CN112904342A

CN112904342A - Sensor system and method for operating a sensor system

Info

Publication number: CN112904342A
Application number: CN202011412148.8A
Authority: CN
Inventors: B·卢卡斯; M·菲舍尔; M·克拉尔; V·格罗斯
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-12-04
Filing date: 2020-12-04
Publication date: 2021-06-04
Also published as: DE102019218834A1

Abstract

The invention relates to a sensor system for a motor vehicle having first and second corner radar sensors, which emit first and second radar signals and generate corresponding first and second radar signals. Second radar measurement signal. The analysis and processing device receives the first radar measurement signal and the second radar measurement signal and performs analysis and processing on these radar measurement signals. The actuating device actuates the corner radar sensor in at least two actuation modes, wherein the directional characteristics of the corner radar sensor are different for different actuation modes.

Description

Sensor system and method for operating a sensor system

Technical Field

The invention relates to a sensor system for a motor vehicle and a method for operating a sensor system for a motor vehicle.

Background

Autonomous driving or driver assistance systems require good detection of the surroundings, including detection and classification of objects. For sufficient vehicle safety, braking response to passing traffic (querenden verber) including pedestrians and cyclists is required. These functions require the following sensing means: the sensor device is capable of detecting not only the central region of the motor vehicle, but also lateral regions of the motor vehicle at distances of up to approximately 100 m.

An exemplary method for distance and speed measurement by means of FMCW radars is known from EP 1554602B 1.

Current sensor configurations typically include two corner radar sensors (Eckradarsensor) in the front region, a centrally mounted front radar, and a forward oriented video camera. In addition to the emergency braking function, other comfort functions, such as Automatic Cruise Control (ACC), highway assistance, traffic congestion assistance, etc., are provided by means of the sensor group. For these functions, a higher sensor range and angular accuracy in the central region is generally required. For example, a range of approximately 200 meters should be achieved, wherein the angular accuracy should be less than 1 degree. Since all four sensors are typically networked to fuse data, this configuration incurs a corresponding networking overhead in addition to hardware and installation costs.

Disclosure of Invention

The invention provides a sensor system for a motor vehicle and a method for operating a sensor system for a motor vehicle.

The preferred embodiment is a corresponding further development.

According to a first aspect, the invention therefore relates to a sensor system for a motor vehicle, having a first corner radar sensor for arrangement in a first corner region of the motor vehicle, wherein the first corner radar sensor is designed to emit a first radar signal and to generate a corresponding first radar measurement signal. The sensor system further comprises a second corner radar sensor for arrangement in a second corner region of the motor vehicle, wherein the second corner radar sensor is designed to emit a second radar signal and to generate a corresponding second radar measurement signal. The sensor system further comprises an evaluation device, which is designed to receive and evaluate the first radar measurement signal and the second radar measurement signal. The sensor system further comprises a control device, which is designed to control the corner radar sensor and the evaluation device. The control device controls the corner radar sensor in at least two control modes, wherein the directional characteristic of the corner radar sensor differs for different control modes.

According to a second aspect, the invention relates to a method for operating a sensor system for a motor vehicle, wherein the sensor system has a first corner radar sensor in a first corner region of the motor vehicle, wherein the first corner radar sensor emits a first radar signal and generates a corresponding first radar measurement signal, wherein the sensor system has a second corner radar sensor in a second corner region of the motor vehicle, wherein the second corner radar sensor emits a second radar signal and generates a corresponding second radar measurement signal, and wherein the sensor system has an evaluation device which receives and evaluates the first radar measurement signal and the second radar measurement signal. The method comprises the following steps: in a first operating mode, the corner radar sensor and the evaluation device are operated, wherein the corner radar sensor has a first directional characteristic. Furthermore, the corner radar sensor and the evaluation device are controlled in at least one second control mode, wherein the corner radar sensor has a second directional characteristic that differs from the first directional characteristic.

THE ADVANTAGES OF THE PRESENT INVENTION

The invention makes it possible to monitor a plurality of regions by means of a reduced sensor group consisting of only two corner radar sensors and optionally a vehicle camera. The different directional characteristics can be set, for example, by using different antennas or by corresponding modulation. The directional characteristic is understood to be the angular dependence of the strength of the transmitted radar signal.

In accordance with an embodiment of the sensor system, the control device is designed for controlling the corner radar sensor and the evaluation device in a first control mode in such a way that a first detection region is detected, which comprises a lateral region of the motor vehicle. The control device is also provided for controlling the corner radar sensor and the evaluation device in a second control mode in such a way that a second detection region is detected, wherein the second detection region extends further in a central region in front of the motor vehicle than the first detection region. The control device is also designed to control the corner radar sensor and the evaluation device in a third control mode in such a way that a third detection region is detected, wherein the third detection region extends further in a central region in front of the motor vehicle than the second detection region. The sensor system is thus able to detect completely the lateral regions of the motor vehicle and the central region of the motor vehicle. Hardware and installation costs and networking overhead can thereby be reduced, for example by approximately a quarter.

In a first operating mode, a lateral region of the motor vehicle is detected, so that in particular a braking response to traffic is possible. In a second operating mode, a central region in front of the motor vehicle is detected. In a third operating mode, an additionally expanded central region in front of the motor vehicle is detected.

According to one embodiment of the sensor system, the modulation of the transmitting antenna of the corner radar sensor is different in the different steering modes, in particular in the second and third steering modes. For switching between different steering modes, antenna switching means, i.e. different selections of the transmit antennas, may also be provided.

According to one embodiment of the sensor system, the corner radar sensor has at least one first transmitting antenna and at least one second transmitting antenna, wherein the first transmitting antenna detects a side region of the motor vehicle, wherein the second transmitting antenna has a main lobe in a central region in front of the motor vehicle. The first transmitting antenna can be used in particular for detecting the lateral area in the first operating mode. The second transmitting antenna can be used in particular for detecting a central region in front of the motor vehicle.

According to one embodiment of the sensor system, in the first steering mode, for each corner radar sensor, the at least one first transmitting antenna and the at least one second transmitting antenna operate simultaneously.

According to one embodiment of the sensor system, in the second operating mode, the at least one first transmitting antenna is suspended for a predetermined measuring period. The second transmitting antenna is therefore used to perform a robust measurement, so that more measurement data are available for the central area. Additionally, it is also possible to perform intensive analysis processing on radar data regarding the central area.

According to one embodiment of the sensor system, in the third operating mode, only the at least one second transmitting antenna is operated. Thus only the central region is monitored. This is advantageous in the case of high speeds, since a higher accuracy of the analysis process of the central region can be achieved. At high speeds, the probability of traffic passing through is low, so that the evaluation of the side regions of the motor vehicle can be dispensed with.

According to one embodiment of the sensor system, the main lobe of the at least one second transmitting antenna of the first corner radar sensor overlaps with the main lobe of the at least one second transmitting antenna of the second corner radar sensor. The central region in front of the motor vehicle is therefore preferably monitored by means of two corner radar sensors, so that the accuracy of the evaluation is increased by comparing or fusing the sensor data. Furthermore, it can be provided that the corner radar sensors are synchronized in such a way that they alternately transmit during a measurement pause of the respective other corner radar sensor. In this way the effective measurement cycle time can be halved. Furthermore, the object can be viewed from different angles, which can be taken into account for determining the width of the object, for example in order to calculate an avoidance trajectory.

According to one embodiment of the sensor system, in the first operating mode, the corner radar sensor detects a central region of a range of up to 125 meters in front of the motor vehicle. Additionally or alternatively, in the second operating mode, the corner radar sensor detects a central region of a range of up to 160 meters ahead of the motor vehicle. Additionally or alternatively, in a third operating mode, the corner radar sensor detects a central region of the operating range of up to 200 meters in front of the motor vehicle.

According to one embodiment of the sensor system, the control device is designed to receive a current value of the speed of the motor vehicle. The control device selects the first to third control modes depending on a current value of the speed of the motor vehicle. For example, for speeds less than 100km/h, the steering device may select the first steering mode. For higher speeds, but less than 160km/h, the steering device selects the second steering mode, and for still higher speeds, up to a maximum speed of about 210km/h, the steering device selects the third steering mode.

According to one embodiment of the sensor system, the evaluation device is further designed to perform an elevation angle estimation by evaluating the first radar measurement signal and the second radar measurement signal in the first operating mode and in the second operating mode. The elevation angle estimation may preferably be performed by means of radar data based on measurements of the second transmitting antenna of the corner radar sensor. On the basis of the elevation angle estimate, it is possible to distinguish a drivable object (such as a manhole cover) or a traversable object (such as a bridge) from a real obstacle (such as a vehicle, a two-wheel vehicle or a pedestrian) which is relevant to the importance of the collision. The emergency braking function should only be triggered when such an obstacle occurs.

According to one specific embodiment, the sensor system comprises a vehicle camera which is designed to detect a central region in front of the motor vehicle and to generate a camera measurement signal. The evaluation device is also designed to receive and evaluate the first radar measurement signal, the second radar measurement signal and the camera measurement signal by means of data fusion.

Drawings

The figures show:

FIG. 1 shows a schematic block diagram of a sensor system for a motor vehicle according to an embodiment of the present invention;

FIG. 2 shows a schematic top view of a motor vehicle with a sensor system according to an embodiment of the invention;

FIG. 3 shows a schematic view of a detection zone;

fig. 4 shows a flow chart of a method for operating a sensor system for a motor vehicle.

Throughout the drawings, identical or functionally identical elements and devices are provided with the same reference numerals.

Detailed Description

Fig. 1 shows a schematic block diagram of a sensor system 1 for a motor vehicle. The sensor system 1 comprises a first corner radar sensor 2 and a second corner radar sensor 3, however preferably no central radar sensor.

The

corner radar sensors

2, 3 are arranged in a first or a second corner region of the motor vehicle. Preferably, the

corner radar sensors

2, 3 relate to front radar sensors, i.e. the

corner radar sensors

2, 3 are arranged in the front corner region of the motor vehicle. The

corner radar sensors

2, 3 may also be rear radar sensors, i.e. the

corner radar sensors

2, 3 are arranged in the rear corner regions of the motor vehicle.

The

corner radar sensors

2, 3 include first and

second transmitting antennas

21, 31, 22, 32 and receiving

antennas

23, 33, respectively. The

first transmitting antenna

21, 31 detects predominantly or substantially only a lateral region of the motor vehicle, while the

second transmitting antenna

22, 32 detects predominantly or substantially only a central region in front of the motor vehicle. The main lobes of the second transmit

antennas

22, 32 preferably overlap.

The first and

second transmitting antennas

21, 22, 31, 32 transmit radar signals, and the receiving

antennas

23, 33 receive the reflected radar signals and output radar measurement signals.

The sensor system 1 also comprises an evaluation device 5, which receives and evaluates the radar measurement signals. The analysis processing means 5 may create, inter alia, radar maps and identify and classify objects.

The sensor system 1 also comprises a vehicle camera 4 which detects a central region in front of the motor vehicle and generates a camera measurement signal. The evaluation device 5 performs a data fusion of the first radar measurement signal, the second radar measurement signal and the camera measurement signal.

The sensor system 1 further comprises a control device 6, which is coupled to the

corner radar sensors

2, 3 and the evaluation device 5.

The operating device 6 can select three different operating modes, in particular based on the speed of the motor vehicle. The first steering mode corresponds to the normal mode and a speed of, for example, up to 100km/h is selected. In the first steering mode, the first and

second transmitting antennas

21, 22, 31, 32 of the

corner radar sensors

2, 3 are operated simultaneously. In the first operating mode, a first detection region is therefore detected, which includes not only the lateral regions of the motor vehicle but also the central region in front of the motor vehicle. In a first operating mode, for example, a central region of a range of up to 120 meters in front of the motor vehicle is detected.

The second steering mode corresponds to the remote area mode and is selected, for example, at a speed of 100km/h up to 160 km/h. In the second operating mode, the first transmitting

antenna

21, 31 of the

corner radar sensor

2, 3 is suspended for a predetermined measuring period. The first transmit

antenna

21, 31 may be suspended, for example, in every second or third measurement period. In the second operating mode, a second detection region is detected, which comprises a central region in front of the motor vehicle, which extends further than the first detection region in the first operating mode, for example to 160 meters.

The third steering mode corresponds to the extended remote area mode and is selected, for example, at a speed of 160km/h up to a maximum speed of about 210 km/h. In the third steering mode, only the

second transmitting antenna

22, 32 of the

corner radar sensor

2, 3 is operated. In a third operating mode, the following central region in front of the motor vehicle is detected: the central area extends further than the second detection area in the second steering mode, for example to 200 meters.

Furthermore, it can be provided that, in a certain speed range, for example between 100 and 160km/h, the first operating mode and the second operating mode are constantly switched or switched (toggle)

In the first and second steering modes, the evaluation device 5 can be steered by the steering device 6 to perform an elevation angle estimation by evaluating the first radar measurement signal and the second radar measurement signal. In the first steering mode, the elevation angle estimation can preferably be performed in each cycle, whereas in the second steering mode, the elevation angle estimation is performed only in a predetermined cycle (e.g. in every second or third cycle).

Fig. 2 shows a schematic top view of a motor vehicle F having a sensor system 1, wherein the sensor system 1 can be configured according to one of the above-described embodiments. The sensor system 1 comprises two

corner radar sensors

2, 3, which are arranged in the front region of the motor vehicle F. Furthermore, the vehicle camera 4 is located in the region of the windshield of the motor vehicle F.

Fig. 3 shows a schematic view of the detection area. The

corner radar sensors

2, 3 are mounted at an angle of about 45 degrees relative to the longitudinal axis of the vehicle. In the first manipulation mode, the first detection area 7 is detected. The first detection region extends predominantly in the lateral region of the motor vehicle over a distance of approximately up to 160 meters. In the central region of the front of the motor vehicle, the first detection region 7 extends to a distance of approximately 125 meters.

In the second and third steering mode, a second and third detection region is detected, which is formed by the detection regions 8, 9 of the

second transmitting antennas

22, 32 of the

corner radar sensors

2, 3. Based on different detected radar data and/or different evaluation of the radar data, a detection region extending to approximately 160 meters in the central region is detected in the second steering mode, and a third detection region extending to a distance of approximately 200 meters is detected in the third steering mode.

Furthermore, the

detection regions

10, 11 of the vehicle camera 4 are shown, which are composed of a short range region 10 with an opening angle of approximately 100 degrees and a long range region 11 with a greater range and a smaller opening angle.

The limits of the detection region shown in fig. 3 are to be understood only schematically and are usually not clearly defined.

Fig. 4 shows a flowchart of a method for operating the sensor system 1 for the motor vehicle F. This method can be applied in particular to the sensor system 1 described above. The sensor system 1 comprises a first corner radar sensor 2 in a first corner region of the motor vehicle F and a second corner radar sensor 3 in a second corner region of the motor vehicle F. The sensor system 1 or the motor vehicle F preferably does not comprise a central radar sensor. The

corner radar sensors

2, 3 emit a first or second radar signal and generate a corresponding first or second radar measurement signal. The sensor system 1 also has an evaluation device 5, which evaluation device 5 receives and evaluates the first radar measurement signal and the second radar measurement signal. The

corner radar sensors

2, 3 can have a first or a

second transmitting antenna

21, 22, 31, 32, which detect the side regions or have a main lobe in the central region of the front of the motor vehicle. The main lobes of the first transmit antenna 21 and the second transmit antenna 31 preferably overlap.

In a first method step S1, the vehicle is moving at a speed of less than 100 km/h. In a first operating mode, the

corner radar sensors

2, 3 are operated in order to detect a first detection region 7, which comprises a lateral region of the motor vehicle F. In the first steering mode, the

first transmission antennas

21, 31 and the

second transmission antennas

22, 32 can be steered simultaneously. In the first operating mode, for example, a central region of a distance of up to 125 meters in front of the motor vehicle F can be monitored. No data analysis processing is performed for the more distant regions. In the first steering mode, the elevation angle estimation is preferably performed in each measurement period. In the first maneuver mode, driver assistance functions may be provided, such as Front Cross Traffic Alert (fCTA), Autonomous Emergency Braking (AEB), Forward Collision Warning (FCW), Automatic Cruise Control (ACC), Traffic Jam Assistance (TJA), highway assistance (HWA), and the like.

In a second method step S2, the vehicle may be moving at a higher speed of up to 160 km/h. In the second operating mode, the

corner radar sensors

2, 3 are operated in order to detect a second detection region, which extends further in the central region in front of the motor vehicle F than the first detection region 7. In the second operating mode, the first transmitting

antenna

21, 31 can be suspended for a predetermined measurement period. In the second steering mode, the elevation angle estimation is preferably performed only during a predefined measurement period. The elevation estimation is suspended for the rest of the measurement period. The elevation estimation may be performed, for example, only in every second or third measurement period. In the second operating mode, driver assistance functions such as AEB, FCW, ACC, FWA may preferably be provided, in particular fewer driver assistance functions may be provided than in the first operating mode.

In a third method step S3, the vehicle may be moving at an even higher speed, the

corner radar sensors

2, 3 being actuated in a third actuation mode. A third detection region is thereby detected, which extends further in the central region in front of the motor vehicle F than the second detection region. In the third steering mode, it is preferably possible to operate only the second transmit

antenna

22, 32. In the third steering mode, elevation angle estimation is preferably not performed. In the third operating mode, driver assistance functions such as ACC may preferably be provided, in particular fewer driver assistance functions may be provided than in the second operating mode.

In order to decide which operating mode to select, the speed of the motor vehicle can be continuously monitored. If the speed exceeds or falls below a predefined threshold value, the respective operating mode is selected or switched.

Claims

1. A sensor system (1) for a motor vehicle (F), said sensor system having:

A first corner radar sensor (2) for arrangement in a first corner region of the motor vehicle (F), wherein the first corner radar sensor (2) configured to transmit a first radar signal and generate a corresponding first radar measurement signal;

A second corner radar sensor (3) for arrangement in a second corner region of the motor vehicle (F), wherein the second corner radar sensor (3) configured to transmit a second radar signal and generate a corresponding second radar measurement signal;

an evaluation device (5) configured to receive and evaluate the first radar measurement signal and the second radar measurement signal;

an actuating device (6), which is designed to actuate the corner radar sensors (2, 3) and the evaluation device (5);

The actuating device (6) is designed to actuate the corner radar sensor (2, 3) in at least two actuation modes, wherein the corner radar sensor (2, 3) is used for different actuation modes. 3) The directional characteristics are different.

2. The sensor system (1) according to claim 1, wherein the actuating device (6) is configured for:

a) In a first actuation mode, the corner radar sensors (2, 3) and the evaluation device (5) are actuated in such a way that a first detection region is detected which includes the motor vehicle ( f) side area;

b) In the second actuation mode, the corner radar sensors (2, 3) and the evaluation device (5) are actuated in such a way that a second detection region is detected, wherein the second detection region is The central area in front of the moving vehicle (F) extends farther than the first detection area;

c) In a third actuation mode, the corner radar sensors (2, 3) and the evaluation device (5) are actuated in such a way that a third detection region is detected, wherein the third detection region is The central area in front of the moving vehicle (F) extends farther than the second detection area.

3. The sensor system (1) according to claim 2, wherein the corner radar sensor (2, 3) has at least two transmit antennas (21, 22, 31, 32), wherein at least one first Transmitting antennas (21, 31) detect the side area of the motor vehicle (F), wherein at least one second transmitting antenna (22, 32) has in the central area in front of the motor vehicle (F) main lobe.

4. The sensor system (1) according to claim 3, wherein, in the first steering mode, for each corner radar sensor (2, 3) the at least one first transmit antenna (21, 3) 31) and the at least one second transmit antenna (22, 32) operate simultaneously.

5 . The sensor system ( 1 ) according to claim 3 , wherein, in the second operating mode, the at least one first transmit antenna ( 21 ) is suspended for a predetermined measurement period. 6 . , 31).

6. The sensor system (1) according to any one of claims 3 to 5, wherein, in the third steering mode, only the at least one second transmit antenna (22, 32) is operated.

7. The sensor system (1) according to any one of claims 3 to 6, wherein the main lobe of at least one second transmit antenna (22) of the first corner radar sensor (2) is identical to all The main lobes of at least one second transmitting antenna (32) of the second corner radar sensor (3) overlap.

8. The sensor system (1) according to any one of claims 2 to 7,

In this case, in the first control mode, the corner radar sensors (2, 3) detect a central area in front of the motor vehicle (F) with a range of up to 125 meters, and/or

In this case, the corner radar sensors (2, 3) in the second operating mode detect a central area in front of the motor vehicle (F) with a range of up to 160 meters, and/or

In this case, the corner radar sensors ( 2 , 3 ) detect a central area in front of the motor vehicle (F) with a range of up to 200 meters in the third actuation mode.

9 . The sensor system ( 1 ) according to claim 2 , wherein the evaluation device ( 5 ) is further designed for, in the first actuation mode and in the second In the second steering mode, the elevation angle estimation is performed by analyzing the first radar measurement signal and the second radar measurement signal.

10. The sensor system (1) according to any one of the preceding claims, further comprising a vehicle camera (4), which is designed to detect all the vehicles in front of the motor vehicle (F). describe the central area and generate camera measurement signals;

The analysis and processing device (5) is further configured to receive and analyze the first radar measurement signal, the second radar measurement signal and the camera measurement signal by means of data fusion.

11. A method for operating a sensor system (1) for a motor vehicle (F), wherein the sensor system has a first corner radar in a first corner region of the motor vehicle (F) Sensor (2), wherein the first corner radar sensor (2) emits a first radar signal and generates a corresponding first radar measurement signal, wherein the sensor system has a second radar signal of the motor vehicle (F) a second corner radar sensor (3) in the corner region, wherein the second corner radar sensor (3) emits a second radar signal and generates a corresponding second radar measurement signal, wherein the sensor system has An analysis and processing device (5), which receives and analyzes the first radar measurement signal and the second radar measurement signal, wherein the method comprises the steps of:

a) operating the corner radar sensor (2, 3) and the evaluation device (5) in a first operating mode, wherein the corner radar sensor (2, 3) has a first directional characteristic;

b) Actuating the corner radar sensor ( 2 , 3 ) and the evaluation device ( 5 ) in at least one second actuation mode, wherein the corner radar sensor ( 2 , 3 ) has a different A second directional characteristic of the first directional characteristic.