EP4662465A1 - Unité de capteur, et système et procédé de détection de dommages - Google Patents

Unité de capteur, et système et procédé de détection de dommages

Info

Publication number
EP4662465A1
EP4662465A1 EP24702218.9A EP24702218A EP4662465A1 EP 4662465 A1 EP4662465 A1 EP 4662465A1 EP 24702218 A EP24702218 A EP 24702218A EP 4662465 A1 EP4662465 A1 EP 4662465A1
Authority
EP
European Patent Office
Prior art keywords
damage
sensor unit
sound
microphone
signals
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP24702218.9A
Other languages
German (de)
English (en)
Inventor
Reinhold Tholen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Divft GmbH
Original Assignee
Divft GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Divft GmbH filed Critical Divft GmbH
Publication of EP4662465A1 publication Critical patent/EP4662465A1/fr
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H1/00—Measuring characteristics of vibrations in solids by using direct conduction to the detector
    • G01H1/04—Measuring characteristics of vibrations in solids by using direct conduction to the detector of vibrations which are transverse to direction of propagation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/14—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object using acoustic emission techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/223—Supports, positioning or alignment in fixed situation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/36—Detecting the response signal, e.g. electronic circuits specially adapted therefor
    • G01N29/42—Detecting the response signal, e.g. electronic circuits specially adapted therefor by frequency filtering or by tuning to resonant frequency
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
    • G01N29/449—Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
    • G01N29/46—Processing the detected response signal, e.g. electronic circuits specially adapted therefor by spectral analysis, e.g. Fourier analysis or wavelet analysis
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/02—Mechanical actuation
    • G08B13/04—Mechanical actuation by breaking of glass
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/16—Actuation by interference with mechanical vibrations in air or other fluid
    • G08B13/1654—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems
    • G08B13/1672—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems using sonic detecting means, e.g. a microphone operating in the audio frequency range
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R25/00—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles
    • B60R25/10—Fittings or systems for preventing or indicating unauthorised use or theft of vehicles actuating a signalling device
    • B60R25/1004—Alarm systems characterised by the type of sensor, e.g. current sensing means
    • B60R25/1009—Sonic sensors; Signal treatment therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/023—Solids
    • G01N2291/0232—Glass, ceramics, concrete or stone
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/028—Material parameters
    • G01N2291/0289—Internal structure, e.g. defects, grain size, texture
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/10—Number of transducers
    • G01N2291/101—Number of transducers one transducer
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/18—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
    • G08B13/189—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems
    • G08B13/194—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems
    • G08B13/196—Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength using passive radiation detection systems using image scanning and comparing systems using television cameras
    • G08B13/19639—Details of the system layout
    • G08B13/19647—Systems specially adapted for intrusion detection in or around a vehicle

Definitions

  • the present invention relates to a sensor unit for the acoustic detection of damage events on materials, in particular on glass panes of vehicles, as well as a system comprising such a sensor unit for the acoustic detection of damage events on materials.
  • the invention further relates to a method for the acoustic detection of damage events on materials, in particular on
  • EP 0657 330 A1 discloses an alarm system for detecting broken glass, in which an electrically conductive track is embedded or laid down in a glass pane to be monitored. If the glass breaks, the electrically conductive track is interrupted, triggering an alarm.
  • the application of the electrically conductive track is, however, very Another disadvantage is that this alarm system cannot distinguish between different types of damage (e.g. falling rocks or cracks).
  • WO 2004/011311 A1 describes a breakage detector for a windshield. This detector is also based on an electrically conductive material being applied to the window.
  • the disadvantage here (in addition to the disadvantages already mentioned for EP 0 657 330 A1) is that the transparency of the windshield is impaired by the material applied there.
  • the object of the present invention is therefore to enable or improve automatic damage detection on materials, in particular on vehicle glass panes, while avoiding the disadvantages mentioned above.
  • the sensor unit according to the invention is a sensor unit for the acoustic detection of damage events on materials, in particular on glass panes of vehicles.
  • the sensor unit is intended for attachment to the surface of a material which is to be monitored with regard to the occurrence of damage events; in particular, the Sensor unit intended for attachment to the surface of a glass pane. That side of the sensor unit which is intended for attachment to the surface of a material and which, after attachment of the sensor unit, is adjacent to the mentioned surface of the material (ie rests against this surface), is referred to as the "attachment side".
  • the sensor unit has at least the following components and features:
  • circuit board arranged in the housing and connected to it, with a gap between the underside of the circuit board and the front wall of the housing opposite it;
  • a microphone mounted on the component side of the circuit board with a wall which, together with the circuit board, encloses an interior space;
  • circuit board arranged sound transducer
  • the fastener is either attached to the edge of the side wall and extends to the fastening side, or the fastener is attached to the component side of the board, but outside the microphone and inside the housing, and extends to the fastening side.
  • the housing usually made of plastic or metal, surrounds the circuit board with the microphone on it with its front wall and its surrounding side wall.
  • the wall area of the housing known as the "front wall” limits the sensor unit to the outside on the side opposite the fastening side.
  • the side wall can be designed like the shell of a cylinder, for example, or with a rectangular or square contour.
  • the housing, consisting of the front wall and surrounding side wall, is preferably made in one piece.
  • the housing is preferably open towards the fastening side if the fastening means - as mentioned above - is attached to the component side of the board.
  • the edge of the side wall which extends towards the fastening side has a distance (gap) from this surface when attached to the surface. This can be achieved in particular by selecting the height of the fastening means(s) so that the mentioned distance is maintained.
  • the distance is preferably 1 to 3 mm.
  • fastening means is attached to the edge of the side wall according to the above mentioned alternative, the fastening means which is attached to this edge and the
  • the thickness (height) of the fastening means determines the distance of the edge of the side wall to the material surface. This distance is also preferably 1 to 3 mm, but can also be less.
  • a circuit board connected to the housing is arranged in the housing, whereby it is preferred that there is a distance between the underside of the circuit board and the front wall of the housing opposite it, whereby an intermediate
  • the circuit board is aligned parallel or approximately parallel to the front wall of the housing above it.
  • Microphone is arranged is aligned towards the mounting side.
  • the circuit board is generally aligned approximately parallel to this surface.
  • a commercially available circuit board printed circuit board
  • the circuit board preferably has a thickness in the range of 0.5 - 1.5 mm, in particular 0.8 - 1.2 mm.
  • At least one microphone is mounted on the component side of the circuit board, which has a wall (or “housing” or “capsule”; e.g. made of metal (particularly aluminum) or plastic) which, together with the circuit board, encloses an interior space.
  • a wall or “housing” or “capsule”; e.g. made of metal (particularly aluminum) or plastic
  • the wall of the microphone has a wall area which is opposite the circuit board and faces the fastening side; preferably this wall area has a flat outer surface which, when fastened to the surface of a material, runs parallel or substantially parallel to this surface.
  • the mentioned wall area has a sound opening, which serves to create a connection between the interior of the microphone and the environment of the sensor unit.
  • the sound opening is not arranged above the sound transducer (i.e. opposite it), but offset to the side (i.e. outside the base area of the sound transducer, in plan view), so that the sound entering through the sound opening hits the sound transducer partly directly, partly indirectly - after reflection on various surfaces in the interior of the microphone.
  • the sound opening is covered by a sound-permeable connecting layer, which is attached to the mentioned wall area of the microphone on its outer surface.
  • this connecting layer is located between the mentioned wall area of the microphone and the material surface, thus creating a preferably full-surface contact between the microphone and the material surface.
  • This connecting layer enables the transmission of low-frequency vibrations in the infrasound range, which are caused by a damage event in the material to be monitored, e.g. a pane of glass, to the microphone so that these vibrations (infrasound signals) can be recorded by the microphone (i.e. its sound transducer).
  • this connecting layer suppresses or reduces the background noise caused by vibrations. Such background noise would be caused by the movements of the material surface to be monitored that occur during a damage event if the microphone were to rest directly, i.e. without a connecting layer, on this material surface, e.g. a pane of glass.
  • this connecting layer is thus sound-permeable (ie permeable to airborne sound) and also enables the transmission of infrasound signals; on the other hand, this connecting layer absorbs inherent noise, which which could arise due to the vibration-related movement of the material to be monitored, to which the sensor unit is attached, are prevented or suppressed.
  • the thickness of the connecting layer is preferably 0.1 to 1 mm, in particular 0.2 - 0.6 mm.
  • the sensor unit has at least one fastening means. This is either attached to the edge of the side wall and extends to the fastening side, or the fastening means is attached to the component side of the circuit board, outside the microphone and inside the housing, and extends to the fastening side.
  • the sensor unit when it is attached as intended to a material surface to be monitored, is connected to the material surface to be monitored by the fastening means(s).
  • the fastening means extends, preferably in a ring shape, over the entire circumference of the sensor unit, or two or more individual fastening means, e.g. in the form of supports or segments, can be provided.
  • a double-sided, preferably elastic adhesive tape with a thickness of 0.3 - 3 mm, in particular 1 to 2 mm, is preferably used as the fastening means.
  • a double-sided, elastic PVC adhesive tape with a thickness of 1 - 2 mm can be used.
  • a preferably elastic adhesive layer produced by applying an adhesive can also serve as the fastening means.
  • fastening means is attached to the edge of the side wall as mentioned above, it extends preferably over the entire circumference of the edge of the side wall.
  • fastening means the fastening means mentioned above can be used.
  • the sensor unit according to the invention is advantageously suitable for the acoustic detection of damage events on materials, in particular on glass panes.
  • the combination of the following two features is particularly advantageous:
  • the housing has no direct contact with this material surface because - as described above - the edge of the side wall of the housing is at a distance from this surface when attached to a material surface.
  • a connecting layer which, when the sensor unit is attached to a material surface, creates a Establishes contact between the microphone and the material surface.
  • the sensor unit When the sensor unit is attached to the surface of a material to be monitored as intended, it is only in contact with the surface of the material via the fastening means and the connecting layer. This enables the microphone to record the sound signals (airborne sound) and infrasound signals generated when a damage event occurs, for example when a stone hits a pane of glass, and at the same time suppresses or reduces the recording of disturbing background noise.
  • the frequency range of the sound signals is 0 to 30 kHz; it includes both sound waves that propagate in air (airborne sound) and sound waves that propagate in solids, especially glass.
  • the present invention is based, among other things, on the realization that, in order to detect different damage events as accurately as possible, it is essential to use a sensor unit that is able to use the microphone arranged in the sensor unit to detect the sound signals generated by a damage event (ie airborne sound) and also the infrasound signals generated thereby.
  • the special features of the sensor unit prevent the strong infrasound signals of a damage event from superimposing the airborne sound signals; at least the extent of such superimposition is reduced.
  • this sensor unit is generally I think I am able to separate the infrasound signals and the airborne sound signals of a damage event and to record both types of signals.
  • the impact of a stone on a pane of glass creates a second important component because the impact causes a local natural vibration of the pane, which generates an infrasound signal in the frequency range of 1 to 50 Hz.
  • This signal also spreads directly in the damaged material (pane of glass) and reaches the microphone faster than the noise generated by the damage event (stone impact).
  • the latter only spreads by air conduction, whereas the infrasound signal also spreads directly in the damaged material (structure-borne sound). Infrasound spreads much faster in glass and other solid bodies than sound in air.
  • the sensor unit according to the invention can be used advantageously to detect different damage events. in particular in the system according to the invention for the acoustic detection of damage events to materials, as described below.
  • the circuit board bulges towards the front wall of the housing (i.e. away from the fastening side) when the sensor unit is fastened to a material to be monitored.
  • This can be achieved, for example, by dimensioning the height of the fastening means or/and the height of the side wall of the housing such that the microphone (with the connecting layer located thereon) exerts pressure on the circuit board, whereby the circuit board is elastically deformed and bulges in the direction mentioned.
  • the circuit board can bulge in the above-mentioned positions between the underside of the
  • the elastic deformation of the circuit board and the resulting spring tension means that the microphone with its connecting layer is pressed against the surface of the material by a contact pressure when the sensor unit is attached to it. This ensures a reliable connection between the sensor unit and the material surface and improves the transmission of the sound signals.
  • the housing has, when the sensor unit is attached to a material surface, e.g. a glass pane, no direct contact with this material surface (as explained above). Between the microphone and the material surface there is a connecting layer which, when the sensor unit is attached to a material surface, creates contact between the microphone and the material surface. As explained above, the microphone is pressed against the surface of the material by a contact pressure when the sensor unit is attached to such a material.
  • a material surface e.g. a glass pane
  • Circuit in particular an integrated circuit, is arranged and electrically connected to the microphone, e.g. via conductor tracks in the circuit board.
  • the electronic circuit is designed in particular to carry out one or more of the following functions: preamplifier, analog-digital converter, audio filter, noise suppression. This makes it possible, among other things, to convert the analog signal of the sound transducer into a digital signal and to amplify it. Alternatively, these functions can also be carried out by a separate circuit outside the sensor unit.
  • Miniaturized microphones are preferably used as microphones, in particular microphones made using SMD technology, e.g.
  • Electret microphones or MEMS microphones the latter being particularly preferred.
  • a MEMS transducer is used as the sound transducer, wherein a circuit board connected to the MEMS
  • An integrated circuit in particular an ASIC, is arranged in an electrically conductive manner on the sound transducer.
  • the integrated circuit or ASIC is preferably designed to carry out one or more of the following functions: preamplifier, analog-digital converter, audio filter, noise suppression.
  • MEMS microphones comprising a circuit board with sound transducer (MEMS transducer), ASIC and housing
  • MEMS microphone (wall) with sound opening, are suitable for use in a sensor unit according to the invention or for the construction of such a sensor unit and are preferred due to their small dimensions and high sensitivity.
  • An example of a commercially available MEMS microphone is the MEMS
  • SMD component from the manufacturer Adafruit Industries (New York) with the type designation "SPW2430" (dimensions: approx. 16mm x 14mm x 3mm).
  • a MEMS microphone is particularly preferably equipped with a sound opening that is arranged laterally offset from the sound transducer (sound pickup), so that the sound entering through the sound opening strikes the sound transducer partly directly and partly indirectly (after reflection from surfaces in the interior of the microphone).
  • the surface of the encapsulation material (“molding”, e.g. "glob top molding") with which the ASIC is encapsulated also serves as a sound-reflecting surface.
  • the ASIC of the MEMS microphone is particularly designed to carry out one or more
  • the MEMS microphone is designed to perform the following functions: preamplifier, analog-digital converter, audio filter, noise suppression.
  • the MEMS microphone preferably has an integrated analog-digital converter so that a digital audio signal is output. If the MEMS microphone used outputs an analog audio signal, a downstream analog-digital converter is preferably used to generate a digital audio signal.
  • the microphone of the sensor unit is preferably a microphone designed to detect sound in the frequency range from 50 Hz to 20 kHz (audible sound range), in particular from 50 to 15 kHz, and infrasound ⁇ 50 Hz, in particular in the
  • MEMS microphones are generally designed to record sound and infrasound in the frequency ranges mentioned.
  • the properties of the various MEMS microphones can be found in the respective manufacturer information.
  • the sensitivity of such MEMS microphones is usually in the range of -45 to -35 dBV, with a signal-to-noise ratio in the range of 57 - 65 dB (A).
  • Microphone is designed to record ultrasonic signals (> 20 kHz).
  • MEMS microphones as described above, generally also record a proportion of sound signals in the ultrasonic range. Although this proportion is comparatively small, these ultrasonic signals can be used to specifically detect different damage patterns, e.g. stone chip patterns, ie can be taken into account in the evaluation.
  • the sensor unit is usually equipped with means for supplying power or voltage to the microphone and, if necessary, an electronic circuit, as well as for forwarding the analog or digital signal generated by the sensor unit; such means are known to those skilled in the art (e.g. electrical connections, plug connections, electrical connecting cables).
  • the power supply of the sensor unit can comprise batteries, rechargeable batteries, solar cells, capacitors (preferably supercapacitors) or similar means known to those skilled in the art.
  • the sensor unit according to the invention can be attached to a variety of different materials in order to record damage events occurring there. Examples and preferred materials and areas of application are:
  • Glass panes of (air/land/water) vehicles in particular motor vehicles (cars, trucks, buses, rail vehicles, cable cars, etc.); also glass panes on stationary facilities (architecture/buildings, industrial plants, etc.).
  • the sensor unit is preferably attached to the inside of a glass pane (e.g. of a motor vehicle).
  • metal structures and components particularly the bodywork and components of motor vehicles.
  • the sensor unit can be used to detect the following damage events:
  • Sheet metal parts scratches in plastic parts or in composite parts; breakage damage in plastic parts or in composite parts; impact or breakage damage to vehicle exterior mirrors; impact or breakage damage to lighting devices, in particular headlights and taillights. It is preferably used to record damage to vehicles, in particular motor vehicles.
  • the present invention further comprises a system for the acoustic detection of damage events on materials, in particular on glass panes of vehicles.
  • Detection means that the type of damage event that has occurred is detected, preferably also its other properties (e.g. the strength or intensity of the damage event).
  • Acoustic means that the detection is based on sound signals (including infrasound). For example, the following types of damage events on glass panes can be distinguished: Scratches
  • the system according to the invention enables the detection and differentiation of such damage events. It can also be used to differentiate between non-damaging, noise-generating physical effects (e.g. impact of a rubber ball on a pane of glass) and actual damage events.
  • the system according to the invention for the acoustic detection of damage events is based on the knowledge that a certain damage event - depending on the type and energy (strength) as well as the type of material damaged - generates a certain acoustic pattern during its duration, which is characteristic of the respective type of damage event. According to the present invention, it is of essential importance that both airborne sound signals (particularly in the audible sound range) and infrasound signals of a damage event are recorded and evaluated.
  • the system for acoustic detection of damage events shall comprise at least the following:
  • Attachment to a surface of a material to be monitored wherein the sensor unit is designed to detect the sound signals caused by a damage event (i.e. airborne sound, in particular in the audible sound range) and
  • a damage event i.e. airborne sound, in particular in the audible sound range
  • At least one electronic circuit conductively connected to the microphone which is designed to carry out one or more of the following functions: preamplifier, analog-digital converter, audio filter, noise suppression; the circuit is preferably arranged in the sensor unit;
  • At least one evaluation unit which is connected to the aforementioned circuit of the sensor unit and is designed to evaluate the signals transmitted by the circuit and to detect the damage event based on the result of the evaluation.
  • the system according to the invention advantageously enables the detection of damage in actual time, since the respective damage event and at the same time the type of damage are detected at the time at which the damage event takes place (in contrast to a subsequent assessment of damage).
  • the sensor unit of the system is a sensor unit according to the invention, whereby several sensor units can also be used in combination. Due to the special properties and advantages, as explained above, the sensor unit according to the invention is particularly suitable for use as a component of the system.
  • the electronic circuit which can perform the functions of a preamplifier, analog-digital converter, etc., can, for example, form a unit together with the microphone, as described above.
  • the evaluation unit is preferably a computer which, by means of appropriate software, evaluates the signals received from the sensor unit and also... detection of the damage event, as described in more detail below.
  • each sensor unit can be connected to a respective evaluation unit, or a common evaluation unit can be installed which is set up to receive and evaluate data from two or more sensor units.
  • Microcontrollers are preferably used as the hardware of the evaluation unit. These generally contain a processor (CPU), RAM, program memory, interfaces (e.g. network, USB), input and output ports (I/O ports).
  • the evaluation unit can also contain an analog-digital converter if the sensor unit used does not have an analog-digital converter.
  • a preferred example of a microcontroller is the
  • RP2040 this is a 32-bit microcontroller from the “Raspberry Pi Foundation” (Cambridge, UK). The technical characteristics of this microcontroller are as follows: CPU: 32-bit RP2040 dual-core processor with 133 MHz clock frequency;
  • Random access memory 264 kByte SRAM
  • Program memory 2Mbyte Q-SPI Flash
  • I/O ports 26 multifunctional general-purpose inputs and outputs (GPIO), 3.3V compatible.
  • the microcontroller can also be equipped with a suitable radio module, e.g. Bluetooth or WiFi module, to enable the sending of the evaluation data via a wireless
  • the microcontroller software is preferably designed for pattern recognition of sound signals, whereby the data provided by the sensor unit mentioned is evaluated in all frequency ranges.
  • the evaluation software can preferably be created on the basis of "Raspberry Libraries”.
  • the evaluation unit is designed to carry out an evaluation of the temporal course of infrasound signals and the temporal course of sound signals (airborne sound).
  • the power supply of the evaluation unit can comprise batteries, rechargeable batteries, solar cells, capacitors (preferably supercapacitors) or similar means known to those skilled in the art.
  • the data or signals provided by the sensor unit(s) are evaluated by the evaluation unit at specific intervals, with these intervals preferably being 1 second or less.
  • the detection of sound signals by the sensor unit(s) usually takes place continuously.
  • the temporal progression of the infrasound or airborne sound signals, in particular the amplitudes or frequencies, during the duration of the respective damage event results in a characteristic pattern which can be used by the evaluation unit to identify the type of damage event.
  • this pattern can be characterized using other parameters, as described below.
  • the evaluation unit is preferably designed to carry out the above-mentioned evaluation of the temporal progression of the infrasound and airborne sound signals on the basis of one or more of the following parameters: frequency range, frequency spectrum, gaps in the frequency spectrum, change in frequency over time, minimum/maximum amplitude, amplitude (sound energy or intensity) over time, level decrease at the end, total duration of the damage event.
  • frequency range frequency spectrum
  • gaps in the frequency spectrum change in frequency over time
  • minimum/maximum amplitude amplitude (sound energy or intensity) over time
  • level decrease at the end total duration of the damage event.
  • the evaluation unit is preferably designed to use one or more of the following programs or methods when evaluating the signals and/or to detect a damage event: audio filters, Fourier transformations, wavelet transformations, pattern
  • the evaluation of the signals using software is based on the fact that during a damage event (e.g. stone impact on a glass pane) a signal pattern is created which consists of different sound components (audible noise, infrasound, possibly ultrasound) and is changes over time. It is particularly important that the infrasound signals propagate faster in the material than the audible sound component (noise) propagates in the air, so that the infrasound signals reach the microphone faster than the audible sound signals.
  • the temporal course of the signal pattern can, for example, have an initial phase with a strong infrasound signal, followed by a phase with a strong sound signal in the audible range (e.g. impact noise), followed by a decay phase due to reverberation.
  • software is therefore preferably used that works with adjustable parameters that characterize the mentioned phases or sections. For example, these can be parameters that determine the
  • the evaluation unit is designed to take into account various adjustable threshold values during pattern recognition, so that if a threshold value is exceeded, the occurrence of damage is recognized or the severity of the damage can be classified.
  • the threshold values can be determined using practical tests and thus continuously developed further in order to improve damage detection or to adapt it to special conditions.
  • pattern recognition will be optimized using AI (artificial intelligence) methods.
  • AI artificial intelligence
  • the system ie the software of the The evaluation unit is constantly learning from new data from further damage events.
  • Neural networks or deep learning functions can be used in particular. The use of these methods is particularly advantageous for improving pattern recognition of damage events that are particularly difficult to detect.
  • the evaluation unit is designed to store the data generated during the evaluation and/or to transmit it to another device, preferably by means of a wireless data connection or a radio network, in particular by means of Bluetooth, WLAN or a wireless Internet connection.
  • another device preferably by means of a wireless data connection or a radio network, in particular by means of Bluetooth, WLAN or a wireless Internet connection.
  • other devices include a smartphone, a computer/server, or an on-board diagnostic system or infotainment system of a motor vehicle.
  • the evaluation unit is designed to send a message, e.g. via WLAN, WiFi or Bluetooth, to a mobile device (mobile phone, smartphone, notebook, tablet, etc.) when a damage pattern is detected, which is preferably equipped with an app designed for this purpose.
  • a mobile device mobile phone, smartphone, notebook, tablet, etc.
  • the sent message can also contain the data generated by the evaluation of the evaluation unit.
  • the mobile device or the app installed on it can be set up to forward this message, preferably together with the data of the damage pattern, to a server (e.g. of a service provider).
  • This sending of data from the mobile device to a server preferably takes place automatically, ie without human intervention (program-controlled).
  • the mobile device mentioned is the cell phone or smartphone of the driver of a vehicle in which a damage event has been detected by the evaluation unit.
  • the evaluation unit is designed to assign the pattern of the sound and infrasound signals of a damage event obtained by the evaluation to one of several damage pattern types, the damage pattern types comprising in particular the following: glass stone chip damage, glass breakage damage, glass cracks; accident damage, in particular dents, in
  • Sheet metal parts scratches in sheet metal parts; scratches in plastic parts or in composite parts; breakages in plastic
  • the evaluation unit is designed to detect vandalism damage or parking damage caused by a third party to a vehicle depending on the pattern obtained for the respective damage event.
  • the evaluation unit is designed to generate an alarm or emergency signal depending on the damage event detected, or to transmit an emergency call to a rescue control center.
  • the system comprises at least one camera which is suitable for continuously making video recordings and optionally storing them.
  • a camera is installed in a vehicle which is equipped with a system according to the invention for acoustic detection of damage events.
  • the camera is preferably installed in such a way that its angle of view covers the front area of the vehicle.
  • Such a camera can also be installed to monitor the rear area. In this way, the course of the damage can be recognized visually in addition to acoustic detection. Since the camera is continuously in
  • Operation it also detects and documents the damage progression shortly before the occurrence of a damage event, in particular a frontal collision.
  • the present invention further extends to a vehicle, in particular a motor vehicle, which is equipped with at least one sensor unit or a system according to the above description.
  • the recording of the temporal progression of the signals is generally carried out continuously, i.e. without interruption.
  • the airborne sound and infrasound signals are evaluated at certain intervals, whereby these intervals are preferably 1 second or less.
  • the evaluation of the temporal course of the signals is carried out on the basis of one or more of the following parameters: frequency range, frequency spectrum, gaps in the frequency spectrum, change in frequency over time, minimum/maximum amplitude, amplitude (sound energy or intensity) over time, level decrease at the end, total duration of the damage event.
  • the method comprises a subsequent step in which the pattern of airborne sound and infrasound obtained by evaluating
  • Signals of a damage event are assigned to one of several damage pattern types, whereby these damage pattern types include in particular the following: glass stone chip damage, glass breakage damage, glass cracks; hail damage to glass or sheet metal, accident damage, in particular dents, in sheet metal parts;
  • Composite material parts breakage damage in plastic parts or in composite material parts; impact or breakage damage to vehicle exterior mirrors; impact or breakage damage to lighting devices, in particular to headlights and tail lights of motor vehicles.
  • one or more of the following programs or methods are preferably used: audio filters, Fourier transformations, wavelet transformations, pattern recognition, statistical methods.
  • the evaluation is carried out in such a way that various adjustable threshold values are taken into account during pattern recognition, so that when a threshold value is exceeded, the occurrence of a
  • the method comprises a further step in which the data generated during the evaluation are transmitted to another device, preferably by means of a wireless data connection or a radio network, in particular by means of Bluetooth, WLAN or a wireless Internet connection.
  • the method is designed so that if a damage pattern is detected, a message is sent from the evaluation unit to a mobile device (mobile phone, smartphone, notebook, tablet, etc.) via WLAN, WiFi or Bluetooth, for example, which is preferably equipped with an app designed for this purpose.
  • a mobile device mobile phone, smartphone, notebook, tablet, etc.
  • WLAN wireless local area network
  • WiFi wireless local area network
  • Bluetooth wireless local area network
  • the sent message can also contain the data generated by the evaluation of the evaluation unit.
  • the mobile device or the app installed on it can be set up to forward this message, preferably together with the data of the damage pattern, to a server (for example of a service provider).
  • This sending of data from the mobile device to a server preferably takes place automatically, i.e. without human intervention (program-controlled).
  • the method preferably comprises a further step in which an alarm or emergency signal is generated or an emergency call is transmitted to a rescue control center, depending on the pattern obtained during the evaluation for the respective damage event.
  • a damage event caused by vandalism or parking damage caused by a third party is detected on a vehicle
  • a notification is sent to the driver and/or owner of the vehicle, and optionally the damage pattern of the detected damage event, the detected damage pattern type as well as information on the vehicle part(s) affected by the damage event and information on the time and place of the damage occurrence are stored for the purpose of preserving evidence, whereby the transmission of the notification and the storage are triggered automatically when damage occurs.
  • FIG. 1 is a sectional view showing an embodiment of the sensor unit according to the invention in the state of attachment to a material.
  • FIG. 2 shows (in plan view) a sensor unit according to the invention (as shown in FIG. 1) in the state of attachment to a material.
  • FIG. 3 is a sectional view showing a modification of the embodiment of the invention shown in FIG. 1.
  • Sensor unit in the state of attachment to a material shows .
  • the sensor unit (1) is attached to the surface (11a) of a material (11) to be monitored (e.g. glass pane).
  • a material (11) to be monitored e.g. glass pane
  • the housing (7) of the sensor unit consists of a front wall
  • This side wall extends towards the fastening side (A); the edge (7c) of the side wall (7b) does not touch the surface (Ila) of the material (11), but maintains a distance (d) from this surface so that an air gap is created .
  • the housing is open on one side, namely towards the fastening side (A).
  • a circuit board (6) is arranged in the housing (7) and connected to the housing, as shown in the drawing.
  • the circuit board is aligned approximately parallel to the end wall (7a) of the housing and to the surface (11a) to which the sensor unit (1) is attached. There is a distance (e) between the underside (6a) of the circuit board (6) and the opposite end wall (7a) of the housing (7), so that a cavity is formed between them.
  • a sound transducer (4) is arranged on the component side of the circuit board (6).
  • the microphone (2) has a sound opening (8) which is arranged in a wall area (2 '' ) of the microphone (2) which is opposite the circuit board (6) and faces the fastening side (A).
  • the wall area (2 '' ) is essentially flat and runs approximately parallel to the surface (11a) on which the sensor unit (1) is fastened.
  • the sound opening (8) is not located opposite the sound transducer (4), but at a laterally offset position.
  • a sound-permeable connecting layer (10) with a thickness (a), which is attached to the outer surface in the mentioned area and covers the sound opening (8).
  • the connecting layer (10) is located between this surface and the outer surface of the wall area (2 '' ) of the microphone and connects these two surfaces.
  • Fastening means (9, 9') for fastening the sensor unit (1) to the material surface (11a) are provided on the component side of the circuit board (6); these are located outside the area of the microphone (2) but inside the housing (7) and extend to the fastening side (A) or to the surface (11a) of the material (in the illustrated state of fastening the sensor unit to the surface of a material, the plane of the fastening side of the sensor unit indicated by the dashed line (A) is identical to the surface (11a) of the material).
  • An elastic, double-sided PVC adhesive tape with a thickness of 1-2 mm can be used as the material for the fastening device(s).
  • the height (c) of the fastening means (9, 9 ') is selected so that the edge (7c) of the side wall (7b) has the mentioned distance (d) to the surface
  • the housing therefore has no
  • an electronic circuit (5) e.g. an ASIC, which comprises, for example, a preamplifier and an analog-digital converter.
  • the circuit is encapsulated in an encapsulating material (5a).
  • the sensor unit in the state of attachment to a material (11), is only connected to the surface (11a) of the material (11) via the fastening means (9, 9') and the connecting layer (10).
  • the arrow (12) indicates that the board
  • the curvature of the board is not shown in Fig. 1, but is merely indicated by the arrow (12)).
  • This can be achieved - as shown in Fig. 1 - by choosing the height (c) of the fastening means (9, 9') such that it is shorter than the sum of the height (b) of the microphone and the thickness (a) of the connecting layer (10).
  • the circuit board which is curved in the direction of the arrow (12), exerts pressure (through spring force) on the microphone and the connecting layer (10) located thereon in the direction of the material 11.
  • the sensor unit (1) is mounted on a material to be monitored
  • the circuit board (6) is located inside the housing, shown here transparent, the surrounding edge (7b) of which is shown by a thick line.
  • the position of the microphone (2) on the circuit board is indicated by a dashed line, as are the positions of the sound transducer (4) and the circuit (5) . Both elements are located together in the interior of the microphone (2) (as in Fig. 1).
  • the sound opening (8) is located above the circuit (5) and offset to the side (distance (f) from the sound transducer (4) .
  • the fastening means (9, 9 ' ) are mounted opposite each other in the outer area of the circuit board (6).
  • the sensor unit (1) shown in this drawing is a modification of the sensor unit according to Fig. 1 and differs from it as follows:
  • the fastening means (9, 9') is not attached to the circuit board (6), but to the edge (7c) of the side wall (7b) of the housing (7).
  • the edge (7c) can be bent or folded inwards (ie towards the microphone (2)) as shown in Fig. 3.
  • the edge (7c) has no direct contact with the material surface (11a), but is connected to it via the fastening means (9, 9').
  • Fastening means e.g. a double-sided adhesive tape, preferably extends over the entire circumference of the edge (7c) (not shown).
  • the fastening means (9, 9 ') connects the housing (7) of the sensor unit to the material (11).
  • the height of the fastening means (9, 9 *) in this case corresponds to the distance (d) between the material surface (11a) and the edge (7c) of the side wall (7b) of the housing (7).
  • the housing has no direct contact with the surface (11a), but is only connected to the
  • the arrow (12) indicates that the circuit board (6) bulges (12) towards the front wall (7a) of the housing (7) when the sensor unit is attached to the material (11). This can be achieved by appropriate dimensioning of the side wall (7b) and the height/thickness (d) of the fastening means in relation to the height (b) of the microphone (2) and the thickness (a) of the connecting layer (10).
  • Fig. 4A to 4F show the temporal course (pattern) of the infrasound signals or airborne sound signals for different damage events on a glass pane (stone chips, glass breakage).
  • a production vehicle (car) was fitted with a windshield to which a sensor unit according to the invention was adhesively attached, as described above.
  • the position of the sensor unit on the windshield was varied during the tests (e.g. top left or bottom center).
  • the tests were carried out at an ambient temperature of 26 °C; the test room was open to the outside so that background noise caused by road traffic was present.
  • Fig. 4A to 4F show screenshots of the sound signal patterns recorded using this software.
  • infrasound phase A very strong infrasound signal is generated during the damage event ("infrasound phase"). These infrasound ranges are characterized by a strong overmodulation of the signal and usually have only a few zero crossings on the X-axis. The signals in the airborne sound range are usually not overmodulated (because they have lower energy or lower volume) and are characterized by a large number of zero crossings.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
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  • Analytical Chemistry (AREA)
  • Pathology (AREA)
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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Probability & Statistics with Applications (AREA)
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  • Spectroscopy & Molecular Physics (AREA)
  • Multimedia (AREA)
  • Acoustics & Sound (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

L'invention concerne une unité de capteur pour la détection acoustique d'événements d'endommagement sur des matériaux, un système comprenant une unité de capteur de ce type et un procédé pour la détection acoustique d'événements d'endommagement. L'unité de capteur (1) comprend : • un boîtier (7) comportant une paroi d'extrémité (7a) et une paroi latérale (7b) ; • une carte de circuit imprimé (6) disposée dans le boîtier (7) ; • un microphone (2) monté sur le côté d'assemblage de la carte de circuit imprimé (6) et comprenant une paroi (2', 2'') qui, conjointement avec la carte de circuit imprimé, délimite un espace interne (3) ; • un transducteur acoustique (4) disposé sur la carte de circuit imprimé (6) à l'intérieur (3) du microphone (2) ; • une ouverture pour le son (8) ménagée dans une région de paroi (2'') du microphone (2) ; • une couche de liaison perméable au son (10) qui recouvre l'ouverture pour le son (8) ; et • un moyen de fixation (9, 9') pour fixer l'unité de capteur (1) sur la surface de matériau (11a).
EP24702218.9A 2023-01-09 2024-01-03 Unité de capteur, et système et procédé de détection de dommages Pending EP4662465A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102023000025.6A DE102023000025A1 (de) 2023-01-09 2023-01-09 Sensoreinheit sowie System und Verfahren zur Schadenserkennung
PCT/EP2024/025001 WO2024149622A1 (fr) 2023-01-09 2024-01-03 Unité de capteur, et système et procédé de détection de dommages

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Publication Number Publication Date
EP4662465A1 true EP4662465A1 (fr) 2025-12-17

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EP (1) EP4662465A1 (fr)
DE (1) DE102023000025A1 (fr)
WO (1) WO2024149622A1 (fr)

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Publication number Priority date Publication date Assignee Title
DE102024209067A1 (de) * 2024-09-20 2026-03-26 Volkswagen Aktiengesellschaft Verfahren zum Betrieb eines Kraftfahrzeugs mit einer Windschutzscheibe

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5192931B1 (en) * 1992-02-11 1999-09-28 Slc Technologies Inc Dual channel glass break detector
US5389911A (en) 1993-12-06 1995-02-14 Ford Motor Company Alarm system for detecting glass breakage
US6794882B2 (en) 2002-07-30 2004-09-21 Ppg Industries Ohio, Inc. Rupture detector for windshield assembly
US7388487B2 (en) * 2004-06-17 2008-06-17 Honeywell International, Inc. Method of eliminating impact/shock related false alarms in an acoustical glassbreak detector
DE102006038843A1 (de) * 2006-08-18 2008-02-21 Robert Bosch Gmbh Vorrichtung zur Erfassung von Körperschall
DE102017201481A1 (de) * 2017-01-31 2018-08-02 Robert Bosch Gmbh Mikromechanische Modul und Verfahren zum Erfassen von Schwingungen, insbesondere Körperschall
GB201701924D0 (en) * 2017-02-06 2017-03-22 Belron Int Ltd Systems and methods for damage detection
AU2018371173A1 (en) * 2017-11-22 2020-06-11 Agc Glass Europe Glazing having sensors

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WO2024149622A1 (fr) 2024-07-18

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