JP2001253319A - Vehicle security sensor, drive method for security sensor, and security system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle security sensor wherein a glass break sensor is functionally integrated with an intrusion sensor, to provide a drive method for the security sensor and to provide a vehicle security system using the security sensor. SOLUTION: This security sensor 40 provided in the security system intermittently transmits an ultrasonic wave into a vehicle cabin for a prescribed time each time, receives a reflection ultrasonic wave when the ultrasonic wave is reflected inside the cabin, and detects the presence of person's intrusion into the cabin on the basis of the received reflection ultrasonic wave during each the transmission of the ultrasonic wave. The security sensor 40 receives an ultrasonic wave caused by a break in a window glass and detects the break in the window glass on the basis of the received ultrasonic wave during each the non-transmission of the ultrasonic wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a security sensor for securing and securing a vehicle, a driving method of the security sensor, and a vehicle security system using the security sensor.

[0002]

2. Description of the Related Art Conventionally, for example, a security system for automobiles includes various sensors such as a keyless tuner, a glass break sensor, a tilt sensor, an intrusion sensor, a microcomputer for controlling these sensors, and an alarm controlled by the microcomputer. Some are equipped with vessels.

[0003] Here, the keyless tuner locks or unlocks the door of the vehicle by remote control using radio waves from a transmitter. The glass break sensor detects sound waves generated when the window glass of the vehicle breaks. The tilt sensor detects when the vehicle is tilted by a tow truck or the like. The intrusion sensor detects an intruder in the cabin of the vehicle by ultrasonic waves. The microcomputer sounds an alarm by sounding an alarm based on the detection result of each sensor.

[0004] The security system enters an alert state after the door of the vehicle is locked by a keyless tuner. The alert state refers to a state in which all the sensors are operating and the microcomputer is waiting for a signal output from the detection of each sensor.

[0005]

The above-mentioned security system is usually operated by power supply from a battery when the engine of the vehicle is stopped. Therefore, in order for the security system to operate normally for as long as possible, it is necessary to extend as much as possible the time until the battery is dead, that is, the time until the remaining capacity is reduced due to the discharge of the battery and power cannot be supplied. There is. To this end, it is desirable that the number of sensors employed in the security system be as small as possible.

However, conventionally, the frequency band of the sound wave detected by the glass break sensor is set to the audible frequency band, while the detection frequency band of the intrusion sensor is set to the frequency band of the ultrasonic wave (non-audible frequency band). . For this reason, the glass break sensor and the intrusion sensor are usually installed independently of each other in the vehicle interior.

[0007] The inventors of the present invention have studied the characteristics of sound caused by cracks in the window glass of the automobile. According to this, the frequency band of the sound wave generated when the window glass is broken is wide,
It was found that in addition to the audible frequency band lower than 20 kHz, the frequency band of ultrasonic waves exceeding this range was also included.

In view of the above, the present invention provides a vehicle security sensor in which a glass break sensor is functionally integrated with an intrusion sensor, a driving method of the security sensor, and a vehicle security using the security sensor. The purpose is to provide a system.

[0009]

In order to solve the above-mentioned problems, a vehicle security sensor according to the first aspect of the present invention is provided with an ultrasonic transmitting means (41, 41) provided in a vehicle cabin for transmitting ultrasonic waves. 43), ultrasonic receiving means (42, 44, 43) provided in the vehicle interior for receiving the reflected ultrasonic waves when the ultrasonic waves are reflected in the vehicle interior, and based on the reception output of the ultrasonic receiving means. Detecting means (210, 211, 230, 24) for detecting whether or not a person has entered the vehicle interior
0, 110, 111, 45, 46, 47, 70), the ultrasonic receiving means receives ultrasonic waves generated when the window glass of the vehicle is broken, and the detecting means detects the broken glass based on the received output. Is detected.

As described above, by utilizing the generation of ultrasonic waves when the window glass is broken, the security sensor is used to detect both the presence or absence of an intruder in the vehicle interior and the broken window glass by ultrasonic waves. Since the function is provided, there is no need to employ a glass break sensor independently of the intrusion sensor, that is, the security sensor.

Therefore, when both the intrusion sensor and the glass break sensor are used in the security system, it is not necessary to separately employ the glass break sensor. For this reason, the number of sensors in the security system is reduced by the number of glass break sensors, so that the effective use time of the power supply for supplying power to each sensor, that is, the time until the battery is discharged can be further lengthened.

According to a second aspect of the present invention, in the vehicle security sensor according to the first aspect, the ultrasonic transmitting unit intermittently transmits the ultrasonic waves for a predetermined period, and Is characterized in that a break of the window glass is detected based on a reception output of the ultrasonic wave receiving means while the ultrasonic wave transmitting means is not transmitting the ultrasonic wave.

As described above, the transmission of the ultrasonic wave from the security sensor is performed intermittently as described above, and during the transmission of the ultrasonic wave by the security sensor, the presence or absence of an intruder in the vehicle interior by using the ultrasonic wave. When the window breaks while the security sensor is not transmitting ultrasonic waves, the breakage of the window glass is detected using ultrasonic waves generated from the window glass. Both the presence / absence and the breakage of the window glass can be reliably detected, and the operation and effect of the invention of claim 1 can be further improved.

According to a third aspect of the present invention, in the vehicle security sensor according to the first or second aspect,
The detecting means includes integrating means (45, 46, 47, 230) for integrating the reception output of the ultrasonic wave receiving means, and when the integrated value by the integrating means reaches a threshold value indicating the breakage of the window glass, the window glass concerned Cracks are detected.

Thus, the operation and effect of the invention described in claim 1 or 2 can be achieved while correctly detecting the breakage of the window glass in a manner distinct from the intrusion of a person.

According to a fourth aspect of the present invention, there is provided a vehicle security system comprising the security sensor according to any one of the first to third aspects, and various sensors for detecting a tilt of the vehicle or opening of a door. 30)
In the locked state of the door of the vehicle, the presence or absence of impropriety of the vehicle is detected based on the detection output of the security sensor or the detection outputs of various sensors.

Thus, by employing the security sensor according to any one of claims 1 to 3 in a security system, the number of sensors can be reduced by the number of glass break sensors, and as a result, the security system can be reduced. The effective use period of the power supply to be supplied to the sensor, that is, the time until the battery is dead can be further lengthened.

The above-mentioned various sensors are not limited to the inclination of the vehicle and the opening of the door as described above, but may be an immobilizer or other sensors used for ensuring the security of the vehicle.

According to a fifth aspect of the present invention, there is provided a driving method of a vehicle security sensor, wherein ultrasonic waves are intermittently transmitted into a vehicle interior of a vehicle for a predetermined period, and the ultrasonic waves are reflected in the vehicle interior. When this ultrasonic wave is received, the presence or absence of a person entering the vehicle interior is detected during transmission of the ultrasonic wave based on the received reflected ultrasonic wave. Ultrasonic waves are received, and cracks in the window glass are detected based on the received ultrasonic waves. Thereby, the same function and effect as the invention described in claim 2 can be achieved.

According to a sixth aspect of the present invention, in the driving method of the vehicle security sensor according to the fifth aspect, the reception level of the ultrasonic wave generated by the breakage of the window glass is integrated, and the integrated level is equal to the window glass. When the threshold value indicating the crack of the window glass is reached, it is detected that the window glass is cracked. Thereby, Claim 3
The same operation and effect as the invention described in (1) can be achieved.

Note that the reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example in which the present invention is applied to an automobile security system. As shown in FIGS. 1 and 2, the security system includes a keyless tuner 10, a tilt sensor 20, door switches 30, and two security sensors 40.

The keyless tuner 10 is disposed in the vicinity of the upper part of the instrument panel in the vehicle interior of the vehicle. According to the keyless tuner 10, the keyless tuner 10 is remotely operated by radio waves from a transmitter (not shown). Each door is locked or unlocked. The tilt sensor 20 is disposed at a front portion in the front hood of the vehicle, and the tilt sensor 20 detects when the vehicle is tilted. Each door switch 30
When both left and right front doors and both rear doors of the vehicle are opened, this is detected. In FIG. 2, only the door switches for the left front door and the rear door are shown.

As shown in FIG. 2, each of the security sensors 40 is disposed on each of left and right center pillars in the interior of the vehicle. Each security sensor 40 has the same configuration and function. Therefore, the configuration and function of one of the security sensors 40 will be described as an example.

As shown in FIG. 3, the security sensor 40 includes an ultrasonic transmitter 41 and an ultrasonic receiver 42. The ultrasonic transmitter 41 and the ultrasonic receiver 42
Are arranged close to each other.

The ultrasonic transmitter 41 intermittently transmits ultrasonic waves into the vehicle interior, as described later, based on an oscillation pulse from the oscillation and Doppler processing circuit 43 described later. When the ultrasonic wave of the ultrasonic transmitter 41 is reflected in the vehicle interior, the ultrasonic receiver 42 receives the reflected ultrasonic wave and outputs a reception signal.

The oscillation and Doppler processing circuit 43 intermittently outputs an oscillation pulse to the ultrasonic transmitter 41 at a frequency f (= 40 KHz) as described later.

The oscillation and Doppler processing circuit 43
A Doppler shift amount is calculated based on a difference between a phase of the oscillation pulse and a phase of an amplified signal from the amplifier circuit 44 described later, and a Doppler shift signal is output. The amplification circuit 44 amplifies the reception signal of the ultrasonic receiver 42 and outputs the amplification signal to the oscillation and Doppler processing circuit 43 and the envelope detection circuit 45.

The envelope detection circuit 45 performs envelope detection on the amplitude of the amplified signal from the amplification circuit 44 and outputs an envelope detection signal. The comparison circuit 46 compares the level of the envelope detection signal with the level of the reference signal Vr of the reference power supply 47. The comparison circuit 46 outputs a high-level signal only when the level of the envelope detection signal is higher than the level of the reference signal Vr.

The microcomputer 48 executes the sensor program according to the flowchart shown in FIG.
During this execution, the drive processing of the oscillation and Doppler processing circuit 43, the intrusion into the vehicle interior based on the outputs of the oscillation and Doppler processing circuit 43 and the comparison circuit 46, the breakage of window glass, the alarm output processing, and the like are performed. Do.
Note that the above sensor program is stored in the microcomputer 4
8 is stored in advance in a ROM (not shown).

Returning to FIG. 2, the security system includes a microcomputer 60, which is arranged on the left side of the front hood of the automobile. The microcomputer 6
0 executes the system program according to the flowchart shown in FIG. 4, and during this execution, an alarm process by the alarm 70 based on each output of the keyless tuner 10, the tilt sensor 20, each door switch 30 and each security sensor 40. , A control process of the power supply circuit 80 and an output process to the microcomputer 48. The microcomputer 60 is always supplied with power from the battery B.
The system program is stored in a ROM (not shown) of the microcomputer 60 in advance.

The alarm 70 is a microcomputer 60
And an alarm is issued when there is an unauthorized entry of a person. The power supply circuit 80 supplies power from the battery B to the tilt sensor 20 and each security sensor 40 under the control of the microcomputer 60. In FIG. 2, the keyless tuner 10, the tilt sensor 20, the door switches 30, the security sensors 40, and the microcomputer 60 are described as being located outside the vehicle for convenience.

In the present embodiment configured as described above, the occupant gets off the vehicle and closes the door after the engine of the vehicle stops. Then, when the occupant transmits the radio wave by the transmitter, the keyless tuner 10 receives the radio wave and locks the door of the vehicle. When the microcomputer 60 confirms that the door is locked, it enters a warning state and starts executing the system program according to the flowchart of FIG.

First, in step 90, an operation start request is output to the tilt sensor 20 and each security sensor 40. Accordingly, the tilt sensor 20 and each security sensor 40 are connected to the battery B by the power supply circuit 80.
It is powered by and enters the operating state. At this time, the microcomputer 48 of each security sensor 40
The execution of the sensor program is started according to the flowchart of (1).

In step 200 of FIG. 5, the drive processing of the oscillation and Doppler processing circuit 43 is started. Along with this, the microcomputer 48 generates a drive signal (see reference numeral a in FIG. 6) and generates the oscillation and Doppler processing circuit 43.
Output to As shown in FIG. 6, this drive signal is continuously generated during the intrusion detection period T1 (= 100 ms), and this generation occurs after the window glass break detection period T2 (= 900 ms), as described later. It is done every time.

When the microcomputer 48 intermittently generates the driving signal a as described above, the oscillation and Doppler processing circuit 43 sequentially generates an oscillating pulse at 40 kHz every time the driving signal a is generated, and 41. For this reason, the ultrasonic transmitter 41 transmits an ultrasonic wave (refer to the symbol “b” in FIG. 6) at a frequency of 40 kHz into the vehicle interior.
Here, as shown in FIG. 6, this ultrasonic wave b is transmitted by the ultrasonic transmitter 4 at the generation time and generation interval of the corresponding drive signal a.
Sent from 1. Note that the phase of the ultrasonic wave b is slightly delayed from the phase of the corresponding drive signal a.

When the transmitted ultrasonic wave b is reflected in the vehicle cabin as described above, the reflected ultrasonic wave is received as a reception signal by the ultrasonic receiver 42, and the reception signal is amplified by the amplifier circuit 44. The signal is output to the oscillation and Doppler processing circuit 43 and the envelope detection circuit 45 as shown in FIG.

Then, the oscillation and Doppler processing circuit 43
Generates a Doppler shift signal based on the difference between the phase of the oscillation pulse and the phase of the amplified signal c, and outputs the signal to the microcomputer 48. Further, the envelope detection circuit 45 performs envelope detection on the amplified signal c to generate an envelope detection signal (refer to a symbol d in FIG. 6). Then, the comparison circuit 46 compares the level of the envelope detection signal d of the envelope detection circuit 45 with the level of the reference signal Vr of the reference power supply 47 (hereinafter, referred to as threshold TH1), and the level of the envelope detection signal d If the level is higher than the level of the reference signal Vr, the comparison result of the high level (see the symbol e in FIG. 6) is output to the microcomputer 48.

The microcomputer 48 determines whether or not there is an intruder in the vehicle cabin based on the Doppler shift signal from the oscillation and Doppler processing circuit 43 and the comparison result of the comparison circuit 46. , Step 2
In step 10, a determination of YES is made, and step 21 is executed.
At 1, an alarm command is output to the microcomputer 60.

On the other hand, if it is determined that there is no intruder, a negative determination is made in step 210 and step 220
Proceed to In step 220, whether the output of the drive signal to the oscillation and Doppler processing circuit has continued for T1 (100
ms has been continued). If there is no intruder in the vehicle and the drive signal is continuously output for 100 ms, the determination in step 220 becomes YES. Then, in step 221, the drive stop processing of the oscillation and Doppler processing circuit 43 is performed. As a result, the microcomputer 48 stops the output of the drive signal, thereby stopping the oscillation and the output of the oscillation pulse of the Doppler processing circuit 43 (see reference numeral T1 in FIG. 6). Along with this, it enters the window glass crack detection period T2 (see FIG. 6). on the other hand,
If NO is determined in step 220, step 210
Return to

When the high-level comparison result from the comparison circuit 46 is output to the microcomputer 48 during the window glass break detection period T2 as described above, the high-level comparison result is integrated in step 230. Is done. However, if the high-level comparison result here does not result from the breakage of the window glass as described below, the integrated value does not reach the threshold value TH2 (see FIG. 6) indicating the window glass breakage. For this reason,
The determination in the next step 240 is NO, and thereafter, when T2 elapses (when 900 ms elapses), the determination in step 250 becomes YES.

On the other hand, when the window glass of the automobile breaks, ultrasonic waves resulting from the crack are generated from the window glass toward the vehicle interior. Then, the ultrasonic waves from the window glass are reflected in the vehicle interior, received by the ultrasonic receiver 42, and output to the amplifier circuit 44 as a reception signal. Note that the received signal is also output to the oscillation and Doppler processing circuit 43, but the Doppler shift signal is output from the oscillation and Doppler processing circuit 43 to the microcomputer 48 as a signal without an intruder entering the vehicle interior. Therefore, the determination of YES is not made in step 210.

As described above, when the ultrasonic receiver 42 outputs a received signal to the amplifier circuit 44, the amplifier circuit 44
An amplified signal (see reference numeral c1 in FIG. 6) is generated, and the amplified signal c1 is subjected to envelope detection by the envelope detection circuit 45 and output to the comparison circuit 46 as an envelope detection signal (see reference numeral d1 in FIG. 6). You. Here, the amplified signal c1 and the envelope detection signal d1 are signals indicating the breakage of the window glass.

As described above, when the envelope detection signal d1 is output to the comparison circuit 46, the level of the envelope detection signal d1 is changed to the level of the reference signal Vr of the reference power supply 47 (threshold value TH).
1) is compared in the comparison circuit 46. Then, when the level of the envelope detection signal d1 is higher than the threshold value TH1, a high-level comparison result (see reference numeral e1 in FIG. 6) is output to the microcomputer 48.

Then, the high-level comparison result e1
Are integrated in step 230 (in FIG.
See). Accordingly, when the integrated value exceeds the threshold value TH2, a determination of YES is made in step 240, and in step 211, an alarm command for window glass breakage is issued by a glass break command signal (reference g in FIG. 6). reference)
To the microcomputer 60.

As described above, an alarm command is issued to the microcomputer 60 in step 211 based on the determination of YES in step 210 due to the entry of a person into the vehicle interior or the determination of YES in step 240 due to the breakage of the window glass. Then, in step 100 of FIG.
A determination of S is made. Accordingly, an alarm process is performed in step 111. For this reason, the alarm 70 sounds and gives an alarm.

If the determination in step 100 is NO, then in step 110, the presence or absence of the tilt of the vehicle is determined based on the output of the tilt sensor 20. If the determination in step 110 is NO,
At step 120, at least one of the door switches 30
Based on the two outputs, it is determined whether or not any of the doors of the vehicle is open. If the determination in step 110 or 120 is YES, step 11
At 1, an alarm process is performed. Along with this, the alarm 70 sounds and gives an alarm.

If the determination in step 120 is NO, it is determined in step 130 whether or not the door of the vehicle is unlocked. If unlocked, the process of step 100 is performed based on the determination of NO in step 130. If unlocked, the determination in step 130 is YES, and the execution of the system program is terminated. Thereby, the alert state is released.

The determination at step 250 in FIG.
If it is ES, in step 260, it is determined whether or not there is an operation stop request from the microcomputer 60.
If there is this request, the determination in step 260 becomes YES, and the power supply from the power supply circuit 80 to the tilt sensor 20 and each security sensor 40 is stopped.

As described above, in the present embodiment, as described above, the presence or absence of an intruder in the vehicle interior and the breakage of the window glass are determined by the security sensor 40 using ultrasonic waves. In other words, the security sensor 40 is provided with a function for detecting both the presence or absence of an intruder in the vehicle interior and the breakage of the window glass by ultrasonic waves. Therefore, the security sensor 40 is independent of the security sensor 40. It is not necessary to employ a glass break sensor. Therefore, the number of sensors in the security system is reduced by the glass break sensor,
Along with this, the time until the battery B of the battery B rises can be further lengthened.

Here, the transmission of the ultrasonic waves from the security sensor 40 is performed intermittently as described above, and during transmission of the ultrasonic waves from the security sensor 40, the ultrasonic waves are used to transmit an intruder into the vehicle interior. If the window glass is broken while the transmission of ultrasonic waves from the security sensor 40 is stopped, ultrasonic waves generated from the window glass are used to determine whether the window glass is broken. It is possible to reliably determine both the presence or absence of a person and the broken window glass.

In practicing the present invention, the security sensor 40 is not limited to the Doppler shift amount based on the ultrasonic wave, but may be any physical amount that can be recognized as a person's intrusion into the vehicle interior by the ultrasonic wave. May be used to detect intrusion.

In implementing the present invention, the microcomputer 48 does not need to be always activated (wake-up). During the detection period T2, the microcomputer 48 receives the signal from the first oscillation and Doppler processing circuit 43 or the comparison circuit 46. The sleep state may be maintained until the output signal is input.

In practicing the present invention, any vehicle such as an automobile having a vehicle compartment may be used.
The present invention may be applied to the security system.

In practicing the present invention, each step in the flowcharts of the above embodiments and the like may be realized by a hardware logic configuration as function executing means.

In implementing the present invention, elements other than the ultrasonic transmitter 41 and the ultrasonic receiver 42 in the security sensor 40 may be provided at the same position as the microcomputer 60.

In implementing the present invention, the number of security sensors 40 may be changed as needed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an arrangement position of various elements of FIG. 1 with respect to an automobile.

FIG. 3 is a detailed circuit diagram of the security sensor of FIG. 1;

FIG. 4 is a flowchart showing a system program executed by microcomputer 60 in FIG.

FIG. 5 is a flowchart showing a sensor program executed by the microcomputer 48 of FIG. 3;

FIG. 6 is a time chart showing an output waveform of each circuit element of the security sensor.

[Explanation of symbols]

Reference Signs List 10 keyless tuner, 20 tilt sensor, 30 door switch, 40 security sensor, 41 ultrasonic transmitter, 42 ultrasonic receiver, 43 oscillation and Doppler processing circuit, 44 amplifier circuit, 45 envelope Line detection circuit, 4
6: comparison circuit, 47: reference power supply, 48, 60: microcomputer. 70 ... Alarm.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G08B 13/16 G08B 13/16 A (72) Inventor Hiroyuki Kani 14 Iwatani, Shimowasukamachi, Nishio-shi, Aichi Pref. Inside the Japan Auto Parts Research Institute (72) Inventor Fumio Asakura 14th Iwatani, Shimowakaku-cho, Nishio-shi, Aichi Pref. Inside Denso Corporation (72) Inventor Hiroto Uesaka 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in Denso Corporation (reference) 5C084 AA04 AA07 AA09 BB27 BB31 CC02 CC08 DD04 DD05 DD06 EE06 GG24 GG43 GG57 GG71

Claims (6)

[Claims] 1. An ultrasonic transmitting means (41, 43) provided in a vehicle interior of a vehicle for transmitting ultrasonic waves, and the reflected ultrasonic waves provided in the vehicle interior when the ultrasonic waves are reflected in the vehicle interior. Receiving means (42, 4)
4, 43) and detecting means (210, 211, 23) for detecting whether or not a person has entered the vehicle interior based on the reception output of the ultrasonic receiving means.
0, 240, 110, 111, 45, 46, 47, 7
0), wherein the ultrasonic receiving means receives an ultrasonic wave generated when the window glass of the vehicle is broken, and the detecting means detects the broken glass based on the received output. Sensor. 2. The ultrasonic transmitting means intermittently transmits the ultrasonic waves for a predetermined period, and the detecting means detects the ultrasonic reception while the ultrasonic transmitting means is not transmitting the ultrasonic waves. 2. The method according to claim 1, further comprising the step of detecting the breakage of the window glass based on a reception output of the means.
2. The vehicle security sensor according to claim 1. 3. An integrating means (45, 46, 47, 23) for integrating a receiving output of said ultrasonic receiving means.
The vehicle according to claim 1 or 2, wherein when the integrated value of the integrating means reaches a threshold value indicating the breakage of the window glass, the vehicle is detected as a breakage of the window glass. Security sensor. 4. A security sensor according to claim 1, further comprising: a sensor for detecting inclination of the vehicle or opening of a door.
0, 30), wherein in the locked state of the door of the vehicle, a security system for the vehicle is configured to detect the presence or absence of a fraudulent activity on the vehicle based on the detection output of the security sensor or the detection outputs of the various sensors. 5. An ultrasonic wave is intermittently transmitted into a vehicle interior of a vehicle for a predetermined period, and when the ultrasonic wave is reflected in the vehicle interior, the reflected ultrasonic wave is received, and based on the received reflected ultrasonic wave. Detecting whether or not a person has entered the vehicle interior during the transmission of the ultrasonic wave, and receiving the ultrasonic wave generated by the breakage of the window glass during the non-transmission of the ultrasonic wave, and receiving the ultrasonic wave based on the received ultrasonic wave. A driving method of a vehicle security sensor for detecting breakage of glass. 6. The method according to claim 1, further comprising: integrating a reception level of an ultrasonic wave caused by the breakage of the window glass; and detecting a breakage of the window glass when the integrated level reaches a threshold value indicating the breakage of the window glass. A driving method of the vehicle security sensor according to claim 5.