Evaluating a sensor signal from an ultrasonic sensor arranged on a metal plate

Abstract

The invention relates to a method for evaluating a sensor signal (21) from an ultrasonic sensor (11) arranged on a metal plate (3), wherein: the ultrasonic sensor emits ultrasonic signals (19) through the metal plate, receives echo signals (20), and outputs the sensor signal; for a reception time period (23), the echo signal is received and an associated sensor signal profile is provided; the sensor signal profile is sampled temporally discretely at predefined times in the associated reception time period; each sensor signal profile is assigned an associated reception signal data set having associated sample values (24); a predefined number of reception signal data sets are selected; the sample values determined at a sampling time are combined in each case to form a sample data set; the sample data sets are transformed into the frequency domain, and associated transformed sample data sets are high-pass filtered and transformed back; a predefined number of successive filtered sample data sets are combined in order to form an associated combination value (37); the combination value is compared with a comparison value (36), and, in accordance with the comparison, a comparison signal (30) is output.

Description

[0001] 2023PF00052

[0002] 1

[0003] Evaluating a sensor signal from a device mounted on a metal sheet

[0004] ultrasonic sensor

[0005] The invention relates to a method for evaluating a sensor signal from an ultrasonic sensor arranged on a metal sheet, wherein the ultrasonic sensor has a detection range through the metal sheet, wherein the ultrasonic sensor emits ultrasonic signals successively in a time-discrete manner, receives echo signals and outputs the sensor signal depending on the reception of the echo signals, wherein for a respective reception period, which is predetermined depending on the emission of the respective ultrasonic signal for a predetermined transit time range of the ultrasonic signal, the respective echo signal is received and a corresponding sensor signal profile is provided depending on the respective sensor signal, wherein the sensor signal profile is sampled in a time-discrete manner at predetermined times of the respective reception period.wherein a respective sensor signal profile is assigned a respective received signal data set with respective sampled values. The invention further relates to a computer program product and a computer-readable data carrier. The invention further relates to an evaluation unit for evaluating a sensor signal from an ultrasonic sensor arranged on a metal sheet and coupled to the evaluation unit in a signal-technical manner, wherein the ultrasonic sensor detects a detection area through the metal sheet, wherein the ultrasonic sensor emits ultrasonic signals successively in a time-discrete manner, receives echo signals, and, depending on the reception of the echo signals, outputs sensor signals to the evaluation unit, wherein the evaluation unit is configured for a respective reception period, which can be predefined depending on the emission of the respective ultrasonic signal for a predetermined transit time range of the ultrasonic signal.to receive a respective echo signal and, depending on the corresponding respective sensor signal, to provide a corresponding sensor signal profile, wherein the evaluation unit is configured to sample the sensor signal profile at predetermined times of the respective reception period in a time-discrete manner and to assign a respective received signal data set with respective sample values ​​to a respective sensor signal profile. Furthermore, the invention also relates to a sensor device for detecting an environment of the sensor device, comprising an ultrasonic sensor arranged on a metal sheet, wherein the ultrasonic sensor detects a detection area through the metal sheet, and comprising an evaluation unit signal-technically coupled to the ultrasonic sensor for evaluating a sensor signal of the 2023PF00052.

[0006] 2

[0007] Ultrasonic sensor. Finally, the invention also relates to a motor vehicle with a sensor device for detecting the vehicle's surroundings.

[0008] Generic methods, computer program products, computer-readable data carriers, evaluation units, sensor units, and motor vehicles are extensively known in the prior art. Ultrasound is frequently used for environmental sensing of the motor vehicle. Objects within the detection range of the ultrasonic sensor can be determined using ultrasound. For this purpose, ultrasonic signals, which are generally provided as ultrasonic pulses, are emitted by the ultrasonic sensor. Echo signals are then received by the ultrasonic sensor as reflections of each ultrasonic pulse, preferably occurring between two successive ultrasonic signals or pulses. Depending on the reception of the echo signals, the ultrasonic sensor generates corresponding sensor signals, which are made available for further evaluation by an evaluation unit.The evaluation unit can then be used, for example, to identify objects in the surroundings. This allows for the implementation of a wide variety of functions, particularly in motor vehicles. These can include safety functions that improve the vehicle's safety during normal operation, such as obstacle detection, the detection of dangerous driving situations, and / or the like. For example, DE 10 2019 103 782 A1 discloses a door assembly for a vehicle with an ultrasonic system and an ultrasonic module. Furthermore, user-operated controls can also be defined, enabling a user to open, for example, a tailgate, a door, a hood, or the like on a motor vehicle. In this context, US 11,572,728 B2 discloses, for example, a device and a method for controlling a vehicle door.

[0009] Even though the state of the art has proven its worth, disadvantages remain. Generally, the use of an ultrasonic sensor requires, particularly in motor vehicles, a through-hole in the outer skin, which is usually made of sheet metal. The ultrasonic sensor is then positioned within this through-hole. While this largely prevents the outer skin from affecting the ultrasonic sensor's operation, it also makes the sensor accessible from the outside and vulnerable to external influences, especially during operation. 2023PF00052

[0010] 3. The ultrasonic sensor is therefore essentially unprotected during normal ferry operation of the motor vehicle.

[0011] The invention is based on the objective of enabling the reliable use of the ultrasonic sensor even in a protected arrangement, for example behind an outer skin of the motor vehicle.

[0012] The invention proposes a method, a computer program product, a computer-readable data carrier, an evaluation unit, a sensor device and a motor vehicle as a solution according to the independent claims.

[0013] Advantageous further training opportunities arise from the characteristics of the dependent requirements.

[0014] With regard to a generic method, the invention particularly proposes that a predetermined number of temporally successive received signal data sets are selected, wherein the sample values ​​determined at a respective sampling time of the selected received signal data sets are combined into a respective time-specific sample data set, wherein the sample data sets are transformed into the frequency domain to form respective sample data set transforms, the sample data set transforms are high-pass filtered and subsequently back-transformed to form filtered sample data sets, wherein the filtered sample data sets are further processed by combining a predetermined number of temporally successive filtered sample data sets to form a respective combination value, wherein the combination value is compared with a reference value.and a comparison signal is issued depending on the comparison.

[0015] With regard to a generic computer program product, the invention particularly proposes that the computer program product comprises program code means, which are stored in a computer-readable medium, in order to carry out a method for evaluating a sensor signal from an ultrasonic sensor arranged on a metal sheet, wherein the ultrasonic sensor has a detection range through the metal sheet, wherein the ultrasonic sensor emits ultrasonic signals successively in a time-discrete manner, receives echo signals and outputs the sensor signal depending on the reception of the echo signals, for a respective reception period which is predetermined depending on the emission of the respective ultrasonic signal for a predetermined transit time range of the ultrasonic signal, the 2023PF00052

[0016] 4. To receive the respective echo signal and, depending on the corresponding sensor signal, to provide a corresponding sensor signal profile, wherein the sensor signal profile is sampled discretely in time at predetermined times of the respective reception period, wherein a respective received signal data set with respective sample values ​​is assigned to a respective sensor signal profile, wherein a predetermined number of temporally successive received signal data sets are selected, wherein the sample values ​​of the selected received signal data sets determined at a respective sampling time are combined into a respective time-specific sample data set, wherein the sample data sets are transformed into the frequency domain to form respective sample data set transforms, the sample data set transforms are high-pass filtered and then back-transformed to form filtered sample data sets,wherein the filtered sample data sets are further processed by combining a predetermined number of temporally successive filtered sample data sets to form a respective combination value, wherein the combination value is compared with a reference value, and a comparison signal is output depending on the comparison.

[0017] With regard to a generic evaluation unit, the invention particularly proposes that the evaluation unit be configured to select a predetermined number of temporally successive received signal data sets, to combine the sample values ​​of the selected received signal data sets determined at each sampling time into a respective time-specific sample data set, to transform the sample data sets into the frequency domain in order to form respective sample data set transforms, to high-pass filter the sample data set transforms and then to back-transform them in order to form filtered sample data sets, to further process the filtered sample data sets by combining a predetermined number of temporally successive filtered sample data sets to form a respective combination value, and to compare the combination value with a reference value.and to output a comparison signal depending on the comparison.

[0018] With regard to a generic sensor device, the invention specifically proposes that the evaluation unit be designed according to the invention. 2023PF00052

[0019] 5

[0020] With regard to a motor vehicle of the type described, the invention specifically proposes that the sensor device be designed according to the invention.

[0021] The invention is based, among other things, on the idea that when an ultrasonic sensor is mounted on a metal plate, particularly on a surface of the metal plate, a significant echo signal with a short transit time can occur. By appropriately processing and filtering the echo signals, it is possible to filter out this strong signal and process the filtered signal further. This processing makes it possible to realize the sensor functionality of the ultrasonic sensor despite the metal sheet. Therefore, not only can objects in the area detected by the ultrasonic sensor be identified, but also user actions, such as a request to open a door, gestures, and the like, can be detected. This also allows the ultrasonic sensor to be protected by the metal surface or metal plate.Therefore, no openings for the ultrasonic sensors need to be provided in the metal sheet or outer skin of the vehicle.

[0022] To identify objects or user gestures / activities, it is advantageous to evaluate several, preferably sequential, sensor signal profiles. This evaluation can, for example, involve the combined evaluation of at least a portion of these sequential sensor signal profiles. The respective sensor signal profile is determined based on the sensor signal emitted by the ultrasonic sensor in response to receiving the echo signal. This can be done, for example, using the evaluation unit. However, it is also possible for the sensor signal profile to be determined, at least partially, by the ultrasonic sensor itself or by a separate signal processing unit. The sensor signal profile can be at least partially analog or at least partially digital.The ultrasonic signal emitted by the ultrasonic sensor can, for example, be essentially a pulsed signal. The pulse of this pulsed signal can exhibit at least partial oscillation, in particular a damped oscillation.

[0023] The sensor signal profile is sampled discretely at predefined times within the respective reception period. The sensor signal profile therefore preferably extends over the respective reception period during which the corresponding received signals were received by the ultrasonic sensor. The data, 2023PF00052

[0024] The six data points determined by sampling a given sensor signal waveform can be combined into a corresponding received signal dataset with their respective sample values. Therefore, a corresponding received signal dataset can be assigned to each sensor signal waveform.

[0025] According to the invention, a predetermined number of temporally successive received signal data sets are selected. These received signal data sets contain the respective sampled values, sampled at the respective sampling times. The selection of the received signal data sets can be implemented, for example, by means of a time window that captures the predetermined number of received signal data sets. Furthermore, the time window can be shifted cyclically so that a specific set of received signal data sets is always processed for each processing step. The time window can be shifted to process a different selection of received signal data sets. It can also be provided that when a new received signal data set is added to the selection, an already existing received signal data set is removed or excluded from processing.

[0026] The selected received signal data sets are then further processed such that samples from the received signal data sets assigned to a specific sampling time are combined into a respective sample data set. The received signal data sets are thus decomposed, and sample data sets are formed, with each sample data set preferably containing only those samples assigned to a specific sampling time within the received signal data sets. A respective sample data set can therefore be assigned to a specific sampling time. The sample data set preferably contains the samples of all selected received signal data sets at that sampling time.

[0027] The sampled data sets generated in this way are transformed into the frequency domain. This can be done using a suitable transformation formula, for example, a Fourier transform, a Laplace transform, a Z-transform, or the like. For the present application, the Z-transform has proven to be preferred, although the function of the invention is also conceivable with another suitable transformation. A sampled data set transform is determined for the sampled data set. 2023PF00052

[0028] 7

[0029] The sample data sets obtained in this way are each subjected to high-pass filtering using a suitable high-pass filter. The high-pass filtered sample data set transforms are then inversely transformed, i.e., an inverse transformation is applied. In this way, the filtered sample data sets are determined, which are then processed further.

[0030] In particular, it can be taken into account that preferably a time axis within a received signal data set, i.e., a data set time axis, can differ from a time axis relating to the performance of the transformation and high-pass filtering, i.e., a transformation time axis. In addition to the time axis within the received signal data set, a time axis across multiple received signal data sets is therefore particularly well provided.

[0031] For further processing, a further predefined number of filtered sample data sets, preferably sequentially (e.g., using a further windowing method), are selected from these filtered sample data sets. These selected and filtered sample data sets are then combined to form a respective combination value. The combination can be determined by one or more mathematical operations. Here, too, the selection of the filtered sample data sets can be implemented, for example, using a window that captures the predefined number of filtered sample data sets. Furthermore, the window can be cycled through so that a specific set of filtered sample data sets is always processed for each subsequent step, particularly the combination. The window can be shifted to process a different selection of filtered sample data sets.It can be provided that when a new filtered sample data set is added to the selection, an already existing filtered sample data set is removed or excluded from processing. In particular, it can be provided that a combination, preferably a sum, is formed over sample values ​​of several sample data sets that have the same received signal data set time. The number of sample data set values ​​used for the combination can correspond to the number of sample data sets, or a fixed number of cohorts (bins) can be defined that subdivide the sample data set values ​​according to their sample data set time by several propagation delay limits, so that multiple combination values ​​can be generated for one received signal data set time. The "windowing" determined in this way preferably only takes effect subsequently when the formed combination value is 2023PF00052.

[0032] 8

[0033] The values ​​of previous received signal data records are "windowed" to allow for the transformation, filtering, and back-transformation of the resulting at least one linked data record, thereby reducing or removing constant components from the linked values. Preferably, only the sampled data record values ​​from the last received signal time are linked in the application, i.e., the last value of each selected sampled data record. The "windowing" can therefore preferably refer to the number of sampled data records used, as well as to the number of sampled data record values ​​per sampled data record that are then linked. The latter number can also be 1.

[0034] The required number can be determined empirically to reliably identify, for example, a user action or gesture, an object, or the like. For this purpose, the link value can be compared with a suitable reference value to identify the respective object, user action, or user gesture. Depending on the comparison, a corresponding comparison signal can then be generated, which can be made available for further processing, for example, by a vehicle's control system. If, for instance, the gesture is used by a vehicle user to open a vehicle door, the comparison signal can be used by the vehicle's control system to initiate and preferably execute the opening of the vehicle door.Furthermore, it is of course still possible to identify objects that are located within the reception area.

[0035] The functionality of the invention can preferably be implemented, at least partially, by means of an evaluation unit. The evaluation unit can be part of a sensor device that also includes the ultrasonic sensor. The ultrasonic sensor can be at least partially connected to the evaluation unit via a signal transmission system. For this purpose, the evaluation unit can include an electronic hardware circuit. Alternatively or additionally, the evaluation unit can also include a program-controlled computing unit that can be operated as desired by means of a computer program, preferably in the form of a computer program product. 2023PF00052

[0036] 9

[0037] In the present disclosure, a computing unit can be understood, for example, as a data processing device with processing circuits. A computing unit can therefore perform arithmetic operations to process data. These arithmetic operations can also include indexed access to a data structure, such as a lookup table (LUT).

[0038] The computing unit may, in particular, comprise one or more computers, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more systems on a chip (SoCs). The computing unit may also include one or more processors, for example, one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, in particular one or more digital signal processors (DSPs). The computing unit may also comprise a physical or virtual cluster of computers or other units of the aforementioned type.

[0039] The computing unit can also include one or more hardware and / or software interfaces and / or one or more memory units. A memory unit can be implemented as volatile data storage, for example as dynamic random access memory (DRAM) or static random access memory (SRAM), or as non-volatile data storage, for example as read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or flash EEPROM, or ferromagnetic random access memory (FRAM).a magnetoresistive random access memory, MRAM (magnetoresistive random access memory), or a phase-change random access memory, PCRAM (phase-change random access memory).

[0040] It is further proposed that the signal value be formed by an energy value of the respective sample. This makes it possible to use a reference value 2023PF00052.

[0041] 10. This allows for the scaling of sample values. This enables, among other things, the comparability of sample values, for example, from different ultrasonic sensors. The energy value can, for instance, depend on the received energy of the echo signal received by the ultrasonic sensor, corresponding to the sample value. Furthermore, it is possible to compare the energy values ​​of different sample signals, including samples from different reception periods, for example, to compare the effects of changes in the energy of emitted ultrasonic signals from a particular ultrasonic sensor.

[0042] Furthermore, it is proposed that the reference value be varied. The reference value can be selected, for example, depending on the type of determination, such as whether a gesture or user action is to be determined, whether an object is to be identified, and / or the like. The reference value can be selected specifically for the respective function. During the evaluation, the reference value can also be changed as needed. In addition, the reference value can also be selected depending on the respective sampling time within the respective reception period. It can be provided that the reference value is selected only for a predetermined number of consecutive sampling times. This makes it possible to create a multitude of determination possibilities through evaluation and thereby further improve the flexibility of the invention.

[0043] Furthermore, it is proposed that the filtered sample data sets be additionally filtered to reduce interference during the linking process. The filtering method can be selected based on how the ultrasonic sensor is connected to the metal sheet. For example, the ultrasonic sensor can be pressed onto a surface of the metal sheet. Alternatively, the ultrasonic sensor can be bonded to the metal sheet using a material-bonded connection, such as adhesive bonding. This can result in differences in the evaluation, which can be addressed by varying or adjusting the propagation delay cutoff time. Preferably, the filtering method is selected such that echo signals from the metal sheet or other interfering reflections can be filtered out or at least suppressed for further processing.Furthermore, the interference suppression allows the inventive method to be adapted to different arrangements and / or different ultrasonic sensors. It can also be taken into account that, for example, a thickness of 2023PF00052.

[0044] 11 of the metal sheet or other properties can affect the echo signals, which can be excluded from further processing by means of the propagation delay limit. The function of the invention can be further improved by this. The interference suppression can, for example, include reducing or suppressing a DC component or a constant component in the logic value. The interference suppression can also include reducing or suppressing interference components in the logic value, which, for example, reduces or suppresses signal noise or the like. Preferably, interference suppression refers to windowing and filtering.

[0045] According to a training course, it is proposed that the predefined number of consecutive received signal data sets and / or the predefined number of consecutive filtered sample data sets be varied. This allows the evaluation to be specifically tailored to determine particular properties, for example, regarding the identification of a user action, a user gesture, an object, and / or the like. For example, if a user action or a user gesture is to be recorded, a kind of capture window can be overlaid on consecutive received signal data sets, and only those received signal data sets that fall within the capture window's area are processed further. The capture window shifts over time across the captured received data sets.This makes it possible, for example, to reliably capture user actions or gestures. The movement of an object can also be reliably determined in this way. Overall, the function of the invention can be further improved. The specified number of received signal data sets and filtered sample data sets need not be the same.

[0046] It is further proposed that the specified times be the same for at least a portion of the respective reception periods. This ensures that, at least for the respective reception periods used for evaluation, the sampling times occur at the same times. This can further improve the determination functionality during further processing. Depending on requirements, however, it is also possible to provide different sampling times for another portion of the respective reception periods. This can be advantageous, for example, for better identifying artifacts or the like. Overall, a further improvement in the functionality of the invention can be achieved. 2023PF00052

[0047] 12

[0048] According to a further training, it is proposed that the specified times within each reception period be equidistant. This means that the specified times are consecutive and equidistant from one another.

[0049] This allows for reliable functionality, particularly with regard to further signal processing, because, for example, a very low sampling rate can be chosen. In principle, however, it is also possible to make the specified sampling points at least partially non-equidistant, for example, to minimize sampling in an area where echo signals from the metal sheet are expected, thereby increasing the data processing speed.

[0050] It is particularly advantageous if the linking process involves at least an addition or a multiplication. This makes it possible to calculate specific sums or product values ​​for a given sampling time based on the specified number of filtered sample data sets. A combination of these operations, or with other mathematical operations, is also possible. Depending on the further signal processing required for the specific determination functionality, the respective sums or product values ​​can then be combined as needed to achieve the most reliable determination functionality possible. This can be adapted, for example, to a function for detecting or determining a user action, a user gesture, an object, and / or the like.

[0051] It can be provided that the linking only occurs for samples from the filtered sample data sets whose sample value falls within a predefined range. This makes it possible to design the determination functionality more precisely. For example, value ranges can be specified within the linking process, so that only values ​​within a predefined range are considered for comparison. This makes it possible to reduce processing effort and / or increase processing speed. This also further improves the functionality of the invention.

[0052] Furthermore, it is proposed that the sampled values ​​be normalized. Normalization offers the possibility of further improving subsequent processing. For example, the sampled value with the largest value can be chosen as the reference value. However, it can also be stipulated that the sampled value in the region of the propagation delay limit be set to 2023PF00052.

[0053] 13

[0054] A reference value is used for normalization. Of course, other suitable values ​​can also be used for normalization. For example, a value of the ultrasound signal itself can be used as a reference value. Overall, there is the possibility of further improving the function of the invention.

[0055] The advantages and effects specified for the method according to the invention also apply equally to the computer program product according to the invention, the computer-readable data carrier, the evaluation unit of the invention, the sensor device of the invention, and the motor vehicle equipped with the sensor device, and vice versa. In particular, method features can therefore also be formulated as device features and vice versa.

[0056] Further features of the invention are evident from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as those subsequently mentioned in the description of the figures and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations without departing from the scope of the invention. Thus, embodiments that are not explicitly shown and explained in the figures, but which can be derived and generated from the explained embodiments by separate combinations of features, are also to be considered as encompassed and disclosed by the invention. Embodiments and combinations of features that do not exhibit all the features of an originally formulated independent claim are also to be considered disclosed.Furthermore, embodiments and combinations of features, in particular those set out above, are to be considered disclosed which go beyond or deviate from the combinations of features set out in the cross-references of the claims.

[0057] For use cases or application situations that may arise during the procedure and are not explicitly described here, it may be provided that, according to the procedure, an error message and / or a request for user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0058] Showing: 2023PF00052

[0059] 14

[0060] Fig. 1 shows a schematic side view of a motor vehicle with a sensor device arranged on a door of the motor vehicle, which includes an ultrasonic sensor.

[0061] Fig. 2 shows a schematic representation of the sensor device according to Fig. 1;

[0062] Fig. 3 shows a schematic diagram representation of sampled values ​​that have been determined by sampling a sensor signal profile of a sensor signal of the ultrasonic sensor during a reception period and that form a received signal data set.

[0063] Fig. 4 is a schematic diagram representation in which a plurality of received signal data sets are graphically recorded as in Fig. 3.

[0064] Fig. 5 is a schematic diagram representation like Fig. 4, in which a plurality of filtered sample data sets are graphically captured.

[0065] Fig. 6 shows a schematic diagram representation of a sum value when summing a given number of consecutive sampled signals according to Fig. 5, and

[0066] Fig. 7 shows a schematic flowchart for evaluating a sensor signal.

[0067] Fig. 1 shows a schematic side view of a motor vehicle 1 with a sensor device 10 arranged on a door 2 of the motor vehicle 1. The sensor device 10 serves to detect the environment 5 of the motor vehicle 1, in particular to detect objects such as items, persons, and / or the like. The sensor device 10 can also detect users of the motor vehicle. In particular, it is possible with the sensor device 10 to detect, for example, an action or gesture by the user. In the present embodiment, the sensor device 10 is designed to detect the action of a door handle 6 of the door 2 by the user in order to determine the user's intention to open the door. This makes it possible to provide user functionality in addition to object detection.In particular, it is possible to open the door at least partially automatically based on a detected action by the user, thus giving the user access to an interior 7 of the motor vehicle 1 to 2023PF00052.

[0068] 15 enable. In the present embodiment according to Fig. 1, only a single sensor device 10 is shown. In alternative embodiments, however, several sensor devices 10 can be provided accordingly, which are preferably arranged horizontally spaced on a circumference of the motor vehicle.

[0069] Fig. 2 shows a schematic representation of the sensor device 10 according to Fig. 1. Fig. 2 shows that the sensor device 10 has an ultrasonic sensor 11 which is arranged on a metal sheet 3 of the door 2. The metal sheet 3 is part of an outer skin of the motor vehicle 1.

[0070] The ultrasonic sensor 11 is arranged such that it detects a detection area 15 through the metal sheet 3 of the door 2. For this purpose, the ultrasonic sensor 11 is in direct contact with a surface of the metal sheet 3. In the present embodiment, the ultrasonic sensor 11 is arranged on an inner surface of the metal sheet 3, so that it is protected by the metal sheet 3 of the door 2. Furthermore, the sensor device 10 includes an evaluation unit 12 that is signal-linked to the ultrasonic sensor 11 and serves to evaluate sensor signals 21 from the ultrasonic sensor 11.

[0071] The following explains the evaluation of the sensor signal of the ultrasonic sensor 11 with reference to Fig. 7, which shows a corresponding flowchart.

[0072] During normal operation, the ultrasonic sensor 11 emits ultrasonic signals 19 in a time-discrete sequence, in the form of ultrasonic pulses (step 40 in Fig. 7). For this purpose, the ultrasonic sensor 11 has a transmitter / receiver unit 31. The transmitter / receiver unit 31 is connected to a generator 32 of the ultrasonic sensor 11. The emission of the ultrasonic signals 19 can be controlled by means of the generator 32.

[0073] The transmitter / receiver unit 31 receives the respective echo signals 20. Depending on the reception of the echo signals 20, the ultrasonic sensor 11 emits the respective sensor signal 21 (step 41 in Fig. 7).

[0074] A reception period 23 (Fig. 3) is specified, which depends on the transmission of the respective ultrasound signal 19 for a predetermined transit time range of the ultrasound signal or the echo signal 20. (By the 2023PF00052)

[0075] 16

[0076] The reception period 23 is thus a period preferably defined between two successive ultrasound signals 19, within which the echo signals 20, which arrive at the ultrasound sensor 11 in response to the emission of the ultrasound signal 19, can be received by means of the ultrasound sensor 11. For each reception period 23, the respective echo signal 20 is received, and depending on the corresponding sensor signal 21, a corresponding sensor signal profile is provided (step 42 in Fig. 7). The sensor signal profile therefore preferably extends over the temporal extent of the reception period 23.

[0077] The evaluation unit 12 has a scanning unit 26 that samples the signal profile of a respective sensor signal 21 of a respective reception period 23 in a time-discrete manner (step 43 in Fig. 7). For this purpose, the ultrasonic sensor 11 provides a synchronization signal 22, which marks the beginning of a reception period 23. In this way, a respective received signal data set with respective sample values ​​24 is assigned to a respective sensor signal profile (step 44 in Fig. 7), as shown in Fig. 3. In this case, the reception period 23 ends with a subsequent synchronization signal 22. However, the reception period 23 can end before the subsequent synchronization signal 22.

[0078] Fig. 3 shows a schematic diagram of sampled values ​​24, which were determined by sampling a sensor signal 21 from the ultrasonic sensor 11 during a reception period 23 and which form a received signal data set. An abscissa represents time. In this case, the reception period 23 comprises 125 sampling points. The sampling points are chosen to be equidistant in time. An ordinate is assigned to each signal value of the respective sampled value 24, which in this case is a corresponding energy value. The abscissa in Fig. 3 is labeled with reference numeral 17. The ordinate is labeled with reference numeral 18. The energy value is normalized and covers a range from zero to 1000. A graph 16 graphically represents the course of the energy values ​​over the sampling points.An envelope of graph 16 can correspond approximately to the corresponding sensor signal profile of the associated sensor signal 21.

[0079] Figure 1 also shows the evaluation unit 12, which is in communication with the ultrasonic sensor 11. The evaluation unit 12 has a computer unit 13, which is designed as a program-controlled computer unit. Furthermore, the 2023PF00052

[0080] 17

[0081] Evaluation unit 12 includes a data carrier 14, which in this case is designed as an electronic storage unit. A computer program is stored in the electronic storage unit, which instructs the computer unit 13 to provide the desired functionality to evaluation unit 12. Furthermore, evaluation unit 12 may have additional hardware components, for example, to process signals further.

[0082] Figure 2 shows that the evaluation unit 12 has a processing unit 27 which is connected to the scanning unit 26. The respective received signal data sets generated by the scanning unit 26 are made available to the processing unit 27 for further signal processing.

[0083] As can be seen in Fig. 3, the energy values ​​of the sampled values ​​24 from approximately the first 35 sampling points are sometimes very high. These sampling points capture, among other things, echo signals 20, which are at least partially caused by the metal sheet 3. Using the processing unit 27, a predetermined number of temporally consecutive received signal data sets are selected (step 45 in Fig. 7). This can be done, for example, by means of windowing. For instance, 10 or more temporally consecutive received signal data sets can be selected.

[0084] The sample values ​​24 of the selected received signal data sets, determined at each sampling time, are combined into a respective time-specific sample data set (step 46 in Fig. 7). A corresponding sample data set is created for each sampling time. In this embodiment, exactly one sample data set is created for each sampling time. Each sample data set preferably contains a number of samples corresponding to the number of selected received signal data sets.

[0085] The sampled data sets are transformed into the frequency domain (step 47 in Fig. 7) to create the respective sampled data set transforms. These sampled data set transforms are high-pass filtered (step 48 in Fig. 7) and then inverted (step 49 in Fig. 7) to create filtered sampled data sets. For this purpose, filtering can be performed, for example, using a high-pass filter, particularly one based on a Butterworth filter-like functionality.

[0086] The filtered sample data sets are further processed by selecting a predefined number of chronologically consecutive filtered sample data sets 2023PF00052

[0087] 18 (step 50 in Fig. 7). The selection of the filtered sample data sets can also be performed using windowing – as described above for selecting the received signal data sets. Here, it is provided that the operation is performed by summing the sample values ​​of several sample data sets that have the same received signal data set time. The number of sample data set values ​​used for the operation corresponds to the number of sample data sets. In an alternative embodiment, it can be provided that a fixed number of cohorts (bins) are defined, which subdivide the sample data set values ​​according to their sample data set time using several propagation delay limits, so that multiple operation values ​​can be generated for a single received signal data set time.The "windowing" effect determined in this way only comes into play subsequently, when the resulting link value is "windowed" with link values ​​from previous received signal data points. This allows the resulting link data point to be transformed, filtered, and reverse-transformed to reduce or remove constant components from the link values. In this application, only the sample data points from the last received signal point are linked; that is, the last value of each selected sample data point.

[0088] The selected sample data sets are linked, with the link being formed by addition (step 51 in Fig. 7). This allows a respective link value 37 to be generated. The link value 37 is compared with a reference value 36 (Fig. 6), and a reference signal 30 is output depending on the comparison (step 52 in Fig. 7). By appropriately specifying the reference value 36, as well as by specifying the selection of received signal data sets and the selection of sample data sets, further processing enables the detection of user actions through the metal sheet using the ultrasonic sensor 1 1, for example, a manual operation in the area of ​​the door 2 of the vehicle 1, a gesture performed by the user to activate a control function, and / or the like.

[0089] Fig. 4 shows a schematic diagram of a multitude of temporally successive received signal data sets, as depicted in Fig. 3. An abscissa is assigned to each received signal data set, while an ordinate is assigned to the respective sampling times of the received signal data sets. A line thickness is assigned to the respective energy value. It can be seen that particularly in a lower range 33 2023PF00052

[0090] Figure 19 of the diagram in Fig. 4 shows a high energy component in the samples of the different received signal data sets. This component particularly affects samples that were sampled before the respective time ti. In contrast, for samples, especially those in a range greater than 150, an increase in energy can be observed from some consecutive received signal data sets, as indicated by arrows 34 in Fig. 4. In the present configuration, this signal increase or energy increase is due to manual operation by a user in the area of ​​the door handle 6.

[0091] In order to derive an evaluable signal for the actuation of the opening device for the door 2 of the motor vehicle 1, the processing unit 27 performs the corresponding filtering during the linking process, resulting in the schematic diagram shown in Fig. 5. The diagram shown in Fig. 5 is similar to the diagram in Fig. 4. As can be seen in Fig. 5, the values ​​in areas 34 are now amplified due to the filtering, whereas the values, particularly in area 33, are significantly reduced.

[0092] Fig. 6 shows a schematic diagram representing a sum value obtained by summing a predetermined number of consecutive sampled signal data sets according to Fig. 5. This is achieved by means of a summing unit 28 of the evaluation unit 12. In this case, the summing unit 28 sums the corresponding sample values ​​24 from approximately 15 consecutive received signal data sets, thus providing a capture window. In this way, a signal waveform according to graph 35 in Fig. 6 can be obtained. The summing unit 28 provides a sum value 37. The sum value 37 is represented by graph 35 in Fig. 6. For the summing functionality, the summing unit 28 provides the capture window, which can be moved across the received data sets, whereby only the sample values ​​24 of the received signal data sets captured by the capture window are summed. This results in the waveform according to graph 35.The respective sum value 37 is then compared with a sum comparison value 36 using a comparison unit 29. Figure 6 shows that the sum values ​​37 are greater than the sum comparison value 36 in the areas 34. Depending on this, the comparison unit 29 outputs a corresponding comparison signal 30, which is transmitted to the vehicle control unit 4 of the motor vehicle 1. The vehicle control unit 4 recognizes the comparison signal 30 as an action by the user and activates a door opening device of the motor vehicle 2, so that the door 2 of the motor vehicle 1 is opened automatically. 2023PF00052.

[0093] 20

[0094] Regardless of the above, the sensor device 10, using the aforementioned procedure, can also be used to identify objects. These objects can be, for example, obstacles or other people in the vicinity of the vehicle 1. Depending on how the sensor device 10 is used, the respective selection or the sum comparison value 36 can be changed accordingly. This can be useful, for example, if an obstacle in the vicinity of the vehicle 1 is to be detected instead of a gesture or manual operation by the user.

[0095] The exemplary embodiments serve solely to illustrate the invention and are not intended to limit it.

Claims

2023PF00052 Patent claims 1. Method for evaluating a sensor signal (21) of an ultrasonic sensor (11) arranged on a metal sheet (3), wherein the ultrasonic sensor (11) has a detection range (15) through the metal sheet (3), wherein the ultrasonic sensor (11) emits ultrasonic signals (19) successively in a time-discrete manner, receives echo signals (20) and outputs the sensor signal (21) depending on the reception of the echo signals (20), wherein for a respective reception period (23), which is predetermined for a predetermined transit time range of the ultrasonic signal (19) depending on the emission of the respective ultrasonic signal (19), the respective echo signal (20) is received and a corresponding sensor signal profile is provided depending on the respective sensor signal (21), wherein the sensor signal profile is sampled in a time-discrete manner at predetermined times of the respective reception period (23).wherein a respective sensor signal profile is assigned a respective received signal data set with respective sample values ​​(24), characterized in that a predetermined number of temporally successive received signal data sets are selected, wherein the sample values ​​(24) of the selected received signal data sets determined at a respective sampling time are combined into a respective time-specific sample data set, wherein the sample data sets are transformed into the frequency domain to form respective sample data set transforms, the sample data set transforms are high-pass filtered and subsequently back-transformed to form filtered sample data sets, wherein the filtered sample data sets are further processed by combining a predetermined number of temporally successive filtered sample data sets to form a respective combination value (37),where the link value (37) is compared with a comparison value (36), and a comparison signal (30) is output depending on the comparison. 2023PF00052 22 2. Method according to claim 1, characterized in that the signal value is formed by an energy value of the respective sample value (24).

3. Method according to one of the preceding claims, characterized in that the reference value is varied.

4. Method according to one of the preceding claims, characterized in that the filtered sample data sets are additionally cleaned of interference during the linking process.

5. Method according to one of the preceding claims, characterized in that the predetermined number of temporally successive received signal data sets and / or the predetermined number of temporally successive filtered sample data sets is varied.

6. Method according to one of the preceding claims, characterized in that the specified times are the same for at least a part of the respective reception periods (23).

7. Method according to one of the preceding claims, characterized in that the specified times of a respective reception period (23) are equidistant.

8. Method according to one of the preceding claims, characterized in that the linking includes at least an addition or a multiplication.

9. Method according to one of the preceding claims, characterized in that the linking is only carried out for sample values ​​of the filtered sample data sets whose sample value is in a predetermined range.

10. Method according to one of the preceding claims, characterized in that the sampled values ​​(24) are normalized. 2023PF00052 23 11. Computer program product with program code means, which are stored in particular in a computer-readable medium (14) in order to carry out a method for evaluating a sensor signal (21) of an ultrasonic sensor (11) arranged on a metal sheet (3), wherein the ultrasonic sensor (11) has a detection range (15) through the metal sheet (3), wherein the ultrasonic sensor (11) emits ultrasonic signals (19) successively in a time-discrete manner, receives echo signals (20) and, depending on the reception of the echo signals (20), emits the sensor signal (21) for a respective reception period (23), which is predetermined for a specified transit time range of the ultrasonic signal (19) depending on the emission of the respective ultrasonic signal (19), to receive the respective echo signal (20) and, depending on the corresponding respective sensor signal (21), to provide a respective associated sensor signal profile,wherein the sensor signal profile is sampled discretely in time at predetermined times of the respective reception period (23), wherein a respective received signal data set with respective sample values ​​(24) is assigned to a respective sensor signal profile, characterized in that a predetermined number of temporally successive received signal data sets are selected, wherein the sample values ​​(24) of the selected received signal data sets determined at a respective sampling time are combined into a respective time-specific sample data set, wherein the sample data sets are transformed into the frequency domain to form respective sample data set transforms, the sample data set transforms are high-pass filtered and subsequently back-transformed to form filtered sample data sets, wherein the filtered sample data sets are further processed,by combining a predetermined number of temporally successive filtered sample data sets to form a respective combination value (37), wherein the combination value (37) is compared with a comparison value (36), and depending on the comparison a comparison signal (30) is output.

12. Computer-readable data carrier (14) on which a computer program product is stored at least according to claim 11.

13. Evaluation unit (12) for evaluating a sensor signal from a sensor arranged on a metal sheet (3) and connected to the evaluation unit (12) in terms of signal technology 2023PF00052 24 coupled ultrasonic sensor (11), wherein the ultrasonic sensor (11) detects a detection area (15) through the metal sheet (3), wherein the ultrasonic sensor (11) emits ultrasonic signals (19) successively in a time-discrete manner, receives echo signals (20) and, depending on the reception of the echo signals (20), outputs sensor signals (21) to the evaluation unit (12), wherein the evaluation unit (12) is configured to receive a respective echo signal (20) for a respective reception period (23), which can be specified depending on the emission of the respective ultrasonic signal (19) for a predetermined transit time range of the ultrasonic signal (19), and to provide a respective associated sensor signal profile depending on the corresponding respective sensor signal (21), wherein the evaluation unit (12) is configuredto sample the sensor signal profile at predetermined times of the respective reception period (23) in a time-discrete manner and to assign a respective received signal data set with respective sample values ​​(24) to a respective sensor signal profile, characterized in that the evaluation unit (12) is configured to select a predetermined number of temporally successive received signal data sets, to combine the sample values ​​(24) of the selected received signal data sets determined at a respective sampling time into a respective time-specific sample data set, to transform the sample data sets into the frequency domain in order to form respective sample data set transforms, to high-pass filter the sample data set transforms and then to back-transform them in order to form filtered sample data sets, to further process the filtered sample data sets,by linking a predetermined number of temporally successive filtered sample data sets to form a respective link value (37), comparing the link value (37) with a comparison value (36), and outputting a comparison signal (30) depending on the comparison.

14. Sensor device (10) for detecting an environment (5) of the sensor device (10), comprising an ultrasonic sensor (11) arranged on a metal sheet (3), wherein the ultrasonic sensor (11) detects a detection area (15) through the metal sheet (3), and comprising an evaluation unit (12) coupled to the ultrasonic sensor (11) for evaluating a sensor signal (21) of the ultrasonic sensor (11). 2023PF00052 25 characterized in that the evaluation unit (12) is designed according to claim 13.

15. Motor vehicle (1) with a sensor device (10) for detecting an environment (5) of the motor vehicle (1), characterized in that the sensor device (10) is designed according to claim 14.

Images