DE102019106213A1 - Method for determining at least one item of positional information of at least one object in a monitoring area with an optical detection device and optical detection device - Google Patents

Abstract

A method for determining at least one item of positional information of at least one object in a monitoring area with an optical detection device and a detection device is described. In the method, at least one optical transmission signal with a transmission signal propagation main axis is transmitted into the monitoring area. At least one part (35) of the at least one transmission signal reflected on an object that may be present in the monitoring area is reflected as a received signal and at least one part (35) of the received signal whose main reception signal propagation axis is parallel to the main transmission signal propagation axis at least on the side facing the object is received. From a transit time between the transmission of the at least one transmission signal and the reception of the at least one part (35) of the at least one reception signal and / or from a direction of the at least one transmission signal and / or a direction of the at least one part (35) of the at least one reception signal at least one item of positional information of the at least one object is determined. The at least one transmission signal is generated with a transmission signal pattern (36). The transmission signal pattern (36) is varied in temporally following measurement cycles (60) at least in one direction which runs transversely to a transmission signal main axis of the at least one transmission signal. The at least one part (35) of the at least one received signal is received in accordance with the transmission signal pattern (36) and assigned to the at least one transmission signal.

Description

Technical area

• - wenigstens ein optisches Sendesignal mit einer Sendesignal-Ausbreitungshauptachse in den Überwachungsbereich gesendet wird,
• - an einem in dem Überwachungsbereich etwa vorhandenen Objekt wenigstens ein Teil des wenigstens einen Sendesignals als Empfangssignal reflektiert wird und wenigstens ein Teil des Empfangssignals, dessen Empfangssignal-Ausbreitungshauptachse zumindest auf der dem Objekt zugewandten Seite parallel oder koaxial zu der Sendesignal-Ausbreitungshauptachse verläuft, empfangen wird,
• - aus einer Laufzeit zwischen dem Aussenden des wenigstens einen Sendesignals und dem Empfang des wenigstens einen Teils des wenigstens einen Empfangssignals und/oder aus einer Richtung des wenigstens einen Teils des wenigstens einen Sendesignals und/oder einer Richtung des wenigstens einen Empfangssignals wenigstens eine Positionsinformation des wenigstens einen Objekts ermittelt wird.

The invention relates to a method for determining at least one item of positional information of at least one object in a monitoring area with an optical detection device in which

• - At least one optical transmission signal with a transmission signal propagation main axis is sent into the monitoring area,
• - At least a part of the at least one transmission signal is reflected as a received signal on an object possibly present in the monitoring area and at least a part of the reception signal, the reception signal main axis of which runs parallel or coaxially to the main transmission signal propagation axis at least on the side facing the object, is received ,
• - From a transit time between the transmission of the at least one transmission signal and the reception of the at least one part of the at least one reception signal and / or from a direction of the at least one part of the at least one transmission signal and / or a direction of the at least one reception signal at least one position information of the at least an object is determined.

• - mit wenigstens einem Sender zur Erzeugung wenigstens eines optischen Sendesignals, welches mit einer Sendesignal-Ausbreitungshauptachse in den Überwachungsbereich gesendet werden kann,
• - mit wenigstens einem Empfänger zum Empfangen wenigstens eines Teils wenigstens eines Empfangssignals, welches aus wenigstens einem Teil des wenigstens einen Sendesignals besteht, der an einem gegebenenfalls im Überwachungsbereich vorhandenen Objekt reflektiert wird, wobei eine Empfangssignal-Ausbreitungshauptachse des wenigstens einen Empfangssignals zumindest auf der dem Objekt zugewandten Seite parallel oder koaxial zu der Sendesignal-Ausbreitungshauptachse verläuft,
• - und mit wenigstens einer Steuer- und Auswerteeinrichtung zum Steuern des wenigstens einen Senders und des wenigstens einen Empfängers und zur Ermittlung wenigstens einer Positionsinformation aus einer Laufzeit des wenigstens einen Sendesignals und des wenigstens einen Teils des wenigstens einen Empfangssignals und/oder aus einer Richtung des wenigstens einen Sendesignals und/oder aus einer Richtung des wenigstens einen Teils des wenigstens einen Empfangssignals.

The invention also relates to an optical detection device for determining at least one item of position information of at least one object in a monitoring area,

• - With at least one transmitter for generating at least one optical transmission signal, which can be transmitted into the monitoring area with a transmission signal propagation main axis,
• - With at least one receiver for receiving at least a part of at least one received signal, which consists of at least a part of the at least one transmitted signal, which is reflected on an object possibly present in the surveillance area, a received signal propagation main axis of the at least one received signal at least on that of the object facing side runs parallel or coaxially to the main transmission signal propagation axis,
• - And with at least one control and evaluation device for controlling the at least one transmitter and the at least one receiver and for determining at least one position information from a transit time of the at least one transmission signal and the at least one part of the at least one received signal and / or from a direction of the at least a transmission signal and / or from a direction of the at least one part of the at least one reception signal.

State of the art

From the US 9,869,754 B1 a LiDAR system is known. The LiDAR system comprises a light source, a mirror, a scanner, a receiver or a controller. The emitted light beam is aimed at a receiving target. As soon as the emitted beam reaches the receiving target, the receiving target scatters or reflects at least part of the light of the emitted beam and part of the scattered or reflected light can return to the LiDAR system. The scattered or reflected light is represented by an input beam which passes the scanner and is directed to the receiver by means of the mirror. LiDAR is a technology that can be used to measure distances to distant targets.

The invention is based on the object of designing a method and a detection device of the type mentioned at the outset which can be implemented or operated more easily, in particular with a lower expenditure of energy and / or greater accuracy.

Disclosure of the invention

• - das wenigstens eine Sendesignal mit einem Sendesignalmuster generiert wird, wobei das Sendesignalmuster bei zeitlich folgenden Messzyklen zumindest in einer Richtung, welche quer zur Sendesignal-Ausbreitungshauptachse des wenigstens einen Sendesignals verläuft, variiert wird,
• - der wenigstens eine Teil des wenigstens einen Empfangssignals entsprechend dem Sendesignalmuster empfangen und dem wenigstens einen Sendesignal zugeordnet wird.

According to the invention, this object is achieved in the method in that

• the at least one transmission signal is generated with a transmission signal pattern, the transmission signal pattern being varied in subsequent measurement cycles at least in one direction which runs transversely to the transmission signal main axis of the at least one transmission signal,
• the at least part of the at least one received signal is received in accordance with the transmission signal pattern and assigned to the at least one transmission signal.

According to the invention, the at least one transmission signal is provided with a transmission signal pattern. On the receiving side, the at least one received signal is received in accordance with the transmitted signal pattern. In this way, the at least one received signal can be validated.

In the case of the transmission signal patterns, only a characteristic part of the cross section is transverse, in particular perpendicular, to the transmission signal propagation main axis of the at least one Transmission signal generated light energy. In this way, not the entire cross-sectional area of the transmission signal is supplied with light energy. In this way, the overall transmission energy sent can be reduced.

The at least one part of the at least one transmission signal that can be reflected on an object and the corresponding reflected part of the at least one reception signal is a signal pattern part of the transmission signal pattern which carries light energy.

The transmission signal propagation main axis indicates the mean direction in which the at least one transmission signal is propagating. The directions of propagation of the individual parts of the transmission signal pattern can be different. Correspondingly, the main axis of the received signal propagation indicates the mean direction in which the at least one received signal propagates, the direction of propagation of the individual parts of the received signal also being able to be different here.

The at least one received signal can advantageously be received with the receiver in a spatially resolved manner. In this way, the transmission signal pattern can be identified in a correspondingly spatially resolved manner. The at least one part of the at least one received signal can thus be assigned directly to the transmitted signal pattern.

Advantageously, only the reception areas that correspond to the transmission signal pattern can be activated on the receiver side. In this way, energy expenditure on the receiver side can be kept lower overall.

Advantageously, from a transit time between the transmission of the at least one part of the at least one transmission signal and the reception of the corresponding at least one part of the at least one reception signal and / or from a direction of the transmission signal main propagation axis and / or a direction of the reception signal main propagation axis at least one Position information of the at least one object can be determined.

A distance, a speed and / or a direction of the object relative to the detection device can advantageously be determined as position information.

The detection device can advantageously operate according to a time-of-flight method. Optical detection devices operating according to the light pulse transit time method can be designed and designated as time-of-flight (TOF), light detection and ranging systems (LiDAR), laser detection and ranging systems (LaDAR) or the like. A transit time from the emission of a transmission signal, in particular a light pulse, with at least one transmitter and the reception of the corresponding reflected received signal with at least one receiver is measured and a distance between the detection device and the detected object is determined from this.

The at least one detection device can advantageously be designed as a scanning system. A monitoring area can be scanned, i.e. scanned, with transmission signals. For this purpose, the corresponding transmission signals, in particular transmission beams, can be pivoted over the monitoring area with respect to their transmission signal propagation main axis. At least one deflection device, in particular a scanning device, a deflection mirror device or the like, can be used here.

The detection device can advantageously be designed as a laser-based distance measuring system. The laser-based distance measuring system can have at least one laser, in particular a diode laser, as the light source of at least one transmitter. With the at least one laser, in particular, pulsed transmission beams can be transmitted as transmission signals. The laser can be used to emit transmission signals in frequency ranges that are visible or invisible to the human eye. Correspondingly, at least one receiver can have a detector designed for the frequency of the emitted light, in particular with at least one (avalanche) photodiode, at least one diode array, at least one CCD array or the like. The laser-based distance measuring system can advantageously be a laser scanner. With a laser scanner, a monitoring area can be scanned with a particularly pulsed laser beam.

The at least one transmitter can advantageously have at least one surface emitter. A surface emitter, also known as a vertical cavity surface-emitting laser (VCSEL), is a semiconductor laser in which the light is emitted perpendicular to the plane of the semiconductor chip.

The invention can be used in a vehicle, in particular a motor vehicle. The invention can advantageously be used in a land vehicle, in particular a passenger car, a truck, a bus, a motorcycle or the like, an aircraft and / or a watercraft. The invention can also be used in vehicles that are autonomous or at least partially autonomous can be operated. The invention can also be used in stationary operation.

The detection device can advantageously be connected to at least one electronic control device of the vehicle, in particular a driver assistance system and / or a chassis control and / or a driver information device and / or a parking assistance system or the like, or be part of such.

In an advantageous embodiment of the method, the transmission signal pattern can be changed for at least two successive transmission signals. In this way, the transmission signals with different transmission signal patterns can be used and distinguished from one another in subsequent measurement cycles. In this way, a respective characteristic transmission signal pattern can be assigned to each measurement cycle. Measurement cycles following one another can be distinguished in this way and assigned to the respective transmission signals.

The duration of a measuring cycle can advantageously be specified. The duration of the measurement cycle can be specified as the assumed maximum transit time of a transmitted signal and the corresponding received signal in the event of a reflection on an object on the edge of the monitoring area at the maximum distance from the detection device.

The measuring cycles can be carried out according to their duration at a specified clock frequency. When using the detection device in connection with a motor vehicle, the greatest distance of interest can be between 200 m and 300 m. Here the measuring cycles can be carried out with clock frequencies in the order of magnitude of microseconds.

In a further advantageous embodiment of the method, the at least one transmission signal pattern can be varied in two mutually orthogonal directions which run transversely to the main transmission signal propagation axis. In this way, the transmission signal pattern can be varied in a two-dimensional area. The number of possible variations for the transmission signal pattern can thus be increased.

• - wenigstens ein Empfänger zum Empfangen des wenigstens einen Teils des wenigstens einen Empfangssignals wenigstens in einer Richtung, welche quer zur Empfangssignal-Ausbreitungshauptachse des wenigstens einen Empfangssignals verläuft, jeweils begrenzte Empfangsbereiche aufweisen, die während einer Empfangsbereitschaft für den wenigstens einen Teil des wenigstens einen Empfangssignals entsprechend dem Sendesignalmuster des zugehörigen wenigstens einen Sendesignals empfangstechnisch aktiv geschaltet werden
• - und/oder wenigstens ein Sender zum Senden des wenigstens einen Sendesignals kann wenigstens in einer Richtung, welche quer zur Sendesignal-Ausbreitungshauptachse des wenigstens einen Sendesignals verläuft, jeweils getrennte Sendebereiche aufweisen, die entsprechend dem Sendesignalmuster sendetechnisch aktiviert werden.

In a further advantageous embodiment of the method,

• - At least one receiver for receiving the at least one part of the at least one received signal in at least one direction which runs transversely to the main received signal propagation axis of the at least one received signal, each having limited receiving areas that correspond to the at least one part of the at least one received signal during readiness to receive the transmission signal pattern of the associated at least one transmission signal can be switched to active reception
• - And / or at least one transmitter for transmitting the at least one transmission signal can have separate transmission areas at least in one direction which runs transversely to the transmission signal propagation main axis of the at least one transmission signal, which transmission areas are activated according to the transmission signal pattern.

In this way, reproducible transmission signal patterns can be generated with the at least one transmitter. The at least one receiver can be adapted to the transmission signal pattern by switching the reception areas accordingly, so that the at least one reception signal can also be reproducibly received with the receiver in accordance with the transmission signal pattern.

The transmission signal patterns can advantageously be generated in such a way that at least one inactive transmission area is arranged between two active transmission areas. Correspondingly, at least one inactive receiving area can be arranged between two active receiving areas. Corresponding crosstalk between neighboring reception areas of the receiver can thus be avoided.

In a further advantageous embodiment of the method, the direction of the main transmission signal propagation axis of at least two successive transmission signals and the direction of the main reception signal propagation axis can be varied at least in the monitoring area. In this way, the transmission signals can be used for successive measuring cycles. In the successive measurement cycles, corresponding sections of the monitoring area are scanned in accordance with the direction of the main transmission signal propagation axis of their respective transmission signals. By varying the direction of the main transmission signal propagation axis, a large number of sections of the monitoring area, in particular the entire monitoring area, are scanned as closely as possible. Thus, by continuously changing the direction of the main transmission signal propagation axis, the monitoring area can be scanned over an area at least in one spatial direction, in particular in two spatial directions. In this way, a two-dimensional “map” of objects in the monitoring area can be created.

In a further advantageous embodiment of the method, the direction of the main transmission signal propagation axis of the transmission signals and the direction of the main reception signal propagation axis can be set with at least one deflection device. In this way it is not necessary to swivel the transmitter to change the direction of the transmission signal propagation main axis. With the help of the deflection device, the monitored area can be scanned. Furthermore, the main transmission signal propagation axis and the main reception signal propagation axis can run parallel or coaxially to one another at least in the monitoring area. In this way, the transmitted signals can take the same path as the received signals, at least in the monitoring area. The paths of the transmitted signals and the received signals can run over the same deflection device.

The at least one deflection device can advantageously have at least one deflection mirror device. The deflection mirror device can have at least one oscillating mirror, in particular a micro oscillating mirror. The at least one oscillating mirror can be driven to oscillate continuously. Thus, the direction of the main transmission signal propagation axis in the monitoring area and, accordingly, the direction of the main reception signal propagation axis can be continuously changed.

The at least one oscillating mirror can be pivoted in two dimensions. In this way, the direction of the main transmission signal propagation axis and the direction of the main reception signal propagation axis can be changed in two directions. In this way, the monitoring area can be scanned in two dimensions with the transmission signals.

Advantageously, with regard to the direction of propagation of the transmission signals, at least one optical system, in particular with at least one optical lens, can be arranged between the transmitter and the at least one deflection device and / or behind the at least one deflection device. In this way, the beam quality of the transmission signals can be improved.

With regard to the direction of propagation of the received signals, at least one optical system, in particular with at least one optical lens, can advantageously be arranged between the at least one deflection device and the at least one receiver. In this way, the received signals can be focused on the receiver.

In a further advantageous embodiment of the method, the direction of the main transmission signal propagation axis and / or the direction of the main reception signal propagation axis can be determined from a setting of the deflection device before, during or immediately after the transmission of the at least one transmission signal. In this way, the direction of the main transmission signal propagation axis and / or the direction of the main reception signal propagation axis can be determined from the setting of the deflection device. The setting of the deflection device can in particular be determined electronically, in particular with appropriate sensors and / or using appropriate measurement routines.

The direction of the at least one object relative to the detection device can advantageously be determined from the setting of the deflection device.

In a further advantageous embodiment of the method, a setting of the deflecting device can be changed continuously over several measuring cycles. In this way, the monitoring area can be scanned continuously. The entire monitoring area can be scanned with a large number of measuring cycles.

The duration of a measurement cycle can advantageously be so short that the entire monitoring area is scanned at such a high speed that the entire monitoring area is scanned in a negligibly short measurement time compared to the system time in which the detection device is operated. In this way, a quasi-snapshot of the monitored area can be carried out. When the detection device is used in a motor vehicle, the monitoring area can be scanned so quickly that the motor vehicle only moves a negligible distance of a few centimeters during the measurement time.

In a further advantageous embodiment of the method, a distance of the at least one object relative to the detection device can be determined from the transit time of the at least one transmission signal and the corresponding at least one part of the at least one reception signal. The exact position of the object relative to the detection device can thus be determined from the transit time and the setting of any deflection device.

In a further advantageous embodiment of the method, the at least one part of the at least one received signal can be received with a two-dimensional receiver and at least one reception area which is not active in terms of reception can be used as a buffer store for a signal variable generated with the at least one part of the at least one reception signal. In this way, a longer reaction time can be achieved overall.

In a further advantageous embodiment of the method, several received parts of the at least one received signal can be combined on the receiver side. In this way, greater sensitivity can be achieved. In this way, parts of received signals that have been reflected on objects at greater distances can also be recognized, the intensity of which alone is so weak that they cannot be recognized as coming from an object with the individual reception areas of the receiver. In the event that all parts of a transmission signal are reflected and received with the corresponding reception areas of the receiver, the corresponding object can already be detected with the help of the summary in a further channel at a distance that is twice as large as the distance at which the object with the individual reception areas is recognized separately. If the object approaches the detection device, in particular the vehicle, the object can also be detected with the individual reception areas.

Advantageously, all received parts of the at least one received signal can be combined. In this way, the sensitivity can be further improved.

Advantageously, a plurality of received parts of the at least one received signal can be combined regularly, in particular with each clock cycle of the receiver. The combination of the parts can be used as a further receiving channel in addition to the channels in which the parts of the at least one received signal are processed individually.

Alternatively, several received parts of the at least one received signal can occasionally, in particular when required, or irregularly be combined. It is also possible alternately either to combine several received parts of the at least one received signal or to process the received parts of the at least one received signal separately.

The at least one two-dimensional receiver can advantageously have at least one charge-coupled component, in particular a charge-coupled device (CCD) or the like. The so-called pixels of the receiver can serve as reception areas for the at least one reception signal. In the active pixels, the photons of the at least one received signal are converted into charge carriers, in particular electrons, and collected. The charge carriers form a signal variable that characterizes the at least one received signal in the corresponding pixel. The collected charge carriers are clocked and shifted in a defined shifting direction between the pixels that are not active for the corresponding transmission signal pattern. The charge carriers are thus conveyed to the edge of the receiver in accordance with the transmission signal pattern or the reception pattern of the receiver. There the load carriers are read out with a corresponding readout device. The information obtained in this way is fed to evaluation electronics.

The invention also has the advantage that a clock frequency with respect to the measuring cycles can be smaller than when activating receivers in such a way that they are active over larger areas. In this way, an analog-digital converter used to evaluate the signal variables, in particular charge carriers, can be designed more simply or clocked more slowly. A range of the optical detection device can thus be increased overall. Alternatively or in addition, an area of a sensor can be reduced on the receiver side. In particular, smaller CCD chips with fewer pixels can be used. In this way the effort and costs can be reduced. Furthermore, the shift times can be reduced when using a CCD array, since a smaller number of pixels is required. In this way, a measurement can be accelerated overall. Alternatively or additionally, receiving optics can be designed more simply. In particular, receiving optics can consist of only a single lens. Because the number of reception areas on the part of the receiver can be reduced with the invention, the number of channels required on the part of an analog / digital converter can also be reduced. As an alternative or in addition, the amount of energy used for the voltage supply for the detection device can thus be reduced. Alternatively or additionally, an additional image memory can be dispensed with, since the received signals are processed immediately.

Alternatively or additionally, at least one two-dimensional receiver can advantageously be implemented as a diode array or from individual diodes. The diodes can advantageously be implemented as (avalanche) photodiodes. Individual diodes and diode arrays can be read out quickly. The diodes can be controlled individually.

• - der wenigstens eine Sender mehrere Sendebereiche aufweist, welche in wenigstens einer Richtung, die quer zur Sendesignal-Ausbreitungshauptachse verläuft, nebeneinander angeordnet sind und welche wenigstens teilweise getrennt voneinander sendetechnisch aktiv angesteuert werden können,
• - und der wenigstens eine Empfänger mehrere Empfangsbereiche aufweist, welche in wenigstens einer Richtung, die quer zur Empfangssignal-Ausbreitungshauptachse verläuft, nebeneinander angeordnet sind und welche wenigstens teilweise getrennt voneinander empfangstechnisch aktiv angesteuert werden können.

Furthermore, the object is achieved according to the invention in the detection device in that

• - the at least one transmitter has several transmission areas which are arranged next to one another in at least one direction that runs transversely to the main transmission signal propagation axis and which can be actively controlled for transmission at least partially separately from one another,
• and the at least one receiver has a plurality of reception areas which are arranged next to one another in at least one direction that runs transversely to the main axis of the reception signal propagation and which can be actively controlled for reception at least partially separately from one another.

In this way, varying transmission signal patterns can be generated with the at least one transmitter. With the at least one receiver, the reception areas can be activated in such a way that they correspond to the respective transmission signal pattern and can receive the corresponding reception signal.

In an advantageous embodiment, the at least one transmitter can have at least one diode laser with several separately activatable transmission areas and / or several diode lasers which each form at least one activatable transmission area. At least one diode laser can be designed as a so-called VCSEL array.

The at least one receiver can advantageously have at least one charge-coupled component, in particular a diode array, CCD array, individual diodes or the like. A charge-coupled component has a plurality of receiving areas which can be actively controlled separately from one another.

In a further advantageous embodiment, the at least one control and evaluation device can be designed to carry out the method according to the invention.

In addition, the features and advantages shown in connection with the method according to the invention and the detection device according to the invention and their respective advantageous configurations apply mutatis mutandis and vice versa. The individual features and advantages can of course be combined with one another, whereby further advantageous effects can arise that go beyond the sum of the individual effects.

Figure list

• 1 ein Fahrzeug in der Vorderansicht, mit einem Laserscanner zur Überwachung eines Überwachungsbereichs in Fahrtrichtung vor den Fahrzeug;
• 2 den Laserscanner aus der 1, mit einem Sender, einem Empfänger, einer Umlenkspiegeleinrichtung und einer Steuer- und Auswerteinrichtung;
• 3 eine schematische Darstellung des Empfängers des Laserscanners aus den 1 und 2;
• 4 eine stilisierte Seitenansicht des Fahrzeugs aus der 1, bei der die schwenkbare Sendesignal-Ausbreitungshauptachse eines mit dem Sender erzeugten Sendesignals angedeutet ist;
• 5 eine stilisierte Draufsicht des Fahrzeugs aus der 4 mit der angedeuteten schwenkbaren Sendesignal-Ausbreitungshauptachse des Sendesignals;
• 6 den Sender und den Empfänger des Laserscanners aus den 1 bis 3 während zwei Messzyklen, in denen insgesamt zwei Sendesignale mit unterschiedlichen Sendesignalmustern ausgesendet werden.

Further advantages, features and details of the invention emerge from the following description, in which an exemplary embodiment of the invention is explained in more detail with reference to the drawing. The person skilled in the art will expediently also consider the features disclosed in combination in the drawing, the description and the claims individually and combine them into meaningful further combinations. It show schematically

• 1 a vehicle in the front view, with a laser scanner for monitoring a monitoring area in the direction of travel in front of the vehicle;
• 2 the laser scanner from the 1 , with a transmitter, a receiver, a deflecting mirror device and a control and evaluation device;
• 3 a schematic representation of the receiver of the laser scanner from the 1 and 2 ;
• 4th a stylized side view of the vehicle from FIG 1 in which the pivotable transmission signal propagation main axis of a transmission signal generated with the transmitter is indicated;
• 5 a stylized top view of the vehicle from FIG 4th with the indicated pivotable transmission signal propagation main axis of the transmission signal;
• 6th the transmitter and receiver of the laser scanner from the 1 to 3 during two measurement cycles in which a total of two transmission signals with different transmission signal patterns are transmitted.

In the figures, the same components are provided with the same reference symbols.

Embodiment (s) of the invention

In the 1 is a vehicle 10 shown by way of example in the form of a passenger car in the front view. The vehicle 10 comprises a scanning optical detection device, for example in the form of a laser scanner 12 . The laser scanner 12 is exemplary in the front bumper of the vehicle 10 arranged. The laser scanner 12 can also be at another point in the vehicle 10 be arranged.

With the laser scanner 12 can one in the 2 , 4th and 5 designated monitoring area 14th for example in the direction of travel of the vehicle 10 in front of the vehicle 10 on objects 16 to be monitored. This can be done with the laser scanner 12 the monitoring area 14th with corresponding transmission signals 18th are scanned. When there is an object 16 become the broadcast signals 18th on the object 16 at least in part reflected and as received signals 20th to the laser scanner 12 sent back. With an appropriate recipient 22nd of the laser scanner 12 are the received signals 20th receive. With the objects 16 For example, it can be other vehicles, people, animals, lane markings, road signs, obstacles, potholes or the like.

The laser scanner 12 works according to a so-called transit time method, in which a transit time between the transmission of a transmission signal 18th and receiving at least a portion of a corresponding received signal 20th and from this a distance, a speed and / or a direction of the object 16 relative to the vehicle 10 can be determined as position information.

>> The laser scanner 12 assigns a transmitter 24 for sending out transmission signals 18th , the recipient 22nd to receive the received signals 20th , a deflecting mirror device 26th for redirecting the transmission signals 18th and the received signals 20th , a control and evaluation device 28 to control the transmitter 24 , Recipient 22nd and the deflecting mirror device 26th and for evaluating received signals 20th .

The laser scanner also has 12 a transmission optics 25th for shaping the transmission signals 18th behind the transmitter 24 and a receiving optics 30th for focusing the received signals 20th on a sensor 32 Recipient 22nd on.

With the deflection mirror device 26th becomes a main transmission signal propagation axis 19th the broadcast signals 18th as in the 4th and 5 indicated in the surveillance area 14th swiveled so that this with the transmission signals 18th can be scanned. Furthermore, with the deflection mirror device 26th a received signal propagation principal axis 21st the received signals 20th pivoted so that the received signals 20th , like in the 2 indicated to the recipient 22nd be steered. In the 2 are the main transmission signal propagation axis 19th and the received signal propagation main axis 21st shown in parallel for better differentiation. In reality, these can run coaxially.

In addition, the laser scanner 12 a beam splitting and merging device 27 with which the paths of the transmit signals 18th and the received signals 20th , respectively the main transmission signal propagation axis 19th and the received signal propagation main axis 21st , in the direction of the main transmission signal propagation axis 19th in front of and in the direction of the received signal propagation main axis 21st behind the deflecting mirror device 26th can be merged.

The beam splitting and merging device 27 includes a mirror, which is behind the transmission optics 25th is arranged and with respect to the direction of the transmission signal propagation main axis 19th by 45 ° in the direction of the deflecting mirror device 26th is inclined. With the beam splitter and merging device 27 becomes the main transmission signal propagation axis 19th by 90 ° to the deflection mirror device 26th diverted towards. Behind the beam splitting and merging device 27 runs the main transmission signal propagation axis 19th coaxial with the main axis of reception signal propagation 21st .

The beam splitting and merging device 27 is arranged and designed so that the received signals 20th from the deflecting mirror device 26th mainly at the beam splitting and merging device 27 over on a straight path to the receiving optics 30th and to the recipient 22nd reach.

Overall, the beam splitting and merging device 27 causes the broadcast signals 18th and the received signals 20th on the same path before and after the deflecting mirror device 26th run away.

The transmitter 24 has a plurality of transmission areas 34 which can be controlled separately from each other. The transmission areas 34 are for example in the 6th shown. The transmission areas 34 are for example arranged flat in two directions. An area which corresponds to the transmission areas 34 is spanned, extends transversely, for example perpendicular to the transmission direction of the transmission signals 18th . As an example, the sender 24 four columns with four transmission areas each 34 on. The transmission areas 34 thus form a 4 × 4 matrix.

By controlling the transmission areas accordingly 34 can send signals 18th with respective transmission signal patterns 36 to be generated. Each controlled, i.e. activated, transmission area sends 34 a signal pattern part 35 in the form of light energy. The broadcast signal patterns 36 can vary. Two different transmission signal patterns 36 are exemplary in the 6th shown on the left. The active transmission areas 34 are provided with the addition “a” and filled with black to make them easier to differentiate. The active transmission areas 34a emit light and thus generate the corresponding signal pattern parts 35 of the corresponding transmission signal pattern 36 . For example, it is located between two active transmission areas 34a at least one inactive coverage area 34 . Instead of the one in the 6th transmission signal pattern shown 36 can also use other transmission signal patterns 36 with the transmitter 24 to be generated.

The transmitter 24 has, for example, a laser diode in the form of a surface emitter, a so-called VCSEL, with which the corresponding transmission ranges 34 can be realized. The transmitter 24 emits broadcast signals 18th in a range that is not visible to the human eye, for example with a wavelength of 905 nm.

The transmitter 24 is with the control and evaluation device 28 controlled to send out the transmission signals 18th with the respective transmission signal patterns 36 .

The 6th shows an example of two consecutive measuring cycles 60 of the laser scanner 12 over time from top to bottom, with the second measurement cycle for better clarity 60 only the beginning is shown. The time axis is labeled t. At the beginning of each measurement cycle 60 becomes a broadcast signal 18th with the corresponding transmit signal pattern 36 in the monitoring area 14th Posted. The beginning of the measurement cycle 60 is with a corresponding clock 37 initiated. Examples are in the 6th two bars 37 indicated by dashed lines. The duration of each measurement cycle 60 is determined by the clock frequency of the clocks 37 given.

The duration of the measuring cycles 60 corresponds to the maximum transit time of the transmission signal 18th and the reflected received signal 20th at the maximum distance of interest at which an object is on the edge of the monitoring area 14th can be captured. The maximum distance of interest can be, for example, approximately 270 m. The maximum distance of interest can also be smaller or larger. Instead of the maximum distance of interest, the maximum range of the laser scanner 12 for specifying the duration of the measuring cycles 60 and the clock frequencies are used. The duration of the measuring cycles 60 can also be changeable. In this way the laser scanner can 12 can be adapted to operating situations and / or environmental conditions

The deflection mirror device 26th has, for example, a so-called gimbal-mounted micro-oscillating mirror 38 on. The oscillating micro mirror 38 is about two mutually perpendicular pivot axes 40 pivotable.

The deflection mirror device 26th has a position detection device, which is of no further interest here, with which an instantaneous setting of the oscillating micro mirror 38 determined and sent to the control and evaluation device 28 can be transmitted. Depending on the setting of the deflecting mirror device 26th becomes the direction of the main transmission signal propagation axis 19th of the corresponding transmission signal 18th in the surveillance area 14th given. The transmission signal propagation main axis 19th will be so in the surveillance area 14th panned. By recording the setting, or the swivel position, of the micro oscillating mirror 38 can be the direction of the main transmission signal propagation axis 19th in the monitoring area 14th and thus the direction of a detected object 16 relative to the laser scanner 12 be determined.

Recipient 22nd is explained below using the 3 explained in more detail. Recipient 22nd includes the sensor 32 for example in the form of a known CCD array. The sensor 32 has a variety of reception areas 42 , the so-called pixels of the CCD array. The reception areas 42 are arranged flat in two directions. The area covered by the reception areas 42 is spanned, runs transversely or perpendicular to the main axis of the received signal propagation 21st , from which the received signals 20th on the recipient 22nd to meet. The sensor 32 a 4 × 4 matrix of reception areas 42 on. The reception areas 42 can be activated separately from each other. This way you can use the reception areas 42 a reception area pattern 43 be generated, which corresponds to the transmission signal pattern 36 the transmission signal 18th in the corresponding measuring cycle 60 corresponds. Active reception areas 42 are marked with the addition "a" for better differentiation. In the 3 and 6th are an example of the activated reception areas 42a indicated by hatching. As with the corresponding transmit signal pattern 36 is located between two active reception areas 42a at least one inactive reception area 42 .

In the active reception areas 42a become the photons of the corresponding received signal 20th In a way that is not of further interest here, it is converted into electrical charge carriers in the form of electrons and collected. The charge carriers, or the number of charge carriers, serves as the signal variable that defines the received signal 20th characterized. The charge carriers from the active receiving areas 42a are clocked in one sliding direction 44 in the respective neighboring, inactive reception areas 42 postponed. In a final pushing cycle, the load carriers are finally transferred to an analogue readout stage 48 pushed. The selection level 48 is with an analog to digital converter 50 connected, with which the corresponding information is digitized.

The timing of the shift and the control of the reception areas 42 takes place via a so-called "CCD clock distribution and logic module 46" of the receiver 42 . The CCD clock Distribution Logic building block 46 is with the control and evaluation unit 28 , for example a field-programmable gate array (FPGA) 56 , connected.

Recipient 22nd furthermore has a voltage supply unit 52 on with which the recipient 22nd and the corresponding components are supplied with the necessary electrical voltage. The power supply unit 52 is with the power supply 54 of the laser scanner 12 , for example the power supply of the vehicle 10 , connected. Also, the recipient instructs 22nd a phase locked loop 58 which, for example, with a corresponding component of the control and evaluation device 28 can be connected.

When operating the laser scanner 12 be like in the 6th shown with the transmitter 24 Broadcast signals 18th with the clock frequency corresponding to the duration of a measurement cycle 60 with varying transmission signal patterns 36 sent out.

Furthermore, the reception areas 42 of the sensor 32 Recipient 22nd according to the transmission signal pattern 36 activated, the same measuring cycle 60 corresponds. The recipient can do this first 22nd and then the station 24 be controlled.

When sending out each of the broadcast signals 18th at the beginning of a measuring cycle 60 is with the position detection device of the deflecting mirror device 26th the setting of the oscillating micro mirror 38 detected. The transmission signals 18th when a predetermined setting of the oscillating micro mirror is reached 38 be sent out. From the setting of the oscillating micro mirror 38 can, if an object 16 is detected, via the direction of the transmission signal propagation main axis 19th of the transmission signal 18th the direction of the object 16 relative to the laser scanner 12 be determined.

In the in the 6th example shown are the transmit signals 18th each on one object 16 reflected. The individual signal pattern parts 35 at different points on the surface of the object 16 reflected. Some signal pattern parts 35 , for example in the 6th the signal pattern part 35 in the right column of the transmit signal pattern 36 , shines on the object 16 over and is not reflected. The object is exemplary in the example shown 16 oblique to the transmission signal propagation main axis 19th aligned. In this way the signal pattern parts meet 35 at different distances from the laser scanner 12 and thus at different times on the object 16 . The received signals 20th each have the reflected signal pattern parts 35 according to the transmission signal pattern 36 the corresponding transmission signals 18th on.

With the respective active reception areas 42 of the sensor 32 become the corresponding signal pattern parts 35 the received signals 20th receive. The signal pattern part is exemplary 35 from the in the 6th first column from the left received first at a point in time t1. The signal pattern part 35 from the second column from the left is received second at a point in time t2. The signal pattern part 35 from the third column from the left is received as the third at a time t3. The signal pattern part 35 As already mentioned above, the fourth column from the left does not become attached to the object 16 reflected and therefore cannot be received. This marks the signal pattern part 35 the first column from the left shows the time t1 for the generation of the first charge carriers. At time t2, charge carriers continue to be generated in the first column from the left.

During the corresponding measuring cycle 60 become the contents of the reception areas 42 , if necessary with the active reception areas 42a generated charge carriers, as already described above, in the sliding direction 44 for example in four cycles to the readout stage 48 pushed. In the 6th four clock cycles are shown by way of example at times t1 to t5, in which the contents, if the charge carriers are present, of the receiving areas 42 successively to the selection level 48 is pushed. With the selection level 48 the corresponding charge carriers are sent to the analog-digital converter 50 supplied, with the corresponding digital signals are generated.

From the transit time between the transmission of the transmission signal 18th and receiving the corresponding signal pattern part 35 of the received signal 20th becomes the distance of the corresponding reflection point of the object 16 at which the signal pattern part 35 was reflected to the laser scanner 12 certainly.

Optionally, on the recipient's side 22nd several, preferably all, received signal pattern parts 35 of the received signal 20th be summarized. In this way, greater sensitivity can be achieved. Signal sample parts can also be used in this way 35 of received signals 20th working on an object 16 reflected at greater distances can be received. Once the object 16 the laser scanner 12 approaches, the individual signal pattern parts can also 35 with the corresponding reception areas 42 recognized separately.

The received signal sample parts 35 can be done regularly, for example every clock cycle of the receiver 22nd , can be summarized. The summary of the signal pattern parts 35 can be used as a further receiving channel, in the embodiment shown, in which the receiver 22nd four Receiving channels has, as a fifth receiving channel, in addition to the other receiving channels in which the received signal pattern parts 35 individual are recovered, processed.

The use of a 4 × 4 matrix for coverage areas 34 on the side of the sender 24 and for reception areas 42 on the part of the recipient 22nd is only exemplary. There can also be more or fewer columns and / or rows of transmission areas 34 and reception areas 42 to be available. The arrangement of the transmission areas 34 and / or reception areas 42 can also be rectangular instead of square. The number of rows and / or columns on the sender side 24 can also be larger or smaller than the number of rows and / or columns on the receiver side 22nd .

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 9869754 B1 [0003]

Claims (14)

Method for determining at least one item of position information of at least one object (16) in a monitoring area (14) with an optical detection device (12), in which - at least one optical transmission signal (18) with a transmission signal main axis (19) in the monitoring area (14) - at least part (35) of the at least one transmission signal (18) is reflected as a received signal (20) on an object (16) possibly present in the monitoring area (14) and at least a part (35) of the received signal (20) whose main reception signal propagation axis (21) runs parallel or coaxially to the main transmission signal propagation axis (19) at least on the side facing the object (16), - from the at least one part (35) of the at least one reception signal (20) at least one item of position information of the at least one object (16) is determined, characterized in that - the at least one transmission signal (18) with a Sen designal pattern (36) is generated, the transmission signal pattern (36) being varied in temporally following measurement cycles (60) at least in one direction which runs transversely to the transmission signal main axis (19) of the at least one transmission signal (18), - the at least one Part (35) of the at least one received signal (20) is received in accordance with the transmission signal pattern (36) and assigned to the at least one transmission signal (18). Procedure according to Claim 1 , characterized in that the transmission signal pattern (36) is changed for at least two successive transmission signals (18). Procedure according to Claim 1 or 2 , characterized in that the at least one transmission signal pattern (36) is varied in two mutually orthogonal directions which run transversely to the transmission signal main axis (19). Method according to one of the preceding claims, characterized in that - at least one receiver (22) for receiving the at least one part (35) of the at least one received signal (20) at least in a direction which is transverse to the main axis (21) of the received signal propagation of the at least a received signal (20), each having limited receiving areas (42) which are active for reception during a readiness to receive the at least one part (35) of the at least one received signal (20) in accordance with the transmit signal pattern (36) of the associated at least one transmit signal (18) - and / or at least one transmitter (24) for transmitting the at least one transmission signal (18) at least in one direction which runs transversely to the transmission signal propagation main axis (19) of the at least one transmission signal (18) each has separate transmission areas which be activated according to the transmission signal pattern (36). Method according to one of the preceding claims, characterized in that the direction of the main transmission signal propagation axis (19) of at least two successive transmission signals (18) and the direction of the main reception signal propagation axis (21) are varied at least in the monitoring area (14). Method according to one of the preceding claims, characterized in that the main transmission signal propagation axis (19) of the transmission signals (18) and the main reception signal propagation axis (21) are set with at least one deflection device (26). Procedure according to Claim 6 , characterized in that a setting of the deflection device (26) before, during or immediately after the transmission of the at least one transmission signal (18) is used to determine its transmission direction. Procedure according to Claim 6 or 7th , characterized in that a setting of the deflection device (26) is continuously changed over several measuring cycles (60). Method according to one of the preceding claims, characterized in that from the transit time of the at least one transmission signal (18) and the corresponding at least one part (35) of the at least one reception signal (20) a distance of the at least one object (16) relative to the detection device ( 12) is determined. Method according to one of the preceding claims, characterized in that the at least one part (35) of the at least one received signal (20) is received with a two-dimensional receiver (22) and at least one receiving area (42) which is not active in terms of reception as a buffer for one with the at least a part (35) of the at least one received signal (20) generated signal variable is used. Method according to one of the preceding claims, characterized in that several received parts (35) of the at least one received signal (20) are combined on the side of the receiver (22). Optical detection device (12) for determining at least one item of position information at least one object (16) in a monitoring area (14), - with at least one transmitter (24) for generating at least one optical transmission signal (18) which can be transmitted into the monitoring area (14) with a transmission signal propagation main axis (19), - With at least one receiver (22) for receiving at least a part (35) of at least one received signal (20), which consists of at least a part (35) of the at least one transmitted signal (18), which is optionally present in the monitoring area (14) Object (16) is reflected, a received signal propagation main axis (21) of the at least one received signal (20) at least on the side facing the object (16) running parallel or coaxially to the transmission signal propagation main axis (19) - and with at least one Control and evaluation device (28) for controlling the at least one transmitter (24) and the at least one receiver (22) and for determining at least one position information from a transit time of the at least one transmission signal (18) and the at least one part (35) of the at least one reception signal (20) and / or from a direction of the at least one transmission signal (18) and / or from a direction of the at least one part ( 35) of the at least one received signal (20), characterized in that the at least one transmitter (24) has a plurality of transmission areas (34) which are arranged next to one another in at least one direction which runs transversely to the main transmission signal propagation axis (19) and which can be actively controlled for transmission at least partially separately from one another, - and the at least one receiver (22) has several reception areas (42) which are arranged next to one another in at least one direction that runs transversely to the main axis of reception signal propagation (21) and which are at least can be actively controlled in part separately from each other in terms of reception. Detection device according to Claim 12 , characterized in that the at least one transmitter (24) has at least one diode laser with several separately activatable transmission areas (34) and / or several diode lasers, which each form at least one activatable transmission area. Detection device according to Claim 12 or 13 , characterized in that the at least one control and evaluation device (28) for performing the method according to one of the Claims 1 to 11 is designed.

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