JP4203814B2 - Vehicle occupant protection device - Google Patents

Description

  The present invention relates to an occupant protection device for a vehicle such as an automobile airbag system, and more particularly to an occupant protection device for a vehicle that can prevent malfunction.

  In an SRS airbag used in an automobile, the G sensor constantly detects the acceleration of the vehicle body, and the acceleration waveform is converted into a digital code by an A / D converter of the airbag ECU and processed by a microcomputer. When the calculation result satisfies a predetermined condition, the transistor is turned on, and the airbag is deployed by energizing the squib of the airbag module.

  In addition, as shown in FIG. 5, a safety sensor for opening and closing the electrical contact is provided in series with the module ignition circuit by the mechanical structure, and the contact is opened during normal operation to cut off the power supply to the module. When an impact exceeding the set level is received, the contact is closed and the power to the module is turned on. This is a mechanical safing sensor provided mainly to prevent misdeployment of the airbag due to the malfunction of the G sensor or microcomputer. This mechanical sensor reliably detects the impact, and then the G sensor If a collision is detected, current is supplied to the transistor.

  However, the safing sensor is a mechanical system that opens and closes electrical contacts by moving the internal weight in response to the deceleration of the collision, and it has to be manufactured with high accuracy, and quality control is severe and expensive. . Therefore, in recent years, as disclosed in JP-A-2003-237529, an electronic safing system that does not use a mechanical safing sensor has been adopted. In the electronic safing system, the output signals of the collision sensors attached to the front and rear or the left and right of the vehicle are calculated, and an electric safing switch (electronic safing) is driven when the safing threshold is exceeded.

  However, the collision sensor is often arranged in the crash zone, and there is a very high possibility that a signal abnormality such as sensor destruction or signal line disconnection is caused by the collision. In that case, there is a possibility that the microcomputer becomes unable to calculate and electronic safing cannot be driven and the airbag is not deployed. Therefore, in a conventional airbag system, as a means for preventing airbag non-deployment, when the self-diagnosis circuit detects an abnormality of the collision sensor, a safing drive signal is sent until the abnormality is determined. It is also known for its design.

However, in such a system, safing is driven even when a sensor failure occurs due to a cause other than a collision or when an instantaneous signal abnormality of several milliseconds occurs, leading to erroneous deployment of the airbag. There is a problem that reliability increases due to increased factors.
JP 2000-145005 JP2003-237529

  The present invention has been made in view of the above circumstances, and it is an object to be solved to prevent malfunction such as erroneous deployment of an airbag and improve reliability.

The feature of the vehicle occupant protection device of the present invention that solves the above problems is as follows.
G sensor,
A collision sensor for detecting the collision of the vehicle;
A pre-detection device for detecting a vehicle collision in advance;
A control device to which output signals of the G sensor, the collision sensor, and the prior detection device are input;
A protective device for protecting the occupant;
Driving means for driving the protection device by the output from the control device,
The control device
A collision determination unit that determines the presence or absence of a collision based on an output signal of the G sensor;
A safing determination unit that outputs a signal when a collision is determined by a signal from the collision sensor;
A signal abnormality determining unit for detecting an abnormality of the collision sensor;
An AND circuit that outputs a signal when the output of the prior detection device and the output of the signal abnormality determination unit exceed a predetermined threshold;
An OR circuit that outputs a signal when either or both of the safing determination unit and the AND circuit output a signal,
The driving means is driven when both the collision determination unit and the OR circuit output signals .

  The protective device is preferably an airbag device.

  According to the vehicle occupant protection device of the present invention, since the signal from the advance detection device that detects the vehicle collision in advance is used, the protection device is always driven even when the collision sensor is broken or disconnected at the time of the collision. be able to. In addition, it is possible to reliably prevent a problem that the protective device is erroneously driven when a failure occurs in the collision sensor in normal times. Therefore, the reliability is significantly increased.

  The vehicle occupant protection device of the present invention uses a signal from a prior detection device that detects a vehicle collision in advance. If the pre-detection device does not predict a collision, the collision cannot occur, and the collision occurs after the pre-detection device predicts the collision. Therefore, even if the pre-detection device malfunctions or breaks, The output value is input to the control device in advance. Therefore, even if an abnormality such as a failure or disconnection occurs in the collision sensor at the time of a collision, the state can be detected by communication abnormality determination. Therefore, both the communication abnormality determination value of the collision sensor and the output of the prior detection device exceed a predetermined threshold value. In this case, the output from the AND circuit is generated by both outputs and the driving means can be driven, and there is no problem that the protective device is not driven.

  In addition, when there is an abnormality such as a failure or disconnection in the collision sensor during normal times other than a collision, there is no output from the pre-detection device, so there is no output from the AND circuit and it is ensured that the protection device is driven by mistake. Can be prevented.

  As the collision sensor, a G sensor, a safing sensor, an external sensor, or the like can be used. Although one collision sensor may be provided, it is desirable to provide a plurality of collision sensors.

  As the prior detection device, a millimeter wave laser beam device that detects the inter-vehicle distance, a pressure detection device that detects a change in brake hydraulic pressure during sudden braking, or the like can be used. These have been put into practical use as devices that output a pre-crash signal that tightens the seat belt before a collision.

  As the control device, a device using a microcomputer such as an airbag ECU can be used. Examples of the protective device include an airbag, a seat belt, and the like that are activated at the time of collision to minimize the damage to the occupant.

  Hereinafter, the present invention will be described specifically by way of examples.

(Example)
FIG. 1 shows an automobile equipped with the vehicle occupant protection device of the present invention. In this embodiment, the airbag device is a vehicle occupant protection device. A pre-crash sensor 10 that detects the possibility of a collision according to the time it takes to irradiate millimeter wave laser light and receive the reflected light and two front collision sensors 11 are installed at the front of the vehicle body. An output signal is input to the airbag ECU 1. In the airbag ECU 1, a G sensor 12 shown in FIG. 2 is arranged. A driver's seat airbag 13 and a passenger's seat airbag 14 are provided in the passenger compartment, and are deployed by a deployment signal from the airbag ECU 1 mounted at the lower portion of the passenger compartment.

  As shown in FIG. 2, the airbag ECU 1 is provided with a control device 2 composed of a computer, an electronic safety switch 3 driven by a power source 30 different from the battery, and an ignition device 4.

  The control device 2 includes a safing determination unit 20, a signal abnormality determination unit 21, a fixed time hold unit 22, and a collision determination unit 23. The output signals of the two front collision sensors 11 are input to the safing determination unit 20, and the safing determination unit 20 calculates the output signals of the two front collision sensors 11 to calculate whether or not it is a collision. When a collision is determined, a signal is output. The output signals of the two front collision sensors 11 are also input to the signal abnormality determination unit 21. The signal abnormality determination unit 21 monitors the output signals of the two front collision sensors 11 to check whether there is an abnormality such as a failure or disconnection. Is detected and a signal is output when there is an abnormality.

  The output signal of the pre-crash sensor 10 is input to the fixed time hold unit 22, and the output signal of the pre-crash sensor 10 is held for a fixed time. The collision determination unit 23 receives the output signal of the G sensor 12, and the collision determination unit 23 constantly monitors the output signal of the G sensor 12, and if the collision deceleration G data exceeds a predetermined threshold, the collision determination unit 23 It is determined that the signal is output.

  The control device 2 is further provided with an AND gate 24 and an OR gate 25, and output signals from the signal abnormality determination unit 21 and the fixed time hold unit 22 are input to the AND gate 24, respectively. The output signals from the safing determination unit 20 and the AND gate 24 are input to the OR gate 25, respectively. The output signal of the OR gate 25 is input to the electronic safing switch 3. The output signal of the collision determination unit 23 is input to the drive circuit 40 of the ignition device 4. When the output signal of the collision determination unit 23 exceeds a predetermined threshold value and the electronic safing switch 3 is turned on, the driving circuit 40 supplies a current to the squib 41 by supplying power from the power source 30, and the driver's seat air One or both of the bag 13 and the passenger airbag 14 are deployed.

  In the vehicle occupant protection device of the present embodiment configured as described above, the control contents of the control device 2 will be described with reference to the flowchart shown in FIG.

  First, when the engine is started in step 100, a self-diagnosis circuit (not shown) is activated to diagnose each sensor, and if there is an abnormality, that fact is displayed on the display device. When there is no abnormality, the processing of Step 101, Step 103, Step 104, and Step 108 for constantly monitoring the output signals from the respective sensors is performed almost simultaneously.

  In step 101, the output signal of the pre-crash sensor 10 is monitored. The pre-crash sensor 10 sends a signal to the hold unit 22 for a certain time when it is determined that a collision may occur. If it is determined that no collision can occur, the process of step 101 is repeated. It is determined that a collision can occur, and the signal sent to the hold unit 22 for a certain time is sent to the AND gate 24. In the fixed time hold unit 22, the signal sent in step 102 is held for a predetermined time. As shown in FIG. 3, the signal from the pre-crash sensor 10 is held by the hold unit 22 for a predetermined time, so that even if the pre-crash sensor 10 becomes indefinite at the time of collision, transmission to the AND gate 24 is possible. It becomes possible and reliability is improved.

  In Step 103, the signal abnormality determination unit 21 determines the output signals of the two front collision sensors 11, and sends a signal to the AND gate 24 when the front collision sensor 11 has a failure or a disconnection. If there is no failure or disconnection in the front collision sensor 11, the process of step 103 is repeated.

  In Step 104, the safing determination unit 20 calculates the output signals of the two front collision sensors 11, and determines whether or not a predetermined threshold value is exceeded. If the predetermined threshold is exceeded, it is determined that a collision has occurred and a signal is sent to the OR gate 25. If the predetermined threshold value is not exceeded, the process of step 104 is repeated.

  In step 108, the collision determination unit 23 monitors the output signal of the G sensor 12, and determines that the collision has occurred when the predetermined threshold is exceeded, and drives the drive circuit 40 of the ignition device 4. If it is within the predetermined threshold range, no collision has occurred, so the processing of step 108 is repeated.

  In step 105, the AND of the signal abnormality determination unit 21 and the fixed time hold unit 22 is calculated in the AND gate 24, and the process proceeds to step 106 only when both signals are output. That is, the process proceeds to step 106 only when a signal that detects an abnormality of the front collision sensor 11 is output and the pre-crash sensor 10 outputs a signal that predicts a collision. Since the pre-crash sensor 10 always outputs a prediction signal when a collision occurs, the front collision sensor 11 does not function due to the collision, and the process surely proceeds to step 106. Therefore, even if it is not a collision, even if the front collision sensor 11 fails or is disconnected and the signal abnormality determination unit 21 outputs a signal, the pre-crash sensor 10 does not output a prediction signal. It does not hold, and it is possible to reliably prevent the airbag from being erroneously deployed.

In step 106, the signal from the AND gate 24 and the signal from the safing determination unit 20 are calculated by the OR gate 25, and only one or both of them are outputting signals. The fing switch 3 is turned on. When the signal from the AND gate 24 is not output and / or when the signal of the safing determination unit 20 is not output, it is determined that there is no collision, and the processing of steps 101 to 103 is repeated.

  If either the signal from the AND gate 24 or the signal from the safing determination unit 20 is outputting a signal, the electronic safing switch 3 is turned on in step 107. If the output signal of the G sensor 12 exceeds a predetermined threshold value in step 108, it is determined that there is a collision and a signal is sent to the drive circuit 40 of the ignition device 4, and current flows from the power source 30 to the squib 41. Thus, the ignition device 4 is driven and one or both of the driver's seat airbag 13 and the passenger seat airbag 14 are deployed.

  On the other hand, if the output signal of the G sensor 12 does not exceed the predetermined threshold value in step 108, it is determined that there is no collision even if the electronic safing switch 3 is turned on, and the ignition device 4 is not driven. Processing returns to the beginning.

  Therefore, according to the vehicle occupant protection device of the present embodiment, whether or not it is a collision is checked three times, so that the airbag can be prevented from being mistakenly deployed, and the reliability is high.

  The vehicle occupant protection device of the present invention has not only an airbag device but also a pre-detection device for detecting a vehicle collision in advance such as a pre-crash sensor such as a seat belt preliminary restraint device at the time of collision, and safety of the occupant at the time of collision It can be used for various protective devices for enhancing the quality.

It is a principal part perspective view of the motor vehicle which has the passenger | crew protection device of one Example of this invention. It is a block diagram which shows the structure of the passenger | crew protection apparatus of one Example of this invention. It is a time chart which shows a part of control content of the passenger | crew protection apparatus of one Example of this invention. It is a flowchart which shows the control content of the passenger | crew protection apparatus of one Example of this invention. It is a block diagram which shows the structure of the conventional passenger | crew protection apparatus.

Explanation of symbols

1: Airbag ECU 2: Control device 3: Electronic safing switch 4: Ignition device 10: Pre-crash sensor 11: Front collision sensor
12: G sensor 24: AND gate 25: OR gate

Claims (2)

G sensor,
A collision sensor for detecting the collision of the vehicle;
A pre-detection device for detecting a vehicle collision in advance;
A control device to which output signals of the G sensor, the collision sensor, and the advance detection device are input;
A protective device for protecting the occupant;
Driving means for driving the protection device by an output from the control device,
The control device
A collision determination unit that determines the presence or absence of a collision based on an output signal of the G sensor;
A safing determination unit that outputs a signal when a collision is determined by a signal from the collision sensor;
A signal abnormality determination unit for detecting an abnormality of the collision sensor;
An AND circuit that outputs a signal when the output of the prior detection device and the output of the signal abnormality determination unit exceed a predetermined threshold;
An OR circuit that outputs a signal when either or both of the safing determination unit and the AND circuit output a signal,
A vehicular occupant protection apparatus configured to drive the driving means when both the collision determination unit and the OR circuit output signals . The vehicle occupant protection device according to claim 1, wherein the protection device is an airbag device.

Images