JP4526922B2 - Occupant detection device - Google Patents

Description

  The present invention relates to an occupant detection device that determines the state of an occupant seated on a vehicle seat using an output value of a load sensor.

  Conventionally, as shown in FIG. 7, a load sensor 4,... Is attached to a support portion 3,... That supports a seat 1, and an occupant who determines whether the occupant is an adult or a child based on its output value. A detection device is known (see Patent Document 1).

  The seat 1 includes a seat cushion portion 1a that forms a seating surface and a seat back portion 1b that serves as a backrest, and each of the regions divided into four front, rear, left, and right regions has four locations. It is supported from below by the support portions 3.

  Further, the support portions 3,... Are slidably attached to the seat rails 2, 2, and load sensors 4,. As the load sensor 4, a strain type load sensor is used.

  Then, as shown in FIG. 8, the output values output from the four load sensors 4,... Are sent to the occupant determination unit 5, and the total of the output values is compared with the threshold value stored in the EEPROM 8. Is done.

  This threshold is a threshold for determining whether the occupant is an adult or a child. If the total output value is smaller than this threshold, it is determined that the occupant is a child. Determine that you are an adult.

  The determination result is sent to the airbag control unit 6 and used for switching the deployment amount of the airbag 7. That is, when the occupant is an adult, the airbag 7 is deployed as normally set at the time of an accident, and when the occupant is a child, the deployment of the airbag 7 is suppressed or stopped.

The output values of the load sensors 4,... Used in such an occupant detection device are the difference in the characteristics of the individual sensors, the difference in the magnitude of the screw tightening torque when assembling the seat 1 or assembling the vehicle. Since the output value varies even when the occupant is not seated on the seat 1 due to the distortion caused by this, the output value at the time of no load is reset to “0” before shipping the vehicle. .
JP 2004-122927 A (FIGS. 1 to 4)

  However, in the case of a light collision accident in which the airbag 7 is not deployed, or when a large external force is applied to the seat 1, a new distortion occurs in the vehicle body or the seat 1, and the load sensor 4, no load is applied. May not return to “0”.

  If it continues to be used in such a state, it may not be possible to accurately determine the occupant state. However, conventional occupant detection devices may fail if they are not connected to regular inspection equipment at a maintenance shop. I could not recognize that.

  Therefore, the present invention provides an occupant detection device that allows the occupant to recognize the failure at an early stage by causing the occupant detection device itself to diagnose the presence or absence of the failure and notifying by the notification means when the failure occurs. The purpose is to do.

In order to achieve the above object, the present invention provides an output value of a load sensor provided in a support portion supporting the seat as a preset threshold value in order to determine the state of an occupant seated on a vehicle seat. It is an occupant detection device having an occupant determination unit to be compared, and the output value of one load sensor is output from another load sensor among the load sensors respectively disposed in the four regions before and after the plane view of the seat. An estimation unit that estimates from the value, a self-diagnosis unit that detects an abnormality in the output value by comparing the estimated load value calculated by the estimation unit and the output value of the load sensor at that position, and an abnormality in the self-diagnosis unit And a notification means for performing notification when it is determined that the estimation unit performs estimation on the assumption that the ratio of the load on the front and rear of the seat is the same on the left and right sides of the seat. thing And features.

Furthermore, a calculation of the estimated load value before Symbol estimator, Do to put the comparison of the estimated load value of the self-diagnosis unit and the output value of the load sensor in that position, sequentially or simultaneously to a plurality of load sensors and wherein the TURMERIC.

  The invention according to claim 1 configured as described above estimates an output value of one load sensor from a plurality of load sensors from output values of other load sensors, and the self-diagnostic unit estimates the estimated load value. Is compared with the actual output value to diagnose whether the output value is normal.

  If the output value of one of the load sensors is not a normal value due to distortion or the like generated in the vehicle body or the seat, the output value does not match the estimated load value, and if the difference is large, occupant detection is performed. It can be determined that the device has failed.

  When an abnormality is detected by the diagnosis by the self-diagnosis unit in this way, the notification means notifies that there is a failure, so that the occupant can recognize the occurrence of the failure at an early stage and repair it at a maintenance shop. You can take actions such as requesting.

The front Symbol load sensor is disposed is dispersed in each of the four regions of the left and right front and rear plan view, in order to estimate the estimated load value of the position of the load sensor at one location of the from the remaining output values, The estimation error can be reduced.

Furthermore, said calculation of the estimated load value before Symbol estimator, the comparison of the estimated load value of the self-diagnosis unit and the output value of the load sensor in that position, carried out sequentially or simultaneously to a plurality of load sensors.

  In this way, by performing double or triple diagnosis on a plurality of load sensors, it is possible to reduce the possibility of occurrence of detection omissions in which abnormalities are not detected accidentally.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a configuration of an occupant detection device 10 according to the present embodiment.

  First, from the configuration, the occupant detection device 10 according to the present embodiment is based on the load sensors 4A to 4D attached to the four support portions 3,... (See FIG. 2) and their output values. And an occupant determination unit 12 that determines the state of the occupant.

  As shown in FIGS. 2 to 4, the seat 1 is formed of a seat cushion portion 1a and a seat back portion 1b. And this seat 1 is attached via the support part 3, ... on the seat rails 2 and 2 fixed to the vehicle interior floor in parallel, as shown in FIG.3 and FIG.4.

  These support portions 3,... Are attached to a seat frame (not shown) on the lower surface of the seat cushion portion 1a, and are respectively disposed in four regions before and after the plan view as shown in FIG.

  Further, load sensors 4A to 4D are attached to the support portions 3,..., The front right side of the seat cushion portion 1a is a load sensor 4A, the rear right side is a load sensor 4B, and the rear left side is a load sensor 4C. The left side of the part is a load sensor 4D.

  Further, the support portions 3,... Are configured to be slidable along the seat rails 2, 2. The occupant and the load of the seat 1 transmitted from the seat 1 to the support portions 3,. Are transmitted to the seat rails 2 and 2 through the support portions 3.

  As the load sensors 4A to 4D, strain-type load sensors are used, and an output value proportional to the strain generated by the load acting on the support portions 3,.

  The occupant determination unit 12 of the present embodiment includes an estimation unit 13 that estimates the load value of one load sensor (for example, 4D) among the load sensors 4A to 4D, and an estimated load estimated by the estimation unit 13. A self-diagnosis unit 14 that compares the value with the output value of the load sensor 4D and diagnoses the presence or absence of an abnormality is provided.

  In this estimation part 13, the output value of three load sensors 4A-4C transmitted is applied to a computing equation, and an estimated load value is calculated. This estimated load value is estimated as the load value at the position of the load sensor 4D.

  Then, the self-diagnosis unit 14 compares the estimated load value with the actually detected output value of the load sensor 4D, and if the difference is larger than a predetermined value, the output of any of the load sensors 4A to 4D. Since the value is abnormal, it is determined that the estimated load value is not calculated correctly or the output value of the load sensor 4D is not normal.

  When the self-diagnosis unit 14 determines that there is an abnormality as described above, a failure signal is sent to the airbag control unit 6 and the failure display warning lamp 17 as a notification unit is turned on.

  Further, the output values of the load sensors 4A to 4D are used not only when the self-diagnostic unit 14 determines that the load sensor 4A is normal but also when it is determined that the load sensor 4A is abnormal.

  That is, the occupant determination unit 12 determines whether the occupant is an adult or a child by comparing the total of the four output values of the load sensors 4A to 4D with the threshold value stored in the EEPROM 15 as the storage unit. To do.

  The determination result of the occupant determination unit 12 is sent to the airbag control unit 6, and when it is determined that the occupant is a child, the occupant state display lamp 16 displays that the child is an occupant, The deployment of the airbag 7 is suppressed or stopped.

  When it is determined that the occupant is an adult, the airbag control unit 6 performs control so that the airbag 7 is deployed as normally set.

  Next, the operation of the occupant detection device 10 described above will be described with reference to the flowchart shown in FIG.

When the passenger sits on the seat 1 and turns on the ignition key, the four load sensors 4A to 4D detect the load, and output the detected load as an output value (S1). Here, the output value of the load sensors 4A - 4D, respectively and _W A to _W-D.

Furthermore, three output values _W A to _W-C from the output value _W A to _W-D by sending the estimation unit 13, calculates the estimated load value _{X D} position of the load sensor 4D (S2) . Here, it is assumed that in order to calculate the estimated load value X _D, the ratio of the load of the front and rear seat cushion 1a is the same in the left and right sides of the seat cushion 1a.

_{That, W A: W B = X} D: and _{W C.} Given _this, it is possible to obtain the _{X D = W C × W A} / W estimated load value _{X D} as _B.

Then, a comparison between the output value _{W D} of the actual position of the load sensor 4D and the estimated load value _{X D} (S3). If the difference is less than the allowable value of this estimated load value _{X D} and the output value _{W D,} none of the output value _W A to _W-D load sensors 4A~4D is determined to be normal (S4).

If the value of the output value W _A to _W-D thus is diagnosed to be normal, to trust the judgment of the occupant judgment unit 12 that performs a judgment of the occupant state on the basis of the output value W _A to _W-D Therefore, the self-diagnosis process is terminated.

Determining contrast, the difference between the output value W _D and the estimated load value X _D is be less than the allowable value, there is an abnormality in any of the values of the output values W _A to _W-D load sensors 4A~4D (S5).

  Then, a failure signal is transmitted from the self-diagnosis unit 14 to the airbag control unit 6 (S6). When the airbag control unit 6 receives the failure signal, the subsequent determination of the occupant state is not performed accurately, and the failure display warning lamp 17 is turned on to notify the possibility of malfunction (S7). .

  Such self-diagnosis of whether the occupant detection device 10 is normal or abnormal is performed once when the ignition key is turned on. After this self-diagnosis, the occupant determination unit 12 determines the occupant state regardless of the diagnosis result.

The determination of the occupant state, performs the actually detected total value of the output value W _A to _W-D load sensors 4A~4D as passenger weight W. Here, since the occupant is usually seated on the floor, the calculated weight W is smaller than the weight of the occupant.

  Therefore, the correlation between the calculated weight W and the weight of the adult is stored in advance as data, and the weight serving as the boundary between the adult and the child is stored in the EEPROM 15 as a threshold Th.

  The threshold value Th thus stored and the calculated occupant weight W are compared, and if the weight W on the seat 1 is equal to or greater than the threshold Th, it is determined that the adult is an occupant.

  If the weight W on the seat 1 is less than the threshold value Th, it is determined that the child is an occupant.

  The determination result is sent to the airbag control unit 6 and used for controlling the airbag 7 and switching the occupant state display lamp 16.

In such passenger detecting device is configured to 10, of the output value W _A to _W-D of the load sensor 4A~4D attached at four positions, one position estimated load value X _D position of the load sensor 4D other It is calculated from the three output values W _{A to} W _C. Then, to diagnose whether there is an abnormality in the output value W _A to _W-D by comparing the actual output value W _D and the estimated load value X _D.

At this time, if the output values W _{A to} W _D of any of the load sensors 4A to 4D are not normal values due to distortion generated in the vehicle body or the seat 1, the output value W _D and the estimated load value X _{If D} does not match and the difference is large, it can be determined that the occupant detection device 10 has failed.

  When an abnormality is detected by the diagnosis by the self-diagnosis unit 14 in this way, the failure display warning lamp 17 informs that there is a failure, so that the occupant can recognize the occurrence of the failure at an early stage. You can take measures such as requesting repairs from the factory.

Further, the load sensors 4A to 4D are distributed and arranged in respective regions divided into four regions before and after the plan view, and the estimated load value X _{D at} the position of one of the load sensors 4D. Is estimated from the remaining output values W _{A to} W _C , the estimation error can be reduced.

  Examples of the above-described embodiment will be described below. Note that the same or equivalent portions as those described in the embodiment will be described with the same reference numerals.

In the above embodiment, among the load sensor 4A~4D four positions, there has been described a case where the self-diagnosis by calculating the estimated load value X _D position of the load sensor 4D at one location, in this embodiment, The case where the estimated load values X _{A to} X _{C at} the positions of the other load sensors 4A to 4C are also calculated to perform self-diagnosis will be described.

  The processing flow of the occupant detection device 10 of this embodiment is shown in FIG. 6 as a flowchart.

First, when the driver turns on the ignition key seated on the seat 1, the load sensor 4A~4D four positions detects a load, and outputs the sensed load as an output value W _A ~W _D (S11).

Further, among the output values W _{A to} W _D , three output values W _{B to} W _D are transmitted to the estimation unit 13 to calculate the estimated load value X _A at the position of the load sensor 4A (S12). . The estimated load value _{X A can} be obtained as _{X A = W B × W D} / W C.

Then, a comparison between the output value _{W A} of the actual position of the load sensors 4A and the estimated load value _{X A} in the self-diagnosis unit 14 (S13). Here, the estimated load value X _A determination reference coefficients a lower and upper limit values of the judged to be within the range of acceptable values m, determined using n.

For example, the lower limit is set to W _A × the output value W _A and criterion coefficient m (1-m), the upper limit is set to W _A × (1 + n) from the output value W _A and criterion coefficient n. If the estimated load value X _A between the lower limit and the upper limit is entered, it is determined that there is an abnormality in one of the output values W _A ~W _D (S21).

Further, the estimated load value X _A is if falls between the lower limit and the upper limit value, followed by performing the calculation of the estimated load value X _B of the position of the load sensor 4B (S14). This estimated load value X _B also is determined whether falls within the range of acceptable values in the self-diagnosis unit 14 (S15).

Then, if the value of the estimated load value X _B is outside the range of acceptable values, it is determined that there is an abnormality in one of the output values W _A ~W _D (S21), if within the range of acceptable values to calculate the estimated load value _{X C} of the position of the next load sensor 4C (S16).

Furthermore, if within the range of the estimated load value X _C is also allowable value (S17), it performs a calculation of the estimated load value X _D position of the load sensor 4D of one place left (S18), the estimated load value X _D a determination is made whether within the range of acceptable values in the self-diagnosis unit 14 (S19).

For all load sensors 4A~4D in this manner, it makes a comparison between the output value _W A to _W-D and the estimated load value _X A to X _D, if abnormality is detected, the load sensor 4A~4D output value _W a to _W-D is judged to be normal (S20), and terminates the self-diagnostic process.

Then, in comparison with either of the output values _W A to _W-D and the estimated load value _X A to X _D, if the estimated load value _X A to X _D is outside the range of tolerance, the output value _{W A} ~W it is determined that there is abnormality in any one of the _D (S21), and transmits the self-diagnosis unit 14 a fault signal to the air bag control unit 6 (S22).

  Further, when the airbag control unit 6 receives the failure signal, the subsequent determination of the occupant state is not performed accurately, and the failure display warning lamp 17 is turned on in order to notify the possibility of malfunction (see FIG. S23).

In the occupant detection device 10 of the embodiment configured as described above, if no abnormality is detected with respect to one load sensor 4A, the diagnosis of the load sensors 4B to 4D is sequentially repeated, so that the vehicle body or the seat 1 is distorted. despite is abnormality occurs in the output value occurs, the output value W _a and the estimated load value X _a even when, as had been coincidental, other output values W _B ~ by comparing the W _D and the estimated load value X _B to X _D, more likely to abnormality is detected.

  For this reason, it is possible to reduce the possibility of occurrence of a detection failure that prevents an abnormality from being detected accidentally.

  Further, when an abnormality is detected, the processing can be simplified by interrupting the processing and turning on the failure display warning lamp 17.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment, and thus description thereof is omitted.

  Although the best embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are possible. Are included in the present invention.

  For example, in the above-described embodiment, the estimation unit 13 and the self-diagnosis unit 14 are provided in the occupant determination unit 12, but may be provided separately.

Moreover, in the said embodiment, although the number of load sensors 4A-4D was four places, it is not limited to this, What is the number which can diagnose the output value of at least one load sensor with an estimated load value? if this not good even more than.

Furthermore, in the above embodiment, abnormality sequentially if not detected, but subjected to diagnosis and calculation of the estimated load value X _B to X _D, is not limited to this, at the same time the estimated load value X _A to X _D It is also possible to make a diagnosis by calculating.

  Moreover, in the said embodiment, although the distortion type load sensor was used as load sensor 4A-4D, it is not limited to this, For example, a hydraulic type load sensor can also be used.

  In the above-described embodiment, the determination result is used for controlling the airbag 7. However, the present invention is not limited to this. For example, the presence or absence of an occupant is determined, and a seat belt is attached to the occupant. It can also be used for a device that lights a warning lamp only when it is not.

It is a block diagram explaining the structure of the passenger | crew detection apparatus of the best embodiment of this invention. It is the top view which showed the positional relationship of a sheet | seat and a load sensor. It is the front view which showed the positional relationship of a sheet | seat and a load sensor. It is the side view which showed the positional relationship of a sheet | seat and a load sensor. It is the flowchart which showed the flow of the process of a passenger | crew detection apparatus. It is the flowchart which showed the flow of the process of the passenger | crew detection apparatus of an Example. It is a perspective view explaining the structure of the conventional passenger | crew detection apparatus. It is a block diagram explaining the structure of the conventional passenger | crew detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seat 3 Support part 4A-4D Load sensor 10 Occupant detection apparatus 12 Occupant determination part 13 Estimation part 14 Self-diagnosis part 17 Warning lamp for warning display (notification means)

Claims (2)

An occupant detection device having an occupant determination unit that compares an output value of a load sensor provided in a support unit that supports the seat with a preset threshold value in order to determine an occupant state seated on a vehicle seat. And
Of the load sensors arranged respectively in the four areas before and after the plane view of the seat, the estimation unit that estimates the output value of one load sensor from the output values of the other load sensors, and the estimation unit A self-diagnosis unit that detects an abnormality of the output value by comparing the estimated load value and the output value of the load sensor at the position; and a notification unit that performs notification when the self-diagnosis unit determines that the abnormality is detected. ,
The occupant detection device according to claim 1, wherein the estimation unit performs estimation on the assumption that a ratio of a load on a front part and a rear part of the seat is the same on a left side and a right side of the seat . The calculation of the estimated load value in the estimation unit and the comparison between the estimated load value in the self-diagnosis unit and the output value of the load sensor at that position are sequentially or simultaneously performed on a plurality of load sensors, The occupant detection device according to claim 1 .

Images