Device with electromechanical transducer for detecting proximity and / or contact in a motor vehicle

Abstract

The invention relates to a device (100) for detecting a contact and / or an approach to a motor vehicle, comprising: - a vibration generator (110) comprising a first electromechanical transducer (111) configured to be mounted on an external element (10) of the motor vehicle, and an electrical signal generator (112) providing the first electromechanical transducer with an electrical signal oscillating at an excitation frequency; - a rechargeable energy storage device (120) for supplying the electrical signal generator; and - a vibration sensor (130) consisting of a second electromechanical transducer (131) configured to be mounted on the external element of the motor vehicle; wherein the output of the vibration sensor (130) is connected to the rechargeable energy storage device (120) so that at least part of the electrical response signal recharges the rechargeable energy storage device.

Description

Technical Field

[0001] This invention relates to the field of motor vehicles, and more particularly to the field of detecting the presence and / or contact in a motor vehicle in order to detect proximity and / or direct physical contact between the motor vehicle and a target (such as an obstacle or a person). Background Technology

[0002] Prior art includes camera-based systems for detecting contact or proximity to motor vehicles. Analyzing the acquired images allows for the determination of information about the environment surrounding the vehicle for detecting approach or intrusion. In variations, back reflections of laser or ultrasonic signals can be used to identify components approaching the vehicle. However, these solutions have various limitations, particularly their cost, the complexity of their installation on the vehicle, and especially their high energy consumption.

[0003] The object of this invention is to provide a solution that allows for the final detection of contact and / or proximity to a motor vehicle with very low energy consumption. Summary of the Invention

[0004] This objective is achieved using a device for detecting contact with and / or proximity to a motor vehicle, the device being configured to be mounted on the vehicle and comprising:

[0005] a) A vibration generator, comprising:

[0006] - A first electromechanical transducer, configured to generate mechanical motion in response to an electrical excitation signal, and configured to be mounted on an external component of the motor vehicle; and

[0007] - An electrical signal generator configured to provide an electrical excitation signal to a first electromechanical transducer, the electrical excitation signal oscillating at an excitation frequency;

[0008] b) A rechargeable energy storage device configured to supply electrical energy to an electrical signal generator; and

[0009] c) A vibration sensor comprising a second electromechanical transducer configured to generate an electrical response signal in response to mechanical displacement and mounted on the external component of the motor vehicle;

[0010] The output of the vibration sensor is electrically connected to the rechargeable energy storage device so as to recharge the rechargeable energy storage device by at least a portion of the electrical response signal during use.

[0011] External elements of a motor vehicle preferably refer to integrally formed mechanical components that, in use, form at least a portion of the outer surface of the motor vehicle. This relates, for example, to body panels. In variations, it may relate to window glass. Preferably, the external element extends along a surface defined by a maximum width and a maximum length having a ratio between 1 and 5 between length and width, wherein the length and width represent dimensions along two orthogonal axes in the same plane, and the length is greater than or equal to the width.

[0012] In use, the vibration generator generates vibrations that are transmitted to the external components of the motor vehicle.

[0013] The vibration of the external components of a motor vehicle is related not only to the mechanical vibration generated by the first electromechanical transducer, but also to the influence of the surrounding environment of the external components of the motor vehicle.

[0014] For example, direct physical contact between the external components of a motor vehicle and the human operator results in a strong attenuation of the vibrations of the external components of the motor vehicle.

[0015] According to another example, vibrations of external components of a motor vehicle generate sound waves emitted into the environment surrounding the vehicle, which are reflected by possible obstacles around the vehicle. The reflected sound waves are phase-shifted relative to the emitted sound waves, with the phase shift varying simultaneously with the distance between the obstacle and the vehicle. The reflected sound waves also have a frequency shift (Doppler effect) related to the speed of the obstacle relative to the speed of the vehicle. This phase-shifted and frequency-shifted sound wave propagates to the external components of the motor vehicle and affects its mechanical vibrations.

[0016] Therefore, it is understood that measuring the mechanical vibration of external components of a motor vehicle allows for the detection of direct physical contact with and / or relative proximity to the vehicle. In this invention, such measurement is performed by a vibration sensor.

[0017] One of the concepts upon which this invention is based is:

[0018] - An electromechanical transducer configured to generate an electrical response signal in response to mechanical displacement is used as the sensitive element of the vibration sensor; and

[0019] - Vibration sensors are used not only to measure mechanical vibrations, but also to recharge rechargeable energy storage devices that supply vibration generators.

[0020] Therefore, at least a portion of the energy used to generate vibrations is recovered and used to generate new vibrations. Ultimately, the discharge of the rechargeable energy storage device is significantly slowed down.

[0021] Therefore, a contact and / or proximity detection device with very low energy consumption is achieved. Furthermore, the device according to the invention uses only relatively inexpensive components. Finally, the device according to the invention is easily integrated into motor vehicles. It can be fully integrated into the vehicle interior, with the electromechanical transducer located on external components of the motor vehicle and on the vehicle's interior. This avoids any premature degradation or wear of the device according to the invention.

[0022] Preferably, the vibration generated by the first electromechanical transducer is weak enough to be imperceptible to a human operator, but sufficient to be detected by a vibration sensor.

[0023] According to a particularly advantageous embodiment, the device according to the invention further includes a drive unit configured to monitor the energy level of the rechargeable energy storage device and drive the frequency of the electrical excitation signal supplied to the first electromechanical transducer, such that:

[0024] a) When the energy level of the rechargeable energy storage device is less than a predetermined threshold, the frequency of the electrical excitation signal is equal to the resonant frequency of the external components of the motor vehicle.

[0025] b) When the energy level of the rechargeable energy storage device is greater than the predetermined threshold, the frequency of the electrical excitation signal is different from the resonant frequency of the external components of the motor vehicle.

[0026] This therefore involves tracking the charging level of the rechargeable energy storage device in real time and comparing that charging level with a predetermined threshold in real time.

[0027] Throughout the text, the resonant frequency of the external components of a motor vehicle represents the frequency of its eigenmode vibration (especially the fundamental or harmonic modes).

[0028] The frequency of the electrical excitation signal provided at the input of the first electromechanical transducer is equal to the frequency of the mechanical oscillation generated therein. Therefore, when the frequency of the electrical excitation signal is equal to the resonant frequency of the mechanical element, this leads to resonance, and thus to a large amplitude of vibration of the mechanical element (excluding the influence of the external environment).

[0029] When the charge level falls below the predetermined threshold, it is determined that the rechargeable storage device should be recharged. In this case, the drive unit controls the vibration generator to vibrate at an excitation frequency equal to the resonant frequency of the vehicle's external components. The vibration of the vehicle's external components then resonates. The amplitude of the vibration of the vehicle's external components increases, which allows a significant amount of energy to be recovered for recharging the rechargeable energy storage device.

[0030] This operating mode should only be implemented when the charging level of the rechargeable energy storage device requires it. Therefore, permanently high amplitude mechanical vibrations that are prone to causing harmful effects should be avoided.

[0031] Advantageously, the excitation frequency used is the frequency of the fundamental vibration mode of the external components of the vehicle. In a variant, the excitation frequency used is equal to the frequency of the first or even second harmonic vibration mode of the external components of the vehicle. Preferably, the vibration mode of the external components of the vehicle is defined by the following:

[0032] -The pattern along the first axis of the plane of the external element, and

[0033] - Vibration modes along the second axis of the external element, which is orthogonal to the first axis.

[0034] The vibration mode of the external element is called the fundamental mode when both the mode along the first axis and the mode along the second axis are fundamental modes. In all other cases, the vibration mode of the external element is called a harmonic mode. The order of the harmonic vibration mode of the external element corresponds to the highest order of the mode along the first axis and the mode along the second axis.

[0035] When the charge level exceeds a predetermined threshold, the rechargeable energy storage device is considered fully charged. In this case, the drive unit fixes the excitation frequency to a value different from that used in the previous operating mode. The vibration of the vehicle's external components thus has a limited amplitude, which allows for the avoidance of harmful effects from the surrounding environment, especially noise. The trade-off is that the amplitude of the electrical response signal is also smaller, resulting in slower charging of the rechargeable energy storage device. In particular, the amount of energy used to generate vibration is therefore greater than the amount of energy recovered to recharge the rechargeable energy storage device.

[0036] Preferably, in this operating mode, the excitation frequency is therefore fixed to a value different from the frequency of the fundamental vibration mode of the external components of the vehicle. Alternatively, or in a variation, the excitation frequency is therefore fixed to a value different from the frequency of at least the harmonic vibration modes (first and / or second) of the external components of the vehicle.

[0037] Preferably, the device according to the invention further includes a drive unit configured to monitor the energy level of the rechargeable energy storage device and drive the frequency of the electrical excitation signal such that:

[0038] a) When the energy level of the rechargeable energy storage device is less than a predetermined threshold, the frequency of the electrical excitation signal is equal to the resonant frequency of the external components of the motor vehicle.

[0039] b) When the energy level of the rechargeable energy storage device is greater than the predetermined threshold, the frequency of the electrical excitation signal is different from the resonant frequency of the external components of the motor vehicle.

[0040] The resonant frequency of the external components of a motor vehicle is advantageously the frequency of the fundamental vibration mode of the external components of the motor vehicle.

[0041] In a variant, the resonant frequency of the external components of the motor vehicle may be the frequency of the harmonic vibration mode of the external components of the motor vehicle.

[0042] The first electromechanical transducer advantageously includes at least one piezoelectric element.

[0043] The second electromechanical transducer advantageously includes at least one piezoelectric element (which is different from the piezoelectric element forming the first electromechanical transducer when the first electromechanical transducer includes at least one piezoelectric element).

[0044] Preferably, the external components of the motor vehicle are body components for the motor vehicle doors.

[0045] The present invention also covers a component comprising the device according to the invention and external elements of a motor vehicle.

[0046] The invention also covers a component comprising a device according to the invention and an external element of a motor vehicle, wherein a first electromechanical transducer is located at the antinode of a vibration mode associated with the resonant frequency of the external element of the motor vehicle.

[0047] Preferably, the second electromechanical transducer is located at at least one node of a vibration mode associated with the resonant frequency of the external components of the motor vehicle.

[0048] The present invention also covers a system for detecting contact and / or proximity to a motor vehicle, the system comprising a device according to the invention and a computer configured to perform the following operations:

[0049] - Receive at least a portion of the electrical response signal generated by the vibration sensor.

[0050] -Analyze the signal, and

[0051] - Determine information regarding direct physical contact with the vehicle and / or information regarding relative proximity to the vehicle.

[0052] Preferably, the system further includes: an additional detection unit having: an active mode, in which it is configured to perform presence and / or contact detection; and a standby mode, wherein the computer is configured to: when it is determined that there is direct physical contact and / or proximity to the vehicle, provide a wake-up signal to the additional detection unit to cause the additional detection unit to switch from the standby mode to the active mode.

[0053] The additional detection unit advantageously includes at least one of an ultrasonic sensor and an image sensor.

[0054] The system according to the invention may also include external components of a motor vehicle. Attached Figure Description

[0055] Other features and advantages of the invention will become more apparent upon reading the following description. This description is purely illustrative and should be read with reference to the accompanying drawings, in which:

[0056] [ Figure 1 [A motor vehicle equipped with the device according to the invention is shown in an illustrative manner;]

[0057] [ Figure 2 The device according to the first embodiment of the present invention is shown schematically.

[0058] [ Figure 3 [Illustrative representation of its use] Figure 2 The equipment;

[0059] [ Figure 4A ]and[ Figure 4B The evolution of the charging state of the rechargeable energy storage device and the oscillation of the electrical excitation signal supplied to the first electromechanical transducer are schematically shown along the same time axis.

[0060] [ Figure 5A ]and[ Figure 5B The displacement of a person who will come into contact with a vehicle equipped with the device according to the invention and the electrical response signal provided by the second electromechanical transducer are shown schematically along the same time axis.

[0061] [ Figure 6A ]、[ Figure 6B ]and[ Figure 6C The displacement of a person approaching and then moving away from a vehicle equipped with the device according to the invention, the electrical response signal provided by the second electromechanical transducer, and the phase shift of the electrical response signal are shown schematically along the same time axis.

[0062] [ Figure 7 The device according to a second embodiment of the present invention is shown schematically.

[0063] [ Figure 8A ]、[ Figure 8B ]and[ Figure 8C The various possible positions of the first and second electromechanical transducers on external components of a motor vehicle associated with the device according to the invention are shown schematically.

[0064] [ Figure 9A first embodiment of the system for detecting contact and / or proximity according to the present invention is illustrated schematically; and

[0065] [ Figure 10 A second embodiment of the system for detecting contact and / or proximity according to the present invention is shown schematically. Detailed Implementation

[0066] Figure 1 A motor vehicle 1 including the device according to the invention is shown. The device specifically includes a first electromechanical transducer 121 and a second electromechanical transducer 131. The first and second electromechanical transducers 121, 131 are arranged on an external element 10 of the motor vehicle. In the example described below, but in a non-limiting manner, the external element 10 of the motor vehicle more specifically refers to a body element of the motor vehicle. This can refer to the body element belonging to the front door on the driver's side of the motor vehicle 1. In variations, it can refer to a body element located on the hood, at the front of the vehicle, or at the rear of the vehicle (e.g., on the trunk), or at any other location on the motor vehicle.

[0067] Figure 2 A device 100 according to a first embodiment of the present invention is illustrated schematically. The device 100 is intended to form part of a system for detecting contact and / or proximity to a motor vehicle, as described below. The device 100 is intended to be mounted on the motor vehicle.

[0068] The device 100 includes a vibration generator 110, a rechargeable energy storage device 120, and a vibration sensor 130.

[0069] Vibration generator 110 includes, as in Figure 1 The first electromechanical transducer 111 and the electrical signal generator 112 are shown schematically.

[0070] The first electromechanical transducer 111 is constituted by a piezoelectric actuator configured to mechanically deform in real time in response to an electrical excitation signal received at the input. The first electromechanical transducer 111 is configured to dynamically utilize the piezoelectric effect using a frequency-excited electrical signal. At any given moment, the current amplitude of the mechanical deformation is a function of the current amplitude of the electrical excitation signal. In use, the first electromechanical transducer 111 is integrally mounted with the body element 10 of the motor vehicle 1, preferably directly mounted on the body element 10. However, the body element 10 does not constitute part of the device 100 according to the invention.

[0071] In some variations, the first electromagnetic transducer 111 can be based on phenomena other than the piezoelectric effect. In particular, it can utilize induction, where changes in current generate displacement of a moving element integrated with the vehicle body components.

[0072] An electrical signal generator 112 is configured to generate an electrical excitation signal and provide an electrical excitation signal to the first electromechanical transducer. It is configured to provide an excitation signal at an excitation frequency f. E An oscillating electrical frequency signal. An electrical frequency signal is, for example (but in a non-limiting way), a sinusoidal signal or a toothed signal.

[0073] The rechargeable energy storage device 120 is composed of a battery or battery cell. It is configured to supply power to the electrical signal generator 112, thereby providing it with the electrical energy required to generate an electrical excitation signal.

[0074] The vibration sensor 130 is here constituted by a second electromechanical transducer 131, as in Figure 1 The diagram illustrates this. The second electromechanical transducer 131 is composed of a piezoelectric sensor configured to generate an electrical response signal in real time in response to its mechanical deformation. The second electromechanical transducer 131 is therefore configured to dynamically utilize the piezoelectric effect. At any given moment, the current amplitude of the electrical response signal is a function of the current amplitude of the mechanical deformation of the electromechanical transducer 131. In use, the first electromechanical transducer 111 is integrally mounted with the body element 10 of the motor vehicle 1, preferably directly mounted on the body element 10. The current amplitude of the mechanical deformation of the electromechanical transducer 131 is a function of the current amplitude of the deformation of the body element 10.

[0075] The present invention is not limited to the second electromechanical transducer 131 composed of a piezoelectric sensor. For example, the second electromechanical transducer 131 can utilize induction phenomena by means of a membrane configured to be integrally mounted with the body element 10 and placed in a magnetic field by means of at least one magnet. The displacement of the membrane caused by the displacement of the body element induces an induced current corresponding to an electrical response signal. According to another example, the second electromechanical transducer 131 can utilize the capacitance effect by means of a conductive membrane configured to be integrally mounted with the body element 10 and by means of electrodes forming a capacitor with the membrane. The displacement of the membrane caused by the displacement of the body element causes an intensity change at the terminals of the capacitor, the intensity forming an electrical response signal. Preferably, the second electromechanical transducer 131 is of the passive type, that is, it does not require any external energy supply to operate.

[0076] According to the invention, the electrical output of the vibration sensor 130 is connected to the rechargeable energy storage device 120 such that at least a portion of the electrical response signal provided at the output of the vibration sensor 130 electrically recharges the rechargeable energy storage device 120.

[0077] Figure 3 The device 100 in use is shown schematically. (The following text is incomplete and likely refers to a separate topic: "will be combined...") Figure 4A and Figure 4B describe Figure 3 .

[0078] Figure 4A The charging level C of the rechargeable energy storage device 120 is expressed as a function of time t. Figure 4B This shows the electrical excitation signal S provided at the input to the first electromechanical transducer 111. E As a function of time t.

[0079] In use, the electrical signal generator 112 provides a sinusoidal electrical excitation signal S to the first electromechanical transducer 111. E , such as in Figure 4B As indicated in the diagram. In response, the first electromechanical transducer 111 uses an electrically excited signal S. E The frequency generates mechanical vibrations. These mechanical vibrations induce vibrations in the body components 10 on which the first electromechanical transducer 111 is mounted, such as in... Figure 3 That is illustrated schematically.

[0080] The second electromechanical transducer 131 is mounted on the same body component 10. It is subjected to localized vibrations of the body component 10 at its mounting location. These localized vibrations are not only a function of the excitation by the first electromechanical transducer 111, but also a function of the influence of the external environment, especially the influence of personnel approaching or contacting the body component 10. The mechanism of this influence of personnel on the mechanical vibrations of the body component 10 will be described below.

[0081] In response to the local vibrations it experiences, the second electromechanical transducer 131 generates an electrical response signal. This electrical response signal therefore includes information related to the external environment—especially to personnel approaching or contacting the vehicle body component 10. This electrical response signal can therefore be analyzed to extract this information.

[0082] According to the invention, the electrical response signal is also fully or partially (preferably fully) injected at the input of the rechargeable energy storage device 120. This allows for partial recharging of the rechargeable energy storage device 120. Its discharge is thus slowed, and a portion of the energy supplied to the first electromechanical transducer 111 to generate the electrical excitation signal is recovered via the second electromechanical transducer 131. Figure 4A This illustrates the slow discharge of the rechargeable energy storage device 120.

[0083] The following sections describe the effects of the environment on electrical response signals under two specific conditions.

[0084] Figure 5A and Figure 5B The environment in question includes situations involving personnel who will have direct physical contact with the motor vehicle at the body components housing the first and second electromechanical transducers. Figure 5A The person is shown approaching the vehicle, making direct physical contact with a component of the vehicle body, and then ceasing that contact. Figure 5BThe corresponding electrical response signal S is shown. R1 As a function of time. In the absence of direct physical contact between personnel and vehicle body components, the electrical response signal S... R1 It is a sinusoidal signal. When a person has direct physical contact with a vehicle body component, the electrical response signal S... R1 The amplitude drops sharply until it reaches zero. When the direct physical contact is released, the electrical response signal S... R1 The oscillation resumes and the amplitude of the oscillation returns to its initial value. Analyzing the electrical response signal thus allows for the detection of direct physical contact between personnel and motor vehicles, for example, to detect attempts at intrusion and / or breaching of a vehicle.

[0085] Figure 6A , Figure 6B and Figure 6C The environment in question includes situations involving personnel who are near and then away from motor vehicles equipped with the device according to the invention. Figure 6A The person was shown approaching the vehicle and then moving away.

[0086] Figure 6B The corresponding electrical response signal S is shown. R2 As a function of time, the electrical response signal S R2 It is a sinusoidal signal with a substantially constant amplitude. The electrical response signal S R2 The mechanical vibration of the vehicle body components at the location of the second electromechanical transducer 131 is reproduced.

[0087] At each moment, these vibrations result in the following:

[0088] - Mechanical oscillations directly induced by the current mechanical vibration of the first electromechanical transducer 111, and

[0089] - Mechanical oscillations induced by the reflection of the initial sound waves generated by the mechanical vibrations of the vehicle body components at a previous moment onto the person.

[0090] The optical path of the sound wave is generally not an integer multiple of the wavelength of the initial sound wave, resulting in a phase shift in the reflected sound wave relative to the initial sound wave. This phase shift varies as a function of the distance between the device according to the invention and the person on whom the sound wave is reflected. When the object on which the initial sound wave is reflected is moving relative to the device according to the invention, the reflected sound wave also exhibits a frequency shift (Doppler effect) relative to the initial sound wave. This phase shift (and, where applicable, the frequency shift) occurs in the mechanical oscillations induced by the reflected sound wave and thus in the electrical response signal SR2.

[0091] Those skilled in the art will know how to process the electrical response signal S R2This is to extract information related to the phase difference (and, where applicable, the frequency shift). Processing can be performed using wavelet transform and / or searching for similarity to the expected shape (determined during the initial calibration step), etc. This is to analyze the electrical response signal S. R2 It is advantageous to assume that the frequency and phase of the initial sound wave are equal to the electrical excitation signal S. E The frequency and phase.

[0092] Figure 6C This shows the phase shift between the initial sound wave and the reflected sound wave. It corresponds to the electrical response signal S R2 With electrical excitation signal S E The phase shift between them.

[0093] As personnel approach the equipment and vehicle according to the invention, phase shift... The change here is reduced. Then, as personnel move away from the equipment and vehicle according to the invention, the phase shift... The change occurs in the opposite way, showing an increase here. Following the phase shift... This allows inspection personnel to approach the equipment and vehicle according to the invention. Where applicable, the phase shift can be... Values ​​and thresholds Comparison is made in order to identify the presence of objects or persons in the immediate vicinity of the equipment and vehicle according to the invention.

[0094] The example of personnel approaching the device and vehicle according to the invention has already been used. As a supplement or in a variation, the invention allows for the detection of the approach of animals or inanimate obstacles that may be stationary in a land reference frame but moving relative to a moving vehicle. The invention thus allows for obstacle detection rather than presence detection, for example, in the case of assisted driving.

[0095] In a favorable manner, the electrical excitation signal S E The frequency (called the excitation frequency f) E The frequency is different from the fundamental vibration mode of the body component 10. Furthermore, in a more advantageous manner, the excitation frequency f... E The corresponding frequencies differ from the first-order or even second-order vibration modes of the body component 10. This thus avoids amplifying the mechanical resonance of the body component and the resonance phenomenon that easily generates discomfort (strong vibrations and / or annoying acoustic signals) in the environment.

[0096] In the variant, the electrical excitation signal S EThe frequency is equal to the frequency of the vibration mode of the body components (fundamental mode or harmonic mode, especially first-order or even second-order harmonic modes). This variation allows amplification of the mechanical resonance of the body components, and thus amplification of the amplitude of the electrical response signal generated by the vibration sensor 130. This variation allows for maximizing the recharging of the rechargeable energy storage device 112.

[0097] The following is for reference Figure 7 The device 200 according to a second embodiment of the present invention will be described only in relation to it. Figure 2 The device 200 is described in terms of its differences from other devices. Here, device 200 also includes a drive unit 240. The drive unit 240 is configured to:

[0098] - Monitor the energy level or charging rate of the rechargeable energy storage device 200; and

[0099] - The electrical excitation signal S sent by the electrical signal generator 212 to the first electromechanical transducer 211 drives the circuit. E The frequency.

[0100] Device 200 is configured as follows:

[0101] - When the energy level of the rechargeable energy storage device 222 is lower than or equal to a predetermined threshold, the electrical excitation signal S will be activated. E The frequency is fixed as the first excitation frequency value f, which is equal to the resonant frequency of the body component 10. E1 .

[0102] - When the energy level (or charging rate) of the rechargeable energy storage device 220 is greater than the predetermined threshold, the electrical excitation signal S will be activated. E The frequency is fixed to a second excitation frequency value f, which is different from the resonant frequency of the body component 10. E2 .

[0103] In the first case, priority is given to the recharging efficiency of the rechargeable energy storage device. In the second case, priority is given to the comfort of the surrounding environment. This embodiment therefore offers an optimal trade-off, allowing priority to be given to either the recharging efficiency or the comfort of the rechargeable energy storage device based on its state of charge.

[0104] First excitation frequency value f E1 For example, the frequency of the fundamental vibration mode of body component 10. In the variant, f E1 It can be equal to the frequency of the harmonic vibration mode (e.g., first-order or even second-order mode) of the body component 10.

[0105] Second excitation frequency value f E2 Unlike f E1In a favorable variant, it differs not only from the frequency of the fundamental vibration mode of the body component 10, but also from the frequency of the first-order or even second-order or even higher-order harmonic modes.

[0106] Figures 8A to 8C As shown Figure 7 The figures show various arrangements of the first and second electromechanical transducers on the body element 10 of the device. The body element 10 is square or rectangular in shape. In each figure, grayscale represents the normalized vibration amplitude at the considered location on the body element 10. The grayscale scale is shown on the right.

[0107] exist Figure 8A In the middle, the first excitation frequency value f E1 This is equal to the frequency of the fundamental vibration mode of the body component. This frequency is equivalent to, for example, 3 Hz. This fundamental mode is labeled [0; 0], where the number 0 corresponds to the fundamental mode along a first axis of the plane of the body component, and the number 0 corresponds to the fundamental mode along a second axis of the plane of the body component that is orthogonal to the first axis.

[0108] The first electromechanical transducer 211A is composed of a single piezoelectric element located at the center of the body element 10 at the antinode of the fundamental mode vibration.

[0109] This positioning at the vibration midpoint allows for maximizing the amplitude of the mechanical vibration sensed by the first electromechanical transducer 211A. This allows for maximizing the (mechanical or acoustic) signal interacting with the external environment, and thus improves proximity and / or contact detection.

[0110] The second electromechanical transducer 231A is composed of four piezoelectric elements 2311A located at the four corners of the body element 10 at the vibration node of the body element 10.

[0111] This positioning at the vibration node allows minimizing the impact of vibrations directly induced by the first electromechanical transducer 211A on vibrations measured by the second electromechanical transducer 231A. This maximizes the relative influence of the environment, especially the effect of reflected sound waves. Consequently, the signal-to-noise ratio is improved.

[0112] Using the fundamental mode also allows the vibration nodes and antinodes to be physically far apart from each other, which reduces the required accuracy for positioning the first and second electromechanical transducers.

[0113] exist Figure 8B In the middle, the first excitation frequency value f E1The frequency is equal to the frequency of the harmonic vibration mode of the body element, which is labeled [0; 1], where the number 0 corresponds to the fundamental mode along a first axis of the plane of the body element, and the number 1 corresponds to the first harmonic along a second axis orthogonal to the first axis of the plane of the body element. This frequency is equivalent to 19 Hz.

[0114] The second electromechanical transducer 231B is composed of a single piezoelectric element located at the center of the body element 10 and at the vibration node of the body element 10.

[0115] The first electromechanical transducer 211B is composed of two piezoelectric elements 2111B located on either side of the second electromechanical transducer 231B along an axis parallel to the two opposite edges of the body element 10 and passing through the center of the body element 10. These two piezoelectric elements 2111B extend to two corresponding vibration points of the body element 10.

[0116] Furthermore, the first electromechanical transducer 211B is located at at least one vibration midpoint of the body component 10, and the second electromechanical transducer 231B is located at at least one vibration midpoint of the body component 10. Therefore, the reproduction of f... E1 Another value available Figure 8A The advantages of this arrangement.

[0117] exist Figure 8C In the middle, the first excitation frequency value f E1 The frequency of the harmonic vibration mode of the body element is equal to that of the harmonic vibration mode, which is labeled as [1; 1] (where the number 1 corresponds to the first harmonic along the first axis of the plane of the body element, and the number 1 corresponds to the first harmonic along the second axis of the plane of the body element, which is orthogonal to the first axis).

[0118] The first electromechanical transducer 211C is composed of four piezoelectric elements 2111C located at the four corners of a square along the two diagonals of the body element 10 at the corresponding four vibration points of the body element 10.

[0119] The second electromechanical transducer 231C is composed of a single piezoelectric element located at the center of the body element 10 at the vibration node of the body element 10.

[0120] Furthermore, the first electromechanical transducer 211C is located at at least one vibration midpoint of the body component 10, and the second electromechanical transducer 231C is located at at least one node of the body component 10. Therefore, the reproduction of f... E1 Another value available Figure 8A The advantages of this arrangement.

[0121] In a variant not shown, the second electromechanical transducer is located at or near the vibration midpoint of the vehicle body element 10 in order to increase the amplitude of the mechanical vibration measured therefrom and thus increase the amplitude of the electrical response signal used to recharge the rechargeable energy storage device.

[0122] In particular, based on the oscillation frequency available for the electrical excitation signal, the vibration mode of the vehicle body components, and the need to prioritize the recharging efficiency of the rechargeable energy storage device (via the second electromechanical transducer near the vibration node) or the good signal-to-noise ratio for proximity and / or contact detection (via the second electromechanical transducer near the vibration node), those skilled in the art will know to optimize the arrangement of the first and second electromechanical transducers and the number of piezoelectric elements they comprise.

[0123] The arrangement described above can also be applied to the device according to the first embodiment, and wherein the electrical excitation signal S E It always has the frequency of the vibration mode of the body components.

[0124] Therefore, the present invention covers an assembly comprising a device according to the invention—especially according to a first or second embodiment—and a vehicle body element housing first and second electromechanical transducers, wherein:

[0125] - The first electromechanical transducer is located in the central area of ​​the body components; and

[0126] - The second electromechanical transducer is located in multiple peripheral areas of the body components.

[0127] In a variant, the invention encompasses a component comprising a device according to the invention—particularly according to a first or second embodiment—and a vehicle body element housing first and second electromechanical transducers, wherein:

[0128] - The second electromechanical transducer is located in the central area of ​​the body components, and

[0129] - The first electromechanical transducer is located in the following two regions: these two regions are located on both sides of the second electromechanical transducer.

[0130] According to another variation, the invention covers an assembly comprising a device according to the invention—particularly according to a first or second embodiment—and a vehicle body element housing first and second electromechanical transducers, wherein:

[0131] - The second electromechanical transducer is located in the central area of ​​the body components, and

[0132] - The first electromechanical transducer is located in the following multiple areas: these multiple areas are located around the second electromechanical transducer.

[0133] The following describes a system 1000 for detecting contact and / or proximity, the system 1000 including:

[0134] -The device according to the invention, herein being device 100 according to a first embodiment of the invention; and

[0135] - Computer 150, configured to receive at least a portion of an electrical response signal from vibration sensor 130 at an input to analyze the signal, and to provide at an output information 151 regarding approach to and / or direct physical contact with the vehicle.

[0136] Computer 150 includes at least one processor. See below for details. Figure 5A and Figure 5B , Figures 6A to 6C The signal analysis performed by computer 150 is described. In particular, the signal analysis may include signal damping detection associated with direct physical contact between the vehicle body element 10 and a person. As a supplement or in a variation, the signal analysis includes phase shift measurement associated with the displacement of a person near the vehicle body element 10.

[0137] Information 151 may include data regarding the detection of direct physical contact with vehicle body components and / or data regarding the detection of personnel approaching vehicle body components. This data may be transmitted to the vehicle's log. As a supplement or in a variation, this data may be used by additional systems in the motor vehicle, such as alarms that emit audible signals to warn of intrusion in the event of an intrusion.

[0138] In variations not shown, the device according to the invention is the device according to the second embodiment.

[0139] at last, Figure 10 A second embodiment of a system 2000 for detecting contact and / or proximity according to the present invention is shown. This will only be discussed in relation to its... Figure 9 The differences between the systems are used to describe System 2000.

[0140] Here, the system 2000 also includes an additional detection unit 160, which is configured to receive information from the computer 150 regarding the approach to and / or direct physical contact with the vehicle.

[0141] The additional detection unit 160 can perform contact and / or proximity detection based on, for example, image acquisition by means of a camera, or based on laser detection, or based on ultrasonic detection.

[0142] By default, the additional detection unit 160 is in standby mode, in which it does not perform detection and therefore consumes very little electrical energy.

[0143] The additional detection unit 160 is configured to switch from a standby mode to an active mode when it receives information about the approach to and / or direct physical contact with the vehicle. The information about the approach to and / or direct physical contact with the vehicle thus forms a wake-up signal for the additional detection unit 160.

[0144] In active mode, the additional detection unit 160 performs proximity and / or contact detection by means of the device 100 according to the invention, which allows for confirmation or denial of detections based on vibration measurements. After confirming or denying the information provided by the computer 150, the additional detection unit 160 returns to standby mode.

[0145] This embodiment allows for enhanced proximity and / or contact detection by means of an additional detection unit capable of providing more accurate information than the device according to the invention. Furthermore, since the additional detection unit 160 remains in standby mode most of the time, this enhanced information does not result in significantly higher energy consumption.

[0146] In variations not shown, the device according to the invention is the device according to the second embodiment.

[0147] In particular, many variations of the invention can be implemented by combining the various examples described above. The invention can be implemented for frequency values ​​of any type of electrically excited signal, preferably values ​​below 20 Hz to limit acoustic discomfort.

[0148] In another advantageous variation, the device according to the invention may have a standby mode in which no electrical supply is made to the first electromechanical transducer and an active mode in which electrical supply is made to the first electromechanical transducer. The device according to the invention can therefore be configured to switch to the active mode only when the vehicle's motor is turned off and / or only when the vehicle's parking mode is activated.

[0149] This invention finds particularly advantageous applications in preventing vandalism. It allows for the prediction and / or detection of intrusions into motor vehicles. Other applications are also possible, especially obstacle detection in autonomous driving scenarios.

Claims

1. An apparatus for a detection system that detects contact and / or proximity to a motor vehicle by measuring mechanical vibrations of external components of the vehicle, the apparatus being configured to be mounted on the motor vehicle, and characterized in that... It includes: a) A vibration generator, comprising: - A first electromechanical transducer, configured to generate mechanical motion in response to an electrical excitation signal, and configured to be mounted on an external component of the motor vehicle; and - An electrical signal generator configured to provide an electrical excitation signal to the first electromechanical transducer, the electrical excitation signal oscillating at an excitation frequency; b) A rechargeable energy storage device configured to supply electrical energy to the electrical signal generator; and c) A vibration sensor comprising a second electromechanical transducer configured to generate an electrical response signal in response to mechanical displacement and mounted on the external component of the motor vehicle; The output of the vibration sensor is electrically connected to the rechargeable energy storage device so that at least a portion of the electrical response signal during use can recharge the rechargeable energy storage device.

2. The device as described in claim 1, characterized in that, It also includes a drive unit configured to monitor the energy level of the rechargeable energy storage device and drive the frequency of the electrical excitation signal such that: a) When the energy level of the rechargeable energy storage device is lower than a predetermined threshold, the frequency of the electrical excitation signal is equal to the resonant frequency of the external component of the motor vehicle; b) When the energy level of the rechargeable energy storage device is higher than the predetermined threshold, the frequency of the electrical excitation signal is different from the resonant frequency of the external component of the motor vehicle.

3. The device as described in claim 2, characterized in that, The resonant frequency of the external component of the motor vehicle is the frequency of the fundamental vibration mode of the external component of the motor vehicle.

4. The device as described in claim 2, characterized in that, The resonant frequency of the external component of the motor vehicle is the frequency of the harmonic vibration mode of the external component of the motor vehicle.

5. The device as claimed in any one of claims 1 to 4, characterized in that, The first electromechanical transducer includes at least one piezoelectric element.

6. The device as claimed in any one of claims 1 to 4, characterized in that, The second electromechanical transducer includes at least one piezoelectric element.

7. The device as claimed in any one of claims 1 to 4, characterized in that, The external components of the motor vehicle are body components for motor vehicle doors.

8. A component comprising the device as claimed in any one of claims 1 to 7 and the external elements of the motor vehicle.

9. A component comprising the device as claimed in any one of claims 2 to 7 and the external element of the motor vehicle, wherein the first electromechanical transducer is located at the antinode of a vibration mode associated with the resonant frequency of the external element of the motor vehicle.

10. The component of claim 9, wherein the second electromechanical transducer is located at at least one node of a vibration mode associated with the resonant frequency of the external element of the motor vehicle.

11. A system for detecting contact and / or proximity to a motor vehicle, the system comprising the device as described in any one of claims 1 to 7 and a computer configured to perform the following: - Receive at least a portion of the electrical response signal generated by the vibration sensor. - Analyze the signal, and - Determine information regarding direct physical contact with the motor vehicle and / or information regarding relative proximity to the motor vehicle.

12. The system as claimed in claim 11, characterized in that, It also includes: an additional detection unit having: an active mode, in which it is configured to perform presence and / or contact detection; and a standby mode, and the computer is configured to: when it is determined that there is direct physical contact and / or proximity to the motor vehicle, provide a wake-up signal to the additional detection unit to switch the additional detection unit from the standby mode to the active mode.

13. The system as described in claim 12, characterized in that, The additional detection unit includes at least one of an ultrasonic sensor and an image sensor.

14. The system of any one of claims 11 to 13, further comprising the external components of the motor vehicle.

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