JP2012232617A - Safing action determining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safing action determining device capable of determining a safing action using a G sensor of an airbag control unit carrying out the deployment determination of an air bag device.SOLUTION: In the safing action determining device, the multi-directional G sensor 4 capable of individually detecting acceleration imparted to multi-directions of the vehicle is provided at an ACU3 carrying out the deployment determination of the airbag device. Respective acceleration values detected by a front collision G sensor 4b and a side collision G sensor 4a of the multi-directional G sensor 4 are extracted as impact components in the respective directions via respective high pass filters HPF 9, 10 and when the impact components in the X-direction and Y-direction exceed a predetermined value TH/L, the safing action determination such as battery cut-off is carried out.

Description

  The present invention mainly relates to a safing operation determination device used for a vehicle such as an automobile, and more particularly to a safing operation determination device capable of improving reliability without adding a safing sensor.

  2. Description of the Related Art Conventionally, a malfunction prevention device using a safing sensor is known for an airbag control unit in order to determine a collision event with good accuracy (see, for example, Patent Document 1).

  In such a case, in addition to the G sensor provided at the center position of the vehicle, a satellite sensor is provided in the direction in which the detection accuracy of the collision event is to be improved, for example, the front end member or the side door pillar member. Yes.

  When a collision event is detected by the G sensor, satellite sensor, or the like, the airbag control unit makes a deployment determination using a predetermined algorithm and deploys the airbag at an optimal timing.

  In addition to the acceleration in the X-axis direction detected by the G sensor provided in the airbag control unit, the satellite sensor provided in the crashable zone detects whether or not the impact is caused by a collision event. In addition, there is also known one that performs a safing operation determination such as a door unlocking operation.

JP 2001-151053 A

  In the conventional safing operation determination device configured as described above, it is necessary to provide an expensive safing sensor in each direction in which it is desired to improve the detection accuracy of the collision event, which may increase the manufacturing cost. .

  Further, in recent years, in EV cars (electric cars) and HEV cars (hybrid cars), since the safety operation judgment such as a battery shut-off function when a collision event is detected is performed, the accuracy of the safety operation judgment is further improved. Is required.

  In particular, it is necessary to improve the detection performance due to a rear collision from the rear of the vehicle and make a safing operation determination, but it is not desired to increase the number of safing sensors only for the determination of the safing operation due to the rear collision.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a safing operation determination device that can perform safing operation determination using a G sensor of an air bag control unit that determines deployment of an air bag device.

  In order to solve the above-described problem, the invention described in claim 1 includes an air bag device that has a multi-directional G sensor that can individually detect accelerations applied to the multi-directional direction of the vehicle, and makes an air bag apparatus deployment determination. A safing operation determination apparatus using a bag control unit, wherein acceleration values detected by the multi-directional G sensor are extracted as impact components in each direction through high-pass filters, and at least two-direction impact components are predetermined. It is characterized by being a safing operation judging device for judging safing operation when exceeding the value of.

  According to a second aspect of the present invention, there is provided the safing operation determination device according to the first aspect, wherein the acceleration value that has passed through the high-pass filter is subjected to an absolute value conversion and then passed through a low-pass filter to perform envelope processing. It is characterized by being.

  Here, the envelope processing is a general term for a method of performing absolute value rectification on a high frequency component excited in a resonance system, removing a high frequency component with a low-pass filter, and extracting an original low frequency component.

  According to the first aspect configured as described above, at least two-direction acceleration values detected by the multi-directional G sensor are extracted as impact components in each direction when passing through the high-pass filter.

  Then, when the impact component in the two directions exceeds a predetermined value, the safing operation determination is performed.

  This safing operation determination is mainly performed by performing AND processing, for example, on multi-directional impact components so that an acceleration component input other than a collision event is not erroneously determined as a collision event due to an abnormality in the G sensor. , Misdeployment can be prevented.

  Moreover, in addition to preventing such erroneous deployment, it is possible to improve the detection accuracy in the case of a collision, and to accurately perform the safing operation determination such as starting the battery shut-off function. it can.

  Further, according to the second aspect of the present invention, the acceleration value that has passed through the high-pass filter is converted into an absolute value, and when passing through the low-pass filter, an envelope is simply formed and envelope processing is performed. The

  For this reason, it is possible to easily sample at the conventional sampling frequency, and it is possible to quickly make a comparison judgment with a predetermined value set in advance.

1 is a block diagram illustrating a configuration of a safing operation determination device according to an embodiment of the present invention. It is the partially transparent perspective view which looked at the vehicle which applies the safing operation judgment device of an embodiment from the slanting back. It is a graph figure of the raw data which shows the time change of the acceleration value of the two directions which the multidirectional G sensor of embodiment detects at the time of a front collision. It is a graph which shows the acceleration component of 2 directions detected by the frequency component of 100 Hz or less among the acceleration values of 2 directions detected by the multidirectional G sensor of embodiment at the time of a front collision. It is a graph of the raw data which shows the time change of the acceleration value of the two directions which the multidirectional G sensor of embodiment detects at the time of a side collision. It is a graph which shows the bi-directional acceleration component detected by the frequency component of 100 Hz or less among the bi-directional acceleration value detected by the multi-directional G sensor of embodiment at the time of a side collision. In the multidirectional G sensor according to the embodiment, the acceleration values in the two directions detected at the time of the front collision are passed through the high-pass filter. It is the graph figure expanded for description. It is a graph of the output which the multi-directional G sensor of embodiment passed the time change of the acceleration value of the two directions detected at the time of a side collision to the high-pass filter. In the multi-directional G sensor according to the embodiment, (a) is a graph of an output obtained by performing absolute value conversion on the impact component of the acceleration value in the two directions detected at the time of the front collision and passing through the low-pass filter. The graph of the output which converted the impact component of the acceleration value of two directions detected at the time of a side collision into absolute value, and let it pass through a low-pass filter, (c) is the acceleration of two directions by latching each output. It is a timing chart which shows the timing when a component overlaps.

  Next, a safing operation determination apparatus according to an embodiment for carrying out the present invention will be described with reference to FIGS.

  In addition, the same code | symbol is attached | subjected and demonstrated about the same thru | or equivalent part as the said conventional.

  First, the configuration of the safing operation determination device of this embodiment will be described.

  In this safing operation determination device, as shown in FIG. 2, an ACU (airbag control unit) is provided at a substantially central position in the vehicle width direction W in the vicinity of the center console provided in the passenger compartment 2 of the vehicle 1. 3 is installed.

  The ACU 3 is provided with a multidirectional G sensor 4. This multi-directional G sensor 4 detects acceleration in the vehicle longitudinal direction FR, converts it into an electrical signal as a Y-axis direction acceleration value, and outputs it, and also detects acceleration in the vehicle width direction W in the same horizontal plane. The X-axis direction acceleration value is converted into an electrical signal and output.

  In addition to the multi-directional G sensor 4, the ACU 3 is conventionally provided in the crushable zone 8 or the side door pillar members 6 and 6 behind the front end member 5 in the direction in which the collision detection accuracy is desired to be improved. Some or all of the satellite sensors 7a, 7b... Are omitted.

  When a collision event is detected by the multi-directional G sensor 4 and, for example, the satellite sensor 7a of the front end member 5, the deployment determination is performed by a predetermined algorithm in the ACU 3, and an airbag (not shown) is shown. It is configured to deploy the device at the optimal timing.

  In this embodiment, in addition to the Y-axis acceleration value Gy in the vehicle front-rear direction detected by the multidirectional G sensor 4 provided in the ACU 3, the X-axis acceleration value Gx is used to generate a crushable zone. 8 The satellite sensor 7a provided at the front part determines whether the impact is caused by a collision, and determines a safing operation such as a battery shut-off operation or a door unlock operation.

  In the ACU 3, as shown in FIG. 1, the acceleration in the side collision direction is mainly performed so that the multi-directional G sensor 4 can detect the acceleration values of the two axes in the X and Y directions orthogonal to each other. The side collision direction G sensor 4a that converts the value into an electrical signal as an X-axis direction acceleration value and outputs it to an HPF (high-pass filter) 9 and the acceleration value in the front collision direction into an electrical signal as a Y-axis direction acceleration value And it has mainly the front collision direction G sensor 4b output to HPF (high pass filter) 10, and is mainly comprised.

  In each of these HPFs 9 and 10, the X-axis direction acceleration value and the Y-axis direction acceleration value are extracted as impact components in the side collision directions, and are output to the safing deployment determination unit 12 of the main CPU 11. When the two-direction impact component represented by the X and Y axis direction acceleration values exceeds a predetermined value, the safing development judgment unit 12 makes a safing operation judgment. .

  In this embodiment, the X-axis direction acceleration value and the Y-axis direction acceleration value output from each of these HPFs 9 and 10 are respectively input to the absolute value conversion circuits 14 and 15 and converted into absolute values. .

  The absolute value converted X-axis direction acceleration value and Y-axis direction acceleration value pass through each LPF (low-pass filter) 16, 17, and after high frequency components are removed and envelope processing is performed, the main CPU 11 safe Is input to the wing development determining unit 12.

  In this embodiment, high-frequency components of 1 kHz or more are removed when passing through the LPFs (low-pass filters) 16 and 17.

  The safing expansion determination unit 12 receives an X-axis acceleration value after envelope processing input from the LPF 16 and compares and determines whether or not a preset TH / L value is exceeded. Y-axis envelope judgment circuit 18 and Y-axis direction acceleration value after envelope processing inputted from LPF 17 are inputted, and a comparison is made to judge whether or not a predetermined TH / L value is exceeded. A circuit 19 and a safing AND circuit 22 that outputs an ON signal when the values output from the X-axis envelope determination circuit 18 and the Y-axis envelope determination circuit 19 are simultaneously ON. Is provided.

The TH / L value of this embodiment is set such that the maximum acceleration value other than the collision event is the lower limit value TH _L of the TH / L value.

Also, to ensure that all collision events can be output as ON signals, even waveforms with the lowest acceleration level relative to the X-axis direction acceleration value and Y-axis direction acceleration value after envelope processing can be turned ON for a certain period of time. set the value as the upper limit value TH _H of TH / L value, constituting the intermediate value in the range between the lower limit and the upper limit value, so as to set the TH / L value TH _M as threshold used for oN determination Has been.

  Further, in this embodiment, the X-axis envelope determination circuit 18 and the Y-axis envelope determination circuit 19 provided in the safing development determination unit 12 have a latch time setting function capable of setting a predetermined latch time in advance. An X-axis determination unit 20 and a Y-axis determination unit 21 are provided.

  The safing development determination unit 12 reliably holds the ON signals output from the X-axis envelope determination circuit 18 and the Y-axis envelope determination circuit 19 in the ON state within the set latch time. It is configured.

Latch time of this embodiment, Y direction acceleration Gye is, beyond the TH _M threshold TH / L, beyond the timing to the output of ON signal, X-direction acceleration Gxe is a TH _M threshold TH / L Thus, the interval from the timing until the ON signal is output is set to a time obtained by adding a predetermined grace time corresponding to the time when the difference is the largest.

  Further, in this embodiment, the main CPU 11 is provided with a main expansion determination unit 13 and directly inputs the acceleration value in the front collision direction output from the front collision direction G sensor 4b. A main deployment determination unit 13 is provided for determining whether to output a deployment signal of an occupant protection device such as an omitted airbag device.

  The ON / OFF signal output from the main development determination unit 13 is input to the rear collision determination AND circuit 23 together with the ON / OFF signal output from the safing AND circuit 22.

  This rear collision determination AND circuit 23 is connected to the rear collision deployment determination unit 24, and outputs from the output driver unit 25 to various actuators such as a battery cutoff output, a door unlock output, and a fuel cut output for performing a safing operation. Output control is configured to be performed.

  Next, the effect of the safing operation determination device of this embodiment will be described.

  In the safing operation determination device of this embodiment, when the front collision direction G sensor 4b of the multi-directional G sensor 4 provided in the ACU 3 detects a collision at the front of the vehicle, the frequency band is mainly about 100 Hz. In addition, the vehicle body movement amount in the front-rear direction FR of the vehicle 1 is detected. The vehicle body movement amount is output as an electrical signal to the main deployment determination unit 13 provided in the main CPU 11 and used for deployment determination of an occupant protection device such as an airbag device.

  For example, as shown in FIG. 3, the Y-direction acceleration Gy is detected at the solid line portion and the X-direction acceleration Gx is detected at the thin broken line portion in the raw data when the vehicle 1 collides forward from the front.

  Further, as shown in FIG. 5, in the raw data when the vehicle 1 collides from the side, the Y-direction acceleration Gy is detected at the solid line portion and the X-direction acceleration Xy is detected at the thin broken line portion.

  These raw data are generally filtered by the LPF 17 or the like in the frequency region of 1 kHz or less, sent to the main deployment determination unit 13, and used as a vehicle body movement amount for deployment of an occupant protection device such as an airbag device. Judgment is made.

  However, when the high-frequency component is filtered by the LPF 17 or the like when the vehicle 1 makes a forward collision from the front shown in FIG. 3, the Y-direction acceleration Gylp, which is the forward collision direction, as shown in FIG. Although the fluctuation amount h1 is large and easy to detect, the X-direction acceleration Gxlp orthogonal to the frontal collision direction is output as data that has a small fluctuation amount h2 and is difficult to detect.

  Further, when the high-frequency component is filtered by the LPF 17 or the like when the vehicle 1 has a side collision from the side surface shown in FIG. 5, the X-direction acceleration Gxlp, which is the side collision direction, is shown in FIG. Although the fluctuation amount h3 is large and easy to detect, the Y-direction acceleration Gylp orthogonal to the front collision direction is output as data that has a small fluctuation amount h4 and is difficult to detect.

  In this way, large acceleration does not occur in the direction of the other axis orthogonal to the direction in which the impact load is input, which is the collision direction of the vehicle 1. Since only Gxlp or Y-direction acceleration Gylp is generated, it is difficult to use it for determining the safing operation.

  Therefore, in this embodiment, as shown in FIG. 1, before the LPFs 16 and 17 perform filtering of high frequency components by the HPFs 9 and 10 provided in the ACU 3, low frequency components of 100 Hz or less are filtered. Then, the impact component is extracted by being removed.

  As shown in FIG. 7A, when the vehicle 1 collides forward from the front, among the data filtered by the HPFs 9 and 10, the Y-direction acceleration Gyhp is indicated by the solid line portion, and the X-direction acceleration Gxhp is indicated by the thin broken line portion. Detected.

  Among these, as shown in FIG. 7B, when a part is extracted and enlarged for explanation, the LPFs 16 and 17 are expressed in the form of the amplitude of the high-frequency component before the impact component is cut. When the impact component is extracted, it can be seen that the impact component is generated as the Y-direction acceleration Gyhp and the X-direction acceleration Gxhp in both the + and-directions with reference to 0G and in all axial directions.

  As shown in FIG. 8, when a side collision occurs on the side surface of the vehicle 1, among the data filtered by the HPFs 9 and 10, the Y-direction acceleration Gyhp indicated by the solid line portion and the X indicated by the thin broken line portion Both directional accelerations Gxhp obtain almost the same output value, and it can be seen that the fluctuation amount of the Y-direction acceleration Gyhp and the X-direction acceleration Gxhp indicated by the thin broken line portion has a value that can be detected.

  Next, in order to monitor these high frequency components, it is necessary to increase the sampling frequency of the filtered data. In order to monitor the amplitude of the impact component at the current sampling frequency, for example, it is necessary to process the envelope to capture the data.

  First, envelope processing will be described. Here, the envelope processing is a general term for a method of performing absolute value rectification on a high frequency component excited in a resonance system, removing a high frequency component with a low-pass filter, and extracting an original low frequency component.

  In the ACU 3 of this embodiment, the Y direction acceleration Gyhp and the X direction acceleration Gxhp filtered by the HPFs 9 and 10 are converted into absolute values by the absolute value conversion circuits 14 and 15, respectively. And output to the LPFs 16 and 17.

  The LPFs 16 and 17 remove the high frequency components of the Y-direction acceleration Gyhp and the X-direction acceleration Gxhp that have been converted into absolute values, and can easily obtain an envelope.

  At this time, by appropriately adjusting the frequency, it is possible to obtain a frequency component equivalent to the vehicle body movement amount, and it is possible to easily monitor the current sampling frequency.

  When the sampling frequency of the A / D converter of the main CPU 11 of this embodiment is 2 kHz, the envelope is obtained by filtering by the LPFs 16 and 17 so that the data to be captured is 1 kHz or less.

  Next, when the Y-direction acceleration Gyhp and the X-direction acceleration Gxhp output by the LPFs 16 and 17 are output to the main CPU 11, the X-axis determination unit 20 and the Y-axis determination unit of the safing development determination unit 12 are used. The X-axis envelope determination circuit 18 and the Y-axis envelope determination circuit 19 compare and determine whether or not a preset threshold value TH / L is exceeded.

In this embodiment, as shown in FIG. 9A, the TH / L value is set so that the acceleration maximum value other than the collision event becomes the lower limit value TH _L of the TH / L value. .

In addition, even if the waveform having the lowest acceleration level with respect to the X-axis direction acceleration value and the Y-axis direction acceleration value after envelope processing is used for a certain period of time so that an ON signal can be reliably output when all of the collision events occur. it is set a value which can be ON or upper limit TH _H of TH / L value.

Then, TH _M which is an intermediate value between the lower limit value TH _L and the upper limit value TH _H is used, and a TH / L value is set as a threshold value used for ON determination in this embodiment. .

  In this embodiment, as shown in FIG. 1, the Y-direction acceleration Gyhp and the X-direction acceleration Gxhp detected by the multi-directional G sensor 4 pass through the HPFs 9 and 10, respectively, and impact components in the respective directions. Is extracted as an envelope line by the absolute value conversion circuits 14 and 15 and the LPFs 16 and 17.

  9A and 9B, the Y-direction acceleration Gye and the X-direction acceleration Gxe indicated by the solid line and the broken line indicate the two-way impact components of the enveloped envelope line. When a predetermined TH / L value is exceeded, a safing operation determination is made.

  For this reason, it can sample easily with the conventional sampling frequency which has a frequency component equivalent to a vehicle body movement amount, and a comparison judgment with the preset predetermined value can be performed rapidly.

For example, as shown in FIG. 9 (a), the Y-direction acceleration Gye indicated by the solid line and the X-direction acceleration Gxe indicated by the thin broken line portion of the data when the vehicle 1 collides forward from the front are the threshold TH / the L _M in both, at the time of the exceeded, can be performed safing operation determination.

  This safing operation determination is mainly performed by AND processing of the bi-directional impact component by the safing AND circuit 22 so that a collision event is not erroneously determined by an acceleration component input other than the collision event due to an abnormality of the G sensor. This prevents misdeployment.

In this embodiment, as shown in FIG. 9B, among the data when a side collision occurs on the side surface of the vehicle 1, the Y-direction acceleration Gye indicated by the solid line and the X-direction acceleration indicated by the thin broken line portion. Even when the timing at which Gxe exceeds TH _M deviates back and forth on the time axis, as shown in FIG. 9C, the safing development determination unit performs the following operation for a preset latch time t _LAT . Y direction acceleration Gye shown by the solid line and, X-direction acceleration Gxe indicated by the thin broken line portion, from the time that exceeds the TH _M threshold TH / L, it is kept at the ON signal.

For example, first, when the X-direction acceleration Gxe indicated by the thin broken line portion occurs in the vehicle width direction W that is the main shaft, the latch time t _LAT from the time when TH _M of the threshold value TH / L is exceeded by t _xe from the start of measurement. During this period, the signal remains ON.

For this reason, if the Y-direction acceleration Gye indicated by the solid line in the vehicle longitudinal direction FR, which is the other axis, exceeds the threshold TH / L and becomes an ON signal between t _xe and t _xe + t _LAT from the start of this measurement. , by the safing aND circuit 22, later t _ye this both the ON signal, thereby starting the safing operation can in this example.

  In this way, by setting a constant latch time to the ON signal indicated for each Y-direction acceleration Gye and X-direction acceleration Gxe, it is possible to easily sample even the conventional sampling frequency that is increased in speed and reduced in amplitude. Thus, the AND process can be surely performed by increasing the overlap rate of the latch time.

  In this embodiment, when the output value of the safing AND circuit 22 is input to the rear collision determination AND circuit 23 together with the output value of the main development determination unit 13 and both are ON signals, An ON signal is output to the rear impact deployment determination unit 24.

  In the rear impact development determination unit 24, an instruction to perform the safing operation is given to the output driver unit 25 by the input of the ON signal, and various types of battery shutoff output, door unlock output, fuel cut output, etc. The safing output control to the actuator is performed.

  In this embodiment, in addition to the above-described prevention of erroneous deployment, the detection accuracy in the case of a collision is further improved, for example, safing such as starting a battery shut-off function. The operation judgment can be made accurately.

  For example, in this embodiment, as shown in FIG. 2, in addition to the multi-directional G sensor 4, a satellite sensor 7a of the front end member 5 or a satellite sensor 7b of the side door pillar member 6 is partially left. By detecting the collision event, the deployment determination is performed by the algorithm provided in the main deployment determination unit 13 of the ACU 3, and the airbag device (not shown) can be deployed at the optimum timing.

  For this reason, by detecting the acceleration in the main axis direction to which load input is applied due to a collision event by the side collision direction G sensor 4a or the front collision direction G sensor 4b provided integrally with the multidirectional G sensor 4, this The multi-directional G sensor 4 used for safing judgment can be shared for main deployment judgment of an occupant protection device such as an airbag device, and an increase in manufacturing cost can be suppressed.

  Even if the front collision direction G sensor 4b applied to the vehicle longitudinal direction FR breaks down, the multi-directional G sensor 4 provided in the vicinity of the center console in the vehicle width direction in the vehicle interior 2 is integrally integrated. The provided side collision direction G sensor 4a can function normally so as not to be judged as a collision event by the safing AND circuit 22 and the rear collision judgment AND circuit 23, thereby preventing erroneous development.

  Therefore, it is also effective as a fail safe when the front collision direction G sensor 4b fails, and the same effect can be applied when the side collision direction G sensor 4a fails.

  As described above, the safing operation determination device according to the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the safing operation determination device according to the embodiment, and Design changes that do not depart from the gist are included in the present invention.

  For example, in the safing operation determination device of the above-described embodiment, in order to monitor the amplitude of the impact component at the current sampling frequency, it is configured to capture data by processing into an envelope line. Not limited to that, even if the band pass processing is performed using a band pass filter circuit and a component of 100 Hz to 1 kHz is extracted, if the processing can be performed to a frequency that can be monitored with the current sampling frequency, The shape, quantity and frequency are not particularly limited.

  As long as the safing operation determination device of this embodiment is a safing operation determination device used for a vehicle such as an automobile, the power is not limited to an internal combustion engine such as an engine. For example, it may be used for an electric vehicle (EV), a hybrid car (HEV), or the like.

1 Vehicle 3 ACU (Airbag Control Unit)
4 Multi-directional G sensor 4a Side collision direction G sensor 4b Front collision direction G sensor 7a, 7b Satellite sensor 9, 10 HPF (high pass filter)
11 Main CPU
13 Main expansion determination unit 14, 15 Absolute value conversion circuit 16, 17 LPF (low pass filter)
20, 21 X, Y axis judgment unit 22 Safing AND circuit 23 Rear collision judgment AND circuit

Claims (2)

Each of the accelerations applied to the vehicle in multiple directions can be individually detected, and is a safing operation determination device provided in an airbag control unit that determines the deployment of the airbag device,
Each acceleration value detected by the multi-directional G sensor is extracted as an impact component in each direction through a high-pass filter, and a safing operation determination is performed when the impact component in at least two directions exceeds a predetermined value. A safing operation determination device characterized by the above.   2. The safing motion determination apparatus according to claim 1, wherein the acceleration value that has passed through the high-pass filter is subjected to an absolute value conversion and then subjected to an envelope process by passing through the low-pass filter.