JP2008102825A - Glass breaking detection device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple, inexpensive and highly reliable glass braking detection device for highly precisely determining a broken glass. <P>SOLUTION: This glass braking detection device of a vehicle is provided with a vibration generation part mounted on a vehicle; a plurality of vibration detection parts mounted on the glass of a plurality of widow parts of the vehicle; and a decision part for deciding whether or not the glass has been broken based on an output signal from at least one vibration detection part of a plurality of vibration detection parts. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass breakage detection device for a vehicle, and more particularly to a glass breakage detection device for a vehicle that determines the glass breakage of the vehicle by applying vibration to the vehicle and detecting the vibration.

  Various devices have been developed as measures for preventing vandalism and vehicle theft. Among them, since the vandalism and theft of the vehicle enter the vehicle by breaking the window glass of the vehicle, various methods are provided as a glass breakage detection device for the vehicle.

  2. Description of the Related Art Conventionally, as a glass breakage detection device for a vehicle, there is a device that detects vibration of a vehicle, acoustic energy, moving objects, and the like to detect glass breakage and intrusion into the vehicle (Patent Document 1).

The glass breakage detection device for a vehicle includes a detection unit that detects vibration, acoustic energy, and a moving object in the vehicle, and an analysis unit that analyzes a detection signal of the detection unit. Based on this, glass breakage is detected.
JP-A-6-258194

  However, according to the glass breakage detection device for a vehicle disclosed in Patent Document 1, vibrations and acoustic energy in the vehicle are detected and the presence / absence of a moving object is also detected, so that the detection unit becomes complicated and the cost increases. There is an inconvenience.

  Accordingly, an object of the present invention is to provide a glass breakage detection device that has a simple and low-cost configuration, can cope with glass breakage with high accuracy, and is excellent in reliability.

  [1] In order to achieve the above object, the present invention provides a vibration generating unit mounted on a vehicle, a plurality of vibration detecting units respectively mounted on glass of a plurality of window portions of the vehicle, and the plurality of vibrations. There is provided a glass breakage detection device for a vehicle, comprising: a determination unit that determines whether the glass is broken based on an output signal from at least one vibration detection unit of the detection unit.

  [2] The glass breakage detection device for a vehicle according to [1], wherein the determination unit determines which glass of the plurality of window portions is broken.

  [3] The glass breakage detection device for a vehicle according to [1] or [2], wherein the vibration generation unit is mounted on a roof portion in the vehicle.

  [4] The vehicle according to any one of [1] to [3], wherein the vibration generating unit generates vibration at a frequency corresponding to a natural vibration mode of the glass of the window of the vehicle. The glass breakage detection apparatus may be used.

  [5] The vehicle glass breakage detection device according to [1], wherein the determination unit outputs a determination result to an information transmission device and notifies a remote person of the information. .

  ADVANTAGE OF THE INVENTION According to this invention, the response | compatibility with glass breakage can be taken with high precision, and the glass crack detection apparatus excellent in reliability can be provided.

[Embodiment]
FIG. 1 is an overall perspective view showing an attachment state of main devices mounted on a vehicle. The glass breakage detection apparatus according to the embodiment of the present invention is configured to detect vibration transmitted from the vibration generating unit 10 by being mounted on the glass 3 of the window 2 and the vibration generating unit 10 mounted on the indoor ceiling 1a of the vehicle 1. The vibration detection unit 11 to detect, and a determination unit that determines whether the glass is broken based on the output value of the vibration detection unit 11 are configured. Here, the vibration detection unit 11 detects vibrations in the respective windows 3a, 3b, 3c, and 3d of the left and right windows 2a, 2b, 2c, and 2d of the driver seat, the passenger seat, and the rear seat of the vehicle 1, respectively. The parts 11a, 11b, 11c and 11d are mounted. Note that the vibration detector 11 can be mounted only at a necessary location, such as only at the driver side window.

  The vibration generator 10 can be an electromagnetic or piezoelectric vibration generator. The electromagnetic vibration generator 10 operates in the same manner as an acoustic speaker. The coil is driven in a magnetic field of a permanent magnet, and a component having a very large mass can be vibrated by the magnetic field of a dynamic electromagnetic coil. The electromagnetic vibration generator 10 can generate an excitation force proportional to the input current. The piezoelectric type vibration generator 10 operates by generating an excitation force by utilizing a piezoelectric ceramic disk and changing the thickness of the disk in proportion to the supply voltage. By using a high drive voltage and a plurality of discs, it is possible to generate a very high frequency excitation force. The vibration generating unit 10 may generate an ultrasonic wave. Further, the vibration generator 10 generates vibration by an input signal that has been subjected to FM modulation or AM modulation, for example, in order to prevent erroneous detection by the vibration detector 11 and improve the accuracy of glass breakage detection. There may be.

  FIG. 2 is a diagram for explaining the relationship between the generated vibration spectrum of the vibration generating unit 10 used in the embodiment of the present invention and the vibration spectra of the natural vibration modes of the glasses 3a, 3b, 3c, and 3d.

In the embodiment of the present invention, an electromagnetic type vibration generator is used as the vibration generating unit 10, and the vibration frequency characteristic of the vibration to be generated corresponds to the natural vibration mode of the glass 3a, 3b, 3c, 3d, or Includes natural vibration modes. In FIG. 2, the generated vibration spectrum of the vibration generating unit 10 includes the natural vibration modes (basic bending modes) f _a , f _b , f _c , and f _d of the glasses 3a, 3b, 3c, and 3d. 3a, 3b, 3c, 3d may include other natural vibration modes, for example, higher-order bending modes, torsion modes, etc., with vibration frequency characteristics having a broad band including a plurality of natural vibration modes. There may be. The frequencies of the natural vibration modes of the glasses 3a, 3b, 3c, and 3d are set in consideration of boundary conditions with the window portions 2a, 2b, 2c, and 2d. Moreover, the vibration frequency of the vibration generation part 10 can be tuned at arbitrary timing as needed.

  The vibration detecting unit 11 can use a piezoelectric acceleration pickup. A piezoelectric acceleration pickup is a sensor that uses a piezoelectric element such as a single crystal of crystal or titanium sambarium as a spring of a seismo system, and at the same time uses a mechanical electric conversion element, and outputs an electric signal proportional to vibration acceleration. Piezoelectric accelerometers basically have a compression type and a shear type (shear type), depending on how the force is applied to the piezoelectric element. The compression type has a piezoelectric element sandwiched between the base of the sensor and the weight. The shear type has a structure in which a piezoelectric element is fixed between a post and a weight standing perpendicular to the base. Note that the vibration detection unit 11 may be capable of detecting ultrasonic waves.

  The vibration detector 11 is mounted on the glass 3a, 3b, 3c, and 3d of the left and right windows 2a, 2b, 2c, and 2d of the driver seat, the passenger seat, and the rear seat of the vehicle 1, Since the glasses 3a, 3b, 3c, and 3d are attached so as to be vertically movable with respect to the window portions 2a, 2b, 2c, and 2d, the vibration detection units 11a, 11b, 11c, and 11d are connected to the vehicle 1 Are connected by a harness or a cable having a margin capable of relative motion.

  FIG. 3 is a block diagram showing a schematic configuration of the embodiment of the present invention. Vibration generating unit 10, vibrations generated by the vibration generating unit 10 are transmitted to the vehicle 1 and the glasses 3a, 3b, 3c, 3d, and vibration detecting units 11a, 11b, 11c, 11d for detecting the transmitted vibrations, respectively. A filter circuit 20 that extracts a specific frequency generated by the vibration generating unit 10 from the detection signal, a glass breakage determining unit 25 that determines a glass breakage based on an output signal from the filter circuit 20, the vibration generating unit 10 or the glass breakage The control unit 30 is configured to control the determination unit 25.

  Further, the alarm device 40 can issue an alarm based on the determination result by the glass breakage determination unit 25. As alarm means, alarm sound, sound output, light, etc. can be applied.

  Moreover, based on the determination result by the glass breakage determination unit 25, the determination result can be presented from the information transmitting device 50 to the information receiving device 60 possessed by the person concerned in the vehicle 1. The related person is a concept including a person related to the vehicle such as a driver, an owner, or a borrower.

[Operation of glass breakage detector]
FIG. 4 is a flowchart showing the operation of the glass breakage detection apparatus. Hereinafter, operation | movement of the glass crack detection apparatus which concerns on embodiment of this invention is demonstrated according to each step.

  FIG. 5 is a diagram showing the signal at each step shown in the flowchart of FIG.

[Vibration generation step s101]
Input signal of a predetermined level V ₁ of the for generating vibration and a predetermined time t _w drive from the control unit 30 of the vibration generating unit 10 at time t ₁ is input to the vibration generating portion 10 (Figure 5 (a)). Based on this input signal, it is driven by a drive circuit incorporated in the vibration generator 10 to generate vibrations having a predetermined frequency and a predetermined vibration level. The generated vibration is transmitted mainly inside the vehicle 1 and reaches the glass 3a, 3b, 3c, 3d. Here, since the vibration generated in the vibration generating unit 10 includes the natural vibration modes of the glasses 3a, 3b, 3c, and 3d, the vibrations that have reached the glasses 3a, 3b, 3c, and 3d can be efficiently transmitted to the glasses 3a, 3b, 3c and 3d are vibrated.

This vibration step can be executed at predetermined intervals after the time t _{1 in} order to detect glass breaks at regular intervals. Further, when a result that cannot be determined is given by a glass breakage determination unit 25 described later, an input signal whose input level is changed by the control unit 30 is repeatedly input to the vibration generation unit 10.

[Vibration detection step s102]
Vibration detection signals Sa, Sb, Sc, and Sd from the vibration detectors 11a, 11b, 11c, and 11d are input to the 4CH filter circuit 20. The vibration detection signals Sa, Sb, Sc, and Sd are input to the filter circuit 20 at times t _a2 , t _b2 , t _c2 , and t _d2 , respectively, after a predetermined time delay from the vibration generation time t ₁ in the vibration generating unit 10. Is done. FIG. 5 (b), the vibration detection units 11a, 11b, 11c, the vibration detection signal Sa from 11d, Sb, Sc, among Sd, the filter circuit 20 is controlled by the control unit 30, for example, the signal level _{V 2} This shows a case where the vibration detection signal Sa is selected.

[Filtering step s103]
The signal input to the filter circuit 20 includes a vibration detection signal not based on the vibration generator 10 in addition to the vibration detection signal Sa shown in FIG. In order to detect the vibration responding to the vibration generated by the vibration generating unit 10 by the vibration detection unit 11a, by controlling the control section 30, predetermined time t _w from time t _a2 to time to capture the vibration detection signal Sa (FIG. 5C).

Further, a vibration detection signal Sa, which is incorporated in the filter circuit 20, by passing the band-pass filter having a predetermined bandwidth including the natural oscillation mode f _a glass 3a, the vibration of a specific frequency generated by the vibration generating portion 10 The vibration which responds to can be detected.

[Glass Break Determination Step s104]
Based on the signal based on the vibration in the vibration generation unit 10 input from the filter circuit 20 to the glass breakage determination unit 25, the glass breakage is determined.

FIG.5 (d) has shown the signal when the glass crack has generate | occur | produced, and the signal when the glass breakage has not generate | occur | produced. If the glass breakage has not occurred, the signal level V ₃ becomes a predetermined threshold value V _th or more. On the other hand, the signal when the glass breakage has occurred, the signal level V ₄ is significantly reduced and becomes equal to or lower than the threshold value V _th . Alternatively, in a state where the glass is completely broken and the vibration generating unit 10 is peeled from the glass, the signal level becomes zero.

In the glass breakage determination unit 25, for example, a comparator circuit compares a predetermined threshold level _Vth with a signal from the filter circuit 20, and determines whether a glass breakage has occurred based on the output.

  Although the case where the glass breakage of the glass 3a is determined has been described above, also when the glass breakage of the glasses 3b to 3d is determined, the filter circuit 20 is controlled by the control unit 30 and predetermined vibration detection signals Sb, Sc, Alternatively, the same glass crack determination can be performed by selecting Sd.

In the case the determination is not determinable, returns to the vibration generating step s101, then change the level V ₁ of the signal input to the vibration generating portion 10 from the control unit 30, by increasing the vibration level to be generated The glass breakage can be repeatedly determined.

[Alarm step s105]
When it is determined that the glass is broken in the glass break determination step s104, an alarm is issued around the vehicle 1 in the alarm step. The alarm is issued by the alarm unit 40 and can be performed by an alarm sound, voice, light, or the like.

[Information transmission step s106]
When it is determined in the glass breakage determination step s104 that the glass is broken, information can be transmitted together with the alarm step s105 or independently. In the information transmission, the determination result can be notified from the information transmitting device 50 to the information receiving device 60 possessed by the remote person. The remote person is a concept including a person related to the vehicle such as a driver, an owner, and a borrower.

[Effect of the embodiment]
According to the glass breakage detection apparatus for a vehicle according to the embodiment of the present invention described above, the following effects are obtained.

  (1) In the embodiment of the present invention, glass vibration is determined by generating vibration by the vibration generator 10 and detecting the vibration. Therefore, since the vibration intensity level, vibration frequency, vibration generation timing or time are clear, it is possible to distinguish a glass break from other vibrations from the surroundings. As a result, the accuracy of glass breakage determination is greatly improved, false alarms can be greatly reduced, and a highly reliable glass breakage detection device can be realized.

  (2) In the embodiment of the present invention, since vibration is detected by a plurality of vibration detectors 11 for one vibration generator 10, it is advantageous in terms of cost. In addition, since the plurality of vibration detection units 11 are provided, it is possible to determine which glass of the driver seat, the passenger seat, and the rear seat of the vehicle 1 is broken. Furthermore, if the vibration detection part 11 is added, glass breakage determination, such as a fluorocarbon glass and a rear glass, is also possible.

  (3) The vibration generating unit 10 used in the embodiment of the present invention generates vibrations having vibration frequencies corresponding to or including the natural vibration modes of the glasses 3a, 3b, 3c, and 3d. Therefore, even if the vibration generating unit 10 is driven with small vibration energy, the vibration detecting unit 11 can detect the corresponding vibration.

  (4) Although it is difficult to repeatedly determine with a glass breakage detection device that has been used in the past based on a breaking sound from the outside, it is necessary for the glass breakage detection device for a vehicle according to an embodiment of the present invention. Multiple determinations can be made depending on the situation. In particular, since the glass crack determination step can be repeatedly executed by changing the vibration level, a highly reliable glass crack detection device can be obtained.

  (5) If it is determined that the glass is broken, the determination result can be notified to the driver of the vehicle, so the driver can also determine the glass breakage from a remote location, An extremely reliable glass breakage detector can be realized.

FIG. 1 is an overall perspective view showing an attachment state of main devices mounted on a vehicle. FIG. 2 is a diagram for explaining the relationship between the generated vibration spectrum of the vibration generating unit 10 used in the embodiment of the present invention and the vibration spectra of the natural vibration modes of the glasses 3a, 3b, 3c, and 3d. FIG. 3 is a block diagram showing a schematic configuration of the embodiment of the present invention. FIG. 4 is a flowchart showing the operation of the glass breakage detection apparatus. FIG. 5 is a diagram showing the signal at each step shown in the flowchart of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 1a Indoor ceiling part 2, 2a, 2b, 2c, 2d Window part 3, 3a, 3b, 3c, 3d Glass 10 Vibration generating part 11a, 11b, 11c, 11d Vibration detection part 20 Filter circuit 25 Glass crack determination part 30 Control unit 40 Alarm device 50 Information transmitting device 60 Information receiving device

Claims (5)

A vibration generator mounted on the vehicle;
A plurality of vibration detectors respectively mounted on the glass of the plurality of window portions of the vehicle;
A determination unit that determines whether the glass is broken based on an output signal from at least one vibration detection unit of the plurality of vibration detection units;
A glass breakage detection device for a vehicle having   The glass breakage detection device for a vehicle according to claim 1, wherein the determination unit determines which glass of the plurality of window portions is broken.   The glass breakage detecting device for a vehicle according to claim 1, wherein the vibration generating unit is attached to a roof portion in the vehicle.   4. The glass breakage detection device for a vehicle according to claim 1, wherein the vibration generation unit generates vibration at a frequency corresponding to a natural vibration mode of the glass of the window of the vehicle.   The said determination part outputs a determination result to an information transmitter, and notifies a remote person of information, The glass breakage detection apparatus of the vehicle of Claim 1 characterized by the above-mentioned.

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