Device for motion detection and distance determination

Abstract

Device (1) for motion detection and distance determination, comprising a radio module (10) and a control device (20) which is designed to operate the radio module (10) in a radar operating mode for motion detection, in which radar pulse signals (31) are repeatedly transmitted and radar pulse responses (32) are received by the radio module (10) in a radar interval, which were generated by the reflection of the radar pulse signals (31) on objects (30), wherein the control device (20) is further designed to store the received radar impulse responses (32) and to be operated in at least two different evaluation modes (A1, A2, A3), in which signal curves (35, 36, 37) describing a movement of the objects are generated from the radar impulse responses (32) in each case differently and the signal curves (35, 36, 37) describing a movement of the objects (30) are evaluated in accordance with the evaluation mode (A1, A2, A3) for controlling a function.

Description

[0001] The invention relates to a device for motion detection and distance determination based on a radio module suitable for radar and ranging, wherein the radio module is in particular a UWB (ultra-wide-band) radio module.

[0002] In the context of modern technology, there are increasing applications in which people or objects need to be monitored for their movements. Optical sensors are often used for this purpose, but this has several disadvantages. On the one hand, it requires complex image analysis, and on the other hand, distances cannot be determined reliably or only with great effort. In addition, optical sensors can potentially capture image data, which can be problematic in terms of a potential invasion of privacy.

[0003] The disadvantages of optical sensors can be compensated by radar sensors.

[0004] Devices are already known from the prior art and in particular from document DE 10 2023 111 290 A1 which have a UWB radio module and can be operated alternately in a radar operating mode for radar location of objects and in a ranging operating mode for distance determination (ranging) to a unit receiving a ranging pulse signal and transmitting a ranging pulse response, so that UWB radio modules can be used simultaneously or alternately for several functionalities.

[0005] The use of such devices is known in motor vehicles, but is not limited to them. Such devices can also be used, for example, in access control systems for buildings.

[0006] In addition, such devices can also be used in motor vehicles or buildings or in other areas of application for a wide variety of specific tasks or applications.

[0007] With regard to motor vehicles, but again not limited to this, such devices can be used for the detection of children left behind in the vehicle (Child Presence Detection - CPD), for the control of vehicle functions based on body movement or gesture recognition, for seat occupancy detection, theft detection and for a variety of other applications.

[0008] The problem here is that, according to the state of the art, a device specifically designed for this purpose must be provided for each application, so that it is not possible, for example, to use a device intended for operation in motor vehicles in an access control system of a building or to use a device for detecting child abandonment (CPD) instead for detecting a "kick" body movement to control a tailgate or trunk lid.

[0009] It follows that, according to the state of the art, a specific device must be developed and adapted with great effort for each application.

[0010] The invention is therefore based on the object of overcoming the aforementioned disadvantages and of providing a device for motion detection and distance determination that can be used for a wide variety of applications and is easily adaptable to the respective application.

[0011] This problem is solved by the combination of features according to claim 1.

[0012] According to the invention, a device for motion detection and distance determination is therefore proposed, which device has a radio module and a control device. The radio module can preferably be operated by the control device in a ranging operating mode for determining the distance between the radio module and mobile units, for example smart FOBs or other electronic keys, which receive the ranging pulse signal and then transmit a ranging response signal. The ranging can be carried out in accordance with CCC (Car Connectivity Consortium). However, it is essential to the invention that the control device is designed to operate the radio module in a radar operating mode for motion detection, in which the radio module repeatedly transmits radar pulse signals within a radar interval and receives radar pulse responses generated by the reflection of the radar pulse signals from objects.The fact that appropriately controlled radio modules of such devices can be operated both in a ranging mode and in a radar mode is known, for example, from the published patent application DE 10 2023 111 290 A1.

[0013] In this regard, it should be noted that the radio module preferably has a transceiver, i.e. a transmitting / receiving unit, and at least one antenna, but preferably at least two antennas. Although the radio module is further preferably a UWB radio module, the invention is fundamentally not limited to the use of UWB (Ultra Wide Band), since this is also transferable to other radio standards that enable both a radar operating mode and a ranging operating mode. Based on this, the invention provides that the control device is designed to store the received radar impulse responses and to be operated in at least two different evaluation modes, which are correspondingly predefined and stored in the control device. In the evaluation modes, according to the invention, different, i.e.differing depending on the evaluation mode, signal curves describing a movement of the objects are generated and the signal curves describing a movement of the objects are evaluated depending on the evaluation mode to control a function.

[0014] According to the invention, a device for motion detection and distance determination is proposed that can be operated in various, predefined evaluation modes, so that the device for signal generation and subsequent evaluation does not need to be programmed for the specific application. All that is required is to select the evaluation mode and, if necessary, specify the movement patterns explained below—provided these are not already predefined and stored in the control device.

[0015] Accordingly, the device proposed according to the invention can be used, for example, both for a CPD in the interior of a motor vehicle and for gesture control in an access control system of a building.

[0016] For the determination of the signal curves and in particular for the evaluation of the radar impulse responses, it is advantageous if the control device is designed to assign the received radar impulse responses to the respectively transmitted radar impulse signal, by the reflection of which the respective radar impulse response was generated, and to store the assignment.

[0017] Consequently, a radar impulse response can be stored, for example, with a time stamp indicating the time of reception and a time stamp indicating the time of transmission of the associated radar impulse signal, so that during subsequent evaluation it is immediately clear which radar impulse signal generated the radar impulse response.

[0018] Furthermore, the control device can be designed to determine the distances between the radio module and the objects reflecting the radar pulse signal from a respective radar pulse signal and the associated radar pulse response or the association, and to determine the distances and / or the change in the distances and / or the position of the individual objects over time for each object as a signal curve describing the movement of the respective object.

[0019] Although individual signals, each belonging to an object, may first have to be isolated from a radar impulse response, which may partially overlap, the distance between the radio module and an object can be determined in a simplified manner by the radar signal propagation time of the radar impulse signal from the radio module to the object and the radar response signal from the object to the radio module as follows: s=c*tRTT2, with s Distance between radio module and object, c speed of light, t RTT Radar signal round trip time as the sum of the signal travel time of the radar pulse signal from radio module to object and the signal travel time of the radar response signal from object to radio module.

[0020] Since, as stated, a time stamp indicating the reception time and a time stamp indicating the transmission time of the corresponding radar pulse signal can be stored for each radar impulse response, the radar signal propagation time can be determined by: tRTT=tE−tS, with t RTT Radar signal transit time (Round Trip Time) t E Time / timestamp of reception of the radar impulse response ts Time / timestamp of sending the radar pulse signal

[0021] Accordingly, the distance between the radio module and an object or the respective distance between the radio module and several objects can be stored as a respective signal curve, for example, or the change in the distance over time.

[0022] Regardless of a specific signal curve, it is advantageous if the movements of an object are recorded reliably and with a sufficiently high resolution for the respective application.

[0023] For this purpose, the control device can be configured to specify the radar interval to the radio module for recurrently transmitting the radar pulse signals depending on the respective evaluation mode in which the control device is operating. Thus, a specific radar interval can be stored for each evaluation mode.

[0024] Alternatively, and choosing a general approach that is independent of the evaluation modes, it can also be provided that the control device is designed to determine a movement speed of the object from a signal curve describing the movement of an object, ie also for example from the change in distance, to determine a preferred radar interval from the movement speed and to specify the radar interval to the radio module for the recurring transmission of the radar pulse signals.

[0025] If multiple objects are detected, a rule can also be stored in the control device that determines the radar interval based on which object. For example, the radar interval can be determined based on the speed of the fastest object or the nearest object (i.e., the one with the shortest distance to the radio module), or an object within a predetermined distance or range.

[0026] The radar interval is preferably determined by: ΔtRadar=λvmax*4, with Δt Radar Radar interval λ Wavelength of the carrier signal of the radar pulse signal (e.g. 8 GHz for UWB channel 9) v max Movement speed of the object

[0027] Such a radar interval, which is not fixed but can be changed depending on the movement, ensures correct and sufficiently high-resolution detection of the movement, which can adapt automatically and independently of the evaluation mode, so that the radar interval adapts automatically each time the device is used.

[0028] As already explained, various signal waveforms can be generated from the radar impulse responses or from other signal sources, which have an application-specific relevance, so that the signal waveforms are generated depending on the selected evaluation mode and evaluated depending on the selected evaluation mode.

[0029] In order to simplify the evaluation of the radar impulse response, which is complex due to superposition, it can be provided that it is transformed and / or filtered and / or prepared or processed in another way, in particular before the evaluation and / or before the generation of the signal curves describing the movement of individual objects.

[0030] Thus, it can be provided that the control device is designed to separate the radar impulse response into its phase and amplitude characteristics and, if necessary, to store them in a manner that can be assigned to one another. The control device is consequently further designed to generate signal curves describing the movement of the objects from the phase and / or amplitude characteristics of a radar impulse response.

[0031] Based on this, the control device is preferably further designed to generate signal curves describing the movement of the objects over time and / or over distance and / or over movement from the radar impulse response, depending on the evaluation mode.

[0032] If using the radar impulse response over time is advantageous in one evaluation mode, this (first) signal curve can be used. If using the radar impulse response over distance is advantageous in another evaluation mode, this (second) signal curve can be used.

[0033] For example, in an evaluation mode for child left behind detection (CPD), the radar impulse response or the movement of the object isolated from it over time can be evaluated as a signal curve, since breathing movements of people or children detected in radar operating mode lead to a small distance variance over time.

[0034] In an evaluation mode for the detection of a body movement or gesture to control a function, for example a "kick" body movement to open and / or close a rear or trunk lid, the radar impulse response or the resulting isolated movement of the object can be evaluated as a signal curve over the distance instead of over time due to the large distance variance.

[0035] Although the control device can basically operate the radio module in the ranging operating mode and preferably in a CCC-compliant ranging operating mode, it is preferably provided that the control device is designed to operate the radio module alternately in the radar operating mode for motion detection and in a ranging operating mode for determining the distance between the radio module and mobile units, in which ranging pulse signals are sent by the radio module and ranging pulse responses are received which were sent by mobile units after receiving a ranging pulse signal, so that the distances and / or their change and / or the position or their respective signal curves can be determined therefrom as signal curves describing the movement of the mobile units.

[0036] Additionally or alternatively, in ranging mode, the radio module can transmit ranging pulse signals and receive radar pulse responses generated by the reflection of the ranging pulse signals from objects. The ranging pulse signals can, in turn, be stored as described and evaluated depending on the evaluation mode.

[0037] An advantageous variant of the device also provides that the radio module has at least two antennas which are at a predetermined distance from one another and have a predetermined orientation or arrangement. In this case, the control device is designed to determine the directional angle from which the impulse response was received from a phase shift or phase difference between phases of an impulse response received at the at least two antennas. This applies both to radar impulse responses in radar and / or ranging operating mode and to ranging impulse responses. In addition to the information about the movement of the objects or mobile units obtained from the respective impulse responses, the information about the angle from which the respective impulse response was received can also be used in the evaluation. Based on this, the directional angle can be used to evaluate the signal curves depending on the selected evaluation mode.

[0038] The direction angle is determined in a simplified manner as follows: Θ=arcsin(α*λ2*π*d), with Θ Direction angle α measured PDoA (Phase Difference of Arrival) λ Wavelength of the carrier frequency of the impulse response d Distance between the two antennas

[0039] An advantageous development of the invention also provides that the control device is designed to compare the signal curves describing a movement of the objects and / or the movement of the objects with a respective limit value predetermined for each evaluation mode, and to reject signal curves and / or objects for further evaluation based on the comparison.

[0040] In addition, at least one signal pattern can be stored in the control device for each evaluation mode, wherein the control device is designed to compare the signal curves specific to the respective evaluation mode, which describe a movement of the objects, with the signal pattern in the respective evaluation mode and, if there is a sufficiently high match, to generate a control signal which triggers a function.

[0041] For example, for the CPD, a signal pattern typical for the breathing of a person or child can be stored in the control device so that the signal course of the movement over time is compared with the signal pattern typical for breathing.

[0042] In the case of gesture or “kick” recognition, a signal pattern typical for the “kick” or gesture can be stored so that the signal progression of the movement over the distance can then be compared with the signal pattern typical of the “kick” or gesture.

[0043] In addition, specific signal patterns and specific evaluation modes can be provided for different gestures or for different installation situations.

[0044] For example, evaluation modes can be provided for the following use cases: - Detection of children left behind in the vehicle (CPD) - Unlock / open the trunk using a “kick” gesture - Hand gesture to unlock doors or flaps - Hand gesture to activate / deactivate a lighting or vehicle interior lighting or other operating devices - Seat occupancy detection - Theft detection (intrusion detection) - Intrusion prevention - Detection of obstacles when opening doors or flaps

[0045] The features disclosed above can be combined as desired, as long as this is technically possible and they do not contradict each other.

[0046] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below, together with the description of the preferred embodiment of the invention, with reference to the figures. They show: Fig. 1 shows a device according to the invention; Fig. 2 a detailed view of the radio module; Fig. 3 a side view of a device according to the invention.

[0047] The figures are schematic examples. Identical reference numerals in the figures indicate identical functional and / or structural features.

[0048] In Fig. 1 shows the schematic structure of a device 1 according to the invention, which essentially comprises a radio module 10 and a control device 20, which is designed to operate the radio module 10 in a radar operating mode for motion detection and in a ranging operating mode for distance determination.

[0049] Controlled by the control device 20, the radio module 10 in the radar operating mode repeatedly transmits radar pulse signals 31 in a radar interval, which are reflected by objects 30, thereby generating radar pulse responses 32, which are received by the radio module 10, wherein the control device 20 is designed to store the received radar pulse responses 32 for subsequent evaluation.

[0050] In addition to the radar operating mode, the Fig. 1 is further configured or provided for a ranging operating mode, for which the control device 20 is designed to operate the radio module 10 alternately in the radar operating mode for motion detection and in a ranging operating mode for determining the distance between the radio module 10 and mobile units 40. In the ranging operating mode, the radio module 10 transmits ranging pulse signals 41 and receives ranging pulse responses 42, so that, for example, the distance or the distance (ranging) between the radio module 10 and mobile receivers 40 can be determined via the signal propagation time. By adding the evaluation of the phase difference (PDoA), as used for Fig. 2, the position or, from the change in position, the movement of the mobile receiver 40 can also be determined as a signal curve.

[0051] Similar devices are generally known, but these require extensive adaptation to the specific application or use.

[0052] According to the invention, it is therefore provided and Fig. 1 shows that the control device 20 is designed to initially store the received radar impulse responses 32 independently of any intended further processing, wherein at least two and in the present case three different evaluation modes A1, A2, A3 are stored in the control device, so that the control device 20 can be operated in these three evaluation modes A1, A2, A3.

[0053] For each of the evaluation modes A1, A2, A3, a specific processing of the previously stored radar impulse responses 32 is stored in the control device 20, so that only the evaluation mode A1, A2, A3 suitable for the desired application needs to be selected.

[0054] In the present case, the evaluation mode A1 is used to detect gestures or “kick” and to control a trunk lid based thereon. For this purpose, it is provided that in the first evaluation mode A1, a signal curve 35 describing the movement of an object detected in the detection area is generated over time from the radar impulse responses 32, for which purpose the radar impulse responses 32 are previously separated into their phase curve 33 and their amplitude curve 34 and assigned to individual objects, or signal curves 35 describing the movement of individual objects are generated.

[0055] A comparison is then made with a signal pattern 38 stored for the first evaluation mode A1, wherein, if the match is within a predetermined tolerance, a control signal 21 is generated to open or close the rear or trunk lid.

[0056] If the otherwise preferably identical device is to be used for a different application, here for example CPD, the second evaluation mode A2 can be selected instead according to the invention for evaluating the radar impulse response 32. This again involves separating the radar impulse responses 32 into their phase profile 33 and their amplitude profile 34, and assigning or generating individual signal profiles 36 for each object within the desired detection range. If signal profiles were determined for objects located outside the desired detection range, for example, more than 3 m away, these can be discarded for further evaluation.

[0057] The remaining signal curves 36 are generated directly over time or are transformed into a representation over time, since the distance variance is small for a respiratory movement used for CPD.

[0058] The signal curves 36 are then compared with a signal pattern 38 specific to the selected evaluation mode A2 and already stored in the control device 20, which, in evaluation mode A2, corresponds to a respiratory movement of a thorax. If the signal curve 36 matches the signal pattern 38 within predetermined rules or a predetermined tolerance, a control signal 21 is generated, which triggers application-specific measures.

[0059] For clarification, Fig. 3 shows that, in order to detect a person 2 or a child, radar pulse signals 31 are emitted by the device 1 and reflected, inter alia, by the chest of the person 2, which is to be understood as object 30, so that radar pulse responses 32 are reflected back to the device 1, which are influenced by the breathing movement of the person 2 or the chest and thus, with appropriate evaluation, allow detection of a breathing person 2.

[0060] Since the device 1 can also detect the mobile unit 40 in the ranging operating mode and record its position, it is also possible to distinguish whether the object detected in the radar operating mode and classified as a breathing person 2 in the evaluation mode A2 is an authorized user or a person or child left behind.

[0061] In addition to the already explained evaluation modes A1, A2, Fig. 1 shows an example of a further evaluation mode A3, which can be used, for example, for the proximity detection of objects in which, for example, no separation of the radar impulse response 32 into the phase curve 33 and the amplitude curve 34 is provided.

[0062] It is essential, however, that a plurality of further evaluation modes with associated methods for generating a signal curve describing the movement and for evaluating such a signal curve as well as respective associated signal patterns 38 can be stored in the control device 1 or can be imported into the control device 20, so that the device 1 according to the invention can be used for a wide variety of applications without further individual adaptation.

[0063] In addition to the information and signal curves obtained directly from the radar pulse signals 31 and their radar pulse responses 32, as well as the information and signal curves obtained directly from the ranging pulse signals 41 and their ranging pulse responses 42 or their radar pulse responses 32, additional information can be used in the evaluation specific to the respective evaluation mode. In addition to checking whether an object or movement lies within or outside a predetermined range, a directional angle Θ can also be determined via a phase shift, for example.

[0064] The determination of the angle Θ is schematically and simplified for ranging impulse responses 42 in Fig.2, whereby this can also be done with radar impulse responses 32. In each case, the radio module 10 has two antennas 11, which are arranged in a common antenna plane and are spaced apart by a predetermined and known distance d.

[0065] The radio module 10 accordingly has exactly two antennas 11 for receiving the ranging impulse response 42 transmitted from the mobile unit 40 to the radio module 10.

[0066] The angle Θ is determined from a phase shift α between the ranging impulse response 42 received at both antennas 11 or a phase shift α between the carrier waves 43 of the ranging impulse response 42 received at both antennas 11 and the distance d between the antennas 11. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2023 111 290 A1 [0004, 0012]

Claims

[1] Device (1) for motion detection and distance determination, comprising a radio module (10) and a control device (20) which is designed to operate the radio module (10) in a radar operating mode for motion detection, in which radar pulse signals (31) are repeatedly transmitted and radar pulse responses (32) are received by the radio module (10) in a radar interval, which were generated by the reflection of the radar pulse signals (31) on objects (30), wherein the control device (20) is further designed to store the received radar impulse responses (32) and to be operated in at least two different evaluation modes (A1, A2, A3), in which signal curves (35, 36, 37) describing a movement of the objects are generated from the radar impulse responses (32) in each case differently and the signal curves (35, 36, 37) describing a movement of the objects (30) are evaluated in accordance with the evaluation mode (A1, A2, A3) for controlling a function. [2] Device according to claim 1, wherein the control device (20) is designed to assign the received radar impulse responses (32) to the respectively transmitted radar impulse signal (31), by the reflection of which the respective radar impulse response (32) was generated, and to store the assignment. [3] Device according to claim 2, wherein the control device (20) is designed to determine distances (s1, s2) between the radio module (10) and the objects (30) reflecting the radar pulse signal (31) from a respective radar pulse signal (31) and the associated radar pulse response (32) and to determine the distances (s1, s2) and / or their change and / or the position over time for each object as a signal curve (35, 36, 37) describing the movement of the object. [4] Device according to one of the preceding claims, wherein the control device (20) is designed to specify the radar interval to the radio module (10) for the recurring transmission of the radar pulse signals depending on the evaluation mode (A1, A2, A3) in which the control device (20) is operated, or to determine a movement speed of the object from a signal curve (35, 36, 37) describing the movement of an object, to determine a preferred radar interval from the speed of movement and to specify the radar interval to the radio module (10) for the recurring transmission of the radar pulse signals (31). [5] Device according to one of the preceding claims, wherein the control device (20) is designed to separate the radar impulse response (32) into its phase curve (33) and its amplitude curve (34) and to generate signal curves (35, 36) describing the movement of the objects from the phase curve (33) and / or the amplitude curve (34). [6] Device according to one of the preceding claims, wherein the control device (20) is designed to generate, depending on the evaluation mode (A1, A2, A3), from the radar impulse response (32), signal curves (35, 36, 37) describing the movement of the objects (30) over time and / or over distance and / or over movement. [7] Device according to one of the preceding claims, wherein the control device (20) is designed to operate the radio module (10) alternately in the radar operating mode for motion detection and in a ranging operating mode for determining the distance between the radio module (10) and mobile units (40), in which the radio module (10) transmits ranging pulse signals (41) and receives ranging pulse responses (42) which were transmitted by mobile units (40) after receiving a ranging pulse signal (41), and / or in which the radio module (20) transmits ranging pulse signals (41) and receives radar pulse responses (32) which were generated by the reflection of the ranging pulse signals (41) on objects (30). [8] Device according to one of the preceding claims, wherein the radio module (10) has at least two antennas (11) which are spaced apart by a predetermined distance (d) and aligned in a predetermined manner, wherein the control device (20) is designed to determine the directional angle (Θ) from which the impulse response (32, 42) was received from a phase shift (α) between phases of an impulse response (32, 42) received at the at least two antennas (11), wherein the direction angle (Θ) is used depending on the evaluation mode (A1, A2, A3) for evaluating the signal curves (35, 36, 37). [9] Device according to one of the preceding claims, wherein the control device (20) is designed to compare the signal curves (35, 36, 37) describing a movement of the objects (30) and / or the movement of the objects (30) with a respective limit value predetermined for each evaluation mode (A1, A2, A3), and to discard signal curves (35, 36, 37) and / or objects (30) based on the comparison for further evaluation. [10] Device according to one of the preceding claims, wherein at least one signal pattern (38) is stored in the control device (20) for each evaluation mode (A1, A2, A3) and the control device (20) is designed, to compare the signal curves (35, 36, 37) describing a movement of the objects in the respective evaluation mode (A1, A2, A3) with the signal pattern (38) and, if there is a match, to generate a control signal (21) triggering a function.

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