Device for determining occupant

[Technical Field to which the Invention Affiliates] The present invention relates to an occupant determination device that determines an occupant based on an output load value from a load sensor provided on a seat body.

BACKGROUND ART [0002] Conventionally, in the case where an airbag is provided for protecting a occupant (occupant) of a vehicle seat, for example, in order to determine whether or not there is a occupant in the target seat. Alternatively, the vehicle seat is provided with a occupant determination device in order to determine whether the seated person is, for example, an adult or a child. As the occupant determination device, for example, the one shown in Japanese Patent Application Laid-Open No. 9-207638 is known. This calculates the detected load value based on the output load values of the multiple load sensors provided at the plurality of mounting points on the vehicle floor of the seat body and the load sensors, and the vehicle seat based on the calculated detected load value. It is provided with a controller for determining whether or not there is a seated person. Specifically, the controller calculates the detected load value by adding each output load value of each load sensor with an adder, and uses this detected load value and a preset load value (judgment threshold value) in the judgment processing circuit. It is determined whether or not there is a seated person in the vehicle based on the magnitude relationship between the detected load value and the determination threshold value.

[0003] By the way, in such an occupant determination device, the load applied to the load sensor fluctuates due to the shaking of the seated person, the change in posture, or the like when the vehicle is running. Therefore, when applying low-pass filter processing to each sensor signal or switching the occupant judgment by reversing the magnitude relationship between the detected load value and the judgment threshold value so that the occupant judgment does not frequently switch due to temporary load fluctuations. The delay process is performed. As a result, temporary switching of occupant judgment (for example, switching from adult judgment to child judgment) due to shaking of the seated person or change in posture is suppressed.

[0004] By the way, in such an occupant determination device, a delay process is similarly performed for switching the occupant determination even when the occupant is on board or is replaced. For this reason, even in a state where an adult ride is clearly suggested, such as a significant increase in the detected load value due to such occupant boarding or replacement, it takes time to determine (switch) the occupant by the above delay process. Become.

[0005] An object of the present invention is to provide an occupant determination device capable of quickly performing an adult determination when an occupant is on board or is replaced.

[Means for Solving the Problems] In order to solve the above problems, the invention according to claim 1 is detected based on a load sensor provided on the seat body and an output load value of the load sensor. Calculate the load value and based on the detected load value<u style="single">Including adult judgment and child judgment</u>It is equipped with a controller that performs occupant determination, and when the detected load value exceeds a predetermined first determination threshold value and the magnitude relationship with the first determination threshold value is reversed, a delay time is set to make the occupant determination an adult determination. In the occupant determination device to be switched, the detected load value is<u style="single">It was set to a value lower than the first judgment threshold value.</u>When the detected load value exceeds the first determination threshold value and the magnitude relationship with the first determination threshold value is reversed within a predetermined time after exceeding the predetermined second determination threshold value, the controller shortens the delay time. Configuration<u style="single">Then, when the duration after the detected load value exceeds the first determination threshold value exceeds the delay time, the occupant determination is switched to the adult determination.</u>The gist is that.

[0007] The invention according to claim 2 has a first delay time and a second delay time shorter than the first delay time as the delay time in the occupant determination device according to claim 1, and the detection is performed. When the detected load value exceeds the first determination threshold value and the magnitude relationship with the first determination threshold value is reversed outside the predetermined time after the load value exceeds the second determination threshold value, the controller performs the delay. The time is set to the first delay time, and within the predetermined time after the detected load value exceeds the second determination threshold value, the detected load value exceeds the first determination threshold value and becomes the first determination threshold value. It is a gist that the controller sets the delay time to the second delay time when the magnitude relation of the above is reversed.

[0008] The invention according to claim 3 calculates a detected load value based on a load sensor provided on the seat body and an output load value of the load sensor, and is based on the detected load value.<u style="single">Including adult judgment and child judgment</u>It is equipped with a controller that determines the occupant, and the detected load value is<u style="single">It was set to a value lower than the first judgment threshold value.</u>In the occupant determination device that sets the delay time and switches the occupant determination to the adult determination when the magnitude relationship with the first determination threshold is reversed beyond the predetermined first determination threshold, the detected load value is the predetermined first. When the magnitude relationship with the second determination threshold value is reversed beyond the two determination threshold values, the controller switches the occupant determination to the occupant presence determination within a predetermined time, and during the occupant presence determination, the detected load value. When the magnitude relationship with the first determination threshold value is reversed beyond the first determination threshold value, the controller sets the delay time short.<u style="single">Then, when the duration after the detected load value exceeds the first determination threshold value exceeds the delay time, the occupant determination is switched to the adult determination.</u>The gist is that.

[0009] The invention according to claim 4 is that in the occupant determination device according to claim 3, when the detected load value does not exceed the first determination threshold value during the occupant presence determination, the controller uses the controller. The gist is to switch the occupant judgment to the child judgment.

(Action) According to the invention according to claim 1 or 2, the detected load value exceeds the first determination threshold within a predetermined time after the detected load value exceeds the predetermined second determination threshold. When the magnitude relationship with the first determination threshold value is reversed, the delay time is set short. For example, it is assumed that a value smaller than the first judgment threshold value suggested by the occupants including children is set as the second judgment threshold value. At this time, the detected load value exceeds the first judgment threshold within a predetermined time after the detected load value exceeds the predetermined second judgment threshold, that is, in a state where a new ride of the occupant including the child is suggested. If the magnitude relationship with the first determination threshold value is reversed, it can be regarded as a transition corresponding to an increase in the detected load value accompanying the riding of an adult. As described above, in a state where an adult ride is clearly suggested, the adult determination is made quickly by setting the delay time short.

[0011] According to the invention of claim 3 or 4, when the detected load value exceeds a predetermined second determination threshold value and the magnitude relationship with the second determination threshold value is reversed, the controller uses a predetermined time as an upper limit. Switch the occupant judgment to the occupant presence judgment. If the detected load value exceeds the first judgment threshold value and the magnitude relationship with the first judgment threshold value is reversed during this occupant presence judgment, that is, in a state where a new ride of a occupant including a child is suggested, It can be regarded as a transition corresponding to the increase in the detected load value accompanying the riding of an adult. As described above, in a state where an adult ride is clearly suggested, the adult determination is made quickly by setting the delay time short.

[Embodiments of the Invention] Hereinafter, vehicle seats to which one embodiment of the present invention is applied will be described with reference to FIGS. 1 to 8.

[0013] FIG. 1 shows a perspective view of a seat body 1 included in a vehicle seat. The seat body 1 is arranged on the passenger seat side of the vehicle, and the pair of left and right support frames 2 in FIG. 1 are fixed side by side in the front-rear direction (X arrow direction in FIG. 1) with respect to the vehicle floor (not shown). There is.

A pair of front and rear brackets 3 are fixed to the upper surface of each support frame 2, and a lower rail 4 is supported and fixed to the pair of front and rear brackets 3 along the support frame 2. The pair of left and right lower rails 4 are formed in a U-shaped cross section, and a slide groove 5 having an opening above the lower rail 4 and extending in the front-rear direction is formed.

[0015] In the slide grooves 5 formed in each lower rail 4, a pair of left and right upper rails 6 are arranged so as to be slidable in the front-rear direction along the slide grooves 5. As shown in FIG. 2, each upper rail 6 has a lower arm that supports the seat cushion 9 and the seat back 10 of the seat body 1 at predetermined intervals via a pair of left and right front sensor brackets 7 and rear sensor brackets 8. 16 are connected.

As shown in FIG. 3A, the front sensor bracket 7 has upper and lower fastening portions 7a and lower fastening portions 7b at both upper and lower ends, and the upper and lower fastening portions 7a and 7b are curved. A flexible portion 7c is formed. The front sensor bracket 7 is connected to the front side of the lower arm 16 and the upper rail 6 at the upper and lower fastening portions 7a and 7b, respectively. A front right load sensor 21 and a front left load sensor 22 constituting the front load sensor are attached to the bent portions 7c of the front sensor brackets 7 on the right side and the left side, respectively. The front right side load sensor 21 and the front left side load sensor 22 are provided with a strain detection element such as a strain gauge, and electrically measure the amount of deflection of the flexure portion 7c relative to the load applied to the seat cushion 9. It is designed to detect.

As shown in FIG. 3B, the rear sensor bracket 8 has upper and lower fastening portions 8a and lower fastening portions 8b at both upper and lower ends, and the upper and lower fastening portions 8a and 8b are curved. A flexible portion 8c is formed. The rear sensor bracket 8 is connected to the rear side portions of the lower arm 16 and the upper rail 6 at the upper and lower fastening portions 8a and 8b, respectively. The rear right load sensor 23 and the rear left load sensor 24, which constitute the rear load sensor, are attached to the flexible portions 8c of the rear sensor brackets 8 on the right and left sides, respectively. Similar to the front right load sensor 21 and the front left load sensor 22, the rear right load sensor 23 and the rear left load sensor 24 are provided with a strain detecting element such as a strain gauge, and can be applied to the load applied to the seat cushion 9. On the other hand, the amount of bending of the bending portion 8c is electrically detected.

FIG. 4 is a block diagram showing an electrical configuration of the occupant determination device 20 included in the vehicle seat. The occupant determination device 20 includes the load sensors 21 to 24 and a controller 25.

[0019] The controller 25 includes a central processing unit (hereinafter, referred to as CPU) 26, a sensor signal input circuit 27, and an output circuit 28. The sensor signal input circuit 27 includes active filters 27a, 27b, 27c, 27d provided corresponding to the front right load sensor 21, the front left load sensor 22, the rear right load sensor 23, and the rear left load sensor 24, respectively. Have. Then, the load signals from the load sensors 21 to 24 are input to the CPU 26 via these active filters 27a to 27d. These active filters 27a to 27d are well-known low-pass type filters in which an active element such as an amplifier is combined with a passive element composed of, for example, a capacitor and a resistor. Therefore, the active filters 27a to 27d pass only the low frequency signal among the load signals from the load sensors 21 to 24, and the other signals are lost.

By the way, in the CPU 26, the output load values FR and FL for each of the load sensors 21 and 22 are set based on the load signals from the front right load sensor 21 and the front left load sensor 22 that have passed through the active filters 27a and 27b, respectively. It is designed to be calculated. In addition, the output load values RR and RL for each load sensor 23 and 24 are calculated based on the load signals from the rear right load sensor 23 and the rear left load sensor 24 that have passed through the active filters 27c and 27d. There is. Then, the detected load value Ws is calculated by summing these output load values FR to RL.

[0021] The CPU 26 executes various arithmetic processes according to a control program and initial data stored in advance, and outputs the arithmetic results, that is, the occupant determination results, to the output circuit 28. Then, the operation of the airbag device is controlled by outputting this calculation result to, for example, the airbag controller 30 via the output circuit 28.

Next, processing such as occupant determination in the present embodiment will be described with reference to the time charts of FIGS. 5 to 8. In the present embodiment, the CPU 26 determines whether the occupant is an adult, a child, with an occupant, or without an occupant based on the detected load value Ws. In addition, the CPU 26 uses its built-in timer to measure time for various delay processes when switching judgments.

[0023] In the figure, the determination threshold value Wth as the first determination threshold value is a predetermined threshold value set for performing adult determination. The judgment threshold value Wth is set to a suitable value for adult judgment by comparing the magnitude with the detected load value Ws. Further, the occupant presence determination threshold value Wn1 as the second determination threshold value is a predetermined threshold value set for performing the occupant presence determination determination including children. Further, the no-occupant determination threshold value Wn2 is a predetermined threshold value set for determining the absence of an occupant, and is set smaller than the occupant-less determination threshold value Wn1. This is to prevent it from being easily determined that there is no occupant due to a change in the posture of the occupant. The occupant presence determination threshold value Wn1 and the occupant absence determination threshold value Wn2 are set to suitable values for determining the presence / absence of occupants including children by comparing the magnitude with the detected load value Ws, respectively.

[0024] In FIG. 5, the determination transition when the detected load value Ws is lower than the determination threshold value Wth and the child determination is performed will be described. Such a state occurs when the detected load value Ws decreases due to, for example, a change in the posture of the occupant, and the child determination is confirmed. Needless to say, the above-mentioned detected load value Ws is sufficiently small, and the same applies when the determination / confirmation without an occupant is performed, so the explanation is omitted.

[0025] In FIG. 5, it is assumed that the detected load value Ws exceeds the above-mentioned determination threshold value Wth at time T1. At this time, the CPU 26 starts timing the duration in a state where the detected load value Ws exceeds the determination threshold value Wth (Ws Wth). Then, when the duration exceeds the first predetermined time A as the first delay time, the CPU 26 switches the occupant determination from the child determination to the adult determination. This first predetermined time A is the time for the delay process set corresponding to the above-mentioned judgment threshold value Wth, and is a temporary switching of the occupant judgment due to the shaking of the occupant, the change in posture, etc. (from the child judgment to the adult judgment). It is set to a relatively long time to suppress switching). Then, after the time (T1 + A), the adult judgment is continued.

On the other hand, in FIGS. 6 and 7, the determination transition when the detected load value Ws is lower than the occupant presence determination threshold value Wn1 and the occupant-less determination is performed will be described. Such a state occurs, for example, when an occupant has not yet boarded (including replacement), the detected load value Ws is significantly reduced, and the determination of no occupant is confirmed.

[0027] In FIG. 6, it is assumed that the detected load value Ws exceeds the occupant presence determination threshold value Wn1 at time T2. At this time, the CPU 26 starts timing the duration in a state where the detected load value Ws exceeds the occupant presence determination threshold value Wn1 (Ws Wn1). Then, at the time T3 (= T2 + B) when the duration exceeds the predetermined time B, the occupant determination is switched from the occupant-less determination to the occupant-existing determination by the CPU 26. This predetermined time B is the time for delay processing set in response to the above-mentioned occupant determination threshold value Wn1, and is a temporary switching of occupant determination due to vehicle shaking or the like (switching from no occupant determination to occupant presence determination). ) Is set to a suitable time to suppress. Then, after the time T3, the occupant presence determination is continued up to the predetermined time C (time T3 + C).

[0028] It is assumed that the detected load value Ws exceeds the above-mentioned determination threshold value Wth at time T4 while the determination of presence of occupants is continued (within the predetermined time C). At this time, the CPU 26 starts timing the duration in a state where the detected load value Ws exceeds the determination threshold value Wth (Ws Wth). Then, when the duration exceeds the second predetermined time D as the second delay time, the CPU 26 switches the occupant determination from the occupant determination to the adult determination. This second predetermined time D is the time for the delay process set corresponding to the above-mentioned judgment threshold value Wth, and is a temporary switching of the occupant judgment due to the shaking of the occupant, the change in posture, etc. It is set to a value that suppresses (switching). However, here, in response to the fact that the judgment was switched to adult judgment while it was judged that there was an occupant, that is, the detected load value Ws increased in a relatively short period of time, and it was clearly suggested that an adult would ride. The second predetermined time D is set shorter than the first predetermined time A by the amount that the reliability is improved. Then, after the time (T4 + D), the adult judgment is continued.

Further, in FIG. 7, it is assumed that the detected load value Ws exceeds the occupant presence determination threshold value Wn1 at time T5. At this time, in the same manner as above, when the duration in the state where the detected load value Ws exceeds the occupant presence determination threshold value Wn1 (Ws Wn1) exceeds the predetermined time B at the time T6 (= T5 + B), the occupant determination is made by the CPU 26. It is possible to switch from the judgment without occupants to the judgment with occupants. Then, after the time T6, the CPU 26 continues the determination of the presence of an occupant up to the predetermined time C (time T6 + C). In the figure, the detected load value Ws does not exceed the above-mentioned determination threshold value Wth within the predetermined time C, and the CPU 26 switches the occupant determination from the occupant determination to the child determination at the time (T6 + C). Then, after the time (T6 + C), the child judgment is continued.

Further, in FIG. 8, when the detected load value Ws exceeds the occupant-less determination threshold value Wn2 and a determination other than no occupant (adult, child, or occupant presence) is performed. The judgment transition of is described. In the figure, it is assumed that the detected load value Ws falls below the no-occupant determination threshold value Wn2 at time T7. At this time, the CPU 26 starts timing the duration in a state where the detected load value Ws is lower than the no-occupant determination threshold value Wn2 (Ws &lt;Wn2). Then, at a time (T7 + E) in which the duration exceeds the predetermined time E, the occupant determination is switched from any of the above determinations to the no-occupant determination by the CPU 26. This predetermined time E is the time for the delay process set corresponding to the above-mentioned no-occupant determination threshold value Wn2, and is a temporary switching of the occupant determination due to the shaking of the vehicle or the like (from any of the above determinations to the no-occupant determination). It is set to a suitable time to suppress (switching). Then, after the time (T7 + E), the no-occupant determination is continued.

[0031] As described in detail above, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, when the detected load value Ws exceeds the occupant presence judgment threshold value Wn1 and the magnitude relationship with the occupant presence judgment threshold value Wn1 is reversed, the occupant judgment is switched to the occupant presence judgment with the predetermined time C as the upper limit. .. If the detected load value Ws exceeds the judgment threshold Wth and the magnitude relationship with the judgment threshold Wth is reversed during this occupant presence judgment, that is, in a state where a new ride of the occupants including children is suggested, an adult ride It can be regarded as a transition corresponding to the increase in the detected load value Ws. As described above, in a state in which an adult ride (including replacement) is clearly suggested, the adult determination can be made quickly by setting the delay time short.

(2) In the present embodiment, by setting the occupant presence determination, for example, in a system that requires notification immediately after boarding, such as a belt warning system, regardless of whether the adult determination or the child determination is confirmed. Notification is possible based on the determination that there is an occupant. Further, for such a belt warning system, the load sensors 21 to 24 are also used, so that a dedicated sensor for occupant detection becomes unnecessary.

(3) In the present embodiment, the occupant-less determination threshold value Wn2 is set smaller than the occupant-less determination threshold value Wn1. Therefore, it is possible to prevent a child having a weight equivalent to the vicinity of the occupant determination threshold value Wn1 from being easily determined to be unoccupied due to a change in posture or the like.

(4) In the present embodiment, by setting each delay time, it is possible to prevent the occupant determination from being frequently switched due to a temporary load fluctuation during traveling. In the present embodiment, the embodiment of the present invention is not limited to the above embodiment, and may be changed as follows.

[0035] -In the above embodiment, the occupant determination threshold value Wn1 and the occupant-less determination threshold value Wn2 are set to different values, but these may be set to the same value. -In the above embodiment, a pair of left and right front right load sensors 21 and a front left side load sensor 22 are provided on the front portion of the seat body 1, and a pair of left and right rear right load sensors 23 and a rear left side load sensor 24 are provided on the rear portion. .. The number (4) of such sensors and their arrangement are examples, and other numbers and their arrangements may be adopted. In short, one or a plurality of load sensors may be arranged at a predetermined position on the seat body 1 and the occupant may be judged based on the detected load value of the load sensor.

[0036] -The shapes of the front side and rear side sensor brackets 7 and 8 adopted in the above embodiment are examples, and the shapes are arbitrary as long as bending occurs according to the seat weight (seating load).

The mounting positions (front side and rear side sensor brackets 7, 8) of the load sensors 21 to 24 adopted in the above embodiment are examples, and if the seat weight (seating load) is detected, the mounting positions thereof. The position is arbitrary.

[0038] -In the above embodiment, the case of the vehicle seat on the passenger seat side of the vehicle has been described, but the vehicle seat on the driver's seat side may be used. Next, the technical ideas that can be grasped from the above embodiments are described below together with their effects.

(A) In the occupant determination device according to claim 1 or 2, the detected load value exceeds the first determination threshold within a predetermined time after the detected load value exceeds the second determination threshold. When not present, the controller switches the occupant determination to the child determination.

(B) A plurality of load sensors provided on the seat body and a controller for calculating a detected load value by totaling the output load values of the load sensors and determining an occupant based on the detected load value are provided. When the detected load value exceeds a predetermined first determination threshold value and the magnitude relationship with the first determination threshold value is reversed, the detected load is set in the occupant determination device that sets the delay time and switches the occupant determination to the adult determination. When the detected load value exceeds the first determination threshold value and the magnitude relationship with the first determination threshold value is reversed within a predetermined time after the value exceeds the predetermined second determination threshold value, the controller performs the delay time. An occupant determination device characterized by setting a short time.

(C) In the occupant determination device according to the above (b), the load sensors are provided at least at four locations on the front left and right and the rear left and right of the seat body. ..

[Effect of the Invention] As described in detail above, according to the inventions of claims 1 to 4, the adult determination can be quickly performed when the occupant is on board or when the occupant is replaced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a vehicle seat according to the present invention.

FIG. 2 is a side view showing the embodiment.

FIG. 3 is a front view showing front and rear sensor brackets.

FIG. 4 is a block diagram showing an electrical configuration of the same embodiment.

FIG. 5 is a time chart showing an occupant determination mode of the same embodiment.

FIG. 6 is a time chart showing an occupant determination mode of the same embodiment.

FIG. 7 is a time chart showing an occupant determination mode of the same embodiment.

FIG. 8 is a time chart showing an occupant determination mode of the same embodiment.

[Explanation of symbols] 1 Seat body 20 Crew judgment device 21 Front right side load sensor that constitutes the load sensor 22 Front left side load sensor that constitutes the load sensor 23 Rear right side load sensor that constitutes the load sensor 24 Rear left side that constitutes the load sensor Load sensor 25 controller