JPH1159323A - Occupant crash protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an occupant crash protection device preventing the delay of actuation of occupant crash protection means. SOLUTION: An occupant crash protection device which protects occupants by restraining the occupants during vehicle collision includes: one or more occupant crash protection means operated for restraining the occupants; an electronic control unit controlling the actuation of the occupant crash protection means; and an acceleration detection unit for which a communication path with the electronic control unit is formed and which transmits an actuation request signal requesting the actuation of the occupant crash protection means and other signals including a self-diagnostic signal to the electronic control unit via the communication path. The acceleration detection unit inhibits the transmission of the other signals when a value related to vehicle horizontal acceleration becomes equal to or higher than a first threshold, and transmits the actuation request signal when the value related to vehicle horizontal acceleration becomes equal to or higher than a second threshold value higher than the first threshold, and the electronic control unit actuates the occupant crash protection means on receiving the actuation request signal.

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 mounted on a vehicle, and more particularly, to an occupant protection device having a function of protecting an occupant against a lateral collision with the vehicle, that is, a so-called side collision. It is about.

[0002]

2. Description of the Related Art An occupant protection device is a device that activates occupant protection means at the time of a collision and alleviates an injury caused by an occupant hitting indoor equipment of a vehicle body. As an occupant protection means, an airbag or a seat belt pretensioner is used. is there. The airbag is designed to inflate the bag between the occupant and the indoor equipment at the time of the collision to reduce the contact injury between the occupant and the indoor equipment. The purpose is to reduce the contact obstacle between the occupant and the indoor equipment.

[0003] Japanese Patent Application Laid-Open No. 8-119060 discloses an airbag.
As described in the publication, a front collision airbag that starts in response to a collision from the front of the vehicle, a so-called front collision, and a side collision airbag that starts in response to a collision from the side of the vehicle, a so-called side collision. In some cases, these activation controls are performed by one electronic control unit.

[0004]

In this type of occupant protection system, a plurality of sensors for detecting a change in acceleration due to a collision are prepared, and each of the sensors has an optimum sensor according to an acceleration direction to be detected. Placed in place. Normally, a collision judging means is provided for each sensor and is unitized together with the sensor. When a collision is judged on the sensor unit side, a signal for requesting the central electronic control unit to activate the occupant protection means ( (A start request signal).

On the other hand, signals transmitted from the sensor unit to the electronic control unit include, in addition to the start request signal,
There are various signals including a self-diagnosis signal (diag signal) relating to the result of self-diagnosis of a failure of the sensor itself.
The self-diagnosis is normally performed regularly, and the self-diagnosis signal is generated completely independently of the activation request of the occupant protection means, and is transmitted to the electronic control unit at a fixed period, for example, every several tens of ms.

Therefore, in the sensor unit, when a collision is detected by the cooperative operation of the acceleration sensor and the collision judging means and the start request signal is transmitted, the transmission of the self-diagnosis signal may overlap in time. In particular, if a request to activate the occupant protection means occurs while the self-diagnosis signal is being sent
Since the activation request signal is transmitted after the self-diagnosis signal transmission is completed, the activation of the occupant protection means may be delayed.

[0007]

SUMMARY OF THE INVENTION An occupant protection device starting device according to the present invention has been made to solve such a problem, and an occupant that protects an occupant by restraining the occupant in the event of a vehicle collision. In the protection device, one or more occupant protection means operating to restrain the occupant, an electronic control unit for controlling activation of the occupant protection means, and a communication path with the electronic control unit are formed. An acceleration detection unit for transmitting an activation request signal for requesting activation of the occupant protection means to the unit and another signal including a self-diagnosis signal to the electronic control unit via a communication path; When the left-right acceleration-related value of the vehicle becomes equal to or more than the first threshold, transmission of another signal is prohibited, and the second left-right acceleration-related value of the vehicle is higher than the first threshold. When it is above have values are those transmitting an activation request signal, the electronic control unit is intended to activate the occupant protection means when receiving a start request signal.

When the acceleration-related value exceeds the second threshold value, it naturally exceeds the first threshold value.
Transmission of signals other than the activation request signal to the electronic control unit is prohibited. Therefore, transmission of the activation request signal does not overlap with transmission of other signals in time, and there is no transmission delay caused by other signals.

The start request signal and other signals transmitted from the acceleration detection unit to the electronic control unit are binary serial signals, and one or both adjacent bits of the signal have the same value. It is desirable. With this configuration of the signal, the frequency of the transmission signal can be reduced in a pseudo manner, so that the occurrence of noise can be suppressed.

It is desirable that the electronic control unit has a function of activating the occupant protection means when the acceleration-related value in the longitudinal direction of the vehicle becomes equal to or more than a predetermined threshold value.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an arrangement of each component of an occupant protection system according to an embodiment of the present invention. The occupant protection device according to the present embodiment includes, as occupant protection means, airbags 1 to 4 and seat belt pretensioners 5, 6,
Electronic control unit 11, acceleration detection units 7, 8
And front satellite acceleration sensors 9 and 10, each of which is disposed at a predetermined location on the vehicle body 12 as shown in the figure.

Of the airbags, frontal airbags 1 and 2 are disposed in front of a driver's seat and a passenger's seat,
The side collision airbags 3 and 4 are arranged in the driver seat and the passenger seat or in the B pillar portion. These airbags are provided with an ignition device called a squib, and in the event of a collision, the electronic control unit 11 causes the filament inside the squib to generate heat to burn the gas generating agent, thereby opening the airbag.

The seatbelt pretensioners 5 and 6 are arranged at the seatbelt mounting portions of the driver's seat and the passenger's seat, and each has a squib.
At the time of a collision, as in the case of an airbag, the electronic control unit 11 causes the filament inside the squib to generate heat and burn the gas generating agent, but in the case of a pretensioner, the pressure of this gas is used to apply a force to the seat belt. Perform a forced retraction.

The acceleration detection units 7 and 8 are units for detecting a change in acceleration due to a side collision on the side where the acceleration sensors 7 and 8 are arranged. The acceleration-related values, in this case, the integral values of the lateral acceleration in a predetermined period are determined. When the threshold value is exceeded, a start request signal for starting the corresponding airbag or seat belt pretensioner is transmitted to the electronic control unit 11.

When the electronic control unit 11 receives the activation request signal from the acceleration detection unit 7 or 8, the electronic control unit 11 operates the squib of the corresponding airbag or seat belt pretensioner by supplying an ignition current thereto. In addition, an acceleration sensor for detecting a change in acceleration at the time of a frontal collision is provided, and when an integral value of a longitudinal acceleration which is an acceleration-related value in a predetermined period exceeds a predetermined threshold value, a corresponding airbag or seat is provided. Activate the squib of the belt pretensioner.

Front satellite acceleration sensors 9, 10
Is a sensor that detects an offset collision from the front. For example, when a collision occurs in the front left half of the vehicle body 12, the acceleration detected by the acceleration sensor 10 is smaller than the acceleration detected by the acceleration sensor 9. large. In this case, the acceleration sensor 10 is turned on, and the acceleration sensor 9 remains off. At this time, the electronic control unit 1
1, it is determined that an offset collision has occurred, and the front collision airbags 1, 2 or the seat belt pretensioner 5,
The threshold value of the acceleration related value for front collision, which is the operation reference of No. 6, is lowered. As a result, in the case of an offset collision in a front collision, the front airbags 1 and 2 or the seat belt pretensioners 5 and 6 operate even with an impact that is difficult to be detected by the acceleration sensor in the electronic control unit 21. Similarly, in the case of an offset collision in the right half of the vehicle body 12, when the offset collision is determined, the threshold value of the acceleration-related value for front collision is lowered.

Next, the internal configuration of each component and the specific connection will be described with reference to FIG. In FIG. 2, the left and right acceleration detection units, airbags, seat belt pretensioners, and front acceleration sensors, which are arranged in a pair, have the same configuration on the left and right sides. That is, the acceleration detection unit 7, the airbags 1, 3, the seat belt pretensioner 5, and the front acceleration sensor 9 on the driver's seat side are illustrated as representatives. Corresponding to this, the ignition current supply circuit in the electronic control unit 11 for each occupant protection means is also shown only for the driver's seat side, and the ignition current supply circuit for the passenger seat side is omitted.

The electronic control unit 11 includes a DC-DC boost control circuit 22, a satellite power control circuit 23, a 5V power regulator 24, a squib ignition control circuit 25, a squib diagnostic circuit 26, and a communication interface circuit 2.
7 is provided with an integrated integrated circuit 21.

The DC-DC boost control circuit 22 is a circuit that boosts the voltage of 12 V of the vehicle-mounted battery (not shown) to a voltage required for squib ignition, for example, about 15 V. The satellite power supply control circuit 23 is a circuit that controls a power supply control transistor 28 that adjusts the supply of power required for the operation of the acceleration detection unit 7. The 5V power supply regulator 24 is a circuit that supplies a 5V power supply voltage to various circuits inside the integrated integrated circuit 21 and peripheral circuits thereof.

The squib ignition control circuit 25 includes ignition transistors 32 to 34 for switching on and off the ignition current supplied to the squibs 1 a, 3 a, 5 a provided in the airbags 1, 3 and the seat belt pretensioner 5.
It is a circuit that controls 36 to 38. Ignition is microcomputer 3
This is performed based on a start request signal from the acceleration detection unit 7 provided through the communication interface circuit 27 and a start request signal from the communication interface circuit 27.

The squib diagnostic circuit 26 is a circuit for measuring a resistance value while passing a weak current that does not lead to ignition to each of the squibs 1a, 3a and 5a, and self-diagnosing whether or not each squib is normal. is there.

The communication interface circuit 27 is an interface circuit for the electronic control unit 11 to perform digital communication with the acceleration detection units 7 and 8.
The reception of acceleration signals from the front satellite acceleration sensors 9 and 10 is also performed.

The front collision acceleration sensor 29 is an electronic acceleration sensor, and constantly outputs an electric signal corresponding to the detected acceleration, that is, an acceleration signal. Here, as the front collision acceleration sensor 29, a diaphragm type acceleration sensor capable of obtaining an output characteristic linear with respect to deceleration is employed.

The microcomputer 30 receives the acceleration signal output from the front collision acceleration sensor 29 and continuously calculates an integral value of the acceleration in a predetermined period. The integrated value is herein referred to as an acceleration-related value, and the microcomputer 30 compares the acceleration-related value with a predetermined threshold for a frontal collision. When the threshold value is exceeded, the microcomputer 30 issues a start request signal to the squib ignition control circuit. Output to 25. In addition,
The value of the front collision threshold value becomes low when one of the output signals of the front satellite acceleration sensor 9 or 10 input via the communication interface circuit 27 is turned on.

The ignition current circuit for supplying the ignition current to the squibs 1a, 3a and 5a includes a DC-DC boost control circuit 22, which is a power supply, a power control Tr 28, a front collision safing sensor 31, a rectifier diode 42, 43, upstream ignition transistor group 35, downstream ignition transistor group 3
9, a side collision safing sensor 53 in the acceleration detection unit 7.

The front collision safing sensor 31 and the side collision safing sensor 53 are mechanical collision sensors that are turned on when an acceleration exceeding a predetermined value is applied. Acts as a safety switch for

The backup capacitor 44 is a backup power supply for supplying an ignition current to each squib in the event of an abnormality. For example, when a wire harness that supplies power to the electronic control unit from the vehicle-mounted power supply is disconnected from the vehicle in the event of a collision and the ignition current cannot be supplied, the ignition is performed instead of the DC-DC boost control circuit 22. Supply current to the squib.

The acceleration detecting unit 7 includes a 5V power supply regulator 50, a side collision acceleration sensor 51, a microcomputer 52 for performing integral calculation of acceleration and communication with the electronic control unit 11, and the above-described side collision safety sensor. 53. 5V power regulator 50
Is the power control transistor 2 in the electronic control unit 11
8 and serves as a 5V voltage power supply for the side collision acceleration sensor 51 and the microcomputer 52. The side collision acceleration sensor 51 is an electronic acceleration sensor like the front collision acceleration sensor 29, and employs a diaphragm type acceleration sensor.

The microcomputer 52 receives an acceleration signal from the side collision acceleration sensor 51 and continuously calculates an integral value (acceleration-related value) of the acceleration in a predetermined period. This acceleration-related value is constantly monitored.
And a second threshold value higher than this threshold value, and when the second threshold value is exceeded, the airbag or seatbelt pretensioner for side collision corresponding to the electronic control unit 11 is used. Is transmitted.

The microcomputer 52 periodically performs a self-diagnosis in the acceleration detecting unit 7, for example, whether the side collision acceleration sensor 51 is normal or not, and sends the result to the electronic control unit 11. It is sent out as a diagnostic signal at a constant period. However, the transmission of the diagnostic signal is prohibited while the acceleration-related value exceeds the first threshold value.

Next, the operation of the thus configured occupant protection device of the present embodiment will be described.

First, a collision from the front will be described. When the vehicle body 12 receives a collision from the front, a front collision acceleration sensor 29 in the electronic control unit 11 detects a change in acceleration accompanying the collision. Since the microcomputer 30 constantly integrates the constantly changing acceleration value and outputs it as an acceleration-related value, the value of the acceleration-related value rises sharply at the time of a frontal collision. When the acceleration-related value exceeds a preset value for a frontal collision, it is determined that the vehicle is in a frontal collision, and a start request signal is output. The squib ignition control circuit 25 turns on the ignition transistors 32, 33, 36, and 37. .

At this time, the front collision safing sensor 31
Is also turned on due to the collision, the DC-DC boost control circuit 22 sends the signal from the front safing sensor 31, the ignition transistor 32, the squib 1a, and the ignition transistor 36
And a circuit grounded through the DC-DC boost control circuit 22
From the frontal safing sensor 31, the diode 42,
A closed circuit that is grounded via the ignition transistor 33, the squib 5a, and the ignition transistor 37 is formed, and the driver-side airbag 1 and the seatbelt pretensioner 5 are activated. Similarly, the airbag 2 and the seatbelt pretensioner 6 on the passenger seat side, which are not shown in FIG.
Also start.

In the case of an offset collision, which is one of the frontal collisions, only one of the front satellite acceleration sensors 9 and 10 is turned on, and the squib ignition control circuit 2 is turned on.
At 5, the set value for the frontal collision is lowered based on this. Except for this change of the front collision setting value, it operates in the same way as a normal front collision,
If the acceleration-related value exceeds the set value for front-end collision after this change,
The airbags 1, 2 and the seat belt pretensioners 5, 6 are activated.

Next, the operation at the time of a side collision will be described. Body 1
2 receives a collision from the right side, the acceleration detection unit 7
A change in acceleration accompanying the side collision is detected by the side collision acceleration sensor 51, and an acceleration-related value is calculated by the microcomputer 52. When the acceleration-related value becomes equal to or larger than the second threshold value, the microcomputer 52 transmits a start request signal. In response to the start request signal, the electronic control unit 11 causes the squib ignition control circuit 25 to operate the ignition transistor 3
3, 34, 37 and 38 are turned on. At this time, if the side collision safing sensor 53 is closed due to the side collision, the side collision safing sensor 53, the ignition transistor 34, the squib 3a,
A circuit grounded via an ignition transistor 38;
DC boost control circuit 22 to side collision safing sensor 5
3, a circuit that is grounded via the diode 43, the ignition transistor 33, the squib 5a, and the ignition transistor 37 is formed, and the side collision airbag 3 and the seat belt pretensioner 5 on the driver's seat side are activated.

When a collision from the left side of the vehicle body 12 is received, the acceleration detection unit 8 detects the collision and sends a start request signal to the electronic control unit 11, and the electronic control unit 11 responds to the start request signal. The side collision airbag 4 and the seat belt pretensioner 6
Start

Next, the operation of transmitting a start request signal and a diagnosis signal in the acceleration detection unit 7 will be described.

FIGS. 3 and 4 show the acceleration detecting unit 7.
3 is a flowchart showing the operation of the microcomputer 52 in FIG. 3, and FIG. 3 relates to an interruption process for judging a side collision, and FIG. FIG. 5 is a timing chart of a side collision determination and transmission process performed by the microcomputer 52. FIG. 5A shows a time change of an acceleration-related value which is an integral value of the acceleration. b) shows the transmission timing of the diagnosis signal and the activation request signal.

First, a description will be given of the side collision determination interrupt processing. As shown in FIG. 3, the microcomputer 52 samples the acceleration value G from the acceleration signal from the side collision acceleration sensor 50 (step 101), and calculates the integrated value of the acceleration value G sampled within a predetermined period up to the previous time. The current acceleration value is added, and the oldest sampled acceleration value within a predetermined period is deleted from the integrated value (step 102). Here, this operation is called an integral operation.

Next, this integral value, which is an acceleration-related value, is compared with a second threshold value Th2 (step 103). If the integral value is equal to or greater than the second threshold value Th2, a start request signal is transmitted (step 104). If the integral value is smaller than the second threshold value Th2 in step 103, the process proceeds to step 105,
The integrated value is compared with a first threshold value Th1 set to a value smaller than the second threshold value Th2. Here, if the integrated value is equal to or larger than the first threshold value Th1, transmission of signals other than the activation request signal such as the diagnostic signal is prohibited (step 106). If the integrated value is smaller than the first threshold value in step 105, transmission of a diagnostic signal or the like is permitted (step 107).

This interrupt processing is shorter than the cycle (about 50 ms) in the diagnosis signal transmission permission state in the diagnosis signal interrupt processing described later, for example, 0.
It is repeated at a cycle of about 25 ms.

Next, the diagnostic signal transmission interrupt processing of FIG. 4 will be described. First, it is determined whether or not transmission of a diagnostic signal or the like is prohibited in the side collision determination interrupt processing of FIG. 3 (step 201). If the transmission is prohibited, the process skips the later steps 202 and 203 and returns to step 201 again. If it is determined in step 201 that the transmission of a diagnostic signal or the like is not prohibited, the diagnostic signal is transmitted after 50 ms has elapsed (steps 202 and 203).

Next, the timing of a transmission signal when a side collision occurs under such two processes will be described with reference to FIG. Assuming that a side impact occurs at time t1, the acceleration-related value (integral value), which has hardly changed until then, starts to rise sharply, as shown in FIG. Assuming that the acceleration-related value exceeds the first threshold value Th1 at time t2 and exceeds the second threshold value Th2 at time t3, the diagnostic signals 501 and 502 are transmitted every 50 ms until time t2. At this point, the transmission of the diagnostic signal or the like is prohibited by the side collision determination interrupt processing, and the diagnostic signal 503 that would have been transmitted without the side collision is not transmitted.

Therefore, the activation request signal is transmitted at time t3, but the transmission of the activation request signal is not disturbed by the diagnosis signal 503. In the present embodiment, the activation request signal is composed of a sequence of two types of 1-byte (8-bit) code signals.
When the 1 and the other code signal 602 have been transmitted, the activation request signal has been transmitted.

Table 1 shows an example of the type of transmission data and the like.

[0046]

[Table 1]

As shown here, the activation request signal includes 16
Two types of code signals, "98" and "0E", are shown in hexadecimal notation, and these two types of code signals are transmitted alternately at an interval of 96 μs. As the diagnostic signal, a signal indicating normal is “E0” in hexadecimal, and a signal indicating abnormal is “1C”. Therefore, FIG.
Hexadecimal “E0” is sent as signal 501 and signal 502 shown in (b).

FIG. 6 is a diagram showing a configuration of a communication system in the acceleration detection unit 7. The microcomputer 52 writes 8-bit transmission data to be transmitted to the data register 61 when transmitting a start request signal, a diagnostic signal, and the like to the electronic control unit 11. The data written in the data register 61 is transferred to the shift register 62 and serially transmitted to the communication interface 27 of the electronic control unit 11. Therefore, even if the start request signal is written to the data register 61 immediately after the diagnosis signal is transferred from the data register 61 to the shift register 62, the start request signal is not terminated unless the transmission of the diagnosis signal in the shift register 62 is completed. The signal cannot be transmitted.

However, according to this embodiment, before transmitting the activation request signal, the transmission of signals other than the activation request signal, for example, the diagnosis signal, is prohibited. No signal or the like is transmitted, and immediately after the activation request signal is written to the data register 61, the signal is transferred to the shift register 62 and transmitted to the electronic control unit 11.

FIG. 7 is a diagram showing the structure of transmission data.
One start bit is transmitted before the data bit, eight data bits including the parity bit are transmitted, and one stop bit is transmitted last.

By the way, in this embodiment, the type of the data signal including the start bit and the stop bit is selected such that one or both of the adjacent bits before and after are at the same level. With this configuration of the transmission data, the substantial transmission frequency is reduced to half or less, and it is possible to prevent the occurrence of noise due to the high frequency without lowering the communication speed.

Table 2 lists such bit arrangements, assuming that the start bit is low level "0", the stop bit is high level "1", and the communication idle period is high level "1". And

[0053]

[Table 2]

In Table 2, in the transmission data, bit 0 is the least significant bit, bit 7 is the most significant 8-bit data, bit 0 to bit 3 correspond to the lower number in hexadecimal notation, and bit 4 to bit 7 Corresponds to the higher number in hexadecimal. Bit 7 is used as a parity bit.

As can be seen from this table, the hexadecimal "9" used in the start request signal of the present embodiment is described above.
8 "," 0E "and" E "used for the diagnostic signal.
Both "0" and "1C" indicate that "one or both of the adjacent bits at the front and rear are at the same level."
And the generation of noise is suppressed.

[0056]

As described above, according to the occupant protection device of the present invention, when the acceleration detection unit transmits the activation request signal of the occupant protection means to the electronic control unit,
It is not disturbed by other signals such as a diagnostic signal. Therefore, the occupant protection means can be activated at an appropriate timing.

[Brief description of the drawings]

FIG. 1 is a plan view showing an arrangement of each component of an occupant protection device according to an embodiment of the present invention.

FIG. 2 shows an electronic control unit 11 and an acceleration detection unit 7
FIG. 2 is a block diagram clarifying the internal configuration of FIG.

FIG. 3 is a flowchart showing a side collision determination interrupt process executed by a microcomputer 52 in the acceleration detection unit 7;

FIG. 4 is a flowchart showing a diagnostic signal interruption process.

FIG. 5 is a timing chart of side collision determination and signal transmission.

FIG. 6 is a block diagram showing a transmission system of the microcomputer 52.

FIG. 7 is a diagram showing transmission data and a structure.

[Explanation of symbols]

1, 2 ... front collision airbag, 3, 4 ... side collision airbag, 5, 6 ... seat belt pretensioner, 7, 8 ... acceleration detection unit for side collision, 9, 10 ... front satellite acceleration sensor, 11 electronic control unit, 25 squib ignition control circuit, 29 acceleration sensor for front collision, 3
0, 52: microcomputer, 51: side collision acceleration sensor, 35, 39: ignition transistor group, 1a, 3
a, 5a ... squib.

Claims (3)

[Claims] An occupant protection device for protecting an occupant by restraining the occupant in the event of a vehicle collision, comprising: one or more occupant protection means operating to restrain the occupant; and controlling activation of the occupant protection means. An electronic control unit, a communication path is formed with the electronic control unit, and the electronic control unit communicates an activation request signal for requesting the electronic control unit to activate the occupant protection means and another signal including a self-diagnosis signal to the electronic control unit. An acceleration detection unit for transmitting to the electronic control unit via a road, wherein the acceleration detection unit detects the other signal when an acceleration-related value in the left-right direction of the vehicle becomes equal to or greater than a first threshold value. Transmitting the activation request signal when transmission-related values are prohibited and a lateral acceleration-related value of the vehicle becomes equal to or greater than a second threshold value higher than the first threshold value. There, an occupant protection device, wherein the electronic control unit is intended to activate the occupant protection means when receiving the startup request signal. 2. The occupant protection device according to claim 1, wherein the electronic control unit activates the occupant protection unit when a value related to the acceleration of the vehicle in the front-rear direction becomes equal to or greater than a predetermined threshold value. 3. The occupant protection device according to 1. 3. The activation request signal and the other signal transmitted from the acceleration detection unit to the electronic control unit via the communication path are binary serial signals,
2. A signal according to claim 1, wherein one or both adjacent bits of the signal have the same value.
Or the occupant protection device according to 2.