JP3219608B2 - Automotive anti-theft device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle anti-theft device.
With regard to the improvement of the position, the magnitude of the impact applied to the vehicle is accurately determined to improve the reliability of alarm generation .

[0002]

2. Description of the Related Art Various types of anti-theft devices for automobiles have been proposed, and some of them are actually used. For example, Japanese Unexamined Utility Model Publication No. 3-86870 discloses an anti-theft device incorporating a remote control device as shown in FIG. This anti-theft device comprises a transmitter 1,
It has a control main unit 2, a detection unit 3, an alarm unit 4, and an engine control unit 5. The control main unit 2 includes an operation panel 8 and an operation control unit 9 in addition to the receiver 6 and the controller 7. By operating the operation panel 8, the function of the anti-theft device can be stopped. Reference numeral 10 denotes a buzzer for notifying the switching of the operation control unit 9. or,
The detection unit 3 includes a door opening / closing sensor 11, a trunk opening / closing sensor 12, an impact sensor 13, an ignition sensor 14,
And a plurality of sensors for detecting the state of a part that may be operated when the vehicle is stolen. Also, the alarm unit 4
Comprises a light emitter 15 and a horn 16.

When operating the anti-theft device for a vehicle configured as described above, a command signal is issued from the transmitter 1 with the operation panel 8 switched to a state in which the anti-theft device is operated. This command signal includes an ID code unique to each transmitter 1. And the receiver 6
The controller 7 that has received the command signal through the controller 7 transmits the command signal only when the ID code included in the command signal matches the ID code registered in the ID memory of the controller 7 in advance.
Accept the above command signal. When the controller 7 receives the command signal, the anti-theft device is activated or deactivated according to the content of the command signal.

[0004] When the anti-theft device is in operation, when the door or trunk is opened, vibration is applied to the vehicle body, or the ignition switch is operated,
The controller 7 sends an operation signal to the alarm unit 4 to turn on (or blink) the light emitting device 15 and to control the horn 16
A warning sound is issued. At the same time, the controller 7 sends a signal to the engine control unit 5 to prevent the engine from starting regardless of the operation of the ignition switch.

Also, when the impact sensor 13 detects that the automobile has moved, the controller 7 also sends an activation signal to the alarm unit 4 to turn on (or blink) the light emitter 15. Then, an alarm is issued to the alarm 16. For example, when the impact is small, such as when a person touches a part of the car or when a ball or the like hits, a small audible alarm is sounded to call attention. On the other hand, when a large impact such as opening the door is detected, a loud alarm is issued and the light emitter 15 is turned on (or blinks) as necessary.

For this purpose, a determination circuit for determining what kind of operation signal is to be generated according to the detection signal of the impact sensor 13 is required. FIG. 5 shows a circuit conventionally considered for such a purpose. Impact sensor 1
3 via the amplifier 18 and the variable resistor 19 for adjusting the amplifier gain.
It is sent to 0 and 21. The first comparator 20 compares the detection signal with a relatively low first reference value, and when the detection signal exceeds the first reference value, a first alarm which is a small alarm sound. To generate a first alarm signal. The second comparator 21 compares the detection signal with a relatively high second reference value, and issues a second alarm, which is a loud alarm, when the detection signal exceeds the second reference value. A second alarm signal is issued to generate an alarm. FIG. 6 shows the alarm unit 4 (FIG. 4) using such a judgment circuit.
Is a flowchart showing a state in which an alarm is generated.

[0007]

In order to reliably generate an alarm without being confused by noise or the like when an impact is applied to an automobile, it is necessary to increase the degree of amplification of the detection signal by the amplifier 1. Can be considered. However, if the amplification is simply increased, the magnitude of the signal sent to the first and second comparators 20 and 21 exceeds the second reference value, despite the fact that the impact is actually relatively small. A warning sound will be generated. Conversely, when the amplification degree is reduced, the detection accuracy of a small impact deteriorates due to the influence of noise and the like, and the reliability of generating a small audible alarm for calling attention deteriorates. Even if the magnitudes of the first and second reference values are changed, the influence of noise is inevitable. For this reason, it is difficult to improve the reliability of alarm generation by adjusting the amplification degree. Vehicle of the present invention
The anti-theft device has been invented in view of such circumstances.

[0008]

SUMMARY OF THE INVENTION The present invention provides a vehicle anti-theft protection system.
The anti-theft device is the same as the conventional anti-theft device for automobiles described above.
In addition, a shock sensor and the shock sensor
Alarm signal when motion is detected or corresponding to this alarm signal
And a signal from the determination circuit.
And an alarm unit that generates an alarm based on the alarm. In particular, the book
In the anti-theft device for a vehicle according to the invention, the determination circuit
But the detection signal issued from the impact sensor relatively low magnitude first reference value and comparing the relatively high second reference value, the detection signal is first exceeding the first reference value The time difference between the instant and the second instant when the detection signal exceeds the second reference value is determined. If the time difference is longer than a preset reference time, it is determined that the impact is small, and the time difference is determined based on the reference time. If the time is shorter than the time, it is determined that the impact is large, and an alarm is issued to the alarm unit according to the determination result.
An alarm signal or a signal corresponding to this alarm signal to be generated.
Issue an issue .

[0009]

The automobile anti-theft device of the present invention having the above-mentioned structure is provided.
According to the stop device , the magnitude of the impact strength can be determined regardless of the amplification degree of the detection signal from the impact sensor . As a result, the reliability of an alarm generated according to the magnitude determination of the impact strength is improved.

[0010]

FIG. 1 is a block diagram of a vehicle antitheft device according to the present invention.
6 is a flowchart illustrating a method of determining impact strength in a determination circuit to be implemented . First, a reference time T is set, which is set at a factory when the controller 7 of the automobile anti-theft device as shown in FIG. 4 is manufactured. The reference time T is determined by the size of the vehicle on which the anti-theft device is mounted and the size of the impact sensor
3 (see FIGS. 4 and 5), it is determined within a range of about several hundred μsec to several msec, although it slightly varies depending on the installation position. For example, when assembling an impact sensor to the dashboard part of a 2-liter class sedan, the setting is about 1 msec.

In order to detect the magnitude of the impact, a judgment circuit as shown in FIG.
As described above, this determination circuit compares the detection signal of the impact sensor 13 with the first and second reference values. In the case of the present invention, a signal as shown in FIG. Emits.
First, the upper solid line a is a lower signal, which is obtained as a result of comparing the detection signal with a relatively low first reference value. The detection signal is first low-side boundary signal output of the low-potential signal at the moment of exceeding the reference value is decreased momentarily L _a
Becomes The lower dashed line b is a higher-order signal that is obtained as a result of comparing the detection signal with a relatively high second reference value. The detection signal is high side boundary signal L _b output of the high-side signal is reduced momentarily at the moment of exceeding the second reference value.

In the conventional case, the lower boundary signal L _a
As a trigger, a small the first alarm occurs a horn, as a trigger the high-side boundary signal L _b, has occurred the second alarm is a large horn. In the case of the present invention, on the other hand, these low side, high side both boundary signal L _a, first at L _b itself, rather than generating a second alarm, these two boundary signals L _a, L _b The magnitude of the impact is determined from the time difference of (1), and the first alarm or the second alarm is generated according to the result.

That is, the low-order and high-order boundary signals L
_a, if L _b is generated, the detection signal is the first moment when exceeding the first reference value, and the occurrence of the low-side boundary signal L _a, the detection signal is the second The time difference Δt from the time when the high-order boundary signal _Lb is generated, which is the second instant exceeding the reference value, is obtained. And this time difference Δt
Is compared with the preset reference time T. Then, the time difference Δt is longer than the reference time T (Δt>
T) In the case, it is determined that the impact is small, and the first alarm is issued.
A first alarm signal for generating the alarm is issued , and when the time difference Δt is shorter than the reference time T (Δt <T), it is determined that the impact is large, and the second alarm is generated.
A second alarm signal is issued .

[0014] Thus, the time of occurrence of the low-side boundary signal L _a, the length of the time difference △ t between the time of occurrence of high-side boundary signal L _b, concerning the reasons that can determine the magnitude of the impact, the 3 explain. The vertical axis in FIG. 3 represents the magnitude of the detection signal of the impact sensor 13, and the horizontal axis represents the elapsed time.
The solid line α in FIG. 3 represents the detection signal of the impact sensor 13 when a small impact is detected, and the chain line β represents the detection signal when a large impact is detected. When a large shock is detected, the detection signal not only has a high peak value, but also has a sharp rise (high voltage in a short time). On the other hand, the detection signal when a small impact is detected not only has a low peak value, but also has a gradual rise of the signal (so that it takes time for the voltage to rise).

Therefore, the lower boundary signal L generated based on the detection signal when a large impact represented by the chain line β is detected.
time difference between _a and high-side boundary signal L _b △ t is short, the solid lines α
Time difference △ t'the low-side boundary signal L _a and the high-side boundary signal L _b generated based on a detection signal when detecting a large impact indicated by the longer. Therefore, if the reference time T is appropriately determined by experiments or the like, the first and second reference values are particularly changed even when the amplification degree of the detection signal by the amplifier 18 and the variable resistor 19 (FIG. 5) is increased. It is possible to judge the magnitude of the impact strength without making it. As a result, the size determination of the impact strength, and can without being affected by noise, depending on the determination
The reliability of the generated alarm is improved.

In the above description, the case where the determination circuit including the amplifier 18, the variable resistor 19, and the first and second comparators 20 and 21 is provided on the controller 7 side has been described. The determination circuit can be provided in the sensor unit together with the shock measurement coil constituting the shock sensor 13. In this case, signals corresponding to the first and second alarms are output from the sensor unit to the controller 7. The controller emits the light 15 and the horn 1 in order to issue an alarm according to the signal sent from such a sensor unit.
A drive signal is sent to 6. If a determination circuit is provided in the sensor unit in this way, it is not necessary to provide a determination circuit on the controller 7 side.

[0017]

Since the anti-theft device for a vehicle according to the present invention is configured as described above, the amplification of the detection signal from the impact sensor is increased to increase the detection accuracy of a small impact and to call attention. The reliability of the generation of the small alarm can be improved, and the magnitude of the impact can be reliably determined, so that the reliability of the generation of the alarm can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a determination of a vehicle anti-theft device according to the present invention;
9 is a flowchart illustrating a determination method in a circuit .

FIG. 2 is a diagram showing a lower boundary signal and a higher boundary signal.

FIG. 3 is a diagram for explaining the effect of impact strength on the time difference between a lower boundary signal and a higher boundary signal.

FIG. 4 is a block diagram showing an example of a vehicle anti-theft device incorporating an impact sensor.

FIG. 5 is a circuit diagram showing a judgment circuit conventionally considered.

FIG. 6 is a flowchart showing a judgment method conventionally considered.

[Description of Signs] 1 Transmitter 2 Control main unit 3 Detecting unit 4 Alarm unit 5 Engine control unit 6 Receiver 7 Controller 8 Operation panel 9 Operation control unit 10 Buzzer 11 Door opening / closing sensor 12 Trunk opening / closing sensor 13 Impact sensor 14 Ignition Sensor 15 light emitting device 16 horn 18 amplifier 19 variable resistor 20 first comparator 21 second comparator

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01P 15/00 B60R 25/10 G01D 1/18 G01L 5/00

Claims (1)

(57) [Claims] 1. An impact sensor, wherein the impact sensor is an automobile.
Warning signal or this warning when vibration or movement of
A determination circuit for generating a signal corresponding to a signal, and the determination circuit
And an alarm unit that generates an alarm based on a signal from
In the vehicle anti-theft device, the determination circuit compares the magnitude of a detection signal output from the impact sensor with a relatively low first reference value and a relatively high second reference value, and Determines the time difference between the first moment exceeding the first reference value and the second moment the detection signal exceeds the second reference value, and when this time difference is longer than a preset reference time, It is determined that the impact is small, and if the time difference is shorter than the reference time, it is determined that the impact is large, and the alarm is determined according to the determination result.
Alarm signal or this alarm signal to generate an alarm
Theft prevention for automobiles, which emits a signal corresponding to
Stop device .