JPH04103450A - Crew protection device for vehicle - Google Patents

Abstract

PURPOSE:To prevent malfunction due to noise by detecting acceleration at collision of a vehicle with an acceleration sensor, incomplete double integrating the detected output, and outputting a trigger signal to actuate a crew protecting device main body at the integral output over a prescribed threshold value. CONSTITUTION:At collision of a vehicle, an acceleration signal of shock wave form generated at this time is detected with an acceleration sensor 1, supplied to a first and a second incomplete integral circuits 2, 3, and incomplete double integrated. When the integral output from the second incomplete integral circuit 3 is over the reference value in a comparing circuit 4, a high level signal is supplied to a driving circuit 5, and an air bag is expanded to protect crew. Meanwhile at usual running, even when the detected output of the acceleration sensor 1 is supplied to the first and second incomplete integral circuits due to running on uneven road surface or sudden braking, because the integral function is incomplete integral, the integral output of the second incomplete integral circuit 3 is not over the reference value of the comparing circuit 4, and ignition current is not supplied to an ignition device 6.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a vehicle occupant protection device for protecting an occupant during a vehicle collision.

[Conventional technology]

For example, as a conventional vehicle occupant protection device,
There is one as shown in Publication No. 55031. That is,
This publication double-integrates the collision waveform detected by an acceleration sensor using a complete integration circuit connected in series in two stages, and when the integrated output exceeds a predetermined level, it drives an ignition device such as an air bank system. The passenger was protected by inflating the airbag and temporarily fastening the seatbelt.

[Problem to be solved by the invention]

However, such conventional vehicle occupant protection systems are configured to perform complete double integration of the collision waveform from the acceleration sensor, which may result in the integration and accumulation of drift from the acceleration sensor, etc. There has been a problem in that negative acceleration signals and the like during sudden braking while the vehicle is running are integrated and accumulated, which may result in the airbag system malfunctioning. This invention was made to solve the above-mentioned problems, and it is possible to integrate the drift of an acceleration sensor, etc.
It is an object of the present invention to provide an occupant protection device for a vehicle which integrates a negative acceleration signal due to sudden braking when the vehicle is running and prevents the occupant protection device from malfunctioning.

[Means to solve the problem]

The vehicle occupant protection device according to the present invention includes an acceleration sensor that detects acceleration at the time of a vehicle collision, a double integration circuit that incompletely integrates the detection output from the acceleration sensor, and an output of the double integration circuit that is set to a predetermined value. The system consists of a comparator circuit that outputs a trigger signal when a threshold value is exceeded, and an occupant protection device main body that operates in response to the trigger signal from the comparator circuit.

[For use]

The vehicle occupant protection device according to the present invention detects the acceleration of the vehicle at the time of a collision using an acceleration sensor, performs incomplete double integration on this detection output, and outputs a trigger signal when the integrated output exceeds a predetermined darkness value. The passenger protection device itself is operated by

【Example】

Hereinafter, the present invention will be explained in detail based on the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention. First, to explain the configuration, in the figure, 1 is an acceleration sensor that generates acceleration as shown in FIG. 2 when a vehicle collides;
2 is the first incomplete integration circuit with a transfer function of TI/(1+ST1) (TI is the time constant, S is the Laplace operator),
The detection output from the acceleration sensor 1 is incompletely integrated. 3 is a second incomplete integrating circuit;
corresponds to the second incomplete integrating circuit 2 in which the time constant T1 is changed to the time constant T2, and its function is the same as that of the first incomplete integrating circuit. Reference numeral 4 denotes a comparator circuit, which compares the reference value and the integrated output, and when the integrated output exceeds the reference value, outputs a high level signal. 5 is a drive circuit; 6 is an ignition device which is the main body of the occupant protection device; this ignition device 6 operates the airbag based on the output of the drive circuit 5; Next, the operation will be explained. First, when a vehicle collides, an acceleration signal having a collision waveform as shown in FIG. is fed to and subjected to incomplete double integration. When the resulting integrated output from the second incomplete integration circuit 3 exceeds the reference value of the comparator circuit 4, a high level signal is supplied to the drive circuit 5 to instantaneously inflate the airbag to protect the occupant. . In addition, the acceleration sensor 1 may be affected by driving on an uneven road surface or by applying sudden braking during normal driving.
Even if the detection output of is supplied to the first and second incomplete integration circuits 2 and 3, since the integration function is incomplete integration,
Since the charge amount of the capacitors constituting each of the first and second incomplete integrals 2 and 3 decreases, the second
Since the integrated output of the incomplete integration circuit 3 does not exceed the reference value of the comparison circuit 4, the ignition device W6 is
No ignition current is supplied to the It goes without saying that in the above embodiment, the time constants TI and T2 of the first and second incomplete integration circuits 2 and 30 may be the same or may have different values. Further, in the above embodiment, the air hang is expanded by supplying ignition current to the ignition device 6, but it goes without saying that the seat belt tensioning device may be operated.

【Effect of the invention】

As described above, according to the present invention, the configuration includes an acceleration sensor that detects acceleration at the time of a vehicle collision, an incomplete double integration circuit that incompletely integrates the detection output from the acceleration sensor, and an incomplete double integration circuit that incompletely integrates the detection output from the acceleration sensor. Since it consists of a comparator circuit that outputs a trigger signal when the output of the complete double integration circuit exceeds a predetermined darkness value, and the main body of the occupant protection system that operates in response to the trigger signal from this comparator circuit, drift, This has the effect that the occupant protection device main body does not malfunction due to sudden braking or noise such as the output of an acceleration sensor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a vehicle occupant protection device according to an embodiment of the present invention, and FIG. 2 is an output waveform diagram of an acceleration sensor at the time of a collision. 1... Acceleration sensor, 2, 3... Incomplete double integration circuit, 4... Comparison circuit, 6... Occupant protection device body. Patent applicant Kanto Seiki Co., Ltd. (2 others)

Claims (1)

[Claims] Acceleration sensor (1) that detects acceleration at the time of vehicle collision
, an incomplete double integration circuit (2, 3) that incompletely integrates the detection output from this acceleration sensor, and a comparison circuit that outputs a trigger signal when the output of this incomplete double integration circuit exceeds a predetermined threshold. A vehicle occupant protection device comprising a circuit (4) and an occupant protection device main body (6) that operates in response to a trigger signal from the comparison circuit.