Method for operating a sensor device

Abstract

The method relates to a method for operating a sensor device (100) based on radar technology, preferably UWB radar technology, for various vehicle functions outside and / or inside a vehicle (F), wherein a radar measurement (CIR) provides time-of-flight information from which a location (Tap) of a potential target (Z) can be derived, wherein successive radar measurements (CIRs) provide changes in time-of-flight information from which a movement, e.g. a speed, of a potential target (Z) at a location (Tap) can be derived.

Description

[0001] The invention relates to a method for operating a sensor device based on radar technology, preferably UWB radar technology. Furthermore, the invention relates to a corresponding computer program, a corresponding control unit, and a corresponding sensor device, in particular a UWB sensor device, for carrying out a corresponding method.

[0002] UWB sensor devices with radar capabilities, mounted both inside the vehicle (typically one unit per row of seats, but any number is possible) and outside the vehicle (typically one unit at each corner), can be used for various vehicle functions, both inside and / or outside the vehicle. Possible vehicle functions include, for example, intrusion detection, contactless opening of a vehicle hatch or tailgate, tracking of objects (e.g., vehicles and / or people) outside the vehicle, and detection of objects (e.g., children and / or animals) inside the vehicle. In general, UWB sensor devices can be used to detect, locate, track, and classify the movements of passive objects (people, animals, vehicles, etc.). These objects do not need to communicate with the UWB sensor device, but they can.

[0003] UWB radar measurements can be described in terms of fast time. A radar measurement can be analyzed, providing time-of-flight information, to derive a location (often called a tap) based on this information. UWB radar measurements can also be described in terms of slow time. This involves analyzing multiple consecutive radar measurements (channel impulse response, or CIR) to determine changes in the signal at each location. Fast time analysis can be used to determine a location, while slow time analysis can be used to detect movement.

[0004] The standard approach for slow-time analysis is to transfer the analysis to the frequency domain, for example, using the so-called Fast Fourier Transform. To accurately determine the dominant frequencies, and thus the velocities, in radar measurements, this analysis requires a high sampling rate and a large number of data points, both of which may not be available in UWB radar applications. Furthermore, the subsequent computational operations are numerically intensive.

[0005] It is therefore an object of the present invention to overcome at least one of the disadvantages described above, at least partially. In particular, it is an object of the invention to provide an improved method for operating a sensor device based on radar technology, preferably UWB radar technology. Preferably, it is an object of the invention to develop a simple, fast, and efficient analysis of motion to determine whether relevant slow-time information is available at a specific location and needs to be processed. Furthermore, it is an object of the invention to provide a corresponding computer program, a corresponding control unit, and a corresponding sensor device, in particular a UWB sensor device, for carrying out such a method.

[0006] The object of the invention is achieved by a method with the features of the independent method claim. Furthermore, the object of the invention is achieved by a corresponding computer program product, a corresponding control unit, and a corresponding sensor device, in particular a UWB sensor device, with the features of the dependent claims. Features and details described in connection with the different embodiments and / or aspects of the invention naturally also apply in connection with the other embodiments and / or aspects, and vice versa, so that the disclosure relating to the individual embodiments and / or aspects always includes, or can include, reciprocal references.

[0007] The invention provides: a method for operating a sensor device based on radar technology, preferably UWB radar technology, which can serve for various vehicle functions outside and / or inside a vehicle.

[0008] Inside the vehicle, at least one or more sensor devices can be installed per row of seats. Outside the vehicle, at least one or more sensor devices can be installed at each corner and / or on each side of the vehicle.

[0009] Possible vehicle functions include, for example, intrusion detection, contactless opening of a vehicle flap, e.g., a door or tailgate, tracking of objects, e.g., vehicles and / or people, outside the vehicle, detection of objects, e.g., children and / or animals, inside the vehicle, etc.

[0010] The sensor device allows multiple radar measurements to be performed sequentially. A radar measurement can include transmitting a signal (e.g., a UWB signal pulse) and / or receiving a signal, for example, reflected from a potential target.

[0011] A detected target can be an object. Possible objects outside the vehicle include, for example, cars, bicycles, scooters, people, etc. Possible objects inside the vehicle include, for example, people, children, animals, etc.

[0012] A radar measurement can provide time-of-flight information, from which the location (often referred to as a tap, where 1 tap can be approximately 15 cm) of a potential target can be derived.

[0013] Successive radar measurements can provide changes in time-of-flight information, from which movement, e.g., speed, of a potential target at a location can be deduced.

[0014] The proposed procedure comprises the following actions, or in other words, procedural steps: - Selecting a location in a radar measurement, - Recording of successive radar measurements for the specified location. - Determining a significance value for the selected location in the successive radar measurements, - Assessing the selected location as significant or not significant for further analysis, e.g., to determine movement of a potential target at this selected location, depending on the significance level.

[0015] This method can be used to quickly and easily determine whether relevant slow-time information is available at a specific location for further motion analysis. Advantageously, the method can reduce the amount of information or data required for further slow-time motion analysis to as little as 10% of the total amount. This enables a simple, fast, and efficient slow-time analysis. Overall, this provides an improved method for operating a sensor device that requires less computational effort and reduced memory.

[0016] The idea advantageously utilizes the following observations: 1. Random noise is independent of time. 2. If nothing relevant happens at a particular location (or tap), the slow time series will be dominated by random noise. 3. When something relevant happens at a particular location, the slow time series show time-dependent structures.

[0017] The significance value in the sense of the invention can be defined, for example, as a function, e.g., as a ratio, a variation (e.g., standard deviation, variance, etc.) of data values ​​in the CIRs (number n of CIRs in a certain period) and a variation of differences of the data values ​​in the CIRs.

[0018] The significance score (SW) for a selected tap can be expressed, for example, using the following formula: SignificantScore=1n∑i=1n(CIRi−CIRmean)21n∑i=1n(ΔCIRi−ΔCIRmean)2

[0019] These include: C / R i- CIR with the number i, where i = 1, 2, ... to n, where n is the number of radar measurements, CIR mean - Mean of a number n of CIRs, ΔCIR i - Difference between two consecutive CIRs, ΔCIR mean - Mean of differences between two consecutive CIRs.

[0020] To assess whether significant information is contained at a particular location (or tap), the following assessment can be carried out.

[0021] If, in a UWB signal, a typical signal change between two consecutive CIRs at a particular tap is just as important as the typical signal change across multiple CIRs, then that tap does not contain any motion information.

[0022] If, on the other hand, a typical signal change between two consecutive CIRs at a particular tap is greater than the typical signal change across multiple CIRs, then that tap could contain important motion information.

[0023] Furthermore, the procedure can be performed iteratively for different locations, e.g., for all available taps in the radar measurements. This allows different locations to be assessed with regard to relevant movement information, in order to select only the relevant locations and thus reduce the amount of information for further analysis.

[0024] Furthermore, it may be provided that the acquisition of successive radar measurements for a specific location is carried out up to a certain number of consecutive radar measurements. In this way, signal analysis over slow time can be enabled.

[0025] Furthermore, the significance value can be calculated in such a way as to differentiate between ordinary background noise and specific temporal sequences (e.g., exhibiting identifiable frequencies) in successive radar measurements. This allows for a distinction between ordinary background noise and relevant motion information.

[0026] As mentioned above, it is conceivable that the significance value can be determined as a function of, or as a ratio between, a variation of data values ​​in the successive radar measurements and a variation of differences of the data values ​​in the successive radar measurements.

[0027] Advantageously, the procedure, particularly the determination of the significance value and / or the assessment of the selected location as significant or not significant for further analysis, can be performed using a machine learning method. This provides a computationally simple and storage-efficient solution. Furthermore, machine learning methods can reliably and efficiently detect time dependencies and / or frequencies in signals, thus avoiding the need for complex analysis using the so-called Fast Fourier Transform.

[0028] Preferably, a further analysis can be performed at one location, preferably the best one, that has been deemed significant. In this way, only one, or the best, tap can be used for motion analysis.

[0029] Advantageously, up to four locations can be selected as significant for further analysis. This reduces the amount of data required for further analysis and ensures that potential targets are reliably identified, even in cases of uncertainty.

[0030] In principle, it can be advantageous if the method selects as many significant locations as possible, thereby reducing the amount of data required for further analysis to as little as 10% of the data obtained from successive radar measurements. This allows for a balanced solution that reduces the amount of data while still ensuring reliable detection of potential targets.

[0031] Furthermore, it can be provided that a threshold value for significance is determined, depending on which the selected location is considered significant or not significant. This allows for a quick and easy evaluation of selected taps.

[0032] Furthermore, it may be stipulated that when assessing the selected location as significant or insignificant for a desired vehicle function inside and / or outside the vehicle, the position of a potential target relative to the vehicle is taken into account, regardless of whether it is inside or outside the vehicle. This provides a simple additional criterion for evaluating whether a potential target is relevant to the desired vehicle function. For example, in the case of a vehicle function "child detection inside a parked vehicle," it may be determined that potential targets outside the vehicle are disregarded and not evaluated with respect to slow time.

[0033] In principle, it can be advantageous that potential targets outside the vehicle can be neglected for vehicle functions inside the vehicle.

[0034] Furthermore, it may be provided that the procedure for tracking objects, e.g. vehicles and / or persons, is carried out outside and / or inside the vehicle.

[0035] In principle, it can be advantageous that potential targets inside the vehicle can be neglected for vehicle functions outside the vehicle.

[0036] Furthermore, it can be advantageous that if a malfunction of an object is detected during the tracking of objects outside the vehicle, a measure is initiated, e.g., an external camera is activated, a light is switched on, an alarm is issued, etc.

[0037] Furthermore, it can be advantageous to initiate an identification check when tracking an object from outside the vehicle into the vehicle's interior. This enables secure and convenient keyless access control.

[0038] Advantageously, the method can be used to operate multiple sensor devices. This allows for more comprehensive analysis.

[0039] It is conceivable that the information from the multiple sensor devices could be combined to provide various vehicle functions outside and / or inside a vehicle with greater reliability and improved customer comfort.

[0040] Furthermore, the invention provides: A computer program product comprising instructions that, when executed by a computer, cause the computer to perform a corresponding procedure, which can proceed as described above. The same advantages described above in connection with the procedure can be achieved. These advantages are fully referenced here.

[0041] Furthermore, the invention provides: A control unit comprising a storage unit in which a code is stored, and an arithmetic unit, wherein, when the code is executed by the arithmetic unit, a corresponding procedure is carried out, which can proceed as described above. The same advantages described above in connection with the procedure can be achieved. These advantages are fully referenced here.

[0042] In particular, it is conceivable that, when the method is carried out to operate multiple sensor devices, a control unit of one sensor device may have a master function among the multiple sensor devices in order to combine the information from the multiple sensor devices.

[0043] In principle, it is also conceivable that several control units could each have an evaluation function in order to combine the information from the several sensor devices independently of each other.

[0044] Furthermore, the invention provides: A sensor device, in particular a UWB sensor device, comprising a corresponding control unit designed to perform a corresponding method which can proceed as described above. The same advantages described above in connection with the method can be achieved in this process. These advantages are fully referenced herein.

[0045] The invention is explained in more detail below with reference to the accompanying drawings. These schematically depict: Fig. 1 an exemplary vehicle with multiple sensor devices, Fig. 2 exemplary radar measurements for multiple taps, Fig. 3 example radar measurements for a tap, Fig. Four exemplary significance values ​​for multiple radar measurements, each for one tap, and Fig. 5 an exemplary sequence of a proposed procedure.

[0046] The Fig. Points 1 to 5 serve to explain the proposed idea, which envisages: a method for operating a sensor device 100 based on radar technology, preferably UWB radar technology, which can serve for various vehicle functions outside and / or inside a vehicle F.

[0047] In vehicle F, at least one or more sensor devices 100 per seat row can be installed (see...). Fig. 1) Outside the vehicle F, at least one or more sensor devices 100 can also be attached at each corner and / or on each side of the vehicle F.

[0048] Possible vehicle functions that can be provided using the sensor device 100 include, for example, intrusion detection, contactless opening of a vehicle flap, e.g., a door or a tailgate, tracking of objects, e.g., vehicles and / or persons, outside the vehicle F, detection of objects, e.g., children and / or animals, inside the vehicle F, etc.

[0049] Using the sensor device 100, several radar measurements of CIRs can be carried out one after the other (see Fig. 2) A radar measurement CIR can include the transmission of a transmit signal (e.g., a UWB signal pulse) and / or the reception of a received signal (e.g., a reflected UWB signal pulse) reflected from a potential target.

[0050] A detected target can be an object. Possible objects outside the vehicle include, for example, cars, bicycles, scooters, people, etc. Possible objects inside the vehicle include, for example, people, children, animals, etc.

[0051] A radar measurement CIR can provide time-of-flight information from which the location (often referred to as a tap, where 1 tap can be approximately 15 cm) of a potential target Z can be derived (see...). Fig. 2).

[0052] Successive radar measurements (CIRs) can provide changes in time-of-flight information from which a movement, e.g., a speed, of a potential target Z at a location Tap can be derived (see...). Fig. 2).

[0053] As it is Fig. As indicated in section 5, the procedure may include the following procedural steps: 110 Selecting a location Tap in a radar measurement CIR, 120 Capture of consecutive radar measurements CIRs for the specified location Tap. 130 Determining a significance value SW for the selected location Tap in the successive radar measurements CIRs, 140 Assessing the selected location Tap as significant (true - see procedure step 141) or not significant (false - see procedure step 142) for further analysis, e.g. to determine a movement (e.g. a speed) of a potential target Z at this selected location Tap, depending on the significance value SW.

[0054] This method allows for a quick and easy determination of whether relevant slow-time information can be obtained at a specific location for further motion analysis. Advantageously, this method can reduce the amount of information or data required for further slow-time motion analysis by up to 10% of the total amount.

[0055] The following findings were taken into account: 1. Random noise is independent of time. 2. If nothing relevant happens at a particular location (or tap), the slow time series will be dominated by random noise (cf. Fig. 3 below). 3. When something relevant happens at a specific location (Tap), the slow time series show time-dependent structures (cf. Fig. 3 above).

[0056] The significance value (SW, see below) Fig. 4) In the sense of the invention, can be understood, for example, as a function, e.g. as a ratio, a variation (e.g. standard deviation, variance, etc.) of data values ​​in the CIRs (number n of CIRs in a certain period) and a variation of differences of the data values ​​in the CIRs.

[0057] To assess whether significant information is contained at a particular location (or tap), the following assessment can be carried out.

[0058] If, in a UWB signal, a typical signal change between two consecutive CIRs at a specific tap is just as important as the typical signal change across multiple CIRs, then this tap contains no motion information (cf. Fig. 3 below).

[0059] If, on the other hand, a typical signal change between two consecutive CIRs at a particular tap is greater than the typical signal change across multiple CIRs, then this tap could contain important motion information (see below). Fig. 3 above).

[0060] The procedure can advantageously be performed iteratively for different location taps, preferably for all available taps in the radar measurements CIRs, in order to select relevant taps for further analysis.

[0061] In principle, n consecutive radar measurements CIRs can be carried out for the specific location Tap.

[0062] Advantageously, the significance value SW can be formed in such a way that a distinction can be made between ordinary background noise and certain temporal sequences (which, for example, show determinable frequencies) in the successive radar measurements CIRs.

[0063] As mentioned above, the significance value SW can be determined as a function of, or as a ratio between, a variation in data values ​​in the successive radar measurements CIRs and a variation in differences in the data values ​​in the successive radar measurements CIRs.

[0064] The significance score (SW) for a selected tap can be expressed, for example, using the following formula: SignificantScore=1n∑i=1n(CIRi−CIRmean)21n∑i=1n(ΔCIRi−ΔCIRmean)2

[0065] These include: CIR i - CIR with the number i, where i = 1, 2, ... to n, where n is the number of radar measurements of CIRs, CIR mean - Mean of a number n of CIRs, ΔCIR i - Difference between two consecutive CIRs, ΔCIR mean - Mean of differences between two consecutive CIRs.

[0066] Advantageously, the procedure, in particular the determination of the significance value (SW) and / or the assessment of the selected location (Tap) as significant (true) or not significant (false) for further analysis, can be carried out using a machine learning method to reliably and efficiently detect time dependencies and / or frequencies in (UWB) signals.

[0067] For example, further analysis can only be performed at one, preferably the best, location tap that has been judged to be significantly true.

[0068] For example, up to four tap locations can be selected as significant for further analysis.

[0069] In principle, it can be advantageous if the procedure selects as many significant tap locations as possible in order to reduce the amount of data for further analysis by up to 10%.

[0070] As it is Fig. As indicated in section 4, a threshold SW* can be determined for the significance value SW, depending on which the selected location Tap is judged as significantly true or not significantly false.

[0071] The method can consider the position of a potential target Z relative to vehicle F, which may be inside or outside the vehicle F. In this way, for example, a vehicle function such as "child detection inside a parked vehicle" can be determined, so that potential targets outside the vehicle F are disregarded and not evaluated with respect to slow time.

[0072] In principle, for vehicle functions within vehicle F, potential targets outside of vehicle F can be neglected.

[0073] Advantageously, the procedure for tracking objects, e.g. vehicles and / or persons, can be carried out outside and / or inside the vehicle F.

[0074] In principle, for vehicle functions outside the vehicle F, potential targets inside the vehicle F can be neglected.

[0075] If, during the tracking of objects outside the vehicle F, a malfunction of an object is detected, then a measure can be initiated, e.g. an external camera can be activated, a light can be switched on, an alarm can be issued, etc.

[0076] Furthermore, the method for tracking an object during a movement from outside the vehicle F into the vehicle interior can be used to initiate an identification check, e.g. for secure and convenient keyless access control.

[0077] The method can also be used to operate multiple sensor devices 100.

[0078] The information from the multiple sensor devices can be combined to provide various vehicle functions outside and / or inside a vehicle with higher reliability and improved customer comfort.

[0079] A corresponding computer program product, a corresponding control unit ECU and a corresponding sensor device 100, in particular a UWB sensor device, represent further aspects of the invention.

[0080] The preceding description of the figures describes the present invention solely by way of examples. Naturally, individual features of the embodiments can be freely combined with one another, provided it is technically feasible, without departing from the scope of the invention. Reference symbol list 100 sensor device F vehicle Z goal Tap location Tap locations CIR radar measurement CIR radar measurements SW significance level SW* Threshold true significant false not significant n number ECU control unit

Claims

Method for operating a sensor device (100) based on radar technology, preferably UWB radar technology, for various vehicle functions outside and / or inside a vehicle (F), wherein a radar measurement (CIR) provides time-of-flight information from which a location (Tap) of a potential target (Z) can be derived, wherein successive radar measurements (CIRs) provide changes in time-of-flight information from which a movement, e.g., a speed, of a potential target (Z) at a location (Tap) can be derived, and wherein the method comprises: - selecting a location (Tap) in a radar measurement (CIR), - acquiring successive radar measurements (CIRs) for the selected location (Tap).- Determining a significance value (SW) for the selected location (Tap) in the successive radar measurements (CIRs), - Assessing the selected location (Tap) as significant (true) or not significant (false) for further analysis, e.g. to determine a movement of a potential target (Z) at this selected location (Tap), depending on the significance value (SW). The method of claim 1, wherein the method is performed iteratively for different locations (taps), and / or wherein the acquisition of successive radar measurements (CIRs) for the specified location (tap) is performed up to a specified number (n) of successive radar measurements (CIRs). Method according to claim 1 or 2, wherein the significance value (SW) is formed in such a way that it is possible to distinguish between ordinary background noise and certain temporal sequences in the successive radar measurements (CIRs), and / or wherein the significance value (SW) is determined as a function of or as a ratio between a variation of data values ​​in the successive radar measurements (CIRs) and a variation of differences of the data values ​​in the successive radar measurements (CIRs). Method according to one of the preceding claims, wherein the method, in particular comprising the determination of the significance value (SW) and / or the assessment of the selected location (Tap) as significant (true) or not significant (false) for further analysis, is carried out using a machine learning method. Method according to one of the preceding claims, wherein a further analysis is carried out at a, preferably best, location (Tap) that has been judged to be significant (true). Method according to one of the preceding claims, wherein up to four locations (taps) are selected as significant (true) to perform further analysis. Method according to one of the preceding claims, wherein the method selects so many locations (taps) as significant (true) that the amount of data for further analysis is reduced to up to 10% of the data obtained using successive radar measurements (CIRs). Method according to one of the preceding claims, wherein a threshold value (SW*) for the significance value (SW) is determined, depending on which the selected location (Tap) is judged to be significant (true) or not significant (false). Method according to one of the preceding claims, wherein, when assessing the selected location (Tap) as significant (true) or not significant (false) for a desired vehicle function inside and / or outside the vehicle (F), a position of a potential target (Z) relative to the vehicle (F) is taken into account, which may be located inside or outside the vehicle (F), and / or wherein, for vehicle functions inside the vehicle (F), potential targets outside the vehicle (F) may be neglected. A method according to any of the preceding claims, wherein the method for tracking objects, e.g., vehicles and / or persons, is carried out outside and / or inside the vehicle (F), and / or wherein, for vehicle functions outside the vehicle (F), potential targets inside the vehicle (F) can be neglected, and / or wherein, when tracking objects outside the vehicle (F), a malfunction of an object is detected, a measure is initiated, e.g., an external camera is activated, a light is switched on, an alarm is issued, etc., and / or wherein, when tracking an object from outside the vehicle (F) into a vehicle interior, an identification check is initiated. Method according to one of the preceding claims, wherein the method is carried out to operate several sensor devices (100), wherein in particular information from the several sensor devices (100) is combined to provide various vehicle functions outside and / or inside a vehicle (F). Computer program product comprising instructions which, when the computer program product is executed by a computer, cause the computer to perform the method according to any of the preceding claims. Electronic control unit (ECU) comprising a storage unit in which a code is stored and a computing unit, wherein when the code is executed by the computing unit, the method according to one of the preceding claims 1 to 11 is carried out, wherein in particular, when the method is carried out to operate several sensor devices (100), a control unit (ECU) of one sensor device (100) has a master function of the several sensor devices (100) or several control units (ECUs) each have an evaluation function to combine information from the several sensor devices (100). Sensor device (100), in particular a UWB sensor device, comprising a control unit (ECU) according to the preceding claim.

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