JP2011073675A - Circuit device for sensing head-on collision of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a plausibility inspection work for an occupant restricting system to be carried out more positively. <P>SOLUTION: A control device is operated in such a way that an acceleration signal got from an up-front sensor is directly compared with a first threshold value, another comparison is carried out for comparing a velocity signal got through integration of the acceleration signal of the up-front sensor with another second threshold value, it is decided on the basis of a result of logical OR coupling of a result of both comparisons whether a triggering of an occupant restricting means under an operation of a collision sensor within the control device is kept at its standby state, the control device temporarily stores the result of the logical OR coupling over a predetermined time and uses the result of the temporarily stored logical OR coupling over the predetermined time to determine the triggering of the occupant restricting means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a circuit arrangement for sensing a frontal collision in a vehicle having the features of the independent claims.

  Already from the publication GB 2293681A it is known to use an upfront sensor to check the validity of the trigger determination of the central controller for the occupant restraint system.

GB2299361A

  The subject of this invention is enabling it to perform the validity check of a passenger | crew restraint system more reliably.

The problem is
In the control device, the acceleration signal from the upfront sensor is directly compared with the first threshold value, and the speed signal obtained by integrating the acceleration signal of the upfront sensor and another second threshold value are compared. Another comparison is made, and based on the result of the logical OR combination of the results of both comparisons, it is determined whether or not the trigger of the occupant restraint means by the collision sensor in the control device should be in a standby state,
The controller temporarily stores the result of the logical OR combination for a predetermined time, and uses the temporarily stored result of the logical OR combination for the trigger determination of the occupant restraint means over the predetermined time. Solved by a circuit device.

It is a top view in which the collision sensor is arrange | positioned. 1 is a first block circuit diagram of a circuit device according to the present invention; FIG. It is an acceleration-time graph. It is a speed-time graph. It is a block circuit diagram for detecting a validity signal.

  In general, in addition to the acceleration sensor in the control device, another validity sensor is used in order to improve the reliability of the trigger determination of the airbag control device. This validity sensor can be used in the control device, or it can be used decentrally, for example as an upfront sensor, or a corresponding combination. Here, a piezoelectric sensor or a micromechanical semiconductor sensor is used as the acceleration sensor. However, other sensor types can be used.

  In the present invention, a circuit arrangement for sensing a frontal collision is proposed in which the validity signal is formed by an upfront sensor. The validity signal is formed depending on the acceleration signal and the velocity signal which is an integrated acceleration signal. Here, a logical OR combination is performed by comparing the acceleration signal and the velocity signal with respective threshold values. In one development, the validity signal, ie the result of the OR combination, is temporarily stored for a certain time, for example 10 ms. By doing so, a validity signal can be provided for a certain period of time, even if the validity sensor fails due to a frontal collision, for example. Furthermore, it is examined whether or not the signal of the collision sensor arranged in the control device, that is, the signal of the acceleration sensor is also below the noise threshold. If so, the trigger algorithm is not started and therefore triggering of the occupant restraint is prevented. However, the trigger algorithm is started if this signal is above the noise threshold. Furthermore, if there is a respective validity signal or a temporarily stored validity signal, the control device enters a trigger standby state. When a trigger determination is made by the algorithm, the occupant restraint means is triggered.

  The concept of a collision sensor is used here as a superordinate concept, and the upfront sensor represents a collision sensor in the front of the vehicle, usually a crash sensor in a crushable zone. In general, an acceleration sensor is used as a collision sensor. However, strain gauges, pressure sensors and temperature sensors can also be used.

  FIG. 1 shows an overview of a place where an acceleration sensor arranged in a control device and an upfront sensor in a vehicle are provided. The up-front sensor 1 senses acceleration in the X direction. That is, the longitudinal acceleration of the vehicle is sensed here. However, an acceleration sensor structure for detecting a collision is provided in the control device, and this acceleration sensor structure detects acceleration in the X direction and the Y direction (that is, the lateral direction of the vehicle). Thereby, side collisions can also be identified. The upfront sensor 1 is disposed at an appropriate position in the vehicle. Suitable for arranging the upfront sensor 1 is, for example, a radiator support or a hood lock support.

  FIG. 2 shows a circuit arrangement according to the invention as a block circuit diagram. This circuit device has an up-front sensor 1 and a control device 4 having an acceleration sensor structure 2 and a processor 3 and connected to an occupant restraint means 5.

  The up-front sensor 1 is connected to the processor 3 through a line for receiving energy, for example. Therefore, power line communication is possible. That is, the energy transmitted to the sensor 1 is modulated with respect to the sensor data.

  The acceleration sensor structure 2 is connected to the second data input terminal of the processor 3. The processor 3 is connected to an occupant restraining means 5 that is a seat belt tensioner and an air bag via a data output end. Further, the occupant restraint means 5 has an ignition circuit, and triggers the occupant restraint means 5 when a collision is identified. The sensors 1 and 2 have a signal processing unit, and the acceleration signal is amplified and digitized by the signal processing unit. The processor 3 calculates a trigger algorithm depending on the signals transmitted from the collision sensors 1 and 2, and determines whether or not the occupant restraint means 5 should be ignited. The trigger algorithm can use a fixed threshold and / or an adaptively calculated threshold for the sensor signal. By using acceleration and velocity signals, minor and severe collisions can be identified. In a minor collision, it may be necessary to ignite only the seat belt tensioner. On the other hand, in the event of a severe collision, in principle, the airbag may also have to be ignited. Furthermore, the control of the occupant restraint means 5 must be executed depending on the occupant identification. In other words, it should also be identified whether an occupant is present in each vehicle seat and whether the occupant restraint means can be ignited for the occupant without risk.

  FIG. 3 shows an acceleration-time graph of the acceleration sensor sent from the up-front sensor 1. The upfront sensor 1 sends out an acceleration signal 7, which is compared with a predetermined threshold 6. A plurality of up-front sensors 7 may be arranged. At time 8, the signal 7 exceeds the acceleration threshold 6. At this point, a severe collision has been identified and a corresponding validity signal has been transmitted to the processor 3, or the transmitted acceleration signal 7 has detected by the processor 3 that the validity condition for a severe collision has been met. Is done. This gives the option of whether the acceleration sensor 1 transmits only sensor data to the processor 3 or transmits an already evaluated validity signal. The evaluated validity signal indicates whether the upfront sensor signal has exceeded at least one threshold (acceleration and velocity).

  FIG. 4 shows a speed-time graph in which the integrated acceleration signal, i.e. the speed signal, is compared with a threshold value 10. At time 11, it is identified that the validity condition has been met. That is, a slight collision has occurred. This is also detected by the processor 3 or a corresponding electronic device in the sensor 1.

  FIG. 5 shows at a block schematic level how signal processing is performed in conjunction with the validity signal. In block 12, the acceleration signal a is formed by the acceleration sensor 1. This acceleration signal a is compared with a threshold 6 in block 13 and if it exceeds the threshold 6, a validity signal is formed, and this validity signal is supplied to the OR coupling unit 14 as a first input quantity. However, the acceleration signal a is also integrated at block 16 to form a velocity signal. This speed signal is compared to a threshold value 10 at block 17. Whether the output signal of block 17, i.e., threshold 10 has also been exceeded, is guided to OR gate 14 as a second input quantity. If at least one of the thresholds 6 or 10 is exceeded, a validity signal is formed at block 15 to determine whether to trigger the occupant restraint means physically by a trigger decision made by the trigger algorithm. Used for. This depends on the acceleration signal of the acceleration sensor structure 2.

  The validity signal in block 15 is temporarily stored for a predetermined time, for example 10 ms, and can be used for a certain time even if the upfront sensor 1 fails, and if a validity signal is present, the trigger algorithm is activated. Sometimes triggered. The term present means here that the validity signal indicates a collision.

DESCRIPTION OF SYMBOLS 1 Up front sensor 2 Collision sensor in control apparatus 4 Control apparatus 5 Crew restraint means

Claims (4)

A circuit device for triggering occupant restraint means in a vehicle,
At least one collision sensor (2) is provided in the control device (4) for triggering the occupant restraining means,
At least one collision sensor (1) is provided on the front of the vehicle as an up front sensor in order to place the trigger of the occupant restraint means in a standby state.
In the control device (4), the acceleration signal from the up-front sensor (1) is directly compared with the first threshold value (6), and the acceleration signal of the up-front sensor (1) is integrated. Perform another comparison comparing the speed signal (9) determined by the second second threshold (10) and perform a logical OR combination (14) of the results of the two comparisons to obtain the logical OR combination ( 14) on the basis of the result of 14), it is determined whether or not the trigger of the occupant restraint means by the collision sensor in the control device (4) should be in a standby state,
The control device (4) temporarily stores the result of the logical OR combination (14) over a predetermined time, and the occupant restraining means (5) stores the temporarily stored result of the logical OR combination (14) over the predetermined time. A circuit device, characterized in that it is used for trigger determination.   The control device (4) prevents the occupant restraint means (5) from triggering when the signal of the at least one collision sensor (2) in the control device (4) falls below a predetermined threshold. Circuit device. Even if the up-front sensor (1) becomes malfunctioning at the time of a collision, the control device can detect the result of the OR coupling and the at least one collision sensor (2 in the control device (4) when a predetermined threshold is exceeded. ) Signal to start a trigger algorithm in the control device (4),
2. The circuit arrangement according to claim 1, wherein the occupant restraint means (5) is triggered by a trigger determination made by a trigger algorithm.   The circuit arrangement according to claim 3, wherein the trigger algorithm in the control device (4) does not start if the signal of the at least one collision sensor (2) in the control device (4) falls below a third threshold. .

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