JP3023972B2 - Vehicle occupant protection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a vehicle occupant protection device that protects an occupant in the event of a vehicle collision.

[Prior art]

As a conventional vehicle occupant protection device, for example, Japanese Unexamined Patent Publication No.
There is one as shown in 55031. That is, according to this publication, a collision waveform detected by an acceleration sensor is double-integrated by a complete integration circuit connected in series in two stages, and when the integrated output exceeds a predetermined level, an ignition device such as an airbag system is used. To protect the occupants by inflating the airbag and stopping the seat belt. Here, the complete integration circuit is a circuit that performs constant integration of the waveforms in the + and − directions detected by the acceleration sensor from a certain time to a certain time.

[Problems to be solved by the invention]

However, in such a conventional vehicle occupant protection device, since the collision waveform from the acceleration sensor is completely double integrated, the drift of the acceleration sensor or the like is integrated and accumulated, or There is a problem that a negative acceleration signal or the like at the time of sudden braking during running of the vehicle is integrated and accumulated, and as a result, the airbag system may malfunction. The present invention has been made in order to solve the above-described problems, and integrates a drift of an acceleration sensor or the like, or integrates a negative acceleration signal of sudden braking during running of a vehicle to cause a malfunction of an occupant protection device. It is an object of the present invention to obtain a vehicle occupant protection device which is prevented from being caused to be caused.

[Means for Solving the Problems]

An occupant protection system for a vehicle according to the present invention includes an acceleration sensor for detecting an acceleration at the time of a collision of a vehicle, a first incomplete integration circuit for incompletely integrating a detection output from the acceleration sensor, and a first incomplete integration circuit. A second incomplete integrator for incompletely integrating the integrated output of the second integrator, a comparator for outputting a trigger signal when the integrated output of the second incomplete integrator exceeds a predetermined threshold, and receiving a trigger signal from the comparator. And an occupant protection device main body which operates by the operation.

[Operation]

The vehicle occupant protection system according to the present invention detects the acceleration at the time of collision of the vehicle with an acceleration sensor, and performs an incomplete double integration of the detected output to output a trigger signal when the integrated output exceeds a predetermined threshold. In this case, the occupant protection device main body is operated.

【Example】

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention. First, the configuration will be described. In the figure, reference numeral 1 denotes an acceleration sensor that generates an acceleration as shown in FIG. 2 at the time of a vehicle collision, and 2 denotes a first incomplete integration circuit (T1 is a transfer function T1 / (1 + ST1)). A time constant, S is a Laplace operator, and the detection output from the acceleration sensor 1 is incompletely integrated. Reference numeral 3 denotes a second imperfect integration circuit. The second imperfect integration circuit 3 corresponds to a circuit obtained by changing the time constant T1 of the first imperfect integration circuit 2 to a time constant T2. Is the same as that of the incomplete integration circuit. Here, the incomplete integration circuit is a circuit that performs indefinite integration of the waveform in the + direction and the waveform in the − direction detected by the acceleration sensor from the time when the power is turned on to the time when the power is turned off without determining the time. . Reference numeral 4 denotes a comparison circuit which compares the reference value with the integral output and switches the output level to a high level when the integral output exceeds the reference value. Reference numeral 5 denotes a drive circuit, and reference numeral 6 denotes an ignition device serving as an occupant protection device main body. The ignition device 6 operates an airbag based on an output of the drive circuit 5. Next, the operation will be described. First, when the vehicle collides, an acceleration signal having a collision waveform generated at this time as shown in FIG. 2 is detected by the acceleration sensor 1 attached to the vehicle, and the first and second incomplete integration circuits 2 are provided. , 3 and is incompletely double integrated. When the resulting integrated output from the second incomplete integration circuit 3 exceeds the reference value of the comparison circuit 4, a high level signal is supplied to the drive circuit 5 to instantaneously inflate the airbag and protect the occupant. . In addition, even if the detection output of the acceleration sensor 1 is supplied to the first and second incomplete integrating circuits 2 and 3 by running on an uneven road surface or applying a sudden brake during normal running, the integrating function is incomplete. Since the integration is performed, the charge amounts of the capacitors constituting each of the first and second incomplete integrations 2 and 3 decrease, and the integration output of the second incomplete integration circuit 3 Since the reference value is not exceeded, no ignition current is supplied to the ignition device 6 via the drive circuit 5. That is, in the complete integration circuit used in the prior art,
Since it is a circuit that integrates one section from a certain point in time to a certain point in time, if, for example, a sudden brake is applied as described above at a certain point and integrated after that point, the integration time is limited to a specific small time, Compared to the incomplete integration circuit with a long time, the acceleration waveform in the negative direction due to the sudden braking is not affected by the waveform before the sudden braking is applied, that is, since the acceleration generated during traveling is like white noise, The longer the time is integrated, the smaller the integrated value becomes. On the other hand, in a complete integration circuit with a short integration time, the noise components superimposed on the acceleration waveform are accumulated without being canceled out. There is a possibility that the deployment timing of the back or the like is shifted, and the deployment timing is not optimal. However, since the incomplete integration circuit used in this embodiment is a circuit that performs indefinite integration continuously from the power supply, that is, the time when the ignition is turned on, the acceleration waveform in the + direction and the acceleration waveform in the-direction that occur alternately are used. Since noise components superimposed on these acceleration waveforms are always canceled, it is expected that the acceleration waveform in the negative direction due to sudden braking can be canceled, and the deployment timing of malfunction of the airbag system will be shifted as in the past. There is no. In the above embodiment, it is needless to say that the time constants T1 and T2 of the first and second incomplete integrating circuits 2 and 3 may be the same or different values. In the above-described embodiment, the ignition current is supplied to the ignition device 6 to deploy the airbag. However, it goes without saying that the configuration may be such that the seat belt tensioning device is operated.

【The invention's effect】

As described above, the acceleration sensor that detects the acceleration at the time of the vehicle collision, the first incomplete integration circuit that incompletely integrates the detection output from the acceleration sensor, and the integration output of the first incomplete integration circuit A second incomplete integration circuit for performing a complete integration, a comparison circuit for outputting a trigger signal when an integrated output of the second incomplete integration circuit exceeds a predetermined threshold value, and an occupant protection operating in response to the trigger signal from the comparison circuit Since it is composed of the main body of the occupant, the effect of preventing the operation timing of the main body of the occupant protection device from being shifted or malfunctioning due to noises such as drift and acceleration sensor output due to sudden braking can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a vehicle occupant protection device according to one 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 integration circuit, 4 ...
Comparison circuit 6, occupant protection device body.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinichiro Tsurushima 2-1910 Nisshincho, Omiya City, Saitama Prefecture Inside Kanto Seiki Co., Ltd. (72) Inventor Satoru Matsumori 2-1910 Nisshincho, Omiya City, Saitama Kanto Seiki Co., Ltd. (56) References JP-A-49-55031 (JP, A) JP-A-3-253441 (JP, A) JP-A-48-58511 (JP, A) Control Engineering Handbook Editing Committee Control Engineering Handbook, "July 29, 1964, published by Asakura Shoten Co., Ltd., pages 122-127, 810-811. Page 153 (58) Field surveyed (Int. Cl. ⁷ , DB name) B60R 21/32

Claims (2)

(57) [Claims] An occupant protection device for driving an occupant protection device main body by integrating a detection output from an acceleration sensor, determining a magnitude of a collision based on the magnitude of the integrated value, and
The integration is performed by an incomplete integration circuit, and a transfer function of the incomplete integration circuit is represented by T / (1 + ST), where T is a time constant and S is a Laplace operator. Vehicle occupant protection device. 2. A vehicle occupant protection device for driving an occupant protection device body by integrating a detection output from an acceleration sensor, judging a magnitude of a collision based on the magnitude of the integrated value, and
A first incomplete integration of a detection output from the acceleration sensor;
An incomplete integration circuit (2), a second incomplete integration circuit (3) for incompletely integrating the integration output of the first incomplete integration circuit, and a second
A comparison circuit (4) for outputting a trigger signal when an integral output of the incomplete integration circuit exceeds a predetermined threshold value; and an occupant protection device body (6) that operates upon receiving a trigger signal from the comparison circuit. The transfer function of the incomplete integration circuit is T:
The vehicle occupant protection device is characterized by T / (1 + ST) where S is the time constant and S: Laplace Hamako.