Method for operating a sensor of a motor vehicle

Abstract

A method for operating a sensor of a motor vehicle. The method includes: ascertaining an ego trajectory of the sensor, generating adaptation signals for adapting at least one operating parameter of the sensor based on the ascertained ego trajectory and outputting the adaptation signals in order to adapt the at least one operating parameter of the sensor based on the adaptation signals. A device, a sensor system, a motor vehicle, a computer program, and a machine-readable memory medium, are also described.

Claims

1. A method for operating a sensor of a motor vehicle, the method comprising: ascertaining an ego trajectory of the sensor; generating adaptation signals for adapting at least one operating parameter of the sensor based on the ascertained ego trajectory; and outputting the adaptation signals to adapt the at least one operating parameter of the sensor based on the adaptation signals; wherein the ego trajectory is provided to perform an assessment of a non-linearity of the estimated ego trajectory, wherein the assessment includes ascertaining a second derivation of the ego trajectory, wherein as a function of the assessment of the non-linearity as a function of the second derivation, an imaging algorithm is used to generate radar images based on radar signals of a radar sensor, wherein following the assessment of the non-linearity, parameters are selected for the image algorithm, in which an aperture parameter and/or an image size parameter and/or a resolution parameter of the radar sensor is adapted based on the assessment of the non-linearity of the ego trajectory or of the determined second derivation, and wherein the radar image is ascertained with the imaging algorithm based on the selected parameters and on the radar signals of the radar sensor.

2. The method as recited in claim 1, further comprising: receiving sensor signals from at least one further sensor of the motor vehicle and/or of the sensor, the ego trajectory being ascertained based on the sensor signals, the at least one further sensor being an element selected from at least one of the following sensors: an inertial sensor, a uniaxial or multiaxial acceleration sensor, or a uniaxial or multiaxial rotation sensor, or a magnetometer sensor, or a satellite navigation sensor, or a GPS sensor, or a GLONASS sensor, or a Galileo sensor, or an odometry sensor, or a surroundings sensor, or a radar sensor, or a video sensor, or a LIDAR sensor, or a ultrasonic sensor, or an infrared sensor.

3. The method as recited in claim 1, wherein the at least one operating parameter is, in each case, an element selected from at least one of the following parameters: an evaluation algorithm parameter which specifies an evaluation algorithm for evaluating a measurement of the sensor, an aperture parameter which specifies a length of a virtual aperture of the sensor, an image size parameter which specifies an image size of a sensor image of the sensor, an resolution parameter which specifies a resolution and/or a pixel size of a sensor image of the sensor, and/or a measurement characteristic variable parameter which specifies at least one measurement characteristic variable of a measurement to be carried out using the sensor.

4. The method as recited in claim 3, wherein the sensor includes a propagation time measurement sensor, the at least one measurement characteristic variable in each case being an element selected from at least one of the following measurement characteristic variables: an inter-pulse distance, a pulse shape parameter, a bandwidth of a pulse, a sample rate for generating and scanning the pulse, and/or a pulse duration.

5. The method as recited in claim 4, wherein the sensor includes a SAR radar sensor.

6. The method as recited in claim 1, further comprising: ascertaining at least one instantaneous dynamic characteristic variable of the sensor, the adaptation signals being generated based on the at least one instantaneous dynamic characteristic variable.

7. The method as recited in claim 6, wherein the at least one instantaneous dynamic variable of the sensor includes an ego velocity of the sensor and/or an ego acceleration of the sensor.

8. The method as recited in claim 1, wherein the ascertained ego trajectory is restricted to a trajectory, which includes the position of the sensor during a measuring cycle of the sensor, in a ramp sequence, at at least three different points in time.

9. The method as recited in claim 1, wherein the sensor includes a synthetic aperture sensor (SAR sensor).

10. An apparatus to operate a sensor of a motor vehicle, comprising: a device configured to perform the following: ascertaining an ego trajectory of the sensor; generating adaptation signals for adapting at least one operating parameter of the sensor based on the ascertained ego trajectory; and outputting the adaptation signals to adapt the at least one operating parameter of the sensor based on the adaptation signals; wherein the ego trajectory is provided to perform an assessment of a non-linearity of the estimated ego trajectory, wherein the assessment includes ascertaining a second derivation of the ego trajectory, wherein as a function of the assessment of the non-linearity as a function of the second derivation, an imaging algorithm is used to generate radar images based on radar signals of a radar sensor, wherein following the assessment of the non-linearity, parameters are selected for the image algorithm, in which an aperture parameter and/or an image size parameter and/or a resolution parameter of the radar sensor is adapted based on the assessment of the non-linearity of the ego trajectory or of the determined second derivation, and wherein the radar image is ascertained with the imaging algorithm based on the selected parameters and on the radar signals of the radar sensor.

11. A sensor system, comprising: a sensor; and a device to operate the sensor, the device configured to perform the following: ascertaining an ego trajectory of the sensor; generating adaptation signals for adapting at least one operating parameter of the sensor based on the ascertained ego trajectory; and outputting the adaptation signals to adapt the at least one operating parameter of the sensor based on the adaptation signals; wherein the ego trajectory is provided to perform an assessment of a non-linearity of the estimated ego trajectory, wherein the assessment includes ascertaining a second derivation of the ego trajectory, wherein as a function of the assessment of the non-linearity as a function of the second derivation, an imaging algorithm is used to generate radar images based on radar signals of a radar sensor, wherein following the assessment of the non-linearity, parameters are selected for the image algorithm, in which an aperture parameter and/or an image size parameter and/or a resolution parameter of the radar sensor is adapted based on the assessment of the non-linearity of the ego trajectory or of the determined second derivation, and wherein the radar image is ascertained with the imaging algorithm based on the selected parameters and on the radar signals of the radar sensor.

12. A motor vehicle, comprising: a sensor system, including: a sensor of the motor vehicle; and a device to operate the sensor, the device configured to perform the following: ascertaining an ego trajectory of the sensor; generating adaptation signals for adapting at least one operating parameter of the sensor based on the ascertained ego trajectory; and outputting the adaptation signals to adapt the at least one operating parameter of the sensor based on the adaptation signals; wherein the ego trajectory is provided to perform an assessment of a non-linearity of the estimated ego trajectory, wherein the assessment includes ascertaining a second derivation of the ego trajectory, wherein as a function of the assessment of the non-linearity as a function of the second derivation, an imaging algorithm is used to generate radar images based on radar signals of a radar sensor, wherein following the assessment of the non-linearity, parameters are selected for the image algorithm, in which an aperture parameter and/or an image size parameter and/or a resolution parameter of the radar sensor is adapted based on the assessment of the non-linearity of the ego trajectory or of the determined second derivation, and wherein the radar image is ascertained with the imaging algorithm based on the selected parameters and on the radar signals of the radar sensor.

13. A non-transitory machine-readable memory medium, on which is stored a computer program, which is executable by a processor, comprising: a program code arrangement having program code for operating a sensor of a motor vehicle, by performing the following: ascertaining an ego trajectory of the sensor; generating adaptation signals for adapting at least one operating parameter of the sensor based on the ascertained ego trajectory; and outputting the adaptation signals to adapt the at least one operating parameter of the sensor based on the adaptation signals; wherein the ego trajectory is provided to perform an assessment of a non-linearity of the estimated ego trajectory, wherein the assessment includes ascertaining a second derivation of the ego trajectory, wherein as a function of the assessment of the non-linearity as a function of the second derivation, an imaging algorithm is used to generate radar images based on radar signals of a radar sensor, wherein following the assessment of the non-linearity, parameters are selected for the image algorithm, in which an aperture parameter and/or an image size parameter and/or a resolution parameter of the radar sensor is adapted based on the assessment of the non-linearity of the ego trajectory or of the determined second derivation, and wherein the radar image is ascertained with the imaging algorithm based on the selected parameters and on the radar signals of the radar sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the present invention are depicted in the figures and described in greater detail in the description below.

(2) FIG. 1 shows a flowchart of a method for operating a sensor of a motor vehicle, in accordance with an example embodiment of the present invention.

(3) FIG. 2 shows a device, in accordance with an example embodiment of the present invention.

(4) FIG. 3 shows a machine-readable memory medium, in accordance with an example embodiment of the present invention.

(5) FIG. 4 shows a sensor system, in accordance with an example embodiment of the present invention.

(6) FIG. 5 shows a motor vehicle, in accordance with an example embodiment of the present invention.

(7) FIG. 6 shows a first block diagram, in accordance with an example embodiment of the present invention.

(8) FIG. 7 shows a second block diagram, in accordance with an example embodiment of the present invention.

(9) FIG. 8 shows a third block diagram, in accordance with an example embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(10) Identical reference numerals may be used for identical features below.

(11) FIG. 1 shows a flowchart of an example method for operating a sensor of a motor vehicle, including the following steps:

(12) ascertaining 101 an ego trajectory of the sensor,

(13) generating 103 adaptation signals for adapting at least one operating parameter of the sensor based on the ascertained ego trajectory and

(14) outputting 105 the adaptation signals in order to adapt the at least one operating parameter of the sensor based on the adaptation signals.

(15) According to one specific embodiment, it is provided that the method according to the first aspect includes an adaptation of the at least one operating parameter of the sensor based on the output adaptation signals.

(16) FIG. 2 shows a device 201.

(17) Device 201 is configured to carry out all steps of the method according to the first aspect.

(18) Device 201 includes an input 203, which is configured to receive the sensor signals from at least one further sensor of the motor vehicle and/or of the sensor.

(19) Device 201 further includes a processor 205, which is configured to carry out or execute the step of ascertaining an ego trajectory of the sensor and the step of generating adaptation signals.

(20) Processor 205 is configured, for example, to ascertain the ego trajectory of the sensor based on the sensor signals. Processor 205 is configured, for example, to ascertain at least one instantaneous dynamic characteristic variable based on the sensor signals.

(21) Processor 205 is configured, for example, to ascertain at least one instantaneous dynamic characteristic variable of the sensor, the adaptation signals being generated based on the at least one instantaneous dynamic characteristic variable.

(22) Device 201 further includes an output 207, which is configured to output the adaptation signals in order to adapt the at least one operating parameter of the sensor based on the adaptation signals.

(23) Processor 205 is a digital processing unit, for example.

(24) FIG. 3 shows a machine-readable memory medium 301.

(25) Computer program 303 is stored on machine-readable memory medium 301. Computer program 303 includes commands which, when computer program 303 is executed by a computer, prompt the computer to carry out a method according to the first aspect.

(26) FIG. 4 shows a sensor system 401.

(27) Sensor system 401 includes a sensor 403 and device 201 according to FIG. 2.

(28) Device 201 according to one specific embodiment may be integrated into sensor 403.

(29) According to one specific embodiment, it is provided that device 201 is not integrated into sensor 403, i.e., is designed separately from the latter.

(30) Sensor 403 is, for example, a radar sensor, in particular, a SAR radar sensor.

(31) FIG. 5 shows a motor vehicle 501.

(32) Motor vehicle 501 includes device 201 according to FIG. 2.

(33) Motor vehicle 501 includes a SAR radar sensor 503.

(34) Motor vehicle 501 further includes a GNSS sensor 505.

(35) The GNSS signals, i.e., the position signals, of GNSS sensor 505 are provided to input 203 of device 201.

(36) Adaptation signals are accordingly output to SAR radar sensor 503 with the aid of output 207.

(37) This means, therefore, that SAR radar sensor 503 is operated based on the output adaptation signals. This, in particular, by adapting one or multiple operating parameters of SAR sensor 503. This, based on the output adaptation signals.

(38) In one specific embodiment not shown, it is provided that the motor vehicle includes one or multiple additional sensors instead of or in addition to GNSS sensor 505.

(39) FIG. 6 shows a first block diagram 600, which elucidates by way of example the concept described herein for operating a sensor of a motor vehicle.

(40) According to first block diagram 600, a first inertial sensor 601, a second inertial sensor 603, a third inertial sensor 605, and a GNSS sensor 607 are provided.

(41) The respective sensor signals of these four sensors 601, 603, 605, 607 are used in order to estimate an ego trajectory of a SAR radar sensor 619 based on these sensor signals. This estimation is carried out according to a function block 609.

(42) The estimated ego trajectory is provided to a function block 611, according to which the non-linearity of the estimated ego trajectory is assessed. This assessment includes, for example, a determination or ascertainment of a second derivation of the ego trajectory.

(43) As a function of the assessed non-linearity, in particular, as a function of the second derivation, it is provided that a decision is made between a first imaging algorithm 615 and a second imaging algorithm 617 in order to generate radar images based on the radar signals of SAR radar sensor 619.

(44) For this purpose, it is provided that the assessed non-linearity or the determined second derivation according to the location and/or according to the time, i.e., the result, is provided to a function block 613, according to which a decision is made between the two imaging algorithms 615, 617.

(45) Furthermore, the estimated ego trajectory is also provided to function block 613, so that in addition to the assessed non-linearity or the determined derivation, the ego trajectory itself is used in order to decide which of the at least two implemented imaging algorithms is to be used.

(46) An, in particular, optional function block 621 is also provided, which is used, for example, to abstract outwardly the potentially different data formats of the results of the two imaging algorithms 615, 617 in order to offer a uniform interface regardless of the algorithm used.

(47) The radar signals are evaluated with the aid of the selected imaging algorithm in order to generate a radar image 623.

(48) FIG. 7 shows a second block diagram 700, which elucidates by way of example the concept described herein for operating a sensor of a motor vehicle.

(49) In this case, it is provided as a contrast to first block diagram 600 that, for example, an aperture parameter and/or image size parameter and/or resolution parameter of SAR radar sensor 619 is/are adapted based on the assessed non-linearity of the ego trajectory or of the determined second derivation.

(50) This is via a corresponding selection of suitable parameters, which is carried out according to a function block 701.

(51) These parameters are used as input variables for an imaging algorithm 703.

(52) Radar image 623 is ascertained with the aid of imaging algorithm 703 based on these parameters and on the radar signals of SAR radar sensor 619.

(53) FIG. 8 shows a third block diagram 800, which elucidates by way of example the concept described herein for operating a sensor of a motor vehicle.

(54) As a contrast to second block diagram 700 according to FIG. 7, it is provided in the case of third block diagram 800 according to FIG. 8, that there, at least one measurement characteristic variable of SAR radar sensor 619 is ascertained based on the adaptation criterion according to block diagram 611.

(55) For example, an inter-pulse distance and/or a pulse shape parameter (for example, slope of an FMCW ramp, bandwidth of the pulse, sample rate for generating and scanning the pulse, pulse duration) is adapted and/or adjusted based on the estimated ego trajectory. In general, a pulse means, in particular, a radar wave shape suitable for a range Doppler evaluation, for example, a linear FMCW ramp, an OFDM symbol or a coded signal.

(56) In summary, the present invention disclosed herein is based on providing a novel, adaptive activation and evaluation of a sensor, in particular, a SAR radar sensor, for automotive applications. The method is usable, in particular, regardless of modulation for radar systems including a synthetic aperture (for example, fast-chirp radar, pulse compression radar, OFDM radar). In these systems, an ego movement of the sensor, in particular, of the radar sensor is advantageously determined during a measuring cycle and taken into account for an adaptive adaptation of the SAR evaluation and/or of the modulation parameters.

(57) The radar sensor preferably allows for a measurement using arbitrary trajectories, a computing-efficient SAR evaluation being allowed and/or provided by a selection of a maximally suitable SAR imaging algorithm and/or of its configuration.

(58) The present invention, in one advantageous implementation, enables an adaptation of the radar parameters on the transmitter side for optimally utilizing the available computing resources and the provided ego trajectory.

(59) A main features of the present invention is thus based, in particular, on carrying out an estimation of the ego trajectory of a sensor of a motor vehicle, in particular, of a SAR radar sensor, parameters of the radar image and/or the radar modulation parameters being adaptively adapted based on the estimated ego trajectory of the SAR imaging algorithm.

(60) The SAR imaging algorithm and the radar modulation parameters are, in particular, subsumed under the general wording “operating parameters of the sensor.”

(61) The technical advantage of such an adaptive adaptation is, in particular, that depending on the ego trajectory, the most efficient (SAR) imaging algorithm may be used, which is applicable for the driven ego trajectory.

(62) In this way, it is possible to minimize the necessary computing operations for the calculation and/or the ascertainment of the sensor image, in particular, of the SAR radar image. Further radar parameters, in particular, SAR parameters, may also be adaptively selected depending on the ego trajectory such as, for example, a length of a synthetic aperture, an image size and/or pixel size, this as a function, in particular, of an expected resolution.

(63) An optimal choice and parameterization of the imaging algorithm saves computing operations depending on the ego trajectory, and thus a power loss and a latency may be minimized while the quality of the output image remains sufficiently high.

(64) The adapted choice of the most suitable imaging algorithm, in particular, of the most suitable SAR imaging algorithm further advantageously permits an optimal adaptation of the algorithms to the setting and/or to the surroundings of the motor vehicle, which may be more exactly detected as a result than in a non-adaptive approach. In this case, a flexibility with respect to the driven ego trajectory is, in principle, advantageously maintained.

(65) A length of the synthetic aperture may advantageously also be adapted as a function of the ego trajectory and of the available computing resources as well as of the SAR imaging algorithm to be used.

(66) This adaptation may in turn advantageously serve the purpose of meeting the requirements of a computing-efficient algorithm. As a result, the available computing resources may be utilized consistently and optimally for each ego trajectory.

(67) In one specific embodiment, it is provided that to estimate the ego trajectory, the sensor signals of the corresponding sensors, i.e., the sensor measured data and/or sensor signals, are processed using a model-based state estimator.

(68) On the basis of an established criterion, which is evaluated based on the estimated ego trajectory, the algorithm makes at least one decision, which adaptively influences the further measurement and/or processing. This decision may affect one or multiple of the following functional units: choice of the SAR imaging algorithm change of the parameters of the SAR imaging algorithm, for example, length of the virtual aperture SAR image size resolution and/or pixel size of the SAR image change of the wave shape parameter of the transmit signal, for example, inter-pulse and/or inter-ramp distance slope of the FMCW ramps

(69) This criterion may, for example, be that the non-linearity of the ego-trajectory is assessed. For this purpose, the second deviation may be determined according to the location and/or according to the time of the ego trajectory. The aforementioned decisions are adaptively made as a function of their values. In the process, a decision is made in each case between two or multiple alternatives (not depicted).

(70) If the adaptivity relates to the imaging algorithm (see FIG. 6), then a distinction may be made between two algorithms, which take a non-linear trajectory into account, and those that assume a linear ego trajectory and as a result have a lower computing complexity.

(71) If the adaptivity relates to a parameter (see FIG. 7), for example, the length of the virtual aperture, then the latter may be selected to be longer, the less the trajectory deviates from a linear trajectory in the event the algorithm assumes a linear trajectory without an error degree being exceeded. If, however, an algorithm must be used that is also able to process non-linear trajectories and has greater computing complexity as a result, then the image size and/or the resolution and/or pixel size of the SAR image may be reduced in order not to exceed a limited computing capacity (present digital hardware). In this way, the real time capability may be ensured under these conditions as well.

(72) If the adaptivity relates to the wave shape (see FIG. 8), then the linearity of the spatial scanning locations may be achieved in that the pulse repetition duration is selected as a function of the instantaneous velocity. In this way, it is possible to compensate for different velocities or present accelerations. The slope of the ramp may also be adapted depending on the ego velocity. This in turn enables the use of a rapid algorithm.

(73) The approaches shown in FIGS. 6 through 8 may also be combined with one another in a suitable manner. The ego trajectory may take place based on the measured signals of one or of multiple inertial sensors. In addition, a determination of and/or increase in the accuracy of the ego trajectory may take place based on the SAR measured data.