Method for detecting road users

Abstract

The invention relates to a method for detecting road users along at least one traffic route, wherein the method comprises the following steps: emitting transmission signals by means of at least one transmission device for radar radiation, detecting received signals by means of at least one reception device for radar radiation, mixing the transmission signals and the received signals to produce baseband signals and calculating a detection matrix from the baseband signals and evaluating the detection matrix in an evaluation module of an electronic data processing device, wherein peaks of the detection matrix are assigned to objects, checking whether a disturbance criterion is met in a diagnostic module, generating signals from the results of the evaluation in the evaluation module and the check in the diagnostic module, and transmitting the signals to a control module of an electronic data processing device.

Claims

1. A method for detecting road users along at least one traffic route, comprising: emitting transmission signals by at least one transmission device for radar radiation, detecting received signals by at least one reception device for radar radiation, mixing the transmission signals and the received signals to produce baseband signals and calculating a detection matrix from the baseband signals and evaluating the detection matrix in an evaluation module of an electronic data processing device, wherein peaks of the detection matrix are assigned to objects, checking whether a disturbance criterion is met in a diagnostic module, generating signals from the results of the evaluation in the evaluation module and the check in the diagnostic module, and transmitting the signals generated in the generating step to a control module of the electronic data processing device.

2. The method according to claim 1, wherein a disturbance criterion is met when rain and/or snow is detected during evaluation of the detection matrix.

3. The method according to claim 1, wherein the step of calculating a detection matrix calculates a plurality of detection matrices, and wherein the plurality of detection matrices are successively evaluated so that objects can be assigned an actual trajectory and a disturbance criterion is met if a predetermined number of actual trajectories do not follow a target trajectory stored in an electronic database.

4. The method according to claim 1 further comprising detecting a maximum, a minimum, an average signal-to-noise ratio and/or a median signal-to-noise ratio from signal-to-noise ratios of selected peaks of the detection matrix, and wherein a disturbance criterion is met when the maximum, the minimum, the average signal-to-noise ratio and/or the median signal-to-noise ratio is below a predetermined limit.

5. The method according to claim 1 further comprising determining, during the evaluation of the detection matrix, a radar cross-section of selected objects, and wherein a disturbance criterion is met if a maximum, a minimum, an average radar cross-section, and/or a radar-cross section is smaller than a predetermined limit.

6. The method according to claim 1 wherein the at least one reception device has a plurality of receiving antennae, and a standard deviation of the phase differences between in each case two receiving antennae of the plurality of receiving antennae is calculated for selected peaks or objects, and a disturbance criterion is met if a largest, a smallest, an average standard deviation, and/or a median of standard deviations exceeds a predetermined limit.

7. The method according to claim 1 further comprising determining a number of objects to which at least one peak of the detection matrix has been assigned, and wherein a disturbance criterion is met if the number of objects exceeds a predetermined upper limit.

8. The method according to claim 1 wherein a disturbance criterion is met when an interference intensity of the received signals not consisting of reflected transmission signals exceeds a predetermined limit.

9. The method according to claim 3 wherein a disturbance criterion is met if a weighted sum of a maximum, a minimum, an average signal-to-noise ratio, and/or a median signal-to-noise ratio, a maximum, a minimum, an average radar cross-section, and/or a median radar cross-section, a maximum, a minimum, an average standard deviation, and/or a median standard deviation, a deviation of actual trajectories from target trajectories, an interference intensity and/or a number of the objects exceeds or is below a predetermined limit.

10. The method according to claim 1 wherein each of the at least one transmission device and the at least one reception device are parts of a radar sensor, and wherein a position, and/or an orientation, and/or a velocity, and/or an acceleration of the radar sensor is determined by at least one sensor.

11. The method according to claim 9, wherein a disturbance criterion is met when the position and/or the orientation and/or the velocity and/or the acceleration of the radar sensor deviates from a target value by more than a predetermined limit.

12. The method according to claim 1 wherein the signals generated in the generating step contain evaluation signals containing information about the objects detected during evaluation of the detection matrix when no disturbance criterion is met.

13. The method according to claim 11, wherein the signals contain a diagnostic signal in addition to the evaluation signals, which contains the information that no disturbance criterion is met.

14. The method according to claim 1 wherein the signals generated in the generating step contain a diagnostic signal containing information that a disturbance criterion is met when a disturbance criterion is met.

15. The method according to claim 1 wherein the signals generated in the generating step contain evaluation signals about fictitious objects when a disturbance criterion is met.

16. A sensor for detecting road users along at least one traffic route, the sensor being configured to conduct a method according to claim 1.

17. The sensor according to claim 16, comprising the electronic data processing device with the evaluation module and the diagnostic module.

18. The method according to claim 4 wherein the predetermined limit is 100 dB.

19. The method according to claim 5 wherein the selected objects are moving objects.

20. The method according to claim 6 wherein the two receiving antennae ae in the azimuthal and/or elevation direction, and wherein the predetermined limit is 60°.

21. The method according to claim 14 wherein the diagnostic signal contains no information about the objects.

Description

[0056] In the following, an example of an embodiment of the present invention will be explained in more detail by way of the attached figures: They show:

[0057] FIG. 1—the schematic representation of a device according to an example of an embodiment of the present invention,

[0058] FIG. 2—the schematic evaluation according to the distance of objects,

[0059] FIG. 3—the schematic evaluation according to the radial velocity and reflectivity of objects, and

[0060] FIG. 4 the schematic representation of the testing of a disturbance criterion.

[0061] FIG. 1 schematically depicts a radar sensor 2 that has a transmission device 4. The transmission device 4 is configured to emit transmission signals 6. In FIG. 1, they are reflected by a road user 8 and reflected towards the radar sensor 2 in the form of received signals 10. The road user 8 can be, for example, a pedestrian, a cyclist, a passenger vehicle, a truck or another road user.

[0062] The radar sensor 2 comprises a reception device 12 which is configured to detect the received signals 10. In the example of an embodiment shown in FIG. 1, the radar sensor also has an electronic data processing device 14. This device comprises an evaluation module 16 and a diagnostic module 18. It is advantageous, but not absolutely essential, for the evaluation module 16 and the diagnostic module 18 to be part of the same electronic data processing device 14 or for the electronic data processing device 14 to be part of the radar sensor 2.

[0063] From the reception device 12, the received signals 10 are fed to the evaluation module 16, where the detection matrix is calculated and evaluated. The diagnostic module 18 checks whether a disturbance criterion is met. The results of the evaluation in the evaluation module 16 and the check in the diagnostic module 18 are then used to generate signals that are transmitted to another electronic data processing device 20. This device comprises a control module 22 to which the signals are transmitted along a data connection 24. The control module 22 of the electronic data processing device 20 is configured, for example, to control the flow of traffic along a traffic route by, for example, switching a traffic light system, traffic signs or taking other steps that influence the flow of traffic.

[0064] In a preferred design, the electronic data processing device 20 is also part of the radar sensor 2. It is especially preferable if the electronic data processing device 14 and the electronic data processing device 20 are one and the same data processing device, so that the evaluation module 16, the diagnostic module 18 and the control module 22 are part of a single data processing device.

[0065] FIG. 2 shows a result of the evaluation of a detection matrix, wherein the distance (range) is plotted for different measurement cycles. In the range of small distances from the sensor up to 25 m, a large number of detected objects can be recognized, which are displayed in black for better clarity. The dashed white frame marks these objects. Consequently, from the evaluation via the distance, it can be determined that in the example of the embodiment shown, a large number of objects are present at a very small distance from the actual sensor.

[0066] FIG. 3 depicts another evaluation or another part of the evaluation of the detection matrix. The radial velocity, i.e. the velocity of the objects towards or away from the sensor, is shown in the upper area. Again, a large number of objects are found in the low velocity range. The relevant velocity range of objects with radial velocities of, for example, less than 10 m/s is again highlighted by a dashed frame shown in white.

[0067] In the lower section of FIG. 3, the reflectivity, which is a direct measure of the radar cross-section of an object, is plotted for a variety of different measurement cycles. Here, too, an accumulation of objects can be seen in an area where the radar cross section is smaller than 0 dBm.sup.2. Consequently, the results of the three representations in FIGS. 2 and 3 allow a large number of objects to be identified that have a very small radar cross section, are located at a short distance from the sensor and have a low radial velocity. In the example of an embodiment shown, the objects can be identified as rain.

[0068] However, for the sensor to function properly, it is crucial that the rain has a certain strength. This can be detected by counting the individual “rain objects” that can be taken from the evaluations of FIGS. 2 and 3. If the number of rain objects detected in this way exceeds a predetermined limit, the rain must be assumed to be so heavy that the sensor's ability to function is impaired. This can be seen in FIG. 4. The limit set in the example of an embodiment shown is 100 objects. If more objects are detected, the line shown in blue is above the set limit and the functionality of the sensor must be assumed to be limited. In the example of the embodiment shown, this is the case up to measuring cycle 2450, for example. If the counted number of rain objects is below the limit, the functionality of the sensor is not limited, so that no disturbance criterion is met. In the embodiment shown in FIG. 4, a disturbance criterion is met between measurement cycles 72 and 2450 and between 3054 and 3267, but is not met in between and thereafter.

REFERENCE LIST

[0069] 2 radar sensor [0070] 4 transmission device [0071] 6 transmission signals [0072] 8 road user [0073] 10 received signals [0074] 12 reception device [0075] 14 electronic data processing device [0076] 16 evaluation module [0077] 18 diagnostic module [0078] 20 electronic data processing device [0079] 22 control module [0080] 24 data connection