40: Perforated mirror 41: Reflecting surface 42: Through hole 50: Rotating mirror 51: Concave mirror 60: motor 61: rotating shaft 62: rotational angle position sensor 70: circuit unit 71: LD drive circuit 72: amplifier 73: motor drive circuit 74: storage unit 80: control unit 81: detection performance level setting unit 82: measurement processing unit 83: Low detection performance measurement unit 84: High detection performance measurement unit 85: Low detection performance object determination unit 86: High detection performance object determination unit 87: Distance measurement unit 90: Car 92: Pedestrian 94: Fog 96: Pedestrian 100 : Laser radar device 104: Measuring unit 120H, 120L: Photodiode 170: Circuit unit 172H, 172L: Amplifier 180: Control unit 182: Measurement processing unit 183: Low detection performance measuring unit 184: High detection performance measuring unit

Claims (4)

A light projecting portion (10) for generating and projecting laser light;
A scanning unit (50, 60) for irradiating the laser beam projected by the light projecting unit to the outside of the device while changing the irradiation direction;
A light receiving unit (20, 120H, 120L) for receiving the reflected light generated by the laser beam applied to the outside of the device by the scanning unit and reflected outside the device;
A laser radar device (1, 100) having a measuring unit (4, 104) including
The measurement unit has a low detection rate, which is a detection performance level that indicates the ease of detection of an object that is determined by the intensity of the laser light projected by the light projecting unit and the light receiving sensitivity at which the light receiving unit receives the reflected light. A high detection performance level as a detection performance level that can be detected when a low reflection detection target object that is a preset detection target object is a reference angle with respect to the laser radar device at a reference distance, and at the reference distance Detecting the detection target object at two detection performance levels of low detection performance level that does not detect the low reflection detection target object that is the reference angle with respect to the laser radar device,
In the measuring unit having the low detection performance level, a low detection performance measuring process of irradiating the laser beam to the outside of the device while changing the irradiation direction by the scanning unit and receiving the reflected light by the light receiving unit is performed. A low detection performance measurement unit (83, 183) to be executed,
Based on the reflected light received by the light receiving unit by the low detection performance measurement unit executing the low detection performance measurement process, an object exists in the direction irradiated with the laser light by the low detection performance measurement process. A low detection performance object determination unit (85) for determining whether or not
In the measurement unit having the high detection performance level, the low detection performance object determination unit, while irradiating the laser light by the scanning unit, at least in a direction including a direction in which the object is not determined to exist A high detection performance measurement unit (84, 184) that executes a high detection performance measurement process of receiving the reflected light at the light reception unit,
For the direction in which the low detection performance object determination unit does not determine that the object exists, the waveform of the reflected light received by the light receiving unit by the high detection performance measurement unit executing the high detection performance measurement process. A high detection performance object determination unit (86) that determines that the object is present based on the width being shorter than the fog determination width threshold,
The high detection performance object determination unit, for the single direction in which the low detection performance object determination unit did not determine that the object exists, to perform the high detection performance measurement process by the high detection performance measurement unit. When there is a section in which the reflected light detected by the light receiving unit exceeds two object determination thresholds, it is determined that the object is present without comparing the waveform width of the reflected light with the fog determination width threshold. A laser radar device characterized by the above. Oite to claim 1,
A detection performance level setting unit (81) for setting the high detection performance level and the low detection performance level by changing at least one of the intensity of the laser light and the light receiving sensitivity,
The low detection performance measurement unit (83) executes the low detection performance measurement process by setting the detection performance level of the measurement unit to the low detection performance level by the detection performance level setting unit,
The high detection performance measuring unit (84) sets the detection performance level of the measuring unit to the high detection performance level by the detection performance level setting unit and executes the high detection performance measurement process. Laser radar device. In claim 2 ,
While the detection performance level setting unit changes the intensity of the laser light projected by the light projecting unit, the light receiving sensitivity of the light receiving unit that receives the reflected light is not changed, and the low detection performance level and the A laser radar device characterized by setting a high detection performance level. Oite to claim 1,
The light receiving unit includes a first light receiving unit (120H) and a second light receiving unit (120L) arranged at different positions to receive the reflected light,
In the measuring unit (104), the first light receiving unit detects the detection target object at the high detection performance level, and the second light receiving unit detects the detection target object at the low detection performance level. A laser radar device comprising a beam splitter (135) that splits the reflected light at a split ratio.

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