JPH0585298A - Action control device for occupant protecting apparatus - Google Patents

Abstract

PURPOSE:To eliminate the need of repeating collision experiments and enable universal application to any type of car. CONSTITUTION:An action control device for occupant protecting apparatus is provided with a circuit 26 for calculating a relative speed Vp of an occupant against a vehicle after DELTAt has passed based on a lengthwise acceleration G detected by an acceleration sensor 30, and a circuit 32 for judging whether an occupant protecting apparatus 10 should be operated when the relative speed is more than a threshold value. Also, there are provided a circuit 28 for calculating a relative traveling distance Sp of the occupant against the vehicle after DELTAt has passed, and a circuit 36 for determining a timing to operate the occupant protecting apparatus based on the relative traveling distance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant protection device such as an airbag device, and more particularly to an operation control device for the occupant protection device.

[0002]

2. Description of the Related Art As one of operation control devices for an occupant protection device such as an airbag device for protecting an occupant in the event of a vehicle collision, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-212238, the front and rear of the vehicle are disclosed. An operation control having an acceleration detection means for detecting acceleration and a vehicle speed detection means for detecting the traveling speed of the vehicle, and setting the operation timing so that the operation timing of the occupant protection device becomes faster as the vehicle traveling speed becomes higher. Devices are known in the art.

According to such an operation control device, the operation timing of the occupant protection device can be controlled even better than in the case where the acceleration threshold value is constant regardless of the traveling speed of the vehicle.

[0004]

However, in the conventional operation control device for an occupant protection device as described above, the relationship between the vehicle speed and the acceleration threshold value must be determined by assuming a collision in any situation. Therefore, it is necessary to set various conditions for each vehicle type and repeat the collision experiment, which not only requires a great amount of time and cost for tuning the operation control device, but also requires that the operation control device of one vehicle type be used for another vehicle type. There is a problem that it cannot be universally applied to.

In view of the above-mentioned problems in the conventional operation control device for an occupant protection device, the present invention can deal with a collision in any situation without repeating a collision test, and regardless of the vehicle type. It is an object of the present invention to provide an operation control device for an occupant protection device which is improved so as to be universally applicable.

[0006]

According to the present invention, the above object is to provide an acceleration detecting means for detecting longitudinal acceleration of a vehicle, and an occupant for the vehicle after a predetermined time has elapsed based on the detected acceleration. A means for calculating the relative speed, and an operation necessity determination means for determining that the occupant protection device should be operated when the relative speed of the occupant is greater than or equal to a threshold value;
Means for calculating the relative movement distance of the occupant with respect to the vehicle after a predetermined time has elapsed based on the detected acceleration, and operation timing determination means for deciding the timing at which the occupant protection device should be activated based on the relative movement distance of the occupant. An occupant protection device having an output unit that outputs an operation command signal to the occupant protection device at the timing determined by the operation timing determination unit when the operation necessity determination unit determines that the operation should be performed. It is achieved by the operation control device.

[0007]

In an occupant protection device such as an air bag device, whether or not to operate the occupant protection device must be determined according to the degree of injury that the occupant would receive during a collision. The degree of injury that may occur depends on the relative speed of the occupant to the vehicle. Also, the occupant protection device must be in a state where it fulfills its original protection function before the occupant is injured in the event of a vehicle collision, and the occupant protection device starts its original protection function from the time it receives an operation command. It takes a certain amount of time to reach the state of achieving. Further, the timing at which an occupant is injured by a collision with a steering wheel or the like during a vehicle collision is a timing when the relative movement distance of the occupant with respect to the vehicle becomes a predetermined value, for example, the distance between the occupant and the steering wheel before the collision.

According to the above configuration, the relative speed of the occupant with respect to the vehicle after a predetermined time has elapsed is calculated based on the acceleration detected by the acceleration detecting means, and the operation is performed when the relative speed of the occupant is equal to or greater than the threshold value. Whether or not the occupant protection device should be operated is determined by the necessity determination means, and the relative movement distance of the occupant with respect to the vehicle after a lapse of a predetermined time is calculated based on the acceleration detected by the acceleration detection means to determine the operation timing. The means determines the timing at which the occupant protection device should be activated based on the relative movement distance of the occupant, and when the operation necessity determination means determines that the occupant protection device should be activated, it is determined by the operation timing determination means. An operation command signal is output to the occupant protection device at the timing.

Therefore, it is possible to accurately determine whether or not the occupant protection device should be operated, and it is necessary to reliably prevent the occupant from being injured by colliding with the steering wheel or the like when the vehicle collides. The timing for activating the occupant protection device is appropriately determined in accordance with the above, and by doing so, unnecessary operation of the occupant protection device is reliably avoided, and the occupant protection device is activated at a timing that effectively prevents injury to the occupant. Is activated.

[0010]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram showing an embodiment of an operation control device for an occupant protection system according to the present invention, and FIG. 2 is a block diagram showing a main part of the operation control device shown in FIG.

In FIG. 1, reference numeral 10 denotes an airbag device as a passenger protection device. The airbag device 10 includes an inflator 12, which is an ignition device 14.
Is included. The ignition device 14 generates heat when a current flows from the power source 18 due to the switch circuit 16 being closed,
The gas generating agent 20 is ignited to generate gas, which causes the air bag 22 to expand.

The switch circuit 16 of the air bag device 10 is controlled by the operation control device 24 of the present invention as shown. The operation control device 24 has a relative speed calculation circuit 26 and a relative movement distance calculation circuit 28. The relative speed calculation circuit 26 calculates the relative speed Vp of the occupant with respect to the vehicle based on the longitudinal acceleration G of the vehicle detected by the acceleration sensor 30 and outputs the calculation result to the operation necessity determination circuit 32 as described later. ing. The operation necessity determination circuit 32 determines whether or not the relative speed Vp is equal to or higher than a threshold value. When the relative relative speed is equal to or higher than the threshold value, the output circuit 34 determines that the airbag device 10 should be operated. It outputs a signal to that effect.

The relative movement distance calculation circuit 28 calculates the relative movement distance Sp of the occupant with respect to the vehicle based on the acceleration G detected by the acceleration sensor 30, and outputs the calculation result to the operation timing determination circuit 36. It has become. The operation timing determination circuit 36 determines the relative movement distance S
It is determined whether p is greater than or equal to the threshold value, and if the relative movement distance is greater than or equal to the threshold value, the current time is the airbag device 1
As a determination that it is time to output the operation command signal to 0, a signal indicating that is output to the output circuit 34. The output circuit 34 is an operation necessity determination circuit 32.
When signals are input from both of the operation timing decision circuit 36 and the operation timing decision circuit 36, a command signal for closing the switch circuit 16 is output.

In the illustrated embodiment, the relative speed calculation circuit 26, the operation necessity determination circuit 32, and the relative movement distance calculation circuit 2
8, the operation timing determination circuit 36 and the output circuit 34 are shown in FIG.
The microcomputer 38 is constructed as shown in FIG. The microcomputer 38 has a general configuration and includes a CPU 40, a ROM 42, and a RAM.
44 and an input / output port device 46, which are connected to each other by a bidirectional common bus 48.

The input / output port device 46 has an acceleration sensor 3 for detecting the longitudinal acceleration G of the vehicle with the forward direction of the vehicle being positive.
A signal indicating the acceleration G is input from 0. The input / output port device 46 appropriately processes the acceleration signal input thereto, and in accordance with the instruction of the CPU 40 based on the program stored in the ROM 42, the CPU and the RAM.
The processed signal is output to 44. R
The OM 42 stores the control flow shown in FIG.
Further, the input / output port device 46 follows the instruction of the CPU 40,
A command signal is output to the switch circuit 16.

The operation of the illustrated embodiment will now be described with reference to the flow chart shown in FIG. The control according to the flowchart of FIG. 3 is started by closing an ignition switch (not shown).

First, in step 10, the longitudinal acceleration G of the vehicle detected by the acceleration sensor 30 is read, and then step 20 is proceeded to.

In step 20, it is judged whether or not the longitudinal acceleration G is less than or equal to the threshold value G ₁ (negative constant), and when it is judged that G ≦ G ₁ is not satisfied. Returning to step 10, when it is determined that G ≦ G _1, it proceeds to step 30. The threshold value G ₁ is a reference value for determining whether or not there is a high risk of a vehicle collision,
Therefore, the absolute value is set to a relatively small negative value.

In step 30, the timer (not shown in FIG. 2) is started after being reset, so that the count of the elapsed time t from the time when the determination in step 20 is YES is made. Be started.

In the next step 40, the longitudinal acceleration G of the vehicle detected by the acceleration sensor 30 is read, and then the process proceeds to step 50.

In step 50, the vehicle speed V ₁ at the current time is calculated according to the following equation 1, and the deployment of the airbag 22 is completed from the time when the command signal is output from the output circuit 34 for Δt. As the time until, the relative movement distance Sp of the occupant with respect to the vehicle after the elapse of Δt time from the present is estimated and calculated according to the following equation 2.

[0023]

[Equation 1]

[Equation 2]

Further, as shown in FIG. 4, the timer is started at step 30 with G ₂ being a threshold value which is a negative constant whose absolute value is larger than the threshold value G ₁ at step 20. The cumulative value Vi of the longitudinal acceleration G that has become equal to or less than the threshold value G ₂ after the time point is calculated.

Further, based on the vehicle speed V ₁ at the present time calculated as described above, the average value Ga of the longitudinal acceleration of the vehicle after the time when the timer is started is calculated in step 30 according to the following expression 3.

## EQU3 ## Ga = V ₁ / t

Further, based on the map corresponding to the graph shown in FIG. 6, the change amount Vc of the vehicle speed until the end of the collision is calculated, and then the process proceeds to step 60.

The graph shown in FIG. 6 shows the longitudinal acceleration G and FIG. 5 in the latter half of the peak of the longitudinal acceleration waveform as shown in FIG. 5 obtained by the collision experiment at a certain vehicle speed. The relationship with the change amount Vc of the vehicle speed until the end of the collision is obtained as the area of the hatched portion.

At step 60, it is judged if the relative movement distance Sp of the occupant with respect to the vehicle calculated at step 50 is the first threshold value C ₁ or more, and S
When it is determined that p ≥C ₁ is not satisfied, the process returns to step 40, and when it is determined that Sp ≥C ₁ is satisfied, the process proceeds to step 70.

In step 70, it is judged whether or not the cumulative value Vi of the longitudinal acceleration calculated in step 50 is equal to or more than the threshold value Cv, and it is judged that Vi ≥Cv. When it is done, the routine proceeds to step 90, where Vi ≥C.
If it is determined that it is not v, the process proceeds to step 80.

In step 80, it is judged whether or not the relative movement distance Sp of the occupant with respect to the vehicle calculated in step 50 is not less than the second threshold value C ₂ (C ₂ > C ₁ ). If it is determined that Sp ≥C ₂ is not satisfied, the process returns to step 40, and if it is determined that Sp ≥C ₂ is satisfied, the process proceeds to step 90.

In step 90, the longitudinal acceleration G of the current vehicle read in step 40 is calculated in step 50.
If it is determined whether or not the average value Ga of the longitudinal acceleration calculated in step S1 is greater than or equal to G, and it is determined that G ≧ Ga, that is, it is determined that the collision still continues, step 10 is performed.
When it is determined that G ≧ Ga is not satisfied, that is, the collision of the vehicle is about to end, the process proceeds to step 110.

In step 100, assuming that the longitudinal acceleration G remains constant until the time Δt from the present time, the current longitudinal acceleration value remains constant, and the occupant of the vehicle at the time point when the time Δt has elapsed from the present time. The relative speed Vp of the
Then, the process proceeds to step 120.

[Equation 4] Vp = V ₁ + Δt · G

In step 110, the relative speed Vp of the occupant with respect to the vehicle at the time when the collision ends is calculated according to the following equation 5, and then the process proceeds to step 120.

[Equation 5] Vp = V ₁ + Vc

In step 120, step 100
Alternatively, it is determined whether or not the relative velocity Vp calculated in step 110 is equal to or greater than the threshold value Cp (a positive constant), and when it is determined that Vp ≧ Cp, the process proceeds to step 150. If it is determined that Vp ≧ Cp is not established, the routine proceeds to step 130.

In step 130, it is judged whether or not the elapsed time t from the time when the timer is started in step 30 exceeds the threshold value Ct, and t> C.
When it is determined that t is not t, the process returns to step 40, and when it is determined that t> Ct, the process proceeds to step 140. Incidentally, the threshold value Ct in this case is set to the elapsed time at which the collision should have ended if a collision occurs.

In step 140, step 150
Relative velocity V calculated in the RAM 42 and stored in the RAM 42
₁ , the relative movement distance Sp of the occupant with respect to the vehicle, the cumulative value Vi of the longitudinal acceleration, the average value Ga of the longitudinal acceleration, and the variation amount Vc of the vehicle speed until the end of the collision are cleared, and then step 1
Return to 0.

In step 150, the air bag device 10 is operated by outputting a command signal for closing it to the switch circuit 16 via the input / output port device 44, which is then shown in FIG. The control according to the flowchart ends.

Thus, according to the illustrated embodiment, the relative movement distance Sp of the occupant with respect to the vehicle after the elapse of Δt time from the present is calculated in step 50 according to the equation 2, and in steps 60 and 80 the relative movement distance is calculated. By determining whether or not Sp is equal to or greater than the threshold value, it is accurately determined whether or not the present time is the timing to issue the operation command to the airbag device 10.

When it is determined in steps 60 and 80 that the present moment is the timing to issue the operation command to the airbag device, it is determined in step 90 whether or not the collision still continues, and the collision is determined. When it is determined that the vehicle speed continues, the relative speed Vp of the occupant with respect to the vehicle at the time when the time Δt has elapsed is calculated in accordance with the equation 4 in step 100, and the collision is about to end in step 90. If the determination is made in step 110, the relative speed Vp of the occupant with respect to the vehicle is calculated in accordance with equation 5 in step 110, and the relative speed Vp is calculated in step 120 as the threshold value C.
By determining whether or not it is p or more, it is accurately determined whether or not the airbag device should be operated.

In particular, according to the illustrated embodiment, step 70
At this point, it is determined whether or not the cumulative value Vi of the longitudinal acceleration is equal to or greater than the threshold value Cv, that is, whether the collision is a high-speed collision, and the collision is a high-speed collision. Of the relative movement distance Sp is determined with a relatively small threshold value C ₁ , and when it is determined that the collision is a low speed collision, the relative movement distance Sp of the relative movement distance Sp is determined. Since the judgment of the magnitude is made with a comparatively large threshold value C ₂ , compared with the case where the judgment of the magnitude of the relative movement distance Sp is made with a constant threshold value regardless of the magnitude of the vehicle speed at the time of collision. ,
It is possible to more accurately determine the timing at which the operation command is issued to the airbag device.

In the illustrated embodiment, step 90
At this time, it is determined whether or not the collision still continues, and when it is determined that the collision still continues, the relative velocity Vp is calculated according to the equation 4, and it is determined that the collision is about to end. Since the relative velocity Vp is sometimes calculated according to Formula 5, the airbag device should be operated regardless of whether the relative velocity Vp of the occupant is calculated according to Formula 4, for example, regardless of whether or not the collision is in the end state. It is possible to more accurately determine whether or not it is.

Although the present invention has been described above in detail with reference to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art that it is possible.

[0043]

As is apparent from the above description, according to the present invention, it is determined whether or not the occupant protection device should be operated depending on whether or not the relative speed of the occupant with respect to the vehicle is equal to or greater than a threshold value. The timing at which the occupant protection device should be activated is determined by whether or not the relative movement distance of the occupant with respect to the vehicle is equal to or greater than a threshold value.

Therefore, it is appropriately determined whether or not the occupant protection device should be operated, and the timing of the operation is appropriately determined, whereby unnecessary operation of the occupant protection device is reliably avoided and the occupant is injured. It is possible to operate the occupant protection device at a timing that effectively prevents the collision, and it is not necessary to repeat the collision experiment assuming a collision in any situation. It is possible to omit the known tuning of the operation control device.

Further, for example, by adjusting the threshold value for determining the relative movement distance of the occupant with respect to the vehicle according to the vehicle type, the operation control device of the occupant protection device of the present invention can be performed without repeating a collision test for each vehicle type. Can be universally applied to all types of vehicles.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of an operation control device for an occupant protection device according to the present invention.

FIG. 2 is a block diagram showing a main part of the operation control device shown in FIG.

FIG. 3 is a flow chart showing the control achieved by the operation control device of the embodiment shown in FIG.

FIG. 4 is a longitudinal acceleration G of the vehicle and a cumulative value V of the longitudinal acceleration.
It is a graph which shows i.

FIG. 5 is a graph showing how to obtain a vehicle speed change amount Vc until the end of a collision.

FIG. 6 is a graph showing the relationship between the longitudinal acceleration G of the vehicle and the amount of change in vehicle speed Vc until the end of the collision.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Airbag device 12 ... Inflator 16 ... Switch circuit 22 ... Airbag 24 ... Operation control device 26 ... Relative speed calculation circuit 28 ... Moving distance calculation circuit 30 ... Acceleration sensor 32 ... Actuation necessity judgment circuit 34 ... Output circuit 36 ... Operation timing determination circuit 38 ... Microcomputer

Claims (1)

[Claims] 1. An acceleration detecting means for detecting a longitudinal acceleration of a vehicle, a means for calculating a relative speed of an occupant with respect to the vehicle after a lapse of a predetermined time based on the detected acceleration, and a relative speed of the occupant is a threshold value. When the above is the case, operation necessity determination means for determining that the occupant protection device should be operated,
Means for calculating the relative movement distance of the occupant with respect to the vehicle after a predetermined time has elapsed based on the detected acceleration, and operation timing determination means for deciding the timing at which the occupant protection device should be activated based on the relative movement distance of the occupant. An occupant protection device having an output unit that outputs an operation command signal to the occupant protection device at the timing determined by the operation timing determination unit when the operation necessity determination unit determines that the operation should be performed. Operation control device.