JP2003232670A - Occupant weight detection device - Google Patents

Abstract

(57) [Problem] To provide an occupant weight detection device capable of detecting a failure. SOLUTION: A front detection load value obtained by summing output load values of load sensors 21 and 22 provided on a front side of a seat body is lower than a predetermined minus load value, and load sensors 23 and 24 provided on a rear side. When the rear-side detected load value exceeds the predetermined plus load value, the controller 25 detects a failure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant weight detecting device for detecting an occupant weight based on an output load value from a load sensor provided in a seat body.

[0002]

2. Description of the Related Art Conventionally, for example, in the case where an airbag is provided to protect a seated person of a vehicle seat, it is necessary to determine whether or not there is a seated person in the target seat, or For example, an occupant weight detection device is provided on the vehicle seat to determine whether the vehicle seat is an adult or a child. As this occupant weight detection device, for example, one disclosed in Japanese Patent Laid-Open No. 11-351952 is known. This detection device has a configuration in which a plurality of load sensors are provided at a plurality of attachment points of the seat body with respect to the vehicle floor, and the occupant weight is detected based on the output load value of these load sensors.

Further, the detection device has a displacement regulating mechanism for handling a load exceeding a predetermined range in order to prevent the load sensor from being damaged by an abnormal overload applied to the seat body. As a result, it is possible to prevent a load exceeding the predetermined range from being directly applied to the load sensor, and to suppress the damage.

[0004]

However, even if a mechanism for handling such an overload is provided to avoid damage to the load sensor, the load received by the seat body as a whole is not eliminated, so The seat itself may be deformed depending on the degree of. Then, the deformation of the seat body may cause, for example, a zero point shift of the load sensor, which may reduce the occupant weight detection accuracy of the device.

On the other hand, when the strength or rigidity of the entire body is increased in order to suppress the deformation of the seat body, another problem such as an increase in cost and weight arises. Rather, it is preferable to monitor an event (such as an abnormal overload) that may cause a failure in the device and detect the failure based on this, and prompt the user (driver) for early inspection.

An object of the present invention is to provide an occupant weight detection device capable of detecting a defect.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a plurality of load sensors provided in a seat body, and a detected load value based on an output load value of the load sensors. In the occupant weight detection device having a controller for calculating and detecting the occupant weight, a calculation means for calculating a one-sided detection load value based on an output load value of a load sensor provided on one side of the seat body, When the calculated one-side detected load value is below a predetermined negative load value, the controller is to detect a defect.

According to a second aspect of the present invention, an occupant weight including a plurality of load sensors provided in the seat body and a controller for detecting the occupant weight by calculating the detected load value based on the output load value of the load sensors. In the detection device, first calculating means for calculating a one-side detected load value based on an output load value of a load sensor provided on one side of the seat body, and output of a load sensor provided on the other side of the seat body. A second calculation means for calculating the other side detected load value based on the load value, wherein the calculated one side detected load value is below a predetermined negative load value, and the calculated other side detected load value is The gist is that the controller detects a failure when a predetermined plus load value is exceeded.

According to a third aspect of the present invention, in the occupant weight detection apparatus according to the second aspect, one side and the other side of the seat body are front side and rear side, rear side and front side, right side of the seat body. And the left side, and at least one of the left side and the right side
The summary is that it is one.

A fourth aspect of the present invention is based on the occupant weight detection apparatus according to any one of the first to third aspects, wherein the controller drives the informing means upon detection of a defect.

(Operation) In general, when an abnormal overload is applied to the seat body, the seat body may be deformed and the occupant weight detection accuracy may be reduced. It has been confirmed by the present applicant that such a defect is suggested by being unevenly distributed on one side of the seat body and causing a significant negative load. In particular, when a significant negative load is generated due to uneven distribution on one side of the seat body and a significant positive load is generated due to uneven distribution on the other side, for example, an abnormal overload is applied due to a vehicle collision. Be thoughtful.

According to the first aspect of the present invention, the one-side detected load value calculated based on the output load value of the load sensor provided on one side of the seat body falls below a predetermined negative load value, A malfunction is detected by the controller.

According to the second or third aspect of the present invention, the one-side detected load value is calculated based on the output load value of the load sensor provided on one side of the seat body. Also, the other side detected load value is calculated based on the output load value of the load sensor provided on the other side of the seat body. Then, when the one-side detected load value falls below a predetermined negative load value and the other-side detected load value exceeds a predetermined plus load value, the controller detects a malfunction. In particular, the reliability is improved by detecting a defect based on an unbalanced load generated on one side and the other side of the seat body.

According to the fourth aspect of the present invention, the informing means is driven when the malfunction is detected, so that the user's early inspection is promoted.

[0015]

DETAILED DESCRIPTION OF THE INVENTION A vehicle seat to which an embodiment of the present invention is applied will be described below with reference to FIGS.

FIG. 1 is a seat body 1 provided in a vehicle seat.
FIG. The seat body 1 is arranged on the passenger side of the vehicle, and the pair of left and right support frames 2 in FIG. 1 are fixed together with the vehicle floor (not shown) in the front-rear direction (X arrow direction in FIG. 1). There is.

A pair of front and rear brackets 3 is fixed to the upper surface of each support frame 2, and the pair of front and rear brackets 3 is fixed.
On the other hand, the lower rail 4 is supported and fixed along the support frame 2. The pair of left and right lower rails 4 is formed in a U-shape in cross section, and an upper portion thereof is opened, and the opening portion forms a slide groove 5 extending in the front-rear direction.

A slide groove 5 formed on each lower rail 4
A pair of left and right upper rails 6 are disposed on the slide rail 5 so as to be slidable in the front-rear direction along the slide groove 5. Figure 2
As shown in FIG. 3, each upper rail 6 is provided with a lower arm 16 for supporting the seat cushion 9 and the seat back 10 of the seat body 1 at a predetermined interval via a pair of left and right front sensor brackets 7 and rear sensor brackets 8. It is connected.

As shown in FIG. 3 (a), the front sensor bracket 7 has upper and lower end portions as an upper fastening portion 7a and a lower fastening portion 7b, and the upper and lower fastening portions 7a and 7b are curved. The bending portion 7c is formed. The front sensor bracket 7 includes the upper and lower fastening portions 7a and 7b.
At the front arms of the lower arm 16 and the upper rail 6, respectively. A front right side load sensor 21 and a front left side load sensor 22 that are load sensors are attached to the bending portions 7c of the right and left front sensor brackets 7, respectively. The front right side load sensor 21 and the front left side load sensor 22 are provided with a strain detecting element such as a strain gauge, for example, and electrically measure the amount of bending of the bending portion 7c relative to the load applied to the seat cushion 9. It is designed to detect.

As shown in FIG. 3 (b), the rear sensor bracket 8 has upper and lower end portions as an upper fastening portion 8a and a lower fastening portion 8b, and the upper and lower fastening portions 8a and 8b are curved. And a bending portion 8c is formed. The rear sensor bracket 8 has the upper and lower fastening portions 8a and 8b.
In the above, the lower arm 16 and the upper rail 6 are connected to the rear side portions thereof, respectively. A rear right load sensor 23 and a rear left load sensor 24, which constitute a load sensor, are attached to the bending portions 8c of the right and left rear sensor brackets 8, respectively. The rear right side load sensor 23 and the rear left side load sensor 24, like the front right side load sensor 21 and the front left side load sensor 22, are provided with a strain detecting element such as a strain gauge, for example, to detect the load applied to the seat cushion 9. The amount of flexure of the flexure portion 8c relative to each other is electrically detected.

FIG. 4 is a block diagram showing the electrical construction of the occupant weight detection device 20 provided in the vehicle seat. The occupant weight detection device 20 includes the load sensors 21 to 24,
And a controller 25.

The controller 25 includes a CPU (central processing unit) 26, a filter 27, an output circuit 28, and a communication circuit 30. The filter 27 receives the load signal from the load sensors 21 to 24 via the amplifier 27a and inputs it to the CPU 26. CPU2
6, the load sensors 21, 2 are loaded based on load signals from the front right load sensor 21 and the front left load sensor 22 that have passed through the amplifier 27a and the filter 27.
The output load values FR and FL for each 2 are calculated. Further, each load sensor 2 is based on the load signals from the rear right load sensor 23 and the rear left load sensor 24 that have passed through the amplifier 27a and the filter 27.
The output load values RR and RL for 3 and 24 are respectively calculated in the same manner. Then, the detected load value S corresponding to the occupant weight is calculated by summing these output load values FR to RL. Further, by summing the output load values FR and FL of the front side load sensors 21 and 22, the front side detected load value Fr becomes the rear side load sensor 2.
The rear detected load value Rr is calculated by summing the output load values RR and RL of 3, 24. Furthermore, the right side detected load value RH is obtained by summing the output load values FR and RR of the right side load sensors 21 and 23, and the left side detected load value is obtained by summing the output load values FL and RL of the left side load sensors 22 and 24. Each value LH is calculated.

The CPU 26 executes various arithmetic processes according to a control program, initial data and the like stored in advance. For example, the CPU 26 determines whether the occupant is an adult or a child by calculating the detected load value S (passenger weight) in the main routine and comparing this with a predetermined determination threshold value. Then, the CPU 26 outputs the calculation result to the communication circuit 30. The operation result of the airbag device is controlled by outputting the calculation result to, for example, the airbag controller 33 via the communication circuit 30.

In the main routine, the CPU 26 also detects an event that may cause a malfunction of the apparatus, that is, an abnormal overload such as a vehicle collision. Then, the CPU 26 outputs the detection result to the output circuit 28. The detection result is output to an indicator lamp 29 as a notification means stored in, for example, a combination meter via the output circuit 28, so that the indicator lamp 29 is turned on and prompts the user for early inspection. .

Next, in the present embodiment, the mode of detecting a defect will be described with reference to the flowcharts of FIGS. 5 and 6. As described above, this processing is also executed as part of the main routine.

When the processing shifts to this routine, first, in step 101, the CPU 26 performs an input processing.
Specifically, the CPU 26 has the load sensors 21 to 2 filtered by the amplifier 27 a and the filter 27.
The load signal of No. 4 is read, and the output load values FR to RL for each of the load sensors 21 to 24 are calculated.

Next, in step 102, the CPU 2
6 determines whether or not the indicator lighting flag registered in the memory is set. This indicator lighting flag is a flag that is set by detecting a malfunction in a manner described later. Here, if it is determined that the indicator lighting flag is set, the CPU 26 proceeds to step 120 and performs the indicator lighting process. Specifically, CPU2
6 is an indicator lamp 29 through the output circuit 28.
A drive signal is output to the indicator lamp 29 and the indicator lamp 29 is turned on. Then, the CPU 26 directly returns to the main routine.

On the other hand, if it is determined in step 102 that the indicator lighting flag is not set (clear), the CPU 26 proceeds to step 103 to move the front side detected load value Fr, the rear side detected load value Rr, and the right side detected load value R.
H and the left detection load value LH are calculated.

Next, the CPU 26 proceeds to step 104 to judge whether the rear side detected load value Rr is below a predetermined excessive minus load value A or not. The excessive negative load value A is, for example, due to the frontal collision of the vehicle, the seat body 1
It is set to a suitable value for detecting an abnormal negative overload (a load that cannot occur in actual use) that occurs on the rear side. Here, if it is determined that the rear-side detected load value Rr is not below the excessive negative load value A, the CPU 26 determines that an abnormal negative overload has not occurred on the rear side of the seat body 1 in step 107. Move to. When it is determined that the rear-side detected load value Rr is below the excessive minus load value A, the CPU 26 determines in step 105.
Move to.

In step 105, the CPU 26 determines whether or not the front side detected load value Fr exceeds a predetermined excessive plus load value B. The excessive plus load value B is contrary to the abnormal overload on the minus side generated on the rear side of the seat body 1 due to, for example, a frontal collision of the vehicle, and thus the seat body 1 does not.
It is set to a suitable value for detecting an abnormal overload on the positive side that occurs on the front side of the. Here, the front side detected load value Fr
Is determined not to exceed the excessive plus load value B,
The CPU 26 proceeds to step 107 on the assumption that no abnormal overload on the positive side has occurred on the front side of the seat body 1. In addition, the front side detected load value Fr is too large plus the load value B
If it is determined that the value exceeds the limit, the CPU 26 causes the step 1
The flow shifts to 06 to determine a forward collision.

At step 107, the CPU 26 determines whether or not the front side detected load value Fr is below a predetermined excessive minus load value C. This excessive negative load value C
Is set to a suitable value for detecting an abnormal negative overload (a load that cannot occur in the actual use state) that occurs on the front side of the seat body 1 due to a rear collision of the vehicle. Here, if it is determined that the front side detected load value Fr is not below the excessive minus load value C, the CPU 26 determines that no abnormal negative overload has occurred on the front side of the seat body 1 and the step of FIG. Move to 110. When it is determined that the front-side detected load value Fr is less than the excessive minus load value C, the CPU 26 determines in step 108.
Move to.

In step 108, the CPU 26 determines whether or not the rear side detected load value Rr exceeds a predetermined excessive plus load value D. The excessive plus load value D is contrary to the abnormal overload on the minus side generated on the front side of the seat body 1 due to, for example, a rearward collision of the vehicle.
It is set to a suitable value for detecting an abnormal overload on the positive side that occurs on the rear side. Here, the rear detection load value Rr
Is judged not to exceed the excessive plus load value D,
The CPU 26 determines that no abnormal overload on the plus side has occurred on the rear side of the seat body 1 in step 110 of FIG.
Move to. When it is determined that the rear-side detected load value Rr exceeds the excessive plus load value D, the CPU 26 proceeds to step 109 and determines a rearward collision.

In step 110, the CPU 26 determines whether or not the right side detected load value RH is below a predetermined excessive minus load value E. This excessive negative load value E
Is set to a suitable value for detecting an abnormal negative overload (a load that cannot occur in actual use) that is generated on the right side of the seat body 1 due to, for example, a left side collision of the vehicle. Here, if it is determined that the right side detected load value RH is not below the excessive minus load value E, the CPU 26 determines that an abnormal minus overload has not occurred on the right side of the seat body 1 and proceeds to step 112. To do. If it is determined that the right detected load value RH is less than the excessive minus load value E, the CPU 26 proceeds to step 111.

At step 111, the CPU 26 determines whether or not the left side detected load value LH exceeds a predetermined excessive plus load value F. This excessive plus load value F is contrary to the abnormal overload on the minus side generated on the right side of the seat body 1 due to, for example, a collision on the left side of the vehicle.
Is set to a suitable value for detecting an abnormal overload on the positive side that occurs on the left side of the. Here, the left detection load value LH
Is determined not to exceed the excessive plus load value F,
The CPU 26 proceeds to step 112 assuming that no abnormal overload on the positive side has occurred on the left side of the seat body 1. In addition, the left-side detected load value LH is excessively large plus the load value F
If it is determined that the value exceeds the limit, the CPU 26 causes the step 1
The process proceeds to 14 to determine a side collision.

At step 112, the CPU 26 determines whether or not the left side detected load value LH is below a predetermined excessive minus load value G. This excessive negative load value G
Is set to a suitable value for detecting an abnormal negative overload (a load that cannot occur in actual use) that is generated on the left side of the seat body 1 due to, for example, a right side collision of the vehicle. Here, if it is determined that the left-side detected load value LH is not less than the excessive minus load value G, the CPU 26 proceeds to the main routine as it is, assuming that the minus-side abnormal overload does not occur on the left side of the seat body 1. Return. When it is determined that the left-side detected load value LH is less than the excessive minus load value G, the CPU 26 determines in step 113.
Move to.

At step 113, the CPU 26 determines whether or not the right side detected load value RH exceeds a predetermined excessive plus load value H. The excessive plus load value H is contrary to the abnormal overload on the negative side generated on the left side of the seat body 1 due to the right side collision of the vehicle, for example, and the seat body 1
Is set to a suitable value for detecting an abnormal overload on the positive side that occurs on the right side of. Here, the right side detected load value RH
Is determined not to exceed the excessive plus load value H,
The CPU 26 returns to the main routine as it is, assuming that no abnormal overload on the positive side has occurred on the right side of the seat body 1. When it is determined that the right side detected load value RH exceeds the excessive plus load value H, the CPU 26 proceeds to step 114 and determines a side collision.

The CPU 26, which has made the collision determination in any of steps 106, 109, and 114, proceeds to step 115, sets the indicator lighting flag, registers it in the memory, and returns to the main routine. The indicator lighting flag set in accordance with these collision determinations is the above step 1
As described above, the indicator lamp 29 is turned on and the indicator lamp 29 is turned on. Therefore, the user (driver) understands the necessity of early inspection by turning on the indicator lamp 29.

As described in detail above, according to this embodiment, the following effects can be obtained. (1) In the present embodiment, it is possible to detect a defect by the rear-side detected load value Rr falling below a predetermined negative load value A and the front-side detected load value Fr exceeding a predetermined plus load value B.

(2) In this embodiment, the front side detected load value F
If r is below a predetermined negative load value C and the rear side detected load value Rr exceeds a predetermined positive load value D, it is possible to detect a defect.

(3) In this embodiment, the right side detected load value R
When H is below the predetermined negative load value E and the left-side detected load value LH exceeds the predetermined positive load value F, it is possible to detect a defect.

(4) In this embodiment, the left-side detected load value L
When H is below the predetermined negative load value G and the right side detected load value RH exceeds the predetermined positive load value H, it is possible to detect a defect.

(5) In the present embodiment, the reliability can be improved by detecting a defect based on an imbalanced load generated on one side and the other side (front side and rear side, right side and left side) of the seat body 1. .

(6) In the present embodiment, the failure is detected based on the unbalanced load on the one side and the other side of the seat body 1 which shows the characteristics at the time of vehicle collision. Even if an unnatural load that cannot be applied is intentionally applied, it is possible to suppress false detection of this as a defect.

(7) In the present embodiment, the collision direction (front direction, rear direction, side direction) of the vehicle is also determined based on the unbalanced loads on the front side and the rear side, the right side and the left side of the seat body 1. Therefore, for example, by preliminarily experimentally obtaining a tendency of occurrence of a failure depending on the collision direction, inspection / maintenance can be smoothly performed.

(8) In the present embodiment, the indicator lamp 29 is turned on in response to the detection of a defect, so that the user's early inspection can be promoted. (9) In the present embodiment, the indicator lamp 29 is turned on when the malfunction is detected, so that the user can be visually informed smoothly.

The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. -In the above-mentioned embodiment, the occurrence of the problem is notified by turning on the indicator lamp 29 as the notifying means, but it may be notified by, for example, issuing a warning sound by a voice output device. Even with such changes, the same effects as (1) to (8) of the above embodiment can be obtained.

In the above embodiment, the seat body 1
The failure was detected based on the unbalanced load generated on the front side and the rear side, and on the right side and the left side. On the other hand, malfunction may be detected when an unbalanced load occurs on the front side and the rear side of the seat body 1 and on the right side and the left side.

In the above embodiment, the seat body 1
Failure was detected based on the imbalanced load generated on one side and the other side (front side and rear side, right side and left side). On the other hand, the malfunction may be detected only by an unnatural load generated on one side (front side, rear side, right side, left side) of the seat body 1. Specifically, the front side detected load value Fr, the rear side detected load value Rr, the right side detected load value RH, and the left side detected load value LH.
If at least one of the values is less than a predetermined negative load value (negative load that cannot occur in normal use), the malfunction may be detected.

In the above embodiment, the seat body 1
Pair of load sensors 21 arranged on one side and the other side
The output load values FR to RL of 24 to 24 were summed up to calculate the front detection load value Fr, the rear detection load value Rr, the right detection load value RH, and the left detection load value LH. Then, a defect is detected based on these detected load values Fr, Rr, RH, LH. On the other hand, the output load values FR to RL of the load sensors 21 to 24 arranged on one side and the other side of the seat body 1 are replaced with the same detected load values Fr, Rr, RH, and LH as they are. May be detected. For example, the same fault detection is performed by replacing the output load values FR, RR before and after the right side or the output load values FL, RL before and after the left side with the detected load values Fr, Rr. In this case, one load sensor may be provided in front of and behind the seat body 1. Alternatively, the front left and right output load values FR, F
The same fault detection is performed by replacing the output load values RR and RL on the L side or the rear left and right sides with the detected load values RH and LH. In this case, one load sensor may be provided on each of the left and right sides of the seat body 1. Alternatively, similar failure detection is performed based on the output load values FR, RL on the right front side and the left rear side or the output load values FL, RR on the left front side and the right rear side. By the way, such a load imbalance occurring in the diagonal direction occurs due to, for example, a vehicle offset collision (oblique collision).

In the above embodiment, the seat body 1
A pair of left and right front right side load sensors 21 and 22 are provided at the front part, and a pair of left and right rear right side load sensors 23 and 24 are provided at the rear part thereof. The number of such sensors (four) and their arrangement are examples, and other numbers and their arrangements may be adopted. What is essential is that a plurality of load sensors are arranged at predetermined positions of the seat body 1 and the defect detection is performed in accordance with the detected load value based on the output load value of the load sensor according to the above.

The shape of the front and rear sensor brackets 7 and 8 adopted in the above embodiment is an example, and any shape may be used as long as the bending occurs depending on the seat weight (seating load).

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

Next, technical ideas other than the claims that can be understood from the above embodiment will be described below together with their effects. (A) The occupant weight detection device according to claim 4, wherein the informing means is an indicator lamp. According to this configuration, the indicator lamp is driven (lighted) in accordance with the defect detection, whereby the user can be visually informed smoothly.

[0054]

As described in detail above, according to the invention described in any one of claims 1 to 3, it is possible to provide an occupant weight detecting device capable of detecting a defect.

According to the fourth aspect of the present invention, the informing means is driven when the malfunction is detected, so that the user's early inspection can be promoted.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a vehicle seat according to the invention.

FIG. 2 is a side view showing the same 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 flowchart showing a defect detection mode of the same embodiment.

FIG. 6 is a flowchart showing a defect detection mode of the same embodiment.

[Explanation of symbols]

1 seat body 20 Occupant weight detection device 21 Front right load sensor that constitutes the load sensor 22 Front left load sensor that constitutes load sensor 23 Rear right load sensor that constitutes the load sensor 24 Rear left load sensor that constitutes the load sensor 25 controller

Continued front page    (72) Inventor Morio Sakai             Aichi, 2-chome, Asahi-cho, Kariya city, Aichi prefecture             N Seiki Co., Ltd. (72) Inventor Yasuki Hasegawa             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Kentaro Morishita             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor, Fujimoto             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F-term (reference) 3B087 DE08                 3D054 EE10

Claims (4)

[Claims] 1. An occupant weight detection device comprising: a plurality of load sensors provided in a seat body; and a controller for calculating a detected load value based on an output load value of the load sensor to detect an occupant weight. A controller for calculating the one-side detected load value based on the output load value of the load sensor provided on one side, and the controller when the calculated one-side detected load value is below a predetermined negative load value. Is an occupant weight detection device characterized by a defect detection. 2. An occupant weight detection device comprising: a plurality of load sensors provided on a seat body; and a controller for calculating a detected load value based on an output load value of the load sensor to detect an occupant weight. First calculating means for calculating a one-side detected load value based on an output load value of a load sensor provided on one side, and another side detection based on an output load value of a load sensor provided on the other side of the seat body. A second calculation means for calculating a load value, wherein the calculated one-side detected load value is below a predetermined negative load value, and the calculated other-side detected load value exceeds a predetermined plus load value. The occupant weight detection device is characterized in that the controller detects a malfunction when 3. One side and the other side of the seat body are at least one of a front side and a rear side, a rear side and a front side, a right side and a left side, and a left side and a right side of the seat body. Item 3. The occupant weight detection device according to item 2. 4. The occupant weight detection device according to claim 1, wherein the controller drives an informing unit when a malfunction is detected.