JP2008102826A - Glass breaking detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass breaking detection device for reducing the number of components, and for achieving crime prevention and power saving at low costs. <P>SOLUTION: This glass braking detection device is configured to determine whether or not a window glass 30 installed in a vehicle 1 has been broken by using a single device for adding vibration and detecting vibration, and comparing a difference V<SB>d0</SB>between a voltage V<SB>1</SB>input to a vibration addition detection device 40 when vibration is added and a voltage V<SB>2</SB>output from the vibration addition detection device 40 when the vibration is detected with a threshold V<SB>0</SB>. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass crack detection apparatus that applies vibration to glass and determines glass breakage based on detection of vibration propagating through the glass.

  As a conventional glass breakage detection device, one end is grounded, a first resistor provided on the surface or inside of a window glass of a vehicle, and a first resistor are connected in series, and one end thereof is connected to the battery anode. A device including a connected second resistor and voltage detecting means for detecting the voltage of each resistor is disclosed (for example, see Patent Document 1).

According to this glass breakage detecting device, when the window glass of the vehicle is broken, the first resistor provided inside or on the surface of the window glass is disconnected, so that the voltage detected by the voltage detecting means changes. Will do. Thus, by detecting a change in voltage, it becomes possible to determine the breakage of the window glass, and when the window glass breaks, an alarm is issued to the outside, which is useful for crime prevention.
JP 2003-141649 A

  However, according to the conventional glass crack detection device, a special window glass provided with the first resistor or sandwiched inside is required, and the number of parts increases, so that the cost increases. If the first resistor provided on the glass is not broken, the voltage does not change, and therefore there is a possibility that even if the window glass is broken, it cannot be detected. In order to determine whether or not the window glass is broken, voltage must always be applied to the first and second resistors, which consumes battery power.

  Accordingly, an object of the present invention is to propose a glass crack detection device that has a small number of parts, is low cost and is crime prevention and power saving.

  According to an embodiment of the present invention, a vibration addition detection unit that adds vibration to a glass provided in a vehicle and detects the vibration reflected by an edge of the glass, and the vibration addition detection unit includes the vibration. Is applied to the glass, and is output from the vibration addition detector when the vibration applied detector detects the vibration reflected by the edge of the glass. There is provided a glass breakage detection device comprising a determination unit for determining whether or not the glass is broken based on a difference from an output voltage.

  According to such a configuration, it is possible to provide a glass crack detection device that has a small number of parts, is low cost, and is crime prevention and power saving.

[Embodiment]
(Configuration of the embodiment)
FIG. 1 is a schematic configuration diagram of a vehicle equipped with a glass breakage detection apparatus according to an embodiment of the present invention. For the purpose of crime prevention, a case where a glass breaking device is mounted on a vehicle is shown.

  The vehicle 1 includes a main body 2 on which an engine or the like is mounted, and a door 3 that is freely opened and closed with respect to the main body 2. The glass breakage detection device 4 is mounted on the main body 2.

  The door 3 is provided in the vicinity of the window glass 30, a key cylinder 31 that enables the door 3 to be locked and unlocked, and the center of the window glass 30 inside the vehicle 1, and vibration that adds and detects vibration to the window glass 30. An additional detection device 40 is provided.

  For example, the vibration addition detection device 40 uses a phenomenon in which mechanical distortion occurs when a voltage is applied to a crystal such as ZnS or CdS, and converts the applied voltage into mechanical vibration. Elements are used. Further, the vibration detection utilizes a phenomenon in which a voltage is generated at both ends of the crystal when a mechanical strain is generated in the crystal. In the present embodiment, a piezoelectric element is used as the vibration addition detection device 40, but the present invention is not limited to this. In addition, the vibration addition detection device 40 is thin and does not hinder the opening and closing of the window glass 30.

  FIG. 2 is a block diagram of glass breakage detection device 4 according to the embodiment of the present invention.

  The glass breakage detection device 4 includes a vibration addition detection unit 41 that adds and detects vibration using the vibration addition detection device 40, a locking / unlocking unit 42 that processes a signal indicating locking and unlocking from the key cylinder 31, It has a determination unit 43 that determines whether or not the window glass 30 is broken, an alarm unit 44 that issues an alarm when it is determined that the window glass 30 is broken, and a control unit 45 that comprehensively controls each unit.

(Operation)
Hereinafter, the operation of the glass breakage detection apparatus 4 in the embodiment of the present invention will be described according to the flowchart of FIG. 4 with reference to FIGS. 1 to 3.

3 (a) is a schematic diagram for voltages V ₁ and the time entered to the vibration additional detection device 40 according to an embodiment of the present invention. FIG. 3B shows the voltage V ₂ calculated by the vibration addition detection unit 41 from the voltage V ₁ input to the vibration addition detection device 40 and the voltage output from the vibration addition detection device 40 according to the embodiment of the present invention. FIG. The horizontal axis represents time, and the vertical axis represents voltage.

Figure 3 times t ₁ shown in (a), first represents the time interval between the addition of vibration to the window glass 30 from the locking, the time Delta] t, indicative of a time interval, appended vibration. Time t ₁ + Δt is one period, and the addition of vibration is repeated periodically. Note that the period can be arbitrarily set.

  After the occupant stops the vehicle 1 at the parking lot and gets off, the key of the vehicle 1 is inserted into the key cylinder 32 and locked (S10).

  The locking / unlocking unit 42 of the glass breakage detection device 4 receives a locking signal indicating that the locking has been performed from the key cylinder 31, and transmits it to the control unit 45.

Based on the locking signal received from the locking / unlocking unit 42, the control unit 45 transmits an instruction signal for adding vibration to the window glass 30 to the vibration addition detecting unit 41 after the time t ₁ has elapsed (S <b> 11).

  Based on the instruction signal from the control unit 45, the vibration addition detection unit 41 adds vibration to the window glass 30 by the vibration addition detection device 40 at time intervals described below (S12).

As shown in FIG. 3A, the vibration addition detection unit 41 outputs the pulsed voltage V ₁ to the vibration addition detection device 40 three times during the time Δt. During this period, vibration is applied to the window glass 30 three times.

  Here, since power is not supplied from the glass breakage detection device 4 to the vibration sensor 40 during the time when vibration is not added and detected, the battery power consumption is reduced as compared with a device that always performs a detection operation.

The vibration addition detection device 40 adds vibration to the window glass 30 based on the instruction signal from the vibration addition detection unit 41, and the vibration addition detection unit 41 applies the voltage V ₁ to the vibration addition detection device 40 for a time Δt. Then, the circuit for adding vibration is switched to the circuit for detecting vibration, and the detection operation is started from time t ₁ ′ and t ₂ ′ to Δt. And the vibration addition detection apparatus 40 detects the vibration which propagated the window glass 30 and was reflected by the edge of the window glass 30 (S13).

Here, the vibration detected by reflection at the edge of the window glass 30 is detected as a complex vibration, but in order to determine whether or not the window glass 30 is broken, it is necessary to detect fine vibration. And not. Therefore, the vibration adding detector 41, the voltage output from the vibration additional detector 40, was treated using a filter or the like in consideration of the delay in detection by the reflection of the vibration of the maximum voltage, calculates a voltage V _2.

FIG. 3C illustrates a difference V between the voltage V ₁ input to the vibration addition detection device 40 and the voltage V ₂ calculated by the vibration addition detection device 40, which is input to the determination unit 43 according to the embodiment of the present invention. It is the schematic regarding _d0 and time. V ₀ represents a threshold value that serves as a criterion for determining glass breakage, the horizontal axis represents time, and the vertical axis represents voltage.

The vibration addition detection unit 41 calculates a difference V _d0 between the voltage V ₁ and the voltage V ₂ input to the vibration addition detection device 40 (S14), and transmits the difference V _d0 to the determination unit 43.

The determination unit 43 compares the difference V _d0 transmitted from the vibration addition detection unit 41 with the threshold value V ₀ . Or; (No S15), judging section 43, the window glass 30, it is determined that it is not cracked, the process returns to step 11, is a door 3 is unlocked when the difference _{V d0} than the threshold value _{V 0} is smaller The operation continues until the window glass 30 is determined to have been broken and an alarm is issued.

FIG. 3D shows a vibration addition detection unit based on the voltage V ₁ input to the vibration addition detection device 40 and the voltage output from the vibration addition detection device 40 when the window glass 30 according to the embodiment of the present invention is broken. 41 is a schematic diagram regarding the voltage V ₂ ′ calculated by 41 and time. FIG. FIG. 3E is a schematic diagram relating to the difference V _d1 between the voltage V ₁ input to the vibration addition detection device 40 and the voltage V ₂ ′ calculated by the vibration addition detection device 40 according to the embodiment of the present invention, and time. . The horizontal axis represents time, and the vertical axis represents voltage.

The vibration addition detection unit 41 adds vibration to the window glass 30 by the vibration addition detection device 40. The vibration addition detection device 40 detects the vibration reflected by the edge of the window glass 30 and outputs a voltage to the vibration addition detection unit 41. The vibration addition detection unit 41 calculates the voltage V ₂ ′ from the voltage output from the vibration addition detection device 40 shown in FIG. The vibration addition detection unit 41 calculates a difference V _d1 between the calculated voltage V ₂ ′ and the voltage V ₁ (S14), and transmits the difference V _d1 to the determination unit 43.

Here, when the window glass 30 is broken, a part of the window glass 30 is missing or cracked, so that vibrations applied to the window glass 30 are partially absorbed by the crack and reflected. Since the vibration energy becomes small, the voltage V ₂ ′ becomes small, and the difference V _d1 becomes large as shown in FIG.

When the difference V _d1 is larger than the threshold value V ₀ (S15; Yes), the determination unit 43 determines that the window glass 30 is broken and transmits an instruction signal to the alarm unit 44 to warn.

  When the alarm unit 44 receives an alarm instruction signal from the control unit 45, for example, an alarm device (horn) (not shown) mounted on the vehicle 1 is used to alert the surroundings by sound (S16). Or turn on a direction indicator or headlight to alert the surroundings. Alternatively, they may be combined or other means may be used.

(Effect of embodiment)
According to the above-described embodiment, the special window glass 30 is not required, and the device for adding vibration and the device for detecting vibration are combined in one device, so the number of parts is reduced and the cost is low. become. Moreover, the crack of the window glass 30 is determined from the difference between the voltage input to the vibration addition detection device 40 and the voltage calculated by the vibration addition detection unit 41 from the voltage output from the vibration addition detection device 40. Instead of detecting the moment when 30 is broken, it is confirmed that it is not broken, so that malfunctions can be reduced. Further, since the glass breakage detection device 4 periodically adds and detects vibration to the window glass 30 by the vibration addition detection device 40, it is not necessary to always operate the vibration addition detection device 40, thereby saving power.

(Modification 1)
In the present embodiment, power supply and the like of the vibration addition detection device 40 are performed by a harness (not shown). However, both the glass breakage detection device 4 and the vibration addition detection device 40 are provided with a transmission / reception unit, and RFID (Radio Frequency) is provided. It may be configured to be able to supply power using a non-contact power transmission technology such as Identification) and transmit and receive signals wirelessly.

  Furthermore, in the vehicle 1 that locks and unlocks the door when the door locking / unlocking signal of the keyless entry system or the like is received from the outside of the vehicle 1, the existing receiving means can be used as the receiving unit of the glass breakage detecting device 4, The number of parts can be reduced and the cost can be reduced.

(Modification 2)
In the vehicle 1 equipped with the anti-theft system using the location information service, the alarm function of the anti-theft system to the owner of the vehicle 1 is transmitted by transmitting the alarm signal of the glass breakage detection device 4 to the anti-theft system. By using, the abnormality of the vehicle 1 can be notified.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from or changing the technical idea of the present invention.

It is a schematic block diagram of the vehicle carrying the glass crack detection apparatus which concerns on embodiment of this invention. It is a block diagram of the glass crack detection apparatus 4 which concerns on embodiment of this invention. (A) is a schematic diagram for voltages V ₁ and the time entered to the vibration additional detection device 40 according to an embodiment of the present invention. (B) is an overview of the voltage V ₂ calculated by the vibration addition detection unit 41 from the voltage V ₁ input to the vibration addition detection device 40 and the voltage output from the vibration addition detection device 40 according to the embodiment of the present invention, and time. FIG. (C) is a difference V _d0 between the voltage V ₁ input to the vibration addition detection device 40 and the voltage V ₂ calculated by the vibration addition detection device 40, which is input to the determination unit 43 according to the embodiment of the present invention. It is the schematic regarding time. (D) is when the window glass 30 according to the embodiment of the present invention is broken, the vibration adding detection unit 41 from the voltage voltages V ₁ and the vibration additional detector 40 which is input is output to the vibration additional detector 40 calculated as the voltage V _{2 'is} a schematic diagram for time. (E) is a schematic diagram regarding a difference V _d1 between the voltage V ₁ input to the vibration addition detection device 40 and the voltage V ₂ ′ calculated by the vibration addition detection device 40 according to the embodiment of the present invention and time. It is a flowchart which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Main body, 3 ... Door, 4 ... Glass crack detection apparatus, 30 ... Window glass, 31 ... Key cylinder, 40 ... Vibration addition detection apparatus, 41 ... vibration adding detection unit, 42 ... locking-unlocking unit, 43 ... determining unit, 44 ... alarm unit, 45 ... control _{unit, V} 0 ... _{threshold, V} 1, V ₂ ... voltage, V _d0 , V _d1 ... difference, Δt, t ₁ , t ₂ , t ₁ ', t ₂ ' ... time

Claims (5)

A vibration addition detector for adding vibration to the glass provided in the vehicle and detecting the vibration reflected by the edge of the glass;
When the vibration addition detection unit adds the vibration to the glass, the input voltage input to the vibration addition detection unit, and when the vibration addition detection unit detects the vibration reflected by the edge of the glass, A glass breakage detection apparatus comprising: a determination unit that determines whether or not the glass is broken based on a difference from an output voltage output from a vibration addition detection unit.   The glass breakage detection apparatus according to claim 1, wherein the vibration addition detection unit performs addition of the vibration and detection of the vibration by a piezoelectric element.   The vibration addition detection unit sets a period from the start of the addition of the vibration to the start of the next addition of the vibration as one cycle, and the detection of the vibration is performed by detecting the vibration after the addition of the vibration. The glass breakage detection apparatus according to claim 1, wherein the addition and detection of the vibration are repeatedly performed based on the period.   The glass breakage detection apparatus according to claim 1, wherein the determination unit determines that the glass is broken when the difference between the input voltage and the output voltage is greater than a predetermined value. A vibration addition detector for adding vibration to the glass provided in the vehicle and detecting the vibration reflected by the edge of the glass;
When the vibration addition detection unit adds the vibration to the glass, the input voltage input to the vibration addition detection unit, and when the vibration addition detection unit detects the vibration reflected by the edge of the glass, Based on the magnitude of the difference between the output voltage output from the vibration addition detection unit, a determination unit that determines whether or not the glass is broken,
A glass breakage detection apparatus comprising: an alarm unit that issues an alarm when the determination unit determines that the glass is broken.

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