JP4103638B2 - Vehicle occupant protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an occupant protection device for a vehicle that detects the weight of an object on a vehicle seat with a load sensor, detects the acceleration of the vehicle with an acceleration sensor, and protects the occupant according to the output of each sensor.
[0002]
[Prior art]
Conventionally, a load sensor that detects the weight of the occupant has been provided, and when the impact of the vehicle is detected by an impact detection sensor such as an acceleration sensor, the airbag is fully deployed if, for example, the center of gravity of the occupant is in the rear position. In addition, a vehicle occupant protection device for changing the deployment mode of an airbag according to an output from a load sensor, such as prohibiting deployment of an airbag when the center of gravity of the occupant is in the front position, is known.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-87201
[0004]
[Problems to be solved by the invention]
However, when the load sensor fails, the occupant protection device may malfunction or the occupant protection device may not operate when necessary. In addition, it has been desired to accurately detect an abnormality of the load sensor in preparation for such a situation.
[0005]
[Outline of the present invention]
The present invention has been made to cope with the above problems, and an object of the present invention is to provide a vehicle occupant protection device capable of accurately detecting an abnormality of a load sensor.
[0006]
  In order to achieve the above object, a feature of the present invention is that a load sensor for detecting the weight of an object on a vehicle seat and an acceleration sensor for detecting the acceleration of the vehicle are provided, and the load sensor and the acceleration sensor respond to outputs. In the vehicle occupant protection device for protecting the occupant,Seat belt wearing detection means for detecting whether or not the seat belt is worn, and when the seat belt wear detection is detected by the seat belt wearing detection means, and the seat belt wear detecting means detects that the seat belt is worn. Comparison value determining means for determining a comparison value that is smaller than when the seat belt is not detected by the belt wearing detection means, and the acceleration detected by the acceleration sensor is greater than the comparison value determined by the comparison value determining means A determination means for determining an abnormality of the load sensor when the load becomes larger;It is in having established.
  In this case, for example, the comparison value determining means becomes smaller as the weight of the object on the vehicle seat increases, and becomes smaller when the seat belt is worn than when the seat belt is not worn. It has a table that stores a plurality of different values corresponding to the weight and whether or not the seat belt is worn, and by referring to the table, the weight detected by the load sensor and the seat belt wearing detection means The comparison value may be determined according to whether or not the detected seat belt is worn.
[0007]
  In the present invention configured as described above,When the comparison value determining means becomes smaller as the weight detected by the load sensor increases and the seat belt wearing detection means detects the wearing of the seat belt, the seat belt wearing detecting means A comparison value that is smaller than that in the case where it is not detected is determined. The determination means determines the abnormality of the load sensor when the acceleration detected by the acceleration sensor becomes larger than the comparison value determined by the comparison value determination means.Generally, when an impact is applied to the vehicle, the seat frame is deformed, and the load sensor may become abnormal due to the deformation. This deformation increases the impact forceAccording toBigThe That is, the deformation of the seat frame is generally proportional to the integrated value of the weight of the passenger on the seat and the acceleration at the time of collision. Therefore, as the weight of the passenger increases, an abnormality occurs in the load sensor even if the acceleration at the time of collision is small. Further, the deformation of the seat frame usually varies depending on whether or not the seat belt is worn. That is, since the passenger is restrained on the seat when wearing the seat belt, the load applied to the seat frame by the passenger at the time of collision becomes larger than when the passenger does not wear the seat belt. Therefore, according to the present invention, an abnormality of the load sensor is determined in consideration of the weight of the occupant and whether or not the seat belt is worn, so that the abnormality occurring in the load sensor can be estimated with higher accuracy.
[0008]
  Another feature of the present invention is that the vehicle occupant protection device includes an airbag device that protects the vehicle occupant in the event of a vehicle collision, and is further detected by an acceleration sensor when no abnormality of the load sensor is determined by the determination means. The airbag device is deployed to the maximum on the condition that the detected acceleration is greater than the predetermined acceleration value and the load detected by the load sensor is greater than the predetermined load value, and the abnormality of the load sensor is determined by the determination means. And a deployment control means for deploying the airbag device to a minimum on condition that the acceleration detected by the acceleration sensor is larger than the predetermined acceleration value.
[0009]
  According to this, when no abnormality has occurred in the load sensor, the collision of the vehicle is determined using the acceleration detected by the acceleration sensor, and the airbag device is detected using the load detected by the load sensor. When it is determined that an occupant (for example, a person other than a child) who is appropriate to operate the vehicle is on the seat, the airbag device is fully deployed. Therefore, when the load sensor is normal, the occupant is appropriately protected by the airbag device at the time of a vehicle collision. On the other hand, when an abnormality has occurred in the load sensor, the airbag device is deployed to the minimum when a collision of the vehicle is determined using the acceleration detected by the acceleration sensor. Therefore, even when the load sensor is abnormal, it is possible to protect the occupant during a vehicle collision.
[0010]
  Another feature of the present invention is that the acceleration sensor detects the longitudinal acceleration and the lateral acceleration of the vehicle, and the comparison value determining means includes:Independently of the detected longitudinal acceleration and lateral acceleration of the vehicle, the vehicle becomes smaller as the weight detected by the load sensor increases, and seat belt wear detecting means detects the seat belt wear. In this case, the front-rear direction comparison value and the lateral direction comparison value, which are smaller than the case where seat belt wearing is not detected, are determined, respectively, and the determination means compares the detected vehicle longitudinal acceleration. When it becomes greater than the longitudinal comparison value determined by the value determining means, or when the detected lateral acceleration of the vehicle is greater than the lateral comparison value determined by the comparison value determining means, Determine load sensor abnormalityIt is in doing so. The deformation of the seat frame also varies depending on the direction of acceleration of the vehicle during a normal collision. So according to this,Occupant weight andTaking into account whether or not the seat belt is worn, the longitudinal comparison value and the lateral comparison value for the longitudinal acceleration and lateral acceleration of the vehicle are determined independently. Since the abnormality that occurs in the load sensor is determined using the direction comparison value,Abnormalities occurring in the load sensor can be estimated with higher accuracy.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows an airbag apparatus employing an occupant protection device according to the embodiment. This airbag device includes an airbag mechanism AB and an electric control device EL.
[0012]
The airbag mechanism AB is housed in an instrument panel, and is inflated and deployed in a bag shape to protect the head and chest of the front seat occupant, and an inflator 12 that supplies gas to the airbag 11. And. The operation of the inflator 12 is controlled by the electric control device EL.
[0013]
In addition, a seat belt 13 for restraining an occupant seated on the passenger seat S is provided on one side of the seat S along with the airbag device. The seat belt 13 includes a tongue plate 14 assembled so as to be movable at an intermediate portion. The tongue plate 14 is detachably fitted to the buckle 15 fixed to the other side of the sheet S.
[0014]
The electric control device EL includes a buckle switch 21, a load sensor 22, a longitudinal acceleration sensor 23, a lateral acceleration sensor 24, and an electronic control unit 31 to which the sensors 21 to 24 are connected. The buckle switch 21 is a normally open switch that is turned on when an occupant wears the seat belt 13 and the tongue plate 14 engages the buckle 15. The load sensor 22 is fixed to the seat frame of the seat S and detects the weight W of the occupant. The longitudinal acceleration sensor 23 detects the longitudinal acceleration Gx of the vehicle, and the lateral acceleration sensor 24 detects the lateral acceleration Gy of the vehicle. Here, the longitudinal acceleration Gx is positive for the rear of the vehicle and negative for the front. That is, it becomes positive when the vehicle collides forward and becomes negative when the vehicle collides backward. The left-right acceleration Gy is positive in the left direction of the vehicle and negative in the right direction. That is, it becomes positive when the vehicle collides with the right side and becomes negative when the vehicle collides with the left side.
[0015]
The electronic control unit 31 includes a microcomputer including a CPU, a ROM, a RAM, a timer, and the like as main components, and executes the load sensor abnormality estimation program shown in FIG. 2 to estimate an abnormality of the load sensor 22. 4 is executed to control the operation of the airbag mechanism AB when the vehicle collides.
[0016]
A drive circuit 32 is connected to the electronic control unit 31. The drive circuit 32 ignites the inflator 12 of the airbag mechanism AB in accordance with a control signal from the electronic control unit 31 to generate gas in the inflator 12. Specifically, in response to a control signal from the electronic control unit 31, gas is generated in all the chambers of the inflator 12 to maximize the airbag 11, and gas is generated in one chamber of the inflator 12 to generate the airbag. 11 is expanded to the minimum.
[0017]
Explaining the operation of the occupant protection device according to the embodiment configured as described above, when the ignition switch is turned on, the electronic control unit 31 starts to repeatedly execute the load sensor abnormality estimation program of FIG. 2 every predetermined short time. . The execution of the load sensor abnormality estimation program is started in step 100, the longitudinal acceleration Gx detected by the longitudinal acceleration sensor 23 in step 102, the lateral acceleration Gy detected by the lateral acceleration sensor 24, and the buckle switch. Input 21 ON / OFF.
[0018]
Next, at step 104, whether the longitudinal acceleration Gx is greater than the predetermined acceleration Gx1, whether the acceleration Gx is smaller than the predetermined acceleration -Gx2, and the absolute value of the lateral acceleration Gy is the predetermined acceleration Gy1. It is determined whether or not each is larger. The predetermined acceleration Gx1 is set to a certain large value associated with a slight forward collision of the vehicle, the predetermined acceleration −Gx2 is set to a certain small value associated with a slight vehicle rearward collision, and the predetermined acceleration Gy1 is set to a slight lateral direction of the vehicle. It is set to a certain large value accompanying the collision.
[0019]
If the vehicle is in a normal running state or stopped state, “No” is determined in step 104, and the weight W detected by the load sensor 22 is input in step 106. This is because an accurate weight W of the occupant is input before the vehicle collision. In other words, the weight W detected by the load sensor 22 after the vehicle collides does not represent the exact weight of the occupant. In this case, the weight W of the occupant is, for example, the detected weight W that is input within a predetermined time from the detection time point in the past out of the detected weight W that is detected by the processing of step 106 at the normal time when the vehicle is not colliding. The average value of is used.
[0020]
After the processing of step 106 is executed, the processing after step 108 is executed. In this case, the vehicle is in a normal traveling state, and the longitudinal acceleration Gx is smaller than the predetermined acceleration Gx1 and larger than the predetermined acceleration -Gx2. In addition, since the absolute value of the lateral acceleration Gy is smaller than the predetermined acceleration Gy1, “No” is determined in steps 108, 116 and 124, respectively, and the processes in and after step 132 are executed.
[0021]
In step 132, it is determined whether or not the abnormality flag KFL of the load sensor 22 is “1”. The abnormality flag KFL indicates that the load sensor 22 is normal by “0”, and indicates that the load sensor 22 is abnormal by “1”, and is initially set to “0”. In this case, since the abnormality flag is maintained at “0”, it is determined as “No” in Step 132, and the execution of the load sensor abnormality estimation program is temporarily terminated in Step 136.
[0022]
Next, a case where the vehicle collides forward will be described. In this case, since the longitudinal acceleration Gx is greater than the predetermined acceleration Gx1, it is determined as “Yes” in steps 104 and 108, and the processing from step 110 is executed.
[0023]
In step 110, an abnormal estimated acceleration Gth as a comparison value is determined in order to estimate an abnormality occurring in the load sensor 22 with reference to a first acceleration table built in the electronic control unit 31. As shown in FIG. 3A, the first acceleration table stores data indicating the relationship between the presence / absence of wearing the seat belt 13, the weight W of the occupant, and the estimated abnormal acceleration Gth. The occupant weight W is divided from the minimum section below W1 to the maximum section above W4, and gradually increases from the section below W1 toward the section above W4. When the occupant is wearing the seat belt 13, the abnormally estimated acceleration Gth is assigned a value that gradually decreases from Gthe to Gtha for each section from W1 to W4 and above. This is because the deformation of the seat frame causes an abnormality in the load sensor 22, and the deformation of the seat frame is normally proportional to the integrated value of the weight W of the passenger on the seat S and the acceleration at the time of collision. .
[0024]
Even when the occupant is not wearing the seat belt 13, the weight W and the estimated abnormal acceleration Gth are in the same relationship as described above. In other words, as the occupant weight W increases from the section below W1 to the section above W4, the abnormal estimated acceleration Gth gradually decreases from Gthe 'to Gtha'. However, the abnormal estimated accelerations Gthe ′ to Gtha ′ are respectively larger than the abnormal estimated accelerations Gthe to Gtha for the same weight category. This is because the deformation of the seat frame varies depending on whether or not the seat belt 13 is usually worn by the occupant and is restrained on the seat S when the occupant is wearing the seat belt 13, so the seat belt 13 is worn. This is because the load applied by the occupant to the seat frame at the time of collision is greater than when the vehicle is not.
[0025]
After step 110, it is determined in step 112 whether the longitudinal acceleration Gx is larger than the abnormal estimated acceleration Gth. This abnormal estimated acceleration Gth is set to a value larger than the predetermined acceleration Gx1 described above. Even if the vehicle collides forward, if the longitudinal acceleration Gx is smaller than the abnormal estimated acceleration Gth, no abnormality occurs in the load sensor 22. In this case, “No” is determined in Step 112, and Step 116 and thereafter. Execute the process. On the other hand, if the longitudinal acceleration Gx is larger than the estimated abnormal acceleration Gth, “Yes” is determined in step 112, the abnormality flag KFL is set to “1” in step 114, and the processing from step 116 onward is performed. Execute.
[0026]
Since the case where the vehicle collides forward is considered, the longitudinal acceleration Gx is larger than the predetermined acceleration −Gx2, and the absolute value of the lateral acceleration Gy is smaller than the predetermined acceleration Gy1. In this case, “No” is determined in steps 116 and 124, and it is determined in step 132 whether or not the abnormality flag KFL is “1”. In this case, since the abnormality flag KFL is set to “1”, “Yes” is determined in Step 132, and the estimation result that the load sensor 22 is abnormal is stored in the diagnosis in Step 134. Turn on the warning lamp in the combination meter. Thus, the occupant can know that the airbag 11 will not operate properly when the vehicle collides in the future. After the process of step 134, the execution of this load sensor abnormality estimation program is terminated at step 136.
[0027]
Next, a case where the vehicle collides rearward will be described. In this case, since the longitudinal acceleration Gx is smaller than the predetermined acceleration −Gx2, it is determined as “Yes” in Step 116 through the processes of Steps 102, 104, and 108, and the processes after Step 118 are executed.
[0028]
In step 118, similarly to the processing in step 110, the second acceleration table built in the electronic control unit 31 is referred to, and the estimated abnormal acceleration is determined depending on whether the seat belt 13 is worn and the weight W of the occupant. Gth is determined. As shown in FIG. 3B, the second acceleration table stores data indicating the relationship between the presence / absence of wearing of the seat belt 13 in the rear collision, the weight W of the occupant, and the estimated abnormal acceleration Gth. . As in the case of the first acceleration table, the estimated abnormal acceleration Gth increases from Gthj to Gthf as the weight W increases from W1 to W4 or higher when the occupant is wearing the seat belt 13. It becomes gradually smaller and gradually decreases from Gthj ′ to Gthf ′ when the occupant is not wearing the seat belt 13. Further, the abnormal estimated accelerations Gthj ′ to Gthf ′ are larger than the abnormal estimated accelerations Gthj to Gthf for the same weight category, respectively. The abnormal estimated accelerations Gthj to Gthf are smaller than the abnormal estimated accelerations Gthe to Gtha for the same weight category in the first acceleration table, respectively. This is because an occupant applies a large load to the seat back at the time of a rear collision of the vehicle, and the seat frame is deformed by this load and greatly affects an abnormality occurring in the load sensor 22. Similarly, when the seat belt 13 is not worn, the abnormal estimated accelerations Gthj 'to Gthf' are smaller than the abnormal estimated accelerations Gthe 'to Gtha' for the same weight category in the first acceleration table.
[0029]
After step 118, it is determined in step 120 whether the longitudinal acceleration Gx is smaller than the abnormal estimated acceleration -Gth. The abnormal estimated acceleration -Gth is set to a value smaller than the predetermined acceleration -Gx2. Even if the vehicle collides backwards, if the longitudinal acceleration Gx is larger than the abnormal estimated acceleration −Gth, no abnormality occurs in the load sensor 22, so “No” is determined in Step 120 as in the determination process in Step 112. Thereafter, after the processes of steps 124 and 132, the execution of the load sensor abnormality estimation program is temporarily terminated at step 136.
[0030]
On the other hand, if the longitudinal acceleration Gx is smaller than the abnormal estimated acceleration −Gth, it is determined as “Yes” in Step 120, the abnormal flag KFL is set to “1” in Step 122, and thereafter, similarly to the above. Steps 124, 132 and 134 are executed, and in step 136, the execution of the load sensor abnormality estimation program is terminated.
[0031]
Next, a case where the vehicle collides in either of the left and right directions will be described. In this case, since the absolute value of the lateral acceleration Gy is larger than the predetermined acceleration Gy1, it is determined as “Yes” in Step 124 through the processing in Steps 102, 104, 108 and 116, and the processing in Step 126 and subsequent steps. Execute.
[0032]
In step 126, similar to the processing in steps 110 and 118, the third acceleration table built in the electronic control unit 31 is referred to, and an abnormality occurs depending on whether the seat belt 13 is worn and the weight W of the occupant. Estimated acceleration Gth is determined. As shown in FIG. 3C, the third acceleration table stores data indicating the relationship between the presence / absence of wearing of the seat belt 13 in the lateral collision, the weight W of the occupant, and the estimated abnormal acceleration Gth. . As in the case of the first acceleration table and the second acceleration table, the abnormal estimated acceleration Gth increases as the weight W increases from the section of W1 to the section of W4 or more when the occupant is wearing the seat belt 13. It gradually decreases from Gtho to Gthk, and gradually decreases from Gtho ′ to Gthk ′ when the occupant is not wearing the seat belt 13. Further, the abnormal estimated accelerations Gtho 'to Gthk' are respectively larger than the abnormal estimated accelerations Gtho to Gthk for the same weight category. The abnormal estimated accelerations Gtho to Gthk are set to be approximately the same as the abnormal estimated accelerations Gthe to Gtha for the same weight category in the first acceleration table. This is because it is considered that the load applied to the seat frame is almost the same between the front collision and the left-right collision. Similarly, when the seat belt 13 is not worn, the abnormal estimated accelerations Gtho ′ to Gthk ′ are set to approximately the same magnitude as the abnormal estimated accelerations Gthe ′ to Gtha ′ for the same weight category in the first acceleration table. ing.
[0033]
After the process of step 126, it is determined in step 128 whether or not the absolute value of the lateral acceleration Gy is larger than the abnormal estimated acceleration Gth. This abnormal estimated acceleration Gth is set to a value larger than the predetermined acceleration Gy1 described above. Even if the vehicle collides in the left-right direction, if the absolute value of the left-right direction acceleration Gy is smaller than the abnormal estimated acceleration Gth, no abnormality occurs in the load sensor 22. After step 132, the execution of the load sensor abnormality estimation program is temporarily terminated at step 136.
[0034]
On the other hand, if the absolute value of the lateral acceleration Gy is larger than the estimated abnormal acceleration Gth, “Yes” is determined in step 128, the abnormal flag KFL is set to “1” in step 130, and thereafter In the same manner as described above, the processing in steps 132 and 134 is executed, and in step 136, the execution of the load sensor abnormality estimation program is terminated.
[0035]
Next, an airbag operation control program that is repeatedly executed every predetermined time after the ignition switch is turned on will be described. The airbag operation control program is started in step 200 of FIG. 4, and in step 202, it is determined whether or not the abnormality flag KFL is “0”. This is because when the abnormality flag KFL is “0”, that is, the load sensor 22 is normal, the airbag 11 is operated according to the detected weight W, and the abnormality flag KFL is “1”, that is, the load sensor 22 is abnormal. In this case, the airbag 11 is operated according to a predetermined process regardless of the detected weight W. In this case, “No” in steps 108, 116 and 124 in FIG. 2, that is, when the vehicle has not collided in any of the front, rear and left and right directions, and steps 112, 120 and in FIG. When the vehicle collides in any of the front, rear and left / right directions at 128, but the longitudinal acceleration Gx is equal to or less than the abnormal estimated acceleration Gth, the longitudinal acceleration Gx is equal to or greater than the abnormal estimated acceleration −Gth. And when the absolute value of the lateral acceleration Gy is equal to or less than the estimated abnormal acceleration Gth, the abnormality flag KFL remains initially set to “0”. In this case, “Yes” is set in step 202. Determination is made, and the processing after step 204 is executed.
[0036]
In step 204, it is determined whether the longitudinal acceleration Gx is greater than a predetermined acceleration Go. The predetermined acceleration Go is set to a large acceleration necessary for the operation of the airbag 11 due to a vehicle collision, and is set to a value larger than the estimated abnormal acceleration Gth at the time of a frontal collision. If the vehicle is in a normal running state or stopped state, the longitudinal acceleration Gx is smaller than the predetermined acceleration Go. Therefore, “No” is determined in step 204, and the airbag operation control program is executed in step 214. Exit once.
[0037]
Next, the case where the vehicle collides forward and the longitudinal acceleration Gx becomes larger than the predetermined acceleration Go will be described. In this case, it is determined as “Yes” in Step 204, and the processing after Step 206 is executed. In step 206, it is determined whether or not the weight W detected by the load sensor 22 is greater than a predetermined weight Wo. The predetermined weight Wo is set to a weight necessary for an occupant to be actuated to activate the airbag 11. If the detected weight W is equal to or less than the predetermined weight Wo, it is not appropriate to operate the airbag 11 when no one is on the seat S or when a child is on, for example. In step 214, the execution of the airbag operation control program is terminated.
[0038]
On the other hand, if the detected weight W is larger than the predetermined weight Wo, “Yes” is determined in step 206, and the airbag 11 is controlled in accordance with the first operation process in step 208 to be deployed in a predetermined manner. That is, the drive circuit 32 ignites the inflator 12 in accordance with a control signal from the electronic control unit 31 to generate gas in the entire chamber of the inflator 12 and to deploy the airbag 11 to the maximum. Thereby, a passenger | crew is appropriately protected from the impact accompanying the front collision of a vehicle. That is, since the weight W of the occupant is detected by the normal load sensor 22, the airbag 11 can be accurately deployed according to the detected weight W. After step 208, the execution of the airbag operation control program is terminated at step 214.
[0039]
Further, when the longitudinal acceleration Gx is larger than the abnormal estimated acceleration Gth as described above, or when the absolute value of the lateral acceleration Gy is larger than the abnormal estimated acceleration Gth, the abnormal flag KFL is “1”. Since the weight W detected by the subsequent load sensor 22 does not represent an accurate value, it is not appropriate to operate the airbag 11 according to the detected weight W. In this case, it is determined as “No” in Step 202, and the processing after Step 210 is executed.
[0040]
If the vehicle is in a normal running state or stopped state, the longitudinal acceleration Gx is smaller than the predetermined acceleration Go. Therefore, “No” is determined in step 210 and the airbag operation control program is determined in step 214. End execution once.
[0041]
On the other hand, if the vehicle collides forward and the longitudinal acceleration Gx becomes larger than the predetermined acceleration Go, it is determined as “Yes” in Step 210 and the airbag 11 is controlled in Step 212 according to the second operation process. The airbag 11 is deployed in a predetermined manner. That is, the drive circuit 32 ignites the inflator 12 in response to a control signal from the electronic control unit 31 to generate gas in one chamber of the inflator 12 and deploy the airbag 11 to the minimum. Thereby, even if it is a case where the abnormality which arises in the load sensor 22 is estimated, a passenger | crew is effectively protected from the impact accompanying the front collision of a vehicle. After step 212, execution of the airbag operation control program is terminated at step 214.
[0042]
As described above, according to the present embodiment, the abnormal estimated acceleration Gth that decreases as the weight W detected by the load sensor 22 is determined by the processing of steps 110, 118, and 126 of FIG. 2, and the step of FIG. The magnitudes of the longitudinal acceleration Gx and the lateral acceleration Gy respectively detected by the longitudinal acceleration sensor 23 and the lateral acceleration sensor 24 by the processes 112, 120 and 128 are larger than the determined abnormal estimated acceleration Gth. When it became, abnormality of the load sensor 22 was determined. Further, a different estimated abnormal acceleration Gth was determined depending on whether or not the seat belt 13 was worn and the detected acceleration direction. However, in order to determine the abnormal estimated acceleration Gth, for example, the result of whether or not the seat belt 13 is worn may not be used. Further, the acceleration to be detected is, for example, only the acceleration in the front-rear direction Gx, and the acceleration in only one of the front, rear, and left-right directions is used. Gth may be determined.
[0043]
Further, according to the present embodiment, the estimated abnormal acceleration Gth is set to be approximately the same for the forward collision and the lateral collision, but for example, depending on the seat structure, the estimated abnormal acceleration Gth that is different between the forward collision and the lateral collision is set. Can be set.
[0044]
Further, in the present embodiment, the airbag 11 is operated by the first and second operation processes at the time of the frontal collision of the vehicle, but the airbag 11 is also applied at the time of the lateral collision of the vehicle as in the case of the frontal collision. It may be activated.
[0045]
In this embodiment, when the abnormality of the load sensor 22 is estimated and the abnormality flag KFL is set to “1”, the airbag 11 is activated by the second activation process. In this case, The air bag 11 may not be operated.
[0046]
Moreover, in this embodiment, although one load sensor 22 was used and the abnormality of the load sensor 22 was estimated, this invention is applicable also to what used multiple load sensors. When a plurality of load sensors are used in this way, the accuracy of the detected weight is increased, and the airbag can be deployed in various ways according to the weight of the occupant. In this case, the abnormal estimated acceleration may be determined for each load sensor according to the detected weight for each load sensor, or the average value of the detected weights by all the load sensors is calculated, and the abnormal value is determined according to the average value. The estimated acceleration may be determined.
[0047]
In the present embodiment, the occupant protection device according to the present invention is employed in the airbag device. However, the occupant protection device may be employed in a seat belt device or a curtain bag device other than the airbag device.
[Brief description of the drawings]
FIG. 1 is an overall schematic diagram of an occupant protection device according to an embodiment of the present invention.
FIG. 2 is a flowchart of a load sensor abnormality estimation program executed by the electronic control unit of FIG. 1 according to the embodiment of the present invention.
FIG. 3 is a table used when the electronic control unit of FIG. 1 estimates an abnormality of a load sensor according to an embodiment of the present invention.
FIG. 4 is a flowchart of an airbag operation control program executed by the electronic control unit of FIG. 1 according to the embodiment of the present invention.
[Explanation of symbols]
AB ... Airbag mechanism, EL ... Electric control device, 11 ... Airbag, 12 ... Inflator, 13 ... Seat belt, 14 ... Tung plate, 15 ... Buckle, 21 ... Buckle switch, 22 ... Load sensor, 23 ... Longitudinal acceleration Sensor 24 ... Lateral acceleration sensor 31 ... Electronic control unit 32 ... Drive circuit

Claims (4)

In a vehicle occupant protection device that includes a load sensor that detects the weight of an object on a vehicle seat and an acceleration sensor that detects vehicle acceleration, and that protects an occupant in accordance with the output of the load sensor and the acceleration sensor.
Seat belt wearing detection means for detecting whether or not a seat belt is worn;
When the seat belt wear detecting means detects the wearing of the seat belt, the seat belt wearing detecting means detects the wearing of the seat belt when the weight decreases as the weight detected by the load sensor increases. Comparison value determination means for determining a comparison value that is smaller than the case where there is not,
An occupant protection device for a vehicle, comprising: a determination unit that determines an abnormality of the load sensor when an acceleration detected by the acceleration sensor becomes larger than a comparison value determined by the comparison value determination unit. . The vehicle occupant protection device according to claim 1,
The comparison value determining means has a plurality of different values that become smaller as the weight of the object on the vehicle seat increases and becomes smaller when the seat belt is worn than when the seat belt is not worn. And a table stored in correspondence with the weight and whether or not the seat belt is worn, and the weight detected by the load sensor and the seat belt detected by the seat belt wearing detection means by referring to the table An occupant protection device for a vehicle that determines a comparison value depending on whether or not the vehicle is worn. The vehicle occupant protection device according to claim 1 or 2 includes an airbag device that protects the vehicle occupant during a vehicle collision,
The condition that the acceleration detected by the acceleration sensor is larger than a predetermined acceleration value and the load detected by the load sensor is larger than a predetermined load value when an abnormality of the load sensor is not determined by the determination means. The airbag apparatus is deployed on the condition that the acceleration detected by the acceleration sensor is larger than the predetermined acceleration value when the determination unit determines that the load sensor is abnormal. A vehicle occupant protection device comprising a deployment control means for deploying the vehicle to a minimum. The vehicle occupant protection device according to claim 1 ,
The acceleration sensor detects a longitudinal acceleration and a lateral acceleration of the vehicle,
The comparison value determining means decreases independently according to the increase in weight detected by the load sensor independently for each of the detected longitudinal acceleration and lateral acceleration of the vehicle, and the seat belt wearing detection means When wearing of a seat belt is detected, the comparative value for the front and rear direction and the comparative value for the lateral direction, which are smaller than when the wearing of the seat belt is not detected by the seat belt wearing detection means, are determined respectively.
The determination means is configured such that when the detected longitudinal acceleration of the vehicle is larger than the longitudinal comparison value determined by the comparison value determining means, or the detected lateral acceleration of the vehicle is the An occupant protection device for a vehicle that determines an abnormality of the load sensor when it becomes larger than a comparative value for lateral direction determined by a comparative value determining means .

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