JP2002005761A - Seated position detecting method and device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple method for determining an ischium interval and its device. SOLUTION: This seated position detecting method includes a first process for determining the right and left symmetric lines of the distribution area of pressures applied to a plurality of pressure sensor elements, a second process for determining the ratio of detection outputs from the pressure sensor elements located at the symmetric positions with the right and left symmetric lines used as a reference, a third process for judging whether the sum of the detection outputs from the pressure sensor elements located at the symmetric positions is a prescribed value or above or not with the right and left symmetric lines used as a reference, a fourth process for ranking the sum of the detection outputs from the pressure sensor elements, a fifth process for determining the ischium position of a seated person based on the maximum detection output within the ranked pressure sensors, and a sixth process for calculating the ischium interval from the determined ischium position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seating position detecting method for detecting a seating position of an occupant of an automobile or the like, and an apparatus using the same.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open Publication No. Hei.
There is one as described in 1-1115678. As shown in FIG. 11 and FIG. 12, the sensor device 2 provided inside the seating portion 1 of the seat and the airbag 3
The present invention relates to an airbag device having a control section 4 for controlling the operation of the presence or absence of deployment, explosive force, deployment speed, deployment direction and the like.

[0003] That is, based on a pressure sensor 6 for measuring a pressure distribution from a seat pressure detected by a plurality of pressure sensor elements 5 for detecting a seat pressure of a seated person T, and a detection output output from the pressure sensor 6. A processing unit 7 for detecting a distance between two pressure peaks (a distance between ischial bones) observed under the buttocks of the seated person T to determine the physique of the seated person T.

[0004] The pressure sensor 6 is formed in a sheet shape.
As shown in the figure, transparent plastic films 8a, 8b
A row electrode 9 printed on the upper plastic film 8a, a column electrode 10 printed on the lower plastic film 8b, and a circular electrode provided at a portion where the row electrode 9 and the column electrode 10 intersect. The pressure sensor elements 5 are arranged and formed in a matrix.

When a pressure is applied to the pressure sensor 6 by the occupant T, the upper and lower pressure-sensitive inks (provided at the intersections between the row electrodes 9 and the column electrodes 10) come into contact with each other, and the electricity between them is applied. Since the resistance changes, the change can be detected and the pressure distribution of the seating portion 1 can be measured. By focusing on the distance between two pressure peaks observed in the pressure distribution of the seating portion 1 based on the measurement, the distance can be measured. Is measured by the processing unit 7,
The physique of the seated person T is determined by determining the size of the lower pelvis of the seated person T (the distance between the ischial bones). When the impact detection sensor 11 detects an impact, the control unit 4 connected to the impact detection sensor 11 and the detonation device 12 for detonating the airbag 3 explodes the detonation device 12 and deploys the airbag 3. At this time, the control unit 4 inputs information on the physique of the occupant T determined by the processing unit 6 of the sensor device 2 from the sensor device 2, and based on the information, determines whether the airbag 3 is deployed or not, and Determine the force, deployment speed, deployment direction, etc.

[0006]

However, in the above-described airbag apparatus, the description is given of obtaining the distance between the ischial bones of the occupant T. However, a method for calculating the distance is described. Is not disclosed.

It is an object of the present invention to provide a simple method for determining the distance between ischial bones and a device therefor.

[0008]

According to a first aspect of the present invention, a position of a seated bone of a seated person is determined based on outputs from a plurality of pressure sensor elements applied by the seated bones of the seated person. In the seating position detection method for detecting, a first step of determining left and right target lines of an area of a pressure distribution applied to the plurality of pressure sensor elements, and from the pressure sensor elements located at target positions based on the left and right target lines. And a second step of determining whether the sum of detection outputs from the pressure sensor elements located at the target position with respect to the left and right target lines is equal to or greater than a predetermined value. A third step of ranking the sum of the detection outputs from the pressure sensor elements, and determining the ischium position of the seated person based on the maximum detection output among the ranked pressure sensors. A fourth step of, is made of a fifth step of calculating the sciatic distance from the determined ischial position.

A second aspect of the present invention compares a sheet-shaped pressure sensor, which is composed of a plurality of pressure sensor elements and is disposed on a seat, with detection outputs output from the plurality of pressure sensor elements constituting the pressure sensor. Left and right target line calculation means for calculating the left and right target lines of the area of the pressure distribution, and a pressure sensor element for outputting a pair of maximum pressures located on the left and right with respect to the left and right target lines calculated by the left and right target line calculation means. And ischal position determining means to be determined.

According to a third aspect of the present invention, the ischial position determining means ranks the pressures based on the output from the pressure detecting element, and determines the position of the pressure sensor element that outputs the maximum pressure as the ischium position. It is a feature.

In a fourth aspect of the present invention, the ischial position determining means further obtains a sum of pressures equal to or higher than a predetermined value among the pressures classified based on the output from the pressure detecting element, and determines the sum as the weight of the seated person. It is characterized by the following.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. Embodiment 1 FIG. Next, a method of obtaining the distance between the ischial bones according to the present invention will be described below. This is described with reference to FIG.
And a flowchart shown in FIG. First, a plurality of circular pressure sensor elements (each small cell in FIG.
The position of 5) is determined by considering the horizontal axis as the X coordinate and the vertical axis as the Y coordinate, as shown in FIG. 2, and furthermore, at the boundary between the pressure sensor elements 5 arranged in a grid (see FIG. 2). 2, a vertical virtual center line (for example, denoted by a reference symbol L in FIG. 2) is set at Z1 to Z9, and the virtual center line L is set in the horizontal direction and the pressure sensor The element 5 is moved as one unit. That is, the position of the virtual center line L is changed from Z1 → Z2 → Z in the horizontal direction.
They are sequentially moved in the order of 3 → Z4 → Z5 → Z6 → Z7 → Z8 → Z9.

Accordingly, when the virtual center line L is moved every time the virtual center line L is considered as a reference in the horizontal direction of the coordinates, the pressure P (−) generated on the left side of the virtual center line L is considered.
X, Y) and whether the data based on the pressure P (X, Y) generated on the right side is appropriate as the pressure generated by the occupant T is determined by the conditional expression (1) P (X, Y) / P ( −X, Y) = 1 (2) Filtering is performed based on P (X, Y) + P (−X, Y)> K (predetermined value) to make a determination. When these two conditional expressions are not satisfied, for example, the seated person T sits down with his / her hand on the seat surface of the pressure sensor 6, and the pressure detected under the buttocks of the seated person T seated properly. (It is to be noted that this determination is based on the fact that the pressure distribution observed under the buttocks of a human should be generated symmetrically to the left and right of the center line passing through the backbone of the seated person T. ).

As a result, if the above two conditional expressions are not satisfied, the generated pressure P (X, Y) at the coordinates (X, Y)
Even if Y) and P (−X, Y) are not 0, P (X, Y) = 0 is treated as P (−X, Y) = 0.

That is, this means that the actually measured data (unprocessed data) of the pressure distribution shown in FIG. 3 (A) is converted from step ST10 to step ST19 in the flowchart shown in FIG.
By executing the steps up to the above, the virtual center line L is moved in the X-axis direction as described above in the direction of Z1 → Z2 → Z3 → Z4 →
Signal processing is performed while sequentially moving in the order of Z5 → Z6 → Z7 → Z8 → Z9.
(B), (C), FIGS. 4 (D) to (F), FIGS. 5 (G) to
(I), as illustrated in FIG. 6 (J).

That is, by executing the steps from step ST10 to step ST19 in the flow chart shown in FIG. 7, the pressure distribution data formed symmetrically to the left and right with respect to the virtual center line L is obtained. One large pressure distribution data in the range where the pressure is generated is selected (step ST20).

Next, this will be described in detail with reference to the flowchart shown in FIG. For example, as shown in FIG. 2, the pressure from the buttocks of the seated person T is applied to each of the plurality of pressure sensor elements 5 arranged in a matrix,
Occurs so as to be partially different depending on the shape and the like. As a result, the output from the pressure sensor 6 shows a pressure distribution as shown in FIG. 3A (a white portion has a pressure of 0, and the pressure increases as the color becomes darker). In this pressure distribution data, a virtual center line L is first set at the position Z1 (that is, the origin of the coordinates in this case is set to the virtual center line L in FIG. 2).
Is set at the top position O). In other words, in order to initialize the coordinates for starting the calculation in step ST10 and step ST11, X = X1, Y =
Let it be Y1.

Then, in step ST12, the ratio P (X1,
It is determined whether or not (Y1) / P (-X1, Y1) is substantially 1, and is determined to be substantially 1. Further, the sum of the pressure values, that is, P (X1, Y1) is determined by the load determination in step ST13.
If the value of + P (−X1, Y1) is larger than the predetermined value K, the coordinates (X1, Y1) that generated the pressure, (−X
The output of the pressure sensor element 5 located at (1, Y1) is determined to be the pressure detected under the buttocks of the seated person T, but if the conditional expression is not satisfied, the output of the pressure sensor element 5 is below the buttocks of the seated person T. It is determined that the pressure is not an allowable pressure, and in step ST14, P (X1, Y1) and P (-X1, Y
1) and are replaced with 0.

Thereafter, in step ST15, the abscissa X is changed to X
1 is set to X2 (= X1 + 1).
At 16, the value of the abscissa exceeds the value k of the virtual center line L (k = 1 in this case because it is Z 1), so the process proceeds to step ST 17, and the above calculation is performed by shifting one by one in the vertical direction.
That is, the abscissa X is changed to X1 in step ST17, and the ordinate Y is changed from Y1 to Y2 (= Y1 +
1), and the ordinate is Y2 in step ST19.
Does not exceed Y10, the process returns to step ST12, and a pressure distribution diagram (FIG. 3 (B)) at the virtual center line L at the position Z1 in FIG. 2 is obtained.

Next, by moving the virtual center line L to the position Z2 in FIG. 2 and performing the calculations from step ST10 to step ST20 as described above, a pressure distribution diagram (FIG. 3C) is obtained. However, the difference between this case and the case where the virtual center line L is Z1 is that k is 2 in step ST16 in FIG.
Steps ST16 to ST16 are repeated twice.

Next, by moving the virtual center line L to the position Z3 in FIG. 2 and performing the calculations in steps ST10 to ST20 as described above, a pressure distribution diagram (FIG. 4D) is obtained. However, the difference between this case and the case where the virtual center line L is Z1 is that k becomes 3 in step ST16 in FIG.
Thus, step ST16 is repeated three times.

By repeating this process until the virtual center line L becomes Z9, the pressure distributions shown in FIGS. 4 (E) to 6 (J) are obtained.
Among the plurality of pressure distributions determined for each virtual center line L, the largest one of the pressure distribution areas is determined for each of the virtual center lines L1 to L9. That is, FIG.
(C), areas of the pressure distributions shown in FIGS. 4 (D) to (F), FIGS. 5 (G) to (I), and FIG. 6 (J) (in this case, the number of colored cell parts) Is calculated. When the execution of the above-mentioned flowchart is completed, the flowchart of FIG. 8 is executed, and the instruction to move the virtual center line L in the above calculation is described in the flowchart of FIG. The flowchart shown in FIG. 7 is executed in step ST110 of FIG.

Next, the operation will be described with reference to the flowchart shown in FIG. That is, in step ST100, the position of the virtual center line L (indicated by Z1 to Z9 in FIG. 2) is set as Z1, and in step ST110, the position of the virtual center line L is Z1 in FIG. The calculation is performed according to the flowchart to determine the area S of the pressure distribution, the position of the virtual center line L is set to Z2 in step ST120, and the above calculation is repeated again.

That is, in step ST110 to step ST130, each virtual center line L from Z1 to Z9 is
, The virtual center line L is Z1
The area of the pressure distribution at the time of Z is S1, the maximum area of the pressure distribution at the time of Z2 is S2, the maximum area of the pressure distribution at the time of Z3 is S3, and the maximum area of the pressure distribution at the time of Z4 is S4 and Z5. The maximum area of the pressure distribution at the time of S5 is S5, the maximum area of the pressure distribution at the time of Z6 is S6, and the maximum area of the pressure distribution at the time of Z7 is S.
7, the maximum area of the pressure distribution at Z8 is S8, and the maximum area of the pressure distribution at Z9 is S9.

In steps ST140 and ST150, the area S1 of the pressure distribution when the virtual center line L is Z1 is initially set as the maximum pressure distribution area Smax. In step ST160, the position of the virtual center line L is successively changed. Z in direction
1 → Z2 → Z3 → Z4 → Z5 → Z6 → Z7 → Z8 → Z9
Are sequentially moved as shown in FIG. Then, in step ST170, the area Sn of the pressure distribution at the latest position of the virtual center line L
(N = any value of 2 to 9) is compared with the currently obtained maximum pressure distribution area Smax. If the area Sn of the pressure distribution at the latest position is larger, step ST180 is performed.
Is updated to the maximum pressure distribution area Smax in step ST1.
The process proceeds to 90, and if not large, proceeds to step ST190 without updating.

In step ST190, it is determined whether or not the virtual center line L has been moved to Z9. If the virtual center line L has not reached Z9, the process returns to step ST160. And a seat distance L2 in a direction orthogonal to the virtual center line L of the pressure distribution. Also,
In step ST200, the virtual center line L when the maximum pressure distribution area Smax calculated in step ST180 is calculated is calculated as a sitting position (the position of the backbone of the seated person T). In other words, the portion where the pressure generated most at the symmetric position of the virtual center line L is applied (reference numerals A and B in FIG. 9).
Is determined as the ischial position, and the intermediate position is determined as the position of the spine. The details of this will be described later.

In step ST210, the ratio (= L1 / L2) of the seat distances L1 and L2 in the vertical direction and the horizontal direction is obtained, and if it is determined that the ratio does not fall within the predetermined range, the process proceeds to step ST220. Then, what is above the pressure sensor 6 is determined to be “luggage”, the front collision detonation device 12 is instructed to “deploy the front airbag is unnecessary”, and the side collision detonation device 21 is Is instructed to "deploy the side-impact airbag", but if it is determined that the ratio falls within the predetermined range, the process proceeds to step ST230.

In step ST230, step S230 is performed.
When it is determined that the maximum pressure distribution area Smax obtained in T180 is smaller than a predetermined value, the one above the pressure sensor 6 is determined to be “child or not seated”, and the To instruct the side collision detonating device 21 to "unnecessary to deploy the airbag for side collision". If it is determined that the value is larger than the predetermined value, the step is performed. Proceed to ST250.

At step ST250, the maximum pressure distribution area Smax calculated at step ST180 is obtained.
If it is determined that the virtual center line L at the time when is obtained is more deviated toward the door side than the center of the seating portion 1, step ST26
At 0, it is determined that "the adult has approached the door and is in an irregular sitting state (so-called out-of-position)", and instructs the front-end detonator 12 to "deploy the front-end airbag". The side collision detonating device 21 is instructed that "the deployment of the side collision airbag is unnecessary".

If it is determined in step ST250 that the virtual center line L is at the center of the seating section 1, it is determined in step ST260 that "the adult is in a normal sitting state", Instructs the airbag 12 to "deploy the front airbag" and instructs the side collision detonator 21 to "deploy the airbag for side collision".

Next, a method of calculating the distance between the ischial bones will be described.
The calculation of the distance between the ischial bones is performed according to the flowcharts shown in FIGS. 7 and 10. However, since FIG. 7 has already been described, it is omitted here and will be described based on FIG. The same reference numerals are given to the parts already described in FIG. 8, and only the detailed description thereof will be described, and only different parts will be described below.

In step ST300, the virtual center line L is set to X
The portion of the maximum area S obtained while moving in the axial direction, which is applied to the left and right positions of the virtual center line L where the maximum area Smax calculated in steps ST170 and ST180 is generated (FIG. 9) Is determined as the position of the ischium, and the right coordinate is determined as PR (XR, YR), and the left coordinate is determined as PR (−XL, YL). , Next step ST
The interval between the right coordinate PR (XR, YL) obtained at 310 and the left coordinate PL (-XL, YL) is represented by PR (XR, Y).
R) -PL (-XL, YL) is calculated by calculating the absolute value, and the intermediate position is calculated as the seating position.
Then, in the next step ST320, step ST31
It is determined whether or not the absolute value of PR (XR, YR)-(-XL, YL) calculated at 0 is larger than a predetermined number. If it is smaller, the process proceeds to step ST240, and it is determined that it is larger. If so, the process proceeds to step ST250.

[0033]

As described above, according to the present invention, there is obtained an effect that the distance between the ischial bones can be accurately calculated.
In addition, it is easy to distinguish adults, children, luggage, and the like, and the deployment control of the airbag can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of an occupant protection device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state in which the pressure sensor elements 5 constituting the pressure sensor 6 are arranged in a matrix, and showing where the pressure distribution is coordinated to obtain a pressure distribution.

FIG. 3 is an explanatory diagram illustrating a process of performing signal processing on original data of a pressure distribution with reference to a certain virtual center line L;

FIG. 4 is an explanatory diagram illustrating a process of performing signal processing on original data of a pressure distribution with reference to a certain virtual center line L;

FIG. 5 is an explanatory diagram illustrating a process of performing signal processing on original data of a pressure distribution with reference to a certain virtual center line L;

FIG. 6 is an explanatory diagram illustrating a process of performing signal processing on pressure distribution original data with reference to a certain virtual center line L;

FIG. 7 is a flowchart explanatory diagram for calculating a pressure distribution area to obtain FIG. 3;

FIG. 8 is a flowchart for calculating the distance between the ischial bones and the sitting state.

FIG. 9 is an explanatory diagram of a maximum pressure distribution area.

FIG. 10 is a flowchart for calculating the distance between the ischial bones and the sitting state.

FIG. 11 is a circuit block diagram of a conventional occupant protection device.

FIG. 12 is an explanatory diagram of a pressure sensor 6 and a pressure sensor element 5 arranged on the seating section 1.

FIG. 13 is an explanatory sectional view of the pressure sensor element 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seating part 2 Sensor device 3 Airbag for front collision 4, 20 Control part 5 Pressure sensor element 6 Pressure sensor 7 Processing part 8a, 8b Plastic film 9 Row electrode 10 Column electrode 11 Impact detection sensor 12, 21 Explosion device

Claims (4)

[Claims] 1. A seating position detecting method for detecting the position of a seated bone of a seated person based on outputs from a plurality of pressure sensor elements provided on the seat and applied by the seated bones of the seated person. A first step of determining the left and right target lines of the area of the pressure distribution applied to the pressure sensor element, and a second step of calculating a ratio between detection outputs from the pressure sensor elements located at target positions with reference to the left and right target lines. And a second step of determining whether or not the sum of the detection outputs from the pressure sensor elements located at the target position with respect to the left and right target lines is equal to or greater than a predetermined value; and A third step of ranking the sum, and a fourth step of determining the ischial position of the seated person based on the maximum detection output of the ranked pressure sensors; And a fifth step of calculating the ischial distance from the ischial position. 2. A pressure distribution area comprising a plurality of pressure sensor elements, wherein a sheet-shaped pressure sensor disposed on a seat and detection outputs output from the plurality of pressure sensor elements constituting the pressure sensor are compared. Right and left target line calculating means for calculating the left and right target lines, and a sit bone position for determining a pair of pressure sensor elements that output a pair of left and right maximum pressures based on the left and right target lines calculated by the left and right target line calculating means. A seating position detecting device comprising a determining means. 3. The ischial position determining means performs pressure ranking based on the output from the pressure detecting element, and determines the position of the pressure sensor element that outputs the maximum pressure as the ischium position. The seating position detecting device according to claim 2, wherein 4. The ischium position determining means further calculates a sum of pressures equal to or more than a predetermined value among the pressures classified based on the output from the pressure detection element, and determines the sum as the weight of the seated person. The seating position detecting device according to claim 3, wherein