WO2016169914A1

WO2016169914A1 - Method for operating an optoelectronic sensor for a motor vehicle with adjustment of the transmission of the transmission signals, optoelectronic sensor, driver assistance system, and motor vehicle

Info

Publication number: WO2016169914A1
Application number: PCT/EP2016/058610
Authority: WO
Inventors: Jochen Schenk; Frank SELBMANN
Original assignee: Valeo Schalter Und Sensoren Gmbh
Priority date: 2015-04-22
Filing date: 2016-04-19
Publication date: 2016-10-27
Also published as: DE102015106140A1

Abstract

The invention relates to a method for operating an optoelectronic sensor (5) for a motor vehicle (1), wherein at least one series of measurements (14) is carried out during a first measuring cycle (M1), during which a predetermined number of transmission signals (8) are transmitted by means of a transmission unit (6) of the optoelectronic sensor (5) within a predetermined angular range (12) and the transmission signals reflected by an object (3) are received by means of a receiving unit (7) of the optoelectronic sensor (5) as received signals (9), wherein a location area (16) for the object (3) within the predetermined angular range (12) is determined by means of the optoelectronic sensor (5) on the basis of the received signals (9) received using the receiving unit (7) during the first measuring cycle (M1), and during a subsequent, second measuring cycle (M2) the transmission of the transmission signals (8) is changed within the location area (16).

Description

Method for operating an optoelectronic sensor for a motor vehicle with adaptation of the transmission of the transmission signals, optoelectronic sensor,

Driver assistance system and motor vehicle

The present invention relates to a method for operating an optoelectronic sensor for a motor vehicle, in which during a first measuring cycle at least one series of measurements is performed, in which by means of a transmitting unit of the

Optoelectronic sensor within a predetermined angular range a predetermined number of transmission signal is emitted and the reflected from an object transmission signals are received by means of a receiving unit of the optoelectronic sensor as received signals. The invention also relates to an optoelectronic sensor for a motor vehicle. In addition, the present invention relates to a driver assistance system and a motor vehicle.

The interest in this case is directed in particular to optoelectronic sensors for motor vehicles. Such optoelectronic sensors can be designed, for example, as lidar sensors (Lidar - Light Detection and Ranging) or as laser scanners. Such optoelectronic sensors are mounted, for example, on motor vehicles in order to detect the environment of the motor vehicle while driving or during operation of the motor vehicle. The optoelectronic sensor is in particular a scanning optical measuring device, by means of which objects or obstacles in an environmental region of the

Motor vehicle can be detected. For example, with the optoelectronic sensor, a distance between the motor vehicle and an object after

Light pulse transit time method are measured. The optoelectronic sensor usually comprises a transmitting unit which has, for example, a laser diode with which an optical transmission signal can be transmitted. In addition, the optoelectronic sensor comprises a corresponding receiving unit, which has, for example, at least one photodiode, by means of which the transmission signal reflected by the object can become a received signal.

With the optoelectronic sensor, the sensor signals are emitted in a predetermined angular range. For deflecting the transmission signals or the laser light within the angular range, the optoelectronic sensor has a deflection device, for example a rotating mirror. The transmission signals can be transmitted as light pulses. Thus, the optoelectronic sensor within the predetermined angular range to a fixed angular resolution, which may be, for example, 0.25 °. In this case, corresponding measuring cycles can be carried out for the detection of objects or obstacles with the optoelectronic sensor. Within a measuring cycle several can

Measurement series or scans are performed in which the transmitting unit in each case emits transmission signals within a predetermined horizontal angle range. Due to the predetermined angular resolution of the optoelectronic sensor, only very few measuring points or received signals are obtained from distant objects. Even with very weakly reflective objects, the number of received received signals is relatively low. This brings disadvantages in particular when the objects detected by the optoelectronic sensor are to be classified.

In this context, US 2009/0273770 A1 describes a lidar system for a motor vehicle. In the system, the transmission signals that are emitted by a laser are automatically adjusted to prevent damage to the eyes of a human being. For example, when an object is detected, the distance between the motor vehicle and the object is determined. If the distance falls below a predetermined threshold value, the transmission power of the laser is automatically reduced. It can also be provided that the laser amplitude, the repetition frequency or the optical intensity is adjusted.

It is an object of the present invention to provide a solution, as objects with an optoelectronic sensor of the type mentioned can be reliably detected.

This object is achieved by a method by a

optoelectronic sensor, by a driver assistance system and by a

Motor vehicle with the features according to the respective independent

Claims solved. Advantageous embodiments of the invention are the subject of the dependent claims, the description and the figures.

An inventive method is used to operate an optoelectronic sensor for a motor vehicle. In this case, at least one measurement series is performed during a first measurement cycle, in which a predetermined number of transmission signals are transmitted within a predetermined angular range by means of a transmission unit of the optoelectronic sensor and the transmission signals reflected by an object be received by means of a receiving unit of the optoelectronic sensor as received signals. Furthermore, a residence area for the object within the predetermined angular range is determined by means of the optoelectronic sensor on the basis of the received signals received by the receiving unit during the first measuring cycle. In addition, in a subsequent, second measurement cycle, the transmission of the

Transmission signals within the occupied area changed.

The optoelectronic sensor is for use on a motor vehicle. The optoelectronic sensor can be designed in particular as a lidar sensor or as a laser scanner. With the optoelectronic sensor can objects in one

Be detected surrounding area of the motor vehicle. In particular, a distance between the motor vehicle and the object can be determined by means of the optoelectronic sensor. In order to detect the object or the obstacle, the optoelectronic sensor is used to generate chronologically successive measuring cycles

carried out. At least one series of measurements is carried out during a first measuring cycle. In particular, in the first measurement cycle, a plurality of

Measurement series carried out. In each of the measurement series, a predetermined number of transmission signals are transmitted within a predetermined angular range by means of the transmission unit. In particular, the transmission signals are transmitted with the transmission unit within a predetermined horizontal angle range. The transmission signals are emitted in particular as laser pulses or light pulses. In this case, the laser light is deflected along the predetermined angular range with the aid of a corresponding deflection device, for example with the aid of a rotating mirror. Thus, within the predetermined angular range at discrete angular positions, which are distributed uniformly in particular in the angular range, transmit signals are emitted. These transmission signals are reflected by the object and then arrive again as received signals to a receiving unit of the optoelectronic sensor. In this case, one or more echoes can be received as received signals from a transmitted transmission signal. The receiving unit may for example comprise a corresponding photodiode.

With the optoelectronic sensor is determined based on the received signals that are received during the first measurement cycle, a residence area. This

Location area defines a range within the predetermined angular range in which an object is located or in which a high

Probability the object exists. In a second measurement cycle, which follows the time of the first measurement cycle, then the transmission of the transmission signals within of the occupied area adapted or changed. In particular, the transmission signals or the transmission of the transmission signals are adapted so that more information about the object can be obtained within the location area compared to the first measurement cycle in the second measurement cycle. Thus, the transmission of the transmission signals can be dynamically adjusted based on the information obtained during the first measurement cycle. Thus, it may be possible, for example, distant objects and / or weak

to detect reflective objects more reliably.

Preferably, to vary the transmission of the transmission signals, a number of the transmission signals which are transmitted in the location area are increased. Thus, the number of transmission signals transmitted in the location area can be increased as compared with the area of the angle area other than the location area. In other words, an emission rate or a pulse rate of the transmission unit or the laser diode can be increased for the location area. Alternatively or additionally, the control of the deflection can be adjusted. For example, a rotating mirror, which serves as a deflector, can be operated at a lower rotational speed. Thus, more transmit signals are emitted in the direction of the object within the location area. This can be obtained from the object more scan points or received signals. Thus, the object can be detected more reliably.

In a further embodiment, to change the transmission of the

Transmission signals in the second measuring cycle a first and at least a second

Measurement series carried out, wherein a beginning of the transmission of the predetermined number of transmission signals in the at least one second measurement series compared to the first measurement series is carried out with a predetermined time offset. In other words, the pulse times can be offset in succession in successive measurement series or scans. Thus, it can be achieved that in temporally successive measurement series of the second measurement cycle, the object can be detected with a high angular resolution.

In a further embodiment, in the first measurement series a first number of transmission signals and in the case of the at least one second measurement series a second number of transmission signals different from the first number are transmitted. Previously, the first option for adjusting the transmission of the transmission signals was called increasing the number of transmission signals. Furthermore, as a second option, the time shift of the Transmission of the transmission signals in successive measurement series called. In the present case, the first and second options are combined. Thus, during the second measurement cycle, the number of transmission signals can be increased in each of the measurement series compared to the first measurement cycle. In addition, the

Transmit signals are emitted in the temporally successive measurement series with a temporal offset to each other. Thus, the respective angular range, in which the transmission signals are emitted during the measuring ranges, to each other

be moved. It can also be provided that the first option and the second option in successive measurement series alternately or according to a

Random distribution are performed. Thus, it can be achieved that the object or obstacle can be detected more reliably.

Furthermore, it is advantageous if based on the received signals by means of

optoelectronic sensor, a distance between the optoelectronic sensor and the object is determined and the adjustment is performed if the determined distance exceeds a predetermined minimum distance. In order to ensure laser safety, the adaptation of the transmission signals can be activated, for example, only if the object has a minimum distance to the motor vehicle and no further object in the vicinity is to be expected in this area. In this way, the optoelectronic sensor can be operated safely and reliably.

In a further embodiment, a movement of the object is determined by means of the optoelectronic sensor on the basis of the received signals, and the location area is determined on the basis of the determined movement of the object. For example, a current position of the object can be determined for each measurement cycle or for each measurement series on the basis of the received signals. Based on the positions, a

Relative movement of the object are determined to the motor vehicle. For example, in particular a direction of movement and / or a speed of movement of the object can be determined. This information can now be used to adjust the accommodation area accordingly.

Furthermore, it is advantageous if a number of the transmission signals in the second measuring cycle is reduced in comparison to the first measuring cycle in a region of the angular range which is different from the location region. In other words, in the second measuring cycle, the number of transmission signals for the location area can be increased and reduced in the remaining area. In particular, the number of

Transmitting signals in the residence area and in the area of residence different range in the second measurement cycle can be adjusted so that by transmitting a predetermined transmission power is exceeded. In other words, so that the overall performance is not exceeded, additional laser pulses can be saved at a suitable location. Thus it can be achieved that the

Total transmission power does not exceed a predetermined value and thus

Living things are not endangered by the laser beams.

The residence area is preferably predetermined within a horizontal and / or a vertical angle range. For example, it may be provided that transmission signals are transmitted along a horizontal angle range during a measurement series. In a further measurement series, the transmission signals can then be transmitted in a further horizontal angle range, which is vertically offset in comparison to that of the preceding series of measurements. The residence area can be specified either for horizontal or for vertical angle ranges. It can also be provided that the residence area is specified for both horizontal and vertical angle ranges.

Furthermore, it is advantageous if the object is classified on the basis of the received signals, which are received in the second measuring cycle with the receiving unit. Thus, for example, a corresponding arithmetic unit can be provided with which a classification of the object is carried out on the basis of the received received signals. The arithmetic unit can be part of the optoelectronic sensor, for example. Preferably, the arithmetic unit is part of a driver assistance system or part of the motor vehicle. The arithmetic unit, for example, by an electronic

Control unit be formed. The arithmetic unit can perform a corresponding comparison of the received received signals with differential received signals. Thus, for example, the object can be classified as a motor vehicle, two-wheeler, pedestrian or the like.

An inventive optoelectronic sensor for a motor vehicle is for

Performing a method according to the invention formed. The optoelectronic sensor can be designed in particular as a lidar sensor or as a laser scanner. The optoelectronic sensor may have a transmitting unit for transmitting the transmitting signals and a receiving unit for receiving the receiving signals. In addition, the optoelectronic sensor can have a corresponding deflection unit, for example a rotating mirror, with which the transmission signals within the

Angle range can be deflected. In addition, the optoelectronic sensor have a corresponding arithmetic unit, by means of which the transmission of the transmission signals can be controlled. In addition, with the arithmetic unit of

Resident area are determined by the received signals.

A driver assistance system according to the invention comprises an optoelectronic sensor according to the invention. For example, a distance to an object or obstacle in an environmental region of the motor vehicle can be detected with the optoelectronic sensor.

A motor vehicle according to the invention comprises an inventive

Driver assistance system. The motor vehicle is designed in particular as a passenger car.

The preferred embodiments presented with reference to the process according to the invention

Embodiments and their advantages apply correspondingly to the optoelectronic sensor according to the invention, the driver assistance system according to the invention and the motor vehicle according to the invention.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description, as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures, are not only in the respectively indicated combination but also in others

Combinations or alone, without departing from the scope of the invention. Thus, embodiments of the invention are to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, however, emerge and can be produced by separated combinations of features from the embodiments explained. Embodiments and combinations of features are also to be regarded as disclosed, which thus do not have all the features of an originally formulated independent claim.

The invention will now be described with reference to preferred embodiments and with reference to the accompanying drawings.

Showing: Fig. 1 A motor vehicle according to an embodiment of the present invention, which is a driver assistance system with a

having optoelectronic sensor;

FIGS. 2 to 6 are tabular representations which describe a transmission of transmission signals of the optoelectronic sensor during a measurement cycle;

FIG. 7 shows a surrounding area of the motor vehicle; FIG.

FIGS. 8 and 9 are diagrams spatially describing measurement signals of the optoelectronic sensor.

In the figures, the same and functionally identical elements are the same

Provided with reference numerals.

1 shows a motor vehicle 1 according to an embodiment of the present invention

Invention. The motor vehicle 1 is in the present embodiment as

Passenger cars trained. The motor vehicle 1 comprises a

Driver assistance system 2. With the driver assistance system 2, for example, an object 3, which is located in a surrounding area 4 of the motor vehicle 1, are detected. In particular, a distance between the motor vehicle 1 and the object 3 can be determined by means of the driver assistance system 2.

The driver assistance system 2 comprises an optoelectronic sensor 5. The optoelectronic sensor 5 may be designed as a lidar sensor. Preferably, the optoelectronic sensor 5 is designed as a laser scanner. The optoelectronic

Sensor 5 comprises a transmitting unit 6, with which a transmission signal 8 in the form of an optical signal or in the form of laser light can be emitted. The

Transmitting unit 6 may comprise, for example, a laser diode. With the transmission unit 6, the transmission signals 8 within a predetermined angular range 12th

to be sent out. For example, the transmission signal 8 can be transmitted in a predetermined horizontal angle range. The optoelectronic sensor 5 or the transmitting unit 6 further comprises a not shown here

Deflection device, such as a rotating mirror with which the transmission signals 8 can be deflected within the angular range 12. During a measurement cycle M1, M2 of the optoelectronic sensor 5, a plurality of measurement series 14 can be performed become. In this case, a predetermined vertical section in the surrounding area 4 can be examined for each measurement series 14.

In addition, the optoelectronic sensor 5 comprises a receiving unit 7, which may comprise, for example, a photodiode. With the receiving unit 7, the reflected from the object 3 transmission signal 8 can be received as a received signal 9.

In addition, the optoelectronic sensor 5 comprises a computing unit 10, which may be formed for example by a microcontroller or a digital signal processor. With the arithmetic unit 10, the transmitting unit 6 can be driven to transmit the transmission signal 8. In addition, the arithmetic unit 10 can evaluate the receive signals 9 received by the receiving unit 7. The

Driver assistance system 2 further comprises a control device 1 1, which may be formed for example by an electronic control unit of the motor vehicle 1.

Figures 2 to 6 each show in tabular view the sending of the

Transmitting signals 8 for different angular positions within the angular range 12. FIG. 2 shows a first measurement cycle M1. In this case, individual angular positions 13 within the angular range 12 are shown in the first line. The single ones

In the present case, angular positions 13 show a section of the angular range 12 and extend between -72.50 ° and -72.0 ° in the range of 0.05 °. The selected section of the angle range 12 is chosen here purely by way of example. Even the steps of 0.05 ° are chosen as examples. It may also be provided that the successive steps are not the same. The successive steps could also be 0.04 °, 0.06 °, 0.04 ° and so on. The individual angular positions 13 are assigned in particular to horizontal angular ranges. The individual lines of the table describe respective measurement series 14 which are carried out with the optoelectronic sensor 5 during the measurement cycle M1, M2. The individual areas, which are marked with a plus sign, describe the angular positions 13 at which a transmission signal 8 is transmitted. The remaining areas, which are marked with a minus sign, describe the angular ranges 13 at which no transmission signal 8 is transmitted. In addition, the table shows a column 15, in which the measurement series 14 are marked, in which an object 3 was detected. The measurement series 14, in which an object 3 was detected, are marked with an x. The measurement series 14, in which no object 3 was detected, are marked with a minus sign.

FIG. 2 shows, by way of example, the first measuring cycle M1 in which, within the

Angle range 12 at intervals of 0.25 ° a transmission signal 8 is emitted. Also Here are the distances of 0.25 ° exemplified besti mmt. Present is at the

Measurement series 14, which are marked with B to F, an object 3 detected. By means of the arithmetic unit 10, these measurement series 1 are assigned to a location area 16. The residence area 16 describes the area within the angle range 12 in which the object 3 is or in which an elevated

Residence probability for the object 3 is present. In the present case, the residence area 16 is assigned to individual measurement series 14. It can also be provided that the residence area is assigned to individual angular areas 13.

Figures 3 to 6 also show in tabular view the sending of the

Transmission signals 8 for second measuring cycles M2. The second measuring cycles M2 follow in time on the first measuring cycle M1. In the second measuring cycles M2, the transmission of the transmission signals 8 in the measurement series 14, which are assigned to the location area 16, is adapted.

FIG. 3 shows a first option for modifying the transmission of the transmission signals 8 in the location area 16. In this case, the measurement series which are identified by A, G and H

are marked, not changed. Instead of the measurement series B to F, the measurement series B2 to F2 are performed. In this case, the number of transmission signals 8 transmitted per measurement series 14 is increased. In the present example, the transmission signals 8 are output at angular intervals of 0.10 °. Thus, it can be achieved that the object 3 can be detected more accurately.

4 illustrates a second option based on the tabular view for changing the transmission of the transmission signals 8 in the location area 16. Here, the measurement series B3 to F3 are compared with the first measurement cycle M1. In the present case, a beginning of the respective transmission of the sequence of transmission signals 8 in successive measurement series 14 is shifted by 0.05 ° in each case. The value of 0.05 ° represents a possible variant. In the measurement series 14, which are identified by B3 to F3, this allows a more accurate detection of the object 3.

FIGS. 5 and 6 describe further variants of varying the transmission of the transmission signals 8 in the second measuring cycle M2. In this case, the first option, ie the increase of the number of transmission signals 8, and the second option, as or temporal offset of the transmission between consecutive measurement series 14, are combined. The first and the second option can take place in successive measurement series 14 alternately or according to a random distribution. Fig. 5 shows an example in which the first and the second option combined. Here, instead of the measurement series B to F, the measurement series B4 to F4 are performed. In the example of FIG. 6, the first and second options for the measurement series 14 are determined based on a random distribution. In this case, instead of the measurement series B to F, the measurement series B5 to F5 are performed.

FIG. 7 shows the surrounding area 4 of the motor vehicle 1, in which a further motor vehicle is located as the object 3 on a road in the direction of travel in front of the motor vehicle 1. The object 3 may for example be a motor vehicle which is relatively far away from the motor vehicle 1 and also has a low reflectivity with respect to the transmission signal 8. For example, the object 3 may be a black motor vehicle. In addition, two guide posts 17 are located in the surrounding area 4 of the motor vehicle 1.

FIG. 8 shows measuring signals 18 which were determined by the arithmetic unit 10 on the basis of the received signals 9 during the first measuring cycle M1. The measurement signals 18 are plotted with respect to two spatial directions R1 and R2. R1 may be the horizontal direction with respect to the motor vehicle 1, and R2 may be the vertical direction with respect to the motor vehicle 1. The measurement signals 18 are assigned to a first region 19 of the object 3 or the motor vehicle. The measurement signals 18 in the second regions 20 are assigned to the guide post 17.

In comparison, Fig. 9 shows the measurement signals 19 at a second measurement cycle M2, which was carried out according to one of the previously described methods. It can be seen here that in the first region 19, the number of measuring signals 18 has doubled. Thus, for example, a classification of the object 3 can be performed more accurately. The classification can, for example, with the control device 1 1

be performed. Thus, the object 3 can be classified as a motor vehicle in the second measurement cycle M2. If only the measurement signals 18 of the first measurement cycle M1 according to FIG. 8 are available, there is a risk that the object

for example, classified as a motorcycle.

Claims

claims

1 . Method for operating an optoelectronic sensor (5) for a

Motor vehicle (1), in which during a first measurement cycle (M1) at least one measurement series (14) is performed, in which by means of a transmitting unit (6) of the optoelectronic sensor (5) within a predetermined angular range (12) a predetermined number of transmission signals ( 8) and the transmission signals (8) reflected by an object (3) by means of a receiving unit

(7) of the optoelectronic sensor (5) are received as receive signals (9),

characterized in that

by means of the optoelectronic sensor (5) on the basis of the received signals (9) received by the receiving unit (7) during the first measuring cycle (M1), a residence area (16) for the object (3) within the predetermined one

Angle range (12) is determined and at a subsequent, second

Measuring cycle (M2) the transmission of the transmission signals (8) within the

Stay area (16) is changed.

2. The method according to claim 1,

characterized in that

for changing the transmission of the transmission signals (8) a number of

Transmission signals (8), which are transmitted in the residence area (16) is increased.

3. The method according to claim 1 or 2,

characterized in that

for changing the transmission of the transmission signals (8) in the second measuring cycle (M2) a first and at least one second series of measurements (14) are performed, wherein a beginning of the transmission of the predetermined number of transmission signals

(8) takes place in the at least one second measurement series (14) in comparison to the first measurement series (14) with a predetermined time offset.

4. The method according to claim 3,

characterized in that in the first measurement series (14), a first number of transmission signals (8) and in the case of the at least one second measurement series (14), a second number of transmission signals (8) different from the first number are transmitted.

5. Method according to one of the preceding claims,

characterized in that

a distance between the optoelectronic sensor (5) and the object (3) is determined on the basis of the received signals (9) by means of the optoelectronic sensor (5) and the adaptation of the transmission signals (8) is carried out if the determined distance exceeds a predetermined minimum distance.

6. The method according to any one of the preceding claims,

characterized in that

a movement of the object (3) is determined by means of the optoelectronic sensor (5) on the basis of the received signals (9) and the location area (16) is determined on the basis of the determined movement of the object (3).

7. The method according to any one of the preceding claims,

characterized in that

in a different area of the residence area (16)

Angle range (12) a number of the transmission signals (8) in the second measuring cycle (M2) compared to the first measuring cycle (M1) is reduced.

8. The method according to claim 7,

characterized in that

the number of transmit signals (8) in the location area (16) and in the area other than the location area (16) is changed in the second measurement cycle (M2) so that the transmit power falls below predetermined transmission power.

9. The method according to any one of the preceding claims,

characterized in that

the residence area (16) is specified within a horizontal and / or vertical angle range.

10. The method according to any one of the preceding claims,

characterized in that

the object (3) is classified on the basis of the received signals (9) which are received by the receiving unit (7) in the second measuring cycle (M2).

1 1. Optoelectronic sensor (5) for a motor vehicle (1), which is designed to carry out a method according to one of the preceding claims.

12. Optoelectronic sensor (5) according to claim 1 1,

characterized in that '

the optoelectronic sensor (5) is designed as a lidar sensor or as a laser scanner.

13. Driver assistance system (2) for a motor vehicle (1) having an optoelectronic sensor (5) according to claim 11 or 12.

14. Motor vehicle (1) with a driver assistance system (2) according to claim 13.