JPS5834785B2 - Collision detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a collision sensor is attached to a part that quickly detects a collision of an automobile, etc., and a collision signal is obtained, and the collision state is determined from this signal. The present invention relates to a collision detection device used for collision detection for control purposes.

Conventionally, in this type of device, the output detection signal of the collision sensor of the collision detection field is processed using a contact connector that has electrical contacts and can be physically and non-destructively disconnected to determine the collision state. was transmitting to the circuit.

However, in this device, it is necessary that the sensor position and the signal processing circuit have different optimal positions, and that they are physically separated from each other in an automobile where installation space is limited.

For this reason, electrical wiring is used, but it is necessary to ensure the reliability of the wiring, and there are many problems that need to be solved, such as the durability of the contact connector.

The present invention solves the above-mentioned problems, and by using a radiation electromagnetic field coupling means as a transmission for connecting a collision sensor and a signal processing circuit, flexibility in mounting is achieved and there is no need to use a contact connector. It is an object of the present invention to provide a collision detection device capable of connecting the collision sensor and a signal processing circuit using a contact type.

The present invention will be described below with reference to embodiments shown in the drawings.

First, Fig. 1 shows a diagram of the installation arrangement on a car when a power generation sensor is used as a collision sensor for collision detection, Fig. 2 shows a cross-sectional view of the power generation sensor, and Fig. 3 shows the AC output from the power generation sensor. A time chart of a detection signal period measurement method is shown.

In this collision judgment, judgment is made based on the period of the AC detection signal, but since the voltage peak value of this AC detection signal is proportional to the collision speed, the voltage peak value is used instead of 0 to determine the threshold value. The same method can be applied to a wave height measurement method that determines that the gas bag has been exceeded and generates a signal indicating that the gas bag has been opened.

Now, in FIG. 1, 1 is a car (hereinafter referred to as a vehicle).

), 2 is a power generation sensor, and 3 is a bumper.

That is, since the bumper 3 moves toward the rear of the vehicle body at the time of a collision, an AC detection signal is obtained from the output of the power generation sensor 2 corresponding to the moving speed at that time.

In FIG. 2, reference numeral 21 denotes a shaft made of a magnetic material of the power generation sensor 2, which is connected to the bumper 3 at one end with protruding teeth provided at predetermined intervals in the longitudinal direction.

22 is a permanent magnet, 23 and 24 are stator cores made of magnetic material, and 25 is a power generation winding, from which a zero alternating current detection signal is taken out through output lines 26 and 27.

This power generation sensor 2 generates an alternating current detection signal at a period corresponding to the speed of the collision with respect to time t as shown in FIG. 3 at the time of a collision.

This AC detection signal is shaped into the pulse shown in FIG. 3B, for example, and this pulse is frequency-divided to obtain the periodic signal shown in FIG. 3C.

Using the clock pulse shown in the third diagram as a reference, the periods TI and T2 of this periodic signal are compared with the set period. When T1 or T2 is shorter than the set period, that is, within the time width of T1 or T2, the clock pulse is When the number is less than the predetermined value (in Fig. 3, there are 5 to 6 pieces).

) Generate the ignition instruction signal shown in FIG. 3E at time if to ignite the detonator of the gas bag.

FIG. 4 is a block diagram showing the overall configuration of an actual case of the present invention.

In this figure, 200 is a collision sensor section 0, which is a combination of the power generation winding 25 of the power generation sensor 2 and other circuits.

The sensor section 200 includes a ring oscillator 210 as a logic element.
It has an oscillation inverter 204, 205 and a NAND game) 217, a buffer amplifier 212, and an inverter 216 that constitute the logic elements, and is further provided with a battery 214 and a resistor 211 for supplying power to these logic elements. .

Also, a transmitting pole antenna 41 serving as a first antenna
A choke coil 213 is inserted for matching a.

Here, the first stage of the ring oscillator 210 is composed of the Nant gate 217, and the impark 216 is connected to one input terminal of the ring oscillator 210.

The inverter 216 provides a high level output to the Nant gate 217 when the voltage at the connection point between the power generation winding 25 of the power generation sensor 2 and the resistor 211 is low level.
The ring oscillator 210 is activated to oscillate.

The oscillation signal generated at the output of this ring oscillator 210 is transmitted to a transmitting pole antenna 41 which is a first antenna via a buffer amplifier 212 and a choke coil 213.
ayo0 is emitted.

The transmitting pole antenna 41a may be a pole or cord of an appropriate length attached to the vehicle body.

A receiving pole antenna 42a as a second antenna is provided at an appropriate distance to receive the signal radiated from the transmitting pole antenna 41a. A non-contact connector 4 is configured as a coupling means.

The receiving pole antenna 42a is also the transmitting pole antenna 4.
Like 1a, it can be constructed from a metal pole or vinyl cord.

5 is a signal processing circuit, which includes a receiving pole antenna 42;
A collision state is determined based on a change in the received signal of a.

The signal processing circuit 5 includes a choke coil 55 for matching.
2. Signal detection load resistor 506, balance resistor 551,
It consists of a differential amplifier 509 and a computer 560.

Here, the differential amplifier 509 is connected to the receiving pole antenna 42.
When the level of the received signal a exceeds a predetermined value, a high level output is generated, and below that level, a low level output is generated, which is supplied to the computer 560.

An igniter 6 is connected to the output of the computer 560 for issuing an ignition command to the ignition filament 7 for opening the gas bag.

To explain the operation of the device having the above configuration, if the collision sensor section 200 is currently operating normally, the ring oscillator 210 generates an oscillation signal of a constant frequency, and the oscillation signal is transmitted from the transmitting pole antenna 41a. A corresponding electromagnetic field is emitted.

The radiated electromagnetic field is received by the receiving pole antenna 42a, and the ring oscillator 210 is connected to the output of the differential amplifier 509.
A signal corresponding to the oscillation signal appears.

Therefore, the computer 560 uses the output signal of the differential amplifier 509 to generate the ring oscillator 211 of the 01 collision sensor 200.
It can be detected that the oscillation state is normal.

On the other hand, when a collision occurs, an AC detection signal having a waveform shown in FIG. 3 is generated in the power generation winding 25 of the power generation sensor 2.

When the magnitude of the positive part of this AC detection signal exceeds the threshold level of the impark 216, one input of the Nand gate 217 becomes low level, and the output of the Nand gate 217 is always high level. The ring oscillator 210 then stops oscillating.

Therefore, the ring oscillator 210 will oscillate intermittently during a collision.

The signal processing circuit 5 receives the intermittent oscillation signal via the radiation current electromagnetic field coupling means 4, and the computer 560 determines the magnitude of the collision by measuring the time from one oscillation stop to the next oscillation stop. If the time is smaller than a preset value, it is determined that the collision speed is high, and an output signal is given to the igniter 6 to ignite the gas bag opening filament 7.

Note that the failure alarm device 8 may be connected to the computer 560, and a failure may be displayed when the computer 560 detects that the oscillation signal has stopped.

In addition, in the above-mentioned embodiment as a collision sensor, the power generation winding 25
Although the power generation sensor 2 using the above is illustrated, the present invention is not limited to this, and any other sensor may be used as long as it generates a detection signal in response to a collision, such as one using a piezoelectric element.

As explained in detail above, in the present invention, a radiated electromagnetic field coupling means is used as a transmission path for coupling a collision sensor that is attached to a collision part of a vehicle body and generates a collision signal, and a signal processing circuit that discriminates and processes a collision state. Therefore, flexibility in mounting the collision sensor and signal processing circuit is significantly improved, and there is also the excellent effect of eliminating the need for metal contact type contact connectors in the transmission line near the collision area. .

Furthermore, countermeasures against contact failures such as those mentioned above are particularly important in the system configuration, as they eliminate the risk of contact failures that occur after a particularly large shock occurs in a detection device that detects a car collision. It has the excellent effect of being able to resolve points.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the collision detection device according to the present invention, in which Figure 1 is an installation layout diagram of a collision sensor in a car, Figure 2 is a cross-sectional view of the collision sensor, and Figure 3 is a time diagram of the period measurement method. FIG. 4 is a block diagram showing an embodiment of the apparatus of the present invention. 2... Power generation sensor forming a collision sensor, 4...
... Non-contact connector as radiation electromagnetic field coupling means, 5
... Signal processing circuit, 6 ... Igniter, 7 ... Filament, 8 ... Failure alarm device, 25 ... Power generation winding, 41...
Transmission pole antenna as first antenna, 42.
...Reception pole antenna as the antenna in Figure 2.

Claims (1)

[Scope of Claims] 1. A collision sensor section consisting of a collision sensor element and an oscillation circuit that normally oscillates at a high frequency and stops the 0 oscillation in response to a signal from the sensor element in the event of a collision; radiated electromagnetic field coupling means comprising a first antenna that radiates a signal and a second antenna that receives the radiated signal from the first antenna; A collision detection device comprising a signal processing circuit for determining a collision.