JP2570916B2 - Control device for vehicle safety device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vehicle safety device for detecting a collision from the acceleration of the vehicle and operating the vehicle safety device.

[0002]

2. Description of the Related Art A conventional control device for a vehicle safety device is disclosed in, for example, Japanese Patent Application Laid-Open No. 49-55031, in which the acceleration in the deceleration direction of a vehicle detected by an acceleration sensor of the vehicle (hereinafter referred to as "decrease"). When the vehicle enters a region that cannot occur in normal running, the deceleration thereafter is integrated to calculate the speed, and when the speed changing in the deceleration direction exceeds a predetermined value, It is determined that the vehicle has collided,
Activate safety devices such as airbag devices and seat belt restraints.

Conventionally, an acceleration sensor for a vehicle is provided under a console box or the like, but recently, it has been studied to integrate the acceleration sensor with a vehicle safety device such as an airbag device and to incorporate the sensor into a steering wheel.

[0004]

However, in the case where the acceleration sensor is built into the steering wheel, when the occupant hits the steering wheel, or when the occupant performs the positioning of the steering wheel, any impact is applied to the steering wheel. When acceleration is applied, there is a possibility that the acceleration sensor detects a large acceleration that cannot be detected in normal traveling.

As described above, when the steering wheel is hit or the like, a change such as transition from acceleration to deceleration or transition from deceleration to acceleration occurs, and the deceleration of the vehicle enters a region that cannot occur in normal traveling. After that, acceleration in the acceleration direction (hereinafter simply referred to as acceleration) may be detected, and immediately after that, a relatively large deceleration may be detected.

If a change from the acceleration to the relatively large deceleration is detected, the calculated speed change in the deceleration direction of the vehicle becomes extremely large, and the possibility that the control device makes a collision determination is high. In other words, there is a problem that a vehicle safety device such as an airbag or a seat belt restraining device operates even though the vehicle does not collide.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device for a vehicle safety device capable of preventing a malfunction of the vehicle safety device when an artificial impact or impact is applied to a steering wheel.

[0008]

That is, according to the present invention, which has been made to achieve the above object, as shown in FIG. 1, an acceleration detecting means which is built in a steering wheel of a vehicle and detects acceleration of the vehicle, A calculating means for integrating an output of the acceleration detecting means when an acceleration in a deceleration direction of the vehicle detected by the acceleration detecting means is equal to or more than a predetermined value; and a collision set in advance with the integration result calculated by the calculating means. When the integration result exceeds the collision determination level, the operation control means for operating the vehicle safety device and the acceleration in the vehicle acceleration direction detected by the acceleration detection means are determined in advance. The acceleration determining means for determining whether the reference acceleration exceeds the reference acceleration and the acceleration determining means determine that the acceleration in the acceleration direction of the vehicle exceeds the reference acceleration. When, the gist of the control apparatus for a vehicle safety device characterized by comprising a correction means for increasing correct the collision determination level of the operation control means.

[0009]

The control device for a vehicle safety device having the above-described structure is:
When acceleration detection means incorporated in the steering wheel of the vehicle detects the acceleration of the vehicle, and when the acceleration in the deceleration direction of the vehicle detected by the acceleration detection means is equal to or greater than a predetermined value, the calculation means outputs the output of the acceleration detection means. The operation control means compares the integration result calculated by the calculation means with a preset collision determination level, and when the integration result exceeds the collision determination level, activates the vehicle safety device; The acceleration determining means determines whether the acceleration in the vehicle acceleration direction detected by the acceleration detecting means exceeds a predetermined reference acceleration, and the acceleration determining means determines whether the acceleration in the vehicle acceleration direction is the reference acceleration. When it is determined that the threshold value has been exceeded, the correction means increases and corrects the collision determination level of the operation control means.

[0010]

FIG. 2 is a schematic block diagram showing a specific configuration of a control device for a vehicle safety device according to one embodiment of the present invention.

In FIG. 2, G as an acceleration detecting means
The sensor 1 is built in a handlebar of a driver's seat (not shown) of the vehicle. The acceleration value detected by the G sensor 1 is converted into a digital value by the A / D converter 2,
ECU (electronic control device) which is a main configuration of the control device
The ECU 3 is configured to perform each processing of speed calculation, speed comparison, acceleration determination, and correction, which will be described later, by the ECU 3.

Here, in the speed calculation process, when the deceleration detected by the G sensor 1 is a deceleration that cannot occur in normal traveling, a speed thereafter is obtained.
The speed comparison process compares the speed obtained by the speed calculation process with a predetermined reference speed (collision determination level) in order to determine whether to operate the vehicle safety device. The acceleration discrimination processing compares the detected acceleration with a predetermined reference acceleration in order to determine whether the acceleration detected by the G sensor 1 falls within a predetermined acceleration region. According to the magnitude of the acceleration detected by the sensor 1, the reference speed, which is a reference for determining whether or not to operate the vehicle safety device, is corrected.

In order to perform such processing, an initial value Vtho of a collision determination threshold Vth as a reference speed serving as a reference for determining whether to operate the vehicle safety device is stored in a ROM 4 built in the ECU 3. And an acceleration threshold Gth as a reference acceleration used to determine whether to correct the initial value Vtho,
It is stored in advance.

The ROM 4 stores reference deceleration data serving as a reference for determining whether or not to perform the speed calculation processing. Readable and writable RA built in ECU3
M5 stores the corrected collision determination threshold Vth.

The ignition circuit 6 supplies an ignition current to an ignition device 7 in response to a collision determination signal from the ECU 3. The ignition device 7 ignites by this ignition current to generate a large amount of gas. It is configured to expand.

Next, the operation of the above-described ECU 3 will be described in detail. FIG. 3 is a flowchart for explaining the operation of the above-described ECU 3, and FIG. 4 is a flowchart for explaining the Vth correction operation shown in FIG.

As shown in FIG. 3, first, in step 10, acceleration data from the G sensor 1 is read via the A / D converter 2. Subsequently, in step 11, it is determined whether or not to correct the collision determination threshold Vth, and if necessary, Vth is corrected. Subsequently, in step 12, the deceleration data from the G sensor 1 is compared with the reference deceleration data read from the ROM 4. When the deceleration data from the G sensor 1 is larger than the reference deceleration data, that is, when a deceleration that is too large to be detected in normal traveling is detected, the deceleration data is subjected to an integral operation to perform speed calculation. Obtain data V. The speed data V is compared with the collision determination threshold Vth obtained in step 11, and when V becomes larger than Vth, an ignition command signal is output.

Further, the correction of the collision determination threshold Vth in step 11 is performed according to the procedure shown in FIG. That is, in step 100, in order to determine whether or not the acceleration detected by the G sensor 1 exceeds a predetermined acceleration, the acceleration data obtained in step 10 and the acceleration threshold Gth read from the ROM 4 are used. Compare.

If the acceleration data from the G sensor 1 is larger than Gth, the process proceeds to step 102; otherwise, the process proceeds to step 104. In step 102,
Each time acceleration data exceeding Gth is sampled from the G sensor 1, the collision determination threshold Vth is increased by α. Here, the value of α is 0.02 to 0.025 miles per sampling period. One sampling period is about 0.2 millisecond.

When a hit or the like is applied to the steering wheel, G
The sensor 1 detects a large deceleration immediately after detecting the acceleration. When it is determined in step 100 that the acceleration data from the G sensor 1 has become equal to or smaller than Gth, the process proceeds to step 104.

In step 104, it is determined whether or not the corrected Vth exceeds the initial value Vtho.
When h exceeds Vtho, the collision determination threshold Vth is decreased by β every time the G sensor 1 samples. The value of β is 0. 0 per sampling period.
002-0.0025 miles. The reason why the value of β is smaller than the value of α is that the duration of the deceleration that occurs later is longer than the duration of the acceleration that occurs when a hit or the like is applied to the steering wheel.

If it is determined in step 104 that the collision determination threshold Vth is equal to or lower than Vtho, Vth is output as it is, and the processing in step 12 is performed.

Step 100 functions as acceleration determining means, steps 102, 104 and 106 function as correcting means, and step 12 functions as calculating means and operation control means. FIG. 5 is an example timing chart for explaining a change in acceleration and a change in speed detected when a hit is applied to the steering wheel. FIG. 5A shows changes in the acceleration and deceleration of the vehicle, and FIG. ) Indicates changes in Vth and the speed of the vehicle.

In FIG. 5A, the deceleration increases as the vertical axis increases from the point 0, and the acceleration increases as the axis decreases from the point 0. In FIG. 5B, the speed change in the deceleration direction increases as the vertical axis increases from the point 0, and the speed change in the acceleration direction increases as the axis moves downward from the point 0.

As shown in FIG. 5A, when a hit or the like is applied to the steering wheel, an acceleration occurs immediately before the relatively large deceleration. In the example shown in FIG. 5, at time t0, the deceleration G becomes larger than the reference deceleration, and at time t1.
, The acceleration becomes greater than Gth, and at time t2
In, the acceleration becomes smaller than Gth.

The control device according to the present embodiment does not perform the speed calculation processing for calculating the speed from the deceleration in step 12 until time t0 when the deceleration G exceeds a predetermined deceleration that cannot occur in normal running.

That is, the control device performs speed calculation processing after time t0, but determines whether to operate the vehicle safety device using Vtho without correcting the initial value Vtho of the collision determination threshold until time t1. Make a decision.

That is, the control device in step 12
The deceleration data from the G sensor 1 is compared with the reference deceleration data read from the ROM 4. When the deceleration data from the G sensor 1 is larger than the reference deceleration data, that is, when a deceleration that is too large to be detected in normal traveling is detected, the deceleration data is subjected to an integral operation to perform speed calculation. Obtain data V. By comparing the speed data V with the initial value Vtho of the collision determination threshold, it is determined whether to activate the vehicle safety device.

Then, the control device operates from time t1 to time t1.
2, the collision determination threshold Vth is increased by the gradient α, and from the time t2, the collision determination threshold Vth is reduced by the gradient β until reaching the initial value Vtho. Is compared with the speed data obtained by performing the integration processing on whether or not to activate the vehicle safety device.

The collision determination threshold Vth is equal to the initial value Vt.
After the time point t5 when returning to ho, the control device uses the initial value Vtho for a while to determine whether or not to activate the vehicle safety device, and then resets the speed data to 0, and then resets the speed data to 0. Prepare for vehicle safety device operation determination.

As described above, in this embodiment, the G sensor 1
When the acceleration detected in the step S1 enters a predetermined acceleration region, correction is started (step 11), and the value of the reference speed Vth serving as a reference for collision determination is increased by a positive increment α (step 102). Next, when the acceleration decreases and deviates from the predetermined area, the value of Vth is set to a negative increment-
It is decreased by β (step 106), and when the value of Vth becomes the initial value Vtho, the correction of Vth is terminated.

Therefore, when an impact due to an inadvertent impact or an operation for changing the position of the steering wheel is applied to the steering wheel, while the acceleration due to the impact or impact is being detected, it serves as a reference for collision determination. Since the value of Vth becomes large, even if a large speed change from time t3 to time t4 in the speed change curve A shown in FIG. 5B is detected, it is based on the erroneous recognition that a collision has occurred. The operation command is not issued to the vehicle safety device.

As a result, even if the steering wheel is hit or the like, malfunction of a vehicle safety device such as an airbag or a seat belt restraining device is prevented. Regardless of whether correction is made or not, when a deceleration exceeding a predetermined deceleration is detected, the speed based on the deceleration data is always compared with the speed used as a reference for collision determination. When a speed change exceeding the speed value is detected, it is determined that the vehicle safety device is to be operated.

[0034]

As described above, the control device for a vehicle safety device according to the present invention detects an acceleration exceeding a predetermined reference acceleration when an impact such as a blow is applied to a steering wheel provided with acceleration detecting means. When the determination is made, the collision determination level serving as the reference for the collision determination is increased and corrected.

Therefore, while the acceleration due to the impact or the like is being detected, the criterion for determining the collision is high. Therefore, even if a large speed change occurs such that acceleration occurs immediately before a relatively large deceleration. Malfunction of the vehicle safety device is avoided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a basic configuration of a control device for a vehicle safety device according to the present invention.

FIG. 2 is a schematic block diagram showing a specific configuration of a control device of the vehicle safety device according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of an ECU constituting the control device.

FIG. 4 is a flowchart for explaining a Vth correction operation shown in FIG. 3;

FIG. 5 is a timing chart illustrating an example of a change in acceleration and a change in speed detected when a hit is applied to a steering wheel. FIG. 5 (a) illustrates changes in vehicle acceleration and deceleration, and FIG. ) Indicates changes in Vth and the speed of the vehicle.

[Explanation of symbols]

1 ... G sensor, 3 ... ECU, 4 ... ROM,
5 RAM, 6 ignition circuit, 7 ignition device

Claims (1)

(57) [Claims] 1. An acceleration detecting means built in a steering wheel of a vehicle for detecting acceleration of the vehicle, and the acceleration detecting means when an acceleration in a deceleration direction of the vehicle detected by the acceleration detecting means becomes a predetermined value or more. And a comparison unit that compares the integration result calculated by the calculation unit with a preset collision determination level. If the integration result exceeds the collision determination level, the vehicle safety device is activated. Operation control means for operating, acceleration determination means for determining whether the acceleration in the acceleration direction of the vehicle detected by the acceleration detection means has exceeded a predetermined reference acceleration,
Correction means for increasing the collision determination level of the operation control means when the acceleration determination means determines that the acceleration in the acceleration direction of the vehicle has exceeded the reference acceleration. Control device of the vehicle safety device to perform.