WO2018230202A1 - Chair and posture evaluating method - Google Patents

Abstract

In order to allow the posture of a seated person to be evaluated while limiting the number of sensors, this chair 1 is provided with: a seating part 11 that supports the buttock region of the seated person; three or more pressure sensors 21 provided in the seating part 11; a center of gravity calculating unit that calculates the center of gravity of the seated person on the seating part 11 on the basis of measurement results of the three or more pressure sensors 21; and a posture evaluating part that evaluates the posture of the seated person on the basis of where the center of gravity of the seated person is located in a plurality of areas set on the seating part 11.

Description

Chair and posture judgment method

The present invention relates to a chair and a posture determination method for determining a posture of a seated person.

A system for determining the posture of a chair occupant is known (for example, Patent Document 1 and Patent Document 2).
For example, in the system described in Patent Document 1, a plurality of detection electrodes are provided on each of the seat portion and the backrest portion, and an angle sensor that measures the angle of the backrest portion is provided. The posture of the seated person is determined based on the sensor electrodes and the sensor signals of the angle sensor.

In the system described in Patent Document 2, pressure-sensitive tubes are provided in the seat portion and the backrest portion, respectively, and the posture of the seated person is determined based on the sensor signals of the seat portion and the backrest portion.

JP 2010-233614 A JP 2016-87237 A

However, in the above-described conventional technology, since both the seat part and the backrest part require sensors, the number of sensors required is large. In addition, since signals from both the seat and backrest sensors are transmitted to the control device, wiring is complicated.

The present invention has been made in view of the above problems, and an object thereof is to provide a chair and a posture determination method capable of determining the posture of a seated person while suppressing the number of sensors.

According to the chair according to the present invention, the above-described problem is based on the seating part that supports the buttocks of the seated person, three or more pressure sensors provided in the seating part, and the measurement results of the three or more pressure sensors. The seat occupant is based on a center-of-gravity position calculation unit that calculates the position of the center of gravity of the seated person and the position of the center of gravity of the seated person in the plurality of areas set in the seating part. This is solved by providing an attitude determination unit that determines the attitude of the camera.

Further, according to the posture determination method according to the present invention, the control device calculates the position of the center of gravity of the seated person in the seated part based on the measurement results of three or more pressure sensors provided in the seated part. And a step of determining the posture of the seated person based on which of the plurality of areas set in the seating portion the center of gravity of the seated person is located in the control device. It is solved by.

According to the chair and posture determination method described above, the posture of the seated person can be determined based on the measurement result of the pressure sensor provided in the seating portion. Thereby, the posture of the seated person can be determined with a simple configuration in which the number of sensors is suppressed.

In the chair described above, the three or more pressure sensors are arranged so that a figure connecting the three or more pressure sensors as a vertex forms a two-dimensional plane.
By doing so, the position of the center of gravity of the seated person can be obtained with high accuracy.

In the chair described above, the boundary between the plurality of areas is between the front end portion and the rear end portion of the three or more pressure sensors.
In this way, the posture of the seated person can be accurately determined based on the area where the position of the center of gravity is located.

In the chair described above, the plurality of areas include a first area, a second area, and a third area provided in order from the front between the front end portion and the rear end portion, and the posture determination unit includes: When the position of the center of gravity is in the first area, the posture of the seated person is determined to be the first sitting posture sitting on the front portion of the seating portion with the upper body standing upright. I will do it.
By doing so, the specific posture of the seated person can be determined based on the position of the center of gravity of the seated person.

In the chair, the posture determination unit may be seated on the front portion of the seating portion with the upper body tilted backward when the center of gravity is in the second area. The second sitting posture is determined.
By doing so, the specific posture of the seated person can be determined based on the position of the center of gravity of the seated person.

In the above-described chair, the posture determination unit is seated at the rear portion of the seating portion in a state where the posture of the seated person is upright when the position of the center of gravity is in the third area. It is determined that the posture is the third sitting posture.
By doing so, the specific posture of the seated person can be determined based on the position of the center of gravity of the seated person.

In the chair described above, the distance between the first boundary that is the boundary between the first area and the second area and the rear end is at least four times the distance between the first boundary and the front end. .
By doing so, it can be accurately determined whether the seated person's posture is the first seating posture or the second seating posture.

In the chair described above, a second boundary, which is a boundary between the second area and the third area, is located approximately at the center between the front end portion and the rear end portion.
By doing so, it can be accurately determined whether the seated person's posture is the second seating posture or the third seating posture.

In the chair described above, a target range of the center of gravity position of the seated person is set based on a locus of the center of gravity position of the seated person in the seating part calculated by the center of gravity position calculating unit when the seated person is in a target posture. A target range setting unit for determining whether the seated person is in the target posture based on whether the center of gravity position of the seated person is within the target range; To do.
By doing so, it can be accurately determined whether or not the posture of the seated person is the target posture.

According to the present invention, the posture of a seated person can be determined with a simple configuration in which the number of sensors is suppressed.
According to the present invention, the position of the center of gravity of the seated person can be obtained with high accuracy.
According to the present invention, the posture of the seated person can be accurately determined based on the area where the position of the center of gravity is located.
According to the present invention, the specific posture of the seated person can be determined based on the position of the center of gravity of the seated person.
According to the present invention, it can be accurately determined whether the posture of the seated person is the first sitting position or the second sitting position.
According to the present invention, it is possible to accurately determine whether the seated person's posture is the second sitting posture or the third sitting posture.
According to the present invention, it is possible to accurately determine whether or not a seated person's posture is a target posture.

It is a whole block diagram of a chair. It is a figure which shows the structure of a seating part and a control apparatus. It is a figure which shows the function with which a control apparatus is equipped. It is a figure explaining arrangement and coordinates of a pressure sensor. It is a figure which shows a 1st seating attitude | position. It is a figure which shows a 2nd sitting posture. It is a figure which shows a 3rd sitting posture. It is a figure which shows the relationship between a pressure sensor and a seating attitude | position. It is a figure which shows the relationship between a gravity center position and a seating attitude | position. It is a figure which shows the relationship between an area and a sitting posture. It is a flowchart of a posture determination process. It is another example which shows the relationship between an area and a sitting posture. It is a figure which shows the structure of the chair which concerns on 2nd Embodiment. It is a figure which shows an example of the operation screen displayed on an operation terminal. It is a figure which shows an example of the operation screen displayed on an operation terminal. It is a figure which shows an example of the operation screen displayed on an operation terminal. It is a figure which shows an example of the operation screen displayed on an operation terminal. It is a flowchart of the whole process of the control apparatus which concerns on 2nd Embodiment. It is a flowchart of the attitude | position determination process of the control apparatus which concerns on 2nd Embodiment. It is a flowchart of the attitude | position determination process of the control apparatus which concerns on 2nd Embodiment.

Hereinafter, the chair 1 and the posture determination method according to an embodiment of the present invention (hereinafter, this embodiment) will be described with reference to FIGS. 1 to 20.
The embodiment described below is merely an example for facilitating the understanding of the present invention, and does not limit the present invention. That is, the shape, dimensions, arrangement, and the like of the members described below can be changed and improved without departing from the spirit of the present invention, and the present invention naturally includes equivalents thereof.

In the following description, the “front-rear direction” means the front-rear direction when viewed from the seated person of the chair 1.
The “chair width direction” means the horizontal width direction of the chair 1 and coincides with the left-right direction when viewed from the seated person of the chair 1.
The “vertical direction” means the height direction of the chair 1 and coincides with the vertical direction when the chair 1 is viewed from the front.

[Composition of chair 1]
In FIG. 1, the whole structure of the chair 1 which concerns on 1st Embodiment is shown. As shown in FIG. 1, the chair 1 includes a seating part 11, a backrest part 12, a support 13, a leg part 14, a sensor part 20, and a control device 30 as main components.

The seating part 11 is a part that supports the buttocks of the seated person. Specifically, the upper surface of the seating portion 11 is a seating surface that supports the buttocks of the seated person. A support column 13 is connected to the lower surface of the seating portion 11, and the seating portion 11 is supported by the support column 13.

The backrest 12 is a portion that supports the back of the seated person. The backrest portion 12 is connected to the rear end of the seating portion 11, and the front surface of the seating portion 11 serves as a backrest surface that supports the back of the seated person.

The support column 13 is a columnar member that supports the seat portion 11 from below. The support column 13 includes an expansion / contraction mechanism that expands and contracts in response to an operation by an operation unit (not shown). Thereby, the height of the seating part 11 can be adjusted.

The leg portion 14 is a portion that is attached to the lower portion of the column 13 and supports the column 13. The leg part 14 is provided for every predetermined angle (for example, 60 degree | times, 90 degree | times) centering | focusing on the support | pillar 13, for example. And the caster is attached to the front-end | tip part of the leg part 14, and the movement on the floor of the chair 1 is made easy.

The sensor unit 20 is a device that is provided in the seating unit 11 and detects the sitting state of the seated person of the chair 1.
As shown in FIGS. 1 and 2, the sensor unit 20 has three or more pressure sensors provided in the seating unit 11.
Specifically, the sensor unit 20 includes a first pressure sensor 21a, a second pressure sensor 21b, a third pressure sensor 21c, a fourth pressure sensor 21d, a first transmission unit 22, a second transmission unit 23, and a connection unit 24. Prepare.

The first pressure sensor 21 a is a sensor that is disposed in the right rear portion of the seating portion 11 and measures the pressure applied to the right rear portion of the seating portion 11.
The second pressure sensor 21 b is a sensor that is disposed on the right front portion of the seating portion 11 and measures the pressure applied to the right front portion of the seating portion 11.
The third pressure sensor 21 c is a sensor that is disposed on the left front portion of the seating portion 11 and measures the pressure applied to the left front portion of the seating portion 11.
The fourth pressure sensor 21 d is a sensor that is disposed in the left rear portion of the seating portion 11 and measures the pressure applied to the left rear portion of the seating portion 11.
In the following description, items common to the first pressure sensor 21a to the fourth pressure sensor 21d will be described as the pressure sensor 21.

The sensor unit 20 transmits the pressure measurement values of the plurality of pressure sensors 21 to the control device 30 through the first transmission unit 22, the second transmission unit 23, and the connection unit 24.
Specifically, each pressure sensor 21 is connected to the 1st transmission part 22 which consists of a conducting wire and a conducting wire holding film. And the control apparatus 30 is connected to the 2nd transmission part 23 which is a harness provided with the connector at the front-end | tip part. The first transmission unit 22 and the second transmission unit 23 are connected at the connection unit 24.
Thus, the pressure value measured by each pressure sensor 21 is input to the control device 30 through the first transmission unit 22, the connection unit 24, and the second transmission unit 23.
The pressure value measured by each pressure sensor 21 varies depending on the seating posture of the seated person with respect to the chair 1.

The control device 30 is connected to the sensor unit 20 and receives the measurement value of each pressure sensor 21 of the sensor unit 20. And the control apparatus 30 determines the attitude | position of the seated person of the chair 1 based on the measured value of each pressure sensor 21 received from the sensor part 20. FIG. Details of the posture determination processing by the control device 30 will be described later.

Hereinafter, the configuration of the seating unit 11, the sensor unit 20, and the control device 30 will be described with reference to FIGS.

FIG. 2 is a diagram illustrating the configuration of the seating unit 11 and the control device 30. As shown in FIG. 2, the seat portion 11 includes a resin frame 11a, a pad material 11b, and a skin material 11c.
Specifically, the seat portion 11 is configured by placing a pad material 11b on a resin frame 11a and covering the pad material 11b with a skin material 11c.
A sensor unit 20 is disposed between the pad material 11b and the skin material 11c.

The resin frame 11a is a resin frame member formed in a substantially flat plate shape. A plurality of through holes are formed in the resin frame 11a, and a linear member such as the second transmission unit 23 of the sensor unit 20 can be passed vertically.
The resin frame 11a has a size sufficient to support the pad material 11b from below. Moreover, the edge part (front end part etc.) of the resin frame 11a is curving slightly downward. Accordingly, the resin frame 11a is prevented from hitting the thigh of the seated person, and the sitting comfort in the seated part 11 is improved.

The pad material 11b is a cushion member made of foamed resin such as urethane foam. A pressure sensor 21 (a first pressure sensor 21a, a second pressure sensor 21b, a third pressure sensor 21c, and a fourth pressure sensor 21d) of the sensor unit 20 is provided on the upper surface of the pad material 11b.

A through hole 15 is formed in a substantially central portion of the pad material 11b.
The through hole 15 is a slit inclined so as to descend from the rear to the front. The second transmission part 23 and the connection part 24 of the sensor part 20 are passed through the through hole 15. Specifically, the through hole 15 is a slit having a width through which the connection part 24 can be inserted, and the connection part 24 is held in the through hole 15 in a state where the sensor part 20 is attached to the seating part 11.
And the 2nd transmission part 23 is connected to the control apparatus 30 attached to the lower part of the resin frame 11a through the through-hole 15 of the pad material 11b, and the through-hole of the resin frame 11a.

The skin material 11 c is a member such as a cloth or leather, for example, and covers the pad material 11 b to constitute the surface of the seating portion 11. Further, as described above, the pressure sensor 21 of the sensor unit 20 is disposed between the pad material 11b and the skin material 11c.

2, the control device 30 includes a processor 31, a memory 32, and a communication interface 33 as hardware. The control device 30 is attached to the lower surface of the seating portion 11 in a state of being held in a holding cover together with a battery such as a dry battery serving as a driving power source for the control device 30.

The processor 31 is hardware (for example, CPU) for executing an instruction set described in a program. The processor 31 executes various arithmetic processes based on programs and data stored in the memory 32 and controls each unit of the control device 30.

The memory 32 is a storage device that stores various programs and data. The memory 32 is also used as a work memory for the processor 31. The memory 32 may include an information storage medium such as a flash memory or an optical disk.

The communication interface 33 is a signal receiving unit that is connected to the second transmission unit 23 of the sensor unit 20 and receives a measurement value of each pressure sensor 21 of the sensor unit 20.

FIG. 3 shows functions realized by the processor 31 of the control device 30 operating based on a program stored in the memory 32.
As illustrated in FIG. 3, the control device 30 includes a center-of-gravity position calculation unit 35 and a posture determination unit 36.

[Center of gravity position calculation unit 35]
The center-of-gravity position calculation unit 35 calculates the center-of-gravity position of the seated person in the seating part 11 based on the measurement results of three or more pressure sensors 21. In the present embodiment, the center-of-gravity position calculation unit 35 calculates the position of the center of gravity of the seated person in the seating unit 11 based on the measurement results of the four pressure sensors 21.

The “center of gravity position” is a coordinate indicating the center of gravity position of the seated person in the coordinate system (sitting part coordinate system) set for the seating part 11. The center-of-gravity position calculation unit 35 obtains at least the coordinates of the center-of-gravity position in the front-rear direction as the above-described “center-of-gravity position”. Of course, the center-of-gravity position calculation unit 35 may further obtain left-right coordinates of the center-of-gravity position.
Here, the seating part coordinate system will be described with reference to FIG.

As shown in FIG. 4, the seating part coordinate system is a coordinate system indicating the position on the surface of the seating part 11 when viewed from directly above. Here, the origin of the seating part coordinate system is an intermediate position between the first pressure sensor 21a and the fourth pressure sensor 21d. Then, taking the X axis in the left-right direction and the Y axis in the front-rear direction from the origin, the coordinates of the seating surface of the seating part 11 are represented by (x, y).

In the present embodiment, the coordinates of the first pressure sensor 21a are (x1, 0), the coordinates of the second pressure sensor 21b are (x1, y1), the coordinates of the third pressure sensor 21c are (−x1, y1), the fourth The coordinates of the pressure sensor 21d are (−x1, 0). Although the values of x1 and y1 can be set arbitrarily, in this embodiment, as an example, x1 = 60 mm and y1 = 85 mm.

In addition, the figure which connects the 3 or more pressure sensors 21 with which the sensor part 20 is equipped as a vertex is arrange | positioned so that a two-dimensional plane may be made | formed.
That is, the number of pressure sensors 21 having the same X coordinate among the three or more pressure sensors 21 is two at maximum. In addition, the number of pressure sensors 21 having the same Y coordinate among the three or more pressure sensors 21 is two at the maximum.

Here, in the sitting part coordinate system, the coordinates of the gravity center position G of the seated person are represented as (Gx, Gy).
At this time, the coordinate Gy in the front-rear direction (Y-axis direction) of the gravity center position G is calculated by the following equation (1).
Gy = y1. (B + C) / (A + B + C + D) (1)
A, B, C, and D are pressure values measured by the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d, respectively.

The center-of-gravity position calculation unit 35 is mainly realized by the processor 31, the memory 32, and the communication interface 33 of the control device 30 as follows.
The processor 31 receives the pressure values measured by the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d via the communication interface 33. Then, the processor 31 calculates the coordinate Gy in the front-rear direction of the center of gravity position of the seated person in the seating unit 11 based on the above formula (1).
Then, the processor 31 stores the calculated coordinate Gy in the memory 32.
The processor 31 may calculate the coordinate Gy each time a pressure value is received from the sensor unit 20, or may calculate the coordinate Gy at a given timing. For example, the given timing may be a timing when a request for posture determination is received.

[Attitude determination unit 36]
The posture determination unit 36 determines the posture of the seated person based on which of the plurality of areas set in the seating unit 11 is located.

“The center of gravity position of the seated person” is the position of the center of gravity calculated by the center of gravity position calculating unit 35. Note that the above-described “position of the center of gravity of the seated person” includes at least the coordinate position in the front-rear direction in the seating unit coordinate system, for example.

“A plurality of areas” are a plurality of sections set on the upper surface of the seating section 11. Specifically, the “plurality of areas” is defined by a range set in the coordinate system (sitting part coordinate system) of the seating part 11. For example, the “area” may be a region having an arbitrary shape such as a rectangular region, a circular region, or a polygonal region. In the present embodiment, an example in which the “area” is set as a rectangular area will be described. In this case, the memory 32 of the control device 30 stores the coordinates of the upper left and lower right vertices of each rectangular area as data for specifying the “area”.

In the present embodiment, the “plurality of areas” includes the first area, the second area, and the third area. A first seating posture P1, a second seating posture P2, and a third seating posture P3 of the seated person are determined in association with each of the first area, the second area, and the third area.
Hereinafter, the sitting posture of the seated person associated with each of the “plural areas” will be described with reference to FIGS. 5 to 9.

FIG. 5 shows a state in which the seated person U is seated on the chair 1 in the first seating posture P1.
As shown in FIG. 5, the first sitting posture P <b> 1 corresponds to a state where the upper body U <b> 1 of the seated person U stands and the buttocks U <b> 2 of the seated person U is supported by the front part of the seating part 11. . In other words, the first sitting posture P <b> 1 indicates a state in which the upper body U <b> 1 of the seated person U does not lean against the backrest part 12 and the seated person U is seated on the front part of the chair 1.
In the first sitting posture P1, the lumbar vertebra U3 of the seated person U is upright.
The above-mentioned “sitting on the front part of the seating part 11” means a state in which the weight is applied to the front side of the seating part 11 in the front-rear direction.

FIG. 6 shows a state in which the seated person U is seated on the chair 1 in the second sitting posture P2.
As shown in FIG. 6, the second sitting posture P <b> 2 corresponds to a state where the upper part U <b> 1 of the seated person U is tilted backward and the buttocks U <b> 2 of the seated person U is supported by the front part of the seating part 11. To do. In other words, the second sitting posture P <b> 2 is a state in which the upper body U <b> 1 of the seated person U is leaned against the backrest part 12 and the seated person U is seated on the front part of the seating part 11. Indicates.
In the second sitting posture P2, the lumbar vertebra U3 of the seated person U is in the back bay state. That is, in the second sitting posture P2, the lumbar vertebra U3 is curved to the opposite side to the first sitting posture P1.

FIG. 7 shows a state in which the seated person U is seated on the chair 1 in the third seating posture P3.
As shown in FIG. 7, the third sitting posture P3 corresponds to a state in which the upper part U1 of the seated person U stands and the buttocks U2 of the seated person U is mainly supported by the rear part of the seated part 11. To do. In other words, the third sitting posture P3 is a state in which the upper body U1 of the seated person U is slightly leaned against the backrest 12 and the seated person U is seated on the rear side of the chair 1. Indicates.
In the third sitting posture P3, the lumbar vertebra U3 of the seated person U is standing.
The above-mentioned “sitting deeply in the seating portion 11” means a state in which the weight is applied to the rear side of the seating portion 11 in the front-rear direction.

Here, FIG. 8 shows the first pressure sensor 21a, the second pressure sensor 21b, and the third pressure of the sensor unit 20 in each of the first seating posture P1, the second seating posture P2, and the third seating posture P3. The measured values (pressure values) of the sensor 21c and the fourth pressure sensor 21d are shown.
The measurement value of the first pressure sensor 21a is the first measurement value, the measurement value of the second pressure sensor 21b is the second measurement value, the measurement value of the third pressure sensor 21c is the third measurement value, and the fourth pressure sensor 21d The measured value is the fourth measured value.

As shown in FIG. 8, in the first sitting posture P1, the pressure concentrates on the front portion of the seating portion 11. That is, a high pressure value is measured in the second pressure sensor 21b and the third pressure sensor 21c arranged in the front part of the seating part 11, but in the first pressure sensor 21a and the fourth pressure sensor 21d arranged in the rear. Almost no pressure values are measured.

On the other hand, in the second sitting posture P <b> 2, pressure is applied by being dispersed before and after the seating portion 11. That is, pressure values are measured in all of the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d arranged in the seating portion 11.
In the second sitting posture P2, the pressure applied to the front of the seating portion 11 is greater than the pressure applied to the rear. That is, the pressure values detected by the second pressure sensor 21b and the third pressure sensor 21c arranged at the rear are higher than the pressure values detected by the first pressure sensor 21a and the fourth pressure sensor 21d arranged at the front. growing.

In the third sitting posture P3, a larger pressure is applied to the rear portion than the front portion of the seating portion 11 as compared to the second sitting posture P2. That is, in the third seating posture P3, the pressure values detected by the first pressure sensor 21a and the fourth pressure sensor 21d arranged rearward are the second pressure sensor 21b and the third pressure sensor 21c arranged forward. It becomes larger than the pressure value detected at.

FIG. 9 shows the Y coordinate (Gy) of the center of gravity position G of the seated person in each of the first sitting position P1, the second sitting position P2, and the third sitting position P3. In FIG. 9, the Y coordinate of the first pressure sensor 21a and the fourth pressure sensor 21d is 0, and the Y coordinate y1 of the second pressure sensor 21b and the third pressure sensor 21c is y1 = 85 (mm).

As shown in FIG. 9, in the first sitting posture P1, Gy is about 85 mm. In the second sitting posture P2, Gy is approximately 65 mm. In the third sitting posture P3, Gy is about 40 mm.

And as FIG. 9 shows, the 1st seating attitude | position P1 respond | corresponds when the Y coordinate of a gravity center position is larger than 1st threshold value T1 (= 70 mm). The second sitting posture P2 corresponds to a case where the Y coordinate of the center of gravity position is greater than the second threshold value (= 45 mm) and less than or equal to the first threshold value. The third sitting posture P3 corresponds to the case where the Y coordinate of the gravity center position is equal to or smaller than the second threshold value.

Here, FIG. 10 shows the relationship between the sitting posture and the area. A rectangular region connecting the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d is a centroid position detection range A in which the centroid position can be detected.
Here, the center-of-gravity position detection range A is defined as the first area A1, the second area A2, and the third area A3 with the Y = T1 line as the first boundary C1 and the Y = T2 line as the second boundary C2. Divide into areas.

And the boundary (1st boundary C1 and 2nd boundary C2) of 1st area A1, 2nd area A2, and 3rd area A3 is between the front-end part E1 of the pressure sensor 21 of the sensor part 20, and the rear-end part E2. is there.
That is, the center-of-gravity position detection range A is provided between the front end E1 and the rear end E2 of the pressure sensor 21, and includes a first area, a second area, and a third area provided in order from the front. Including.
The front end E1 is the front end of the pressure sensor 21 that is disposed at the forefront among the pressure sensors 21. That is, the positions of the second pressure sensor 21b and the third pressure sensor 21c in the present embodiment correspond to the front end E1.
Further, the rear end portion E2 is a rear end of the pressure sensor 21 arranged at the rearmost among the pressure sensors 21. That is, the positions of the first pressure sensor 21a and the fourth pressure sensor 21d in this embodiment correspond to the rear end E2.

For example, the distance between the first boundary C1 that is the boundary between the first area A1 and the second area A2 and the rear end E2 is four times or more the distance between the first boundary C1 and the front end E1.
Specifically, the distance (d1) between the first boundary C1 and the rear end E2 is 70 mm, and the distance (d2) between the first boundary C1 and the front end E1 is 15 mm. In this case, d1 is at least four times d2.

In addition, a second boundary C2 that is a boundary between the second area A2 and the third area A3 is located substantially at the center between the front end E1 and the rear end E2.
Specifically, the distance (d3) between the front end E1 and the second boundary C2 is 40 mm, and the distance (d4) between the rear end E2 and the second boundary C2 is 45 mm. In this case, the 2nd boundary C2 will be located in the approximate center of the front-end part E1 and the rear-end part E2. For example, d3 / d4 may have a relationship of 0.8 to 1.2.

In the present embodiment, the first area A1 is an area where the Y coordinate is larger than T1. Here, the first area A1 is an area corresponding to the first sitting posture P1.
The second area A2 is an area whose Y coordinate is larger than T2 and equal to or smaller than T1. Here, the second area A2 is an area corresponding to the second sitting posture P2.
The third area A3 is an area whose Y coordinate is T2 or less. Here, the third area A3 is an area corresponding to the third sitting posture P3.

That is, when the center of gravity of the seated person U is in the first area A1, the posture determination unit 36 sits on the front part of the seating part 11 with the upper body standing upright. The first sitting posture P1 is determined.

In addition, when the position of the center of gravity of the seated person U is in the second area A2, the posture determining unit 36 sits on the front part of the seated part 11 with the upper body tilted backward. It is determined that the second sitting posture P2.

Then, when the gravity center position of the seated person U is in the third area A3, the posture determining unit 36 is seated on the rear part of the seated part 11 with the upper body standing upright. It determines with it being the 3rd sitting posture P3.

The posture determination unit 36 is realized by the processor 31 and the memory 32 of the control device 30 as follows.
First, the values of T1 and T2 are stored in the memory 32 in advance.
Then, when Gy calculated by the gravity center position calculation unit 35 is larger than T1, the processor 31 determines that the gravity center position is in the first area A1, and determines the posture of the seated person U as the first sitting posture P1.
Further, when Gy calculated by the gravity center position calculation unit 35 is greater than T2 and equal to or less than T1, the processor 31 determines that the gravity center position is in the second area A2, and sets the posture of the seated person U to the second sitting posture P2. Is determined.
Further, when Gy calculated by the gravity center position calculation unit 35 is equal to or less than T2, the processor 31 determines that the gravity center position is in the third area A3, and determines the posture of the seated person U as the third sitting posture P3. .

The control device 30 may output the determination result by the posture determination unit 36 to a display device, a speaker, etc. (not shown). Further, the control device 30 may operate a vibration motor (not shown) according to the determination result by the posture determination unit 36. That is, when the determination result by the posture determination unit 36 is the first sitting posture P1 and the third sitting posture P3, the control device 30 does not operate the vibration motor because the lumbar spine U3 is in a standing posture. On the other hand, when the determination result by the posture determination unit 36 is the second sitting posture P2, since the lumbar vertebra U3 is in the back bay posture, the control device 30 operates the vibration motor to It is also possible to call attention to correct the posture.

[Flow of attitude determination processing]
Next, a flow of the posture determination process of the seated person of the chair 1 executed by the control device 30 will be described with reference to the flowchart shown in FIG.

As shown in FIG. 11, the processor 31 of the control device 30 acquires a measurement value from the sensor unit 20 via the communication interface 33 (step S1). Specifically, the processor 31 acquires the measured values of the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d of the sensor unit 20.

Then, the processor 31 calculates the position of the center of gravity of the seated person U based on the acquired measurement value (step S2). Here, the Y coordinate (position coordinate in the front-rear direction) of the gravity center position is calculated. The Y coordinate of the center of gravity position is calculated based on the above-described equation (1).

Next, the processor 31 determines whether the calculated gravity center position is located in the first area A1, the second area A2, or the third area A3 (step S3).
Specifically, the processor 31 determines that the gravity center position is located in the first area A1 if the calculated Y coordinate of the gravity center position is greater than TH1.
Further, the processor 31 determines that the gravity center position is located in the second area A2 if the calculated Y coordinate of the gravity center position is greater than TH2 and equal to or less than TH1.
Further, the processor 31 determines that the gravity center position is located in the third area A3 if the calculated Y coordinate of the gravity center position is equal to or less than TH2.

Next, when the gravity center position is in the first area as a result of the determination in S3 (step S3: first area), the processor 31 determines that the sitting posture of the seated person U is the first sitting posture P1. (Step S4).
Further, if the result of determination in S3 is that the position of the center of gravity is in the second area (step S3: second area), the processor 31 determines that the sitting posture of the seated person U is the second sitting posture P2 ( Step S5).
Further, if the result of the determination in S3 is that the position of the center of gravity is in the third area (step S3: third area), the processor 31 determines that the sitting posture of the seated person U is the third sitting posture P3 ( Step S6).

The processor 31 may notify the seated person U of the determination result of the sitting posture by outputting a notification sound according to the determination results of S4, S5, and S6.
Further, the processor 31 may periodically execute the above processing.

[Second Embodiment]
Next, based on FIG. 13 thru | or FIG. 20, the chair 1 which concerns on 2nd Embodiment of this invention is demonstrated.
As shown in FIG. 13, in the chair 1 according to the second embodiment, the control device 30 provided in the chair 1 is connected to the operation terminal 40 so as to be communicable. Then, the chair 1 can be operated by operating the touch panel display 44 as an input device of the operation terminal 40, and information on the seated person U of the chair 1 is displayed on the touch panel display 44 as a display device of the operation terminal 40. It can be displayed.
In the present embodiment, the control device 30 and the operation terminal 40 are provided with a wireless communication chip and perform wireless communication. However, the control device 30 and the operation terminal 40 may be connected to each other by wire. Good.

The operation terminal 40 is a computer such as a smartphone, a tablet terminal, or a personal computer.
As illustrated in FIG. 13, the operation terminal 40 includes a processor 41, a memory 42, a communication interface 43, and a touch panel display 44 as hardware.

The processor 41 is hardware (for example, CPU) for executing an instruction set described in a program. The processor 41 executes various arithmetic processes based on programs and data stored in the memory 42 and controls each unit of the operation terminal 40.
The memory 42 is a storage device that stores various programs and data. The memory 42 is also used as a work memory for the processor 41. Note that the memory 42 may include an information storage medium such as a flash memory or an optical disk.
The communication interface 43 communicates wirelessly with the communication interface 33 of the control device 30 and transmits / receives signals to / from the control device 30.
The touch panel display 44 is a device that allows input by directly touching the display. The processor 41 generates a display screen and displays it on the touch panel display 44 and accepts an operation input from the user via the touch panel display 44.

As shown in FIG. 13, the control device 30 according to the second embodiment includes a center-of-gravity position calculation unit 35, a posture determination unit 36, and a target range setting unit 37 as functions.
The center-of-gravity position calculation unit 35, the posture determination unit 36, and the target range setting unit 37 are each realized by the processor 31 of the control device 30 operating based on a program stored in the memory 32.
The center-of-gravity position calculation unit 35 is not different from the first embodiment, and a description thereof will be omitted. The target range setting unit 37 is not included in the first embodiment. Further, the posture determination unit 36 is different from the first embodiment in terms of processing using the target range set by the target range setting unit 37. Below, the target range setting part 37 is demonstrated first.

The target range setting unit 37 is based on the locus of the center of gravity position of the seated person U in the seating part 11 calculated by the center of gravity position calculating unit 35 when the seated person U is in the target posture. Set.
The “target posture” is a predetermined posture of the seated person U who sits on the seating portion 11 of the chair 1. For example, the above-mentioned “target posture” is a posture in which the seated person U normally sits on the seating portion 11 (hereinafter, standard sitting posture). Further, the target posture is not limited to the above-mentioned standard sitting position, and for example, “end sitting position”, “half-sitting position”, “right tilted sitting position”, “left tilted sitting position”, and the like may be used as the above “target posture”.
The “end sitting position” refers to a state in which the seated person U is seated near the front end of the seating portion 11. For example, the first sitting posture P1 corresponds to the “end sitting position”.
The “half-sitting position” refers to a state where the seated person U is seated on the seating part 11 with the upper body leaning backward and leaning against the backrest part 12. For example, the second sitting posture P2 corresponds to “half-sitting position”.
The “right tilted position” refers to a state in which the seated person U is seated on the seating portion 11 while being tilted to the right.
The “left tilted position” refers to a state in which the seated person U is seated on the seating portion 11 while being tilted to the left.

Further, the above-mentioned “track of the center of gravity position” is a curve formed by connecting the center of gravity positions calculated by the center of gravity position calculating unit 35 when the seated person U is in the target posture.
The “target range” is an area corresponding to the locus of the center of gravity. For example, a target circle that represents the locus of the center of gravity by circle approximation corresponds to the “target range”. The target circle may be a perfect circle or an ellipse.
For example, when the “target range” is represented by a circle, the “target range” is defined by the center position and the radius in the coordinate system (sitting unit coordinate system) of the seating unit 11.
Further, the “target range” is not limited to a circle, and may be a rectangle or any other shape.

The target range setting unit 37 can update the target range as appropriate. For example, a target range can be set for each seated person U sitting on the chair 1. At this time, the target range may be set in association with the identification information of the seated person U so that the target range can be read based on the identification information of the seated person U.

The posture determination unit 36 can perform the same processing as in the first embodiment, and in addition, can perform the following determination.
That is, the posture determination unit 36 determines whether or not the seated person U is in the target posture based on whether or not the gravity center position of the seated person U is within the target range.
Specifically, the posture determination unit 36 determines that the posture of the seated person U is the target posture when the position of the center of gravity of the seated person U is within the target range set by the target range setting unit 37. On the other hand, when the position of the center of gravity of the seated person U is not within the target range set by the target range setting unit 37, the position determination unit 36 determines that the position of the seated person U is not the target position.
Here, the center of gravity position being in the target range may be, for example, that the period in which the center of gravity position is in the target range in the measurement period of the center of gravity position of the seated person U is a predetermined ratio or more.

Next, based on FIG. 14 thru | or FIG. 17, the flow of the process in the chair 1 which concerns on 2nd Embodiment is demonstrated.
An operation screen 50 shown in FIG. 14 is an example of a screen displayed on the touch panel display 44 of the operation terminal 40.
The operation screen 50 shown in FIG. 14 is a menu screen. 14 includes an operation information display area 51 and a barycentric locus display area 52.

The operation information display area 51 includes a posture image display area 51A for displaying an image image and an instruction of the seated posture of the seated person U, a first icon 51B for executing a target range setting process, and the posture of the seated person U. A second icon 51C for executing the determination process is included.

The barycentric locus display area 52 is an area for displaying the locus of the gravity center position of the seated person U calculated by the gravity center position calculating unit 35.
Specifically, the four corners of the barycentric locus display area 52 correspond to the coordinate positions of the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d in the seating portion coordinate system. .
Here, when the first icon 51B in the operation information display area 51 is selected, an operation screen 50 shown in FIG. 15 is displayed.

The operation screen 50 shown in FIG. 15 is a start screen for target range setting processing. As shown in FIG. 15, in the operation information display area 51, a timer display area 51 </ b> T indicating a measurement period of the center of gravity position for setting the target range is displayed together with an instruction for a sitting posture.
In the present example, the timer display area 51T displays the measurement time by counting down. However, the present invention is not limited to this, and the measurement time may be counted up and displayed.

The operation screen 50 shown in FIG. 16 is an end screen of the target range setting process. The operation information display area 51 in FIG. 16 indicates that the remaining time of the timer display area 51T is 0 and that the setting of the target range has been completed.
Here, the center of gravity locus display area 52 displays the center of gravity locus 53A measured in the target range setting process. Further, the center-of-gravity locus display area 52 shows a target range 54 obtained by converting the center-of-gravity locus 53A into an approximate circle using a predetermined algorithm. Note that the inside of the approximate circle is the target range 54.
Also, a menu display icon 50M is displayed at the top of the operation screen 50 in FIG. 16, and the menu screen shown in FIG. 14 can be transitioned to by selecting the menu display icon 50M.

FIG. 17 shows an example of the operation screen 50 displayed when the second icon 51C for executing the posture determination process is selected from the menu screen.
The operation screen 50 shown in FIG. 17 includes a posture determination result display area 55 and a barycentric locus display area 52.
Here, the center-of-gravity locus display area 52 displays a center-of-gravity locus 53B that is a locus of the center-of-gravity position of the seated person U measured during the measurement period of the posture determination process. Then, the control device 30 of the chair 1 determines whether or not the center of gravity locus 53B is included in the target range 54. In this example, it is determined that the barycentric locus 53B is included in the target range 54.

The posture determination result display area 55 displays the result of posture determination processing based on the center of gravity position of the seated person U. In the posture determination result display area 55, a first posture image 56A, a second posture image 56B, a third posture image 56C, a fourth posture image 56D, and a fifth posture image 56E are displayed.
The first posture image 56A corresponds to “end sitting position”, the second posture image 56B corresponds to “standard sitting position”, the third posture image 56C corresponds to “half sitting position”, and the fourth posture image 56D. Corresponds to “right tilted position”, and the fifth posture image 56E corresponds to “left tilted position”.
Based on the posture determination result of the control device 30, the determination result specifying frame 57 is displayed in any one of the first posture image 56A to the fifth posture image 56E.
In the example shown in FIG. 17, it is displayed that the posture of the seated person U is determined to be the standard sitting position.

Next, the flow of processing executed by the control device 30 of the chair 1 according to the second embodiment will be described based on the flowcharts shown in FIGS.

As shown in FIG. 18, the processor 31 of the control device 30 acquires a measured value from the sensor unit 20 (S11). Specifically, the processor 31 acquires the measured values of the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d of the sensor unit 20.

Here, the processor 31 determines whether or not the seating position of the seated person U is appropriate based on the measurement value acquired from the sensor unit 20 (S12). Specifically, the processor 31 determines that the first pressure sensor 21a and the fourth pressure sensor 21d are appropriate when the values are within a predetermined range, and otherwise determines that the values are not appropriate.

When the seating position of the seated person U is not appropriate (S12: No), the processor 31 displays an instruction of the seating position on the touch panel display 44 of the operation terminal 40 through the communication interface 33 (S13).
Here, the instruction of the sitting position may be determined based on the measurement value by the sensor unit 20 to determine which part of the seating unit 11 the seated person U is sitting on, and may be changed according to the determination result.

Next, when starting the setting of the target range (S14: Yes), the processor 31 proceeds to the process of S15.
For example, the processor 31 may execute the process of S15 when receiving a target range setting request from the operation terminal 40. Note that the operation terminal 40 requests the control device 30 to set the target range when the selection of the first icon 51B is received from the operation screen 50 shown in FIG. 14 displayed on the touch panel display 44.

Next, the processor 31 instructs the operating terminal 40 to take a sitting posture so that the seated person U takes the standard sitting position (target posture) (S15), and starts measuring time (S16).
Note that the processor 31 displays an instruction for a sitting posture on the operation screen 50 displayed on the touch panel display 44 of the operation terminal 40 through the communication interface 33.
Further, the processor 31 displays the remaining time and elapsed time of the measurement time in the timer display area 51T of the operation screen 50.

Here, the processor 31 sequentially calculates the position of the center of gravity of the seated person U based on the measurement values sequentially acquired from the sensor unit 20 (S17).
Then, the processor 31 records the locus of the calculated center of gravity position (S18). Further, the processor 31 transmits the locus data of the center of gravity position to the operation terminal 40 and causes the center of gravity locus display area 52 displayed on the touch panel display 44 of the operation terminal 40 to display the locus of the center of gravity position.

Here, as long as the predetermined time has not elapsed since the start of time measurement in S16 (S19: No), the processor 31 returns to S17 and continues the processing.
Then, when a predetermined time has elapsed from the start of timing in S16 (S19: Yes), the processor 31 ends the recording of the center of gravity position and corresponds to the standard sitting position of the seated person U based on the recorded locus of the center of gravity position. A target range is set (S20).
Specifically, the processor 31 sets the approximate circle of the recorded locus of the center of gravity as the target range.

If the target range setting is not started after S20 or in S14 (S14: No), the processor 31 proceeds to S21.
In S21, the processor 31 returns to S14 when the posture determination process is not executed (S21: No), and proceeds to S22 when the posture determination process is executed (S21: Yes).
Whether or not the posture determination process is to be executed is determined based on whether or not the processor 31 has received an execution request for the posture determination process from the operation terminal 40.
For example, when the selection of the second icon 51C is received from the operation screen 50 shown in FIG. 14 displayed on the touch panel display 44, the operation terminal 40 requests the control device 30 to execute the posture determination process.
Details of the posture determination processing in S22 will be described based on the flowcharts shown in FIGS.

As illustrated in FIG. 19, the processor 31 acquires a measurement value from the sensor unit 20 (S31), and calculates the position of the center of gravity of the seated person U based on the measurement value (S32). Here, the measured values of the first pressure sensor 21a, the second pressure sensor 21b, the third pressure sensor 21c, and the fourth pressure sensor 21d are V1, V2, V3, and V4. Then, three of Gy, Gxf, and Gxr are calculated as indices of the center of gravity as follows. Α and β are coefficients, for example, α = 85 and β = 60.
Gy = α × (V2 + V3) / (V1 + V2 + V3 + V4)
Gxf = β × (V2−V3) / (V2 + V3)
Gxr = β × (V1−V4) / (V1 + V4)

When the calculated gravity center position is within the target range (S33: Yes), the processor 31 determines that the posture of the seated person U is the standard sitting position (S34).
Then, the processor 31 displays the determination result of the posture of the seated person U on the touch panel display 44 of the operation terminal 40 (S35). For example, the processor 31 displays the determination result of the posture of the seated person U in the posture determination result display area 55 of the operation screen 50.

In S33, if the center of gravity position is not within the target range (S33: No), the processor 31 proceeds to S36.
In S36, if Gy is α1 or more (S36: Yes), the processor 31 proceeds to S37.
In S37, when the measured value V1 of the first pressure sensor 21a and the measured value V4 of the fourth pressure sensor 21d are each α2 or less (S37: Yes), the processor 31 determines that the posture of the seated person U is the end. The sitting position is determined (S38). Then, the processor 31 displays the determination result on the touch panel display 44 of the operation terminal 40 (S35).

On the other hand, if Gy is not greater than or equal to α1 in S36 (S36: No), if P1 + P4 is not less than α2 in S37 (S37: No), the processor 31 proceeds to S39.
In S39, when Gy is α3 or more (S39: Yes), the processor 31 determines that the posture of the seated person U is the half-sitting position (S40). Then, the processor 31 displays the determination result on the touch panel display 44 of the operation terminal 40 (S35).
Α1, α2, and α3 are threshold values, and α1>α3> α2. Specifically, for example, α1 = 80, α2 = 20, and α3 = 67.

On the other hand, when Gy is not α3 or more in S39 (S39: Yes), the processor 31 proceeds to S41 shown in FIG.
In S41, when Gxr is α4 or more (S41: Yes), the processor 31 determines that the posture of the seated person U is the right-tilting position (S42). Then, the processor 31 displays the determination result on the touch panel display 44 of the operation terminal 40 (S35).
Note that α4 is a positive value, and α4 = 18 as an example.

On the other hand, when Gxr is not α4 or more in S41 (S39: No), the processor 31 proceeds to S43.
In S43, if Gxr is equal to or less than -α4 (S43: Yes), the processor 31 determines that the posture of the seated person U is the left tilted position (S44). Then, the processor 31 displays the determination result on the touch panel display 44 of the operation terminal 40 (S35).
In S43, when Gxr is not −α4 or less (S43: No), the processor 31 determines that the posture of the seated person U is the standard sitting position (S45). Then, the processor 31 displays the determination result on the touch panel display 44 of the operation terminal 40 (S35).
Then, the processor 31 ends the posture determination process in S35 and ends the entire process.

According to the chair 1 according to the second embodiment, the seated person U can easily recognize the state of his / her posture through the operation terminal 40. Moreover, since the target range corresponding to the target posture can be set according to the seated person U, the accuracy of posture determination can be improved according to the individual seated person U.
Moreover, in the chair 1 which concerns on 2nd Embodiment, when not setting a target range, it is good also as using a default target range.

[Summary]
The chair 1 described above is based on the seating part 11 that supports the buttocks of the seated person U, three or more pressure sensors 21 provided on the seating part 11, and the measurement results of the three or more pressure sensors 21. The position of the center of gravity of the seat occupant U is calculated, and the position of the center of gravity of the seat occupant U is determined based on which of the plurality of areas set in the seat section 11 is determined. A posture determination unit 36 for determination.
According to the chair 1, the posture of the seated person U can be determined based on the measurement result of the pressure sensor 21 provided in the seating portion 11. Thereby, since it is not necessary to provide a sensor in the backrest part 12, the number of sensors can be suppressed. That is, according to the chair 1, the posture of the seated person can be determined with a simple configuration in which the number of sensors is suppressed.

In the chair 1, the three or more pressure sensors 21 are arranged so that a figure connecting the three or more pressure sensors 21 as a vertex forms a two-dimensional plane.
By doing so, the position of the center of gravity of the seated person can be obtained from the pressure sensor 21.

In the chair 1, the boundary between the first area A1, the second area A2, and the third area A3 is between the front end E1 and the rear end E2 of the three or more pressure sensors 21.
By doing so, the posture of the seated person U can be accurately determined based on which area the center of gravity of the seated person U is located.

In the chair 1, when the position of the center of gravity of the seated person U is in the first area A <b> 1, the seated person U is seated at the front part of the seated part 11 with the upper body standing upright. It is determined that the posture is P1.
In the chair 1, when the position of the center of gravity of the seated person U is in the second area A <b> 2, the seated person U is seated on the front part of the seating part 11 with the upper body tilted backward. It is determined that the seating posture is P2.
In the chair 1, when the gravity center position of the seated person U is the third area A3, the seated person U is seated at the rear part of the seated part 11 with the upper body standing upright. It is determined that it is P3.
By doing so, the specific posture of the seated person can be determined from the position of the center of gravity of the seated person.

In the chair 1, the distance between the first boundary C1 that is the boundary between the first area A1 and the second area A2 and the rear end E2 is four times or more the distance between the first area A1 and the front end E1.
By doing so, it can be accurately determined whether the posture of the seated person U is the first sitting posture P1 or the second sitting posture P2.

In the chair 1, the 2nd boundary C2 which is a boundary of 2nd area A2 and 3rd area A3 is located in the approximate center of the front-end part E1 and the rear-end part E2.
By doing so, it can be accurately determined whether the posture of the seated person U is the second seating posture P2 or the third seating posture P3.

In the chair 1, the target range of the center of gravity position of the seated person U is set based on the locus of the center of gravity position of the seated person U in the seating part 11 calculated by the center of gravity position calculating unit 35 when the seated person U is in the target posture. A target range setting unit 37 is further provided. The posture determination unit 36 determines whether or not the seated person U is in the target posture based on whether or not the position of the center of gravity of the seated person U is within the target range.
By doing so, it can be accurately determined whether or not the posture of the seated person U is the target posture.

[Other Embodiments]
The present invention is not limited to the above embodiment. For example, in the above embodiment, the sensor unit 20 includes four pressure sensors, but the sensor unit 20 may include three or five or more sensors.

FIG. 12 shows the relationship between the seating posture and the area when there are three pressure sensors constituting the sensor unit 20.
As shown in FIG. 12, the sensor unit 20 includes a first pressure sensor 21a, a second pressure sensor 21b, and a third pressure sensor 21c.
The first pressure sensor 21a is different from the above-described embodiment in that the first pressure sensor 21a is arranged at the rear center part, but the arrangement of the second pressure sensor 21b and the third pressure sensor 21c arranged in the front is different. Absent.

As shown in FIG. 12, even in the case where there are three pressure sensors 21, an area where the Y coordinate is larger than T1 is the first area A1, and an area where the Y coordinate is greater than T2 and smaller than T1 in the gravity center position detection range A. The second area A2, and the area where the Y coordinate is T2 or less is defined as a third area A3.
Then, based on whether the center of gravity is located in the first area A1, the second area A2, or the third area A3, the posture of the seated person U is the first seating posture P1, the second seating posture P2, or the third seating. Whether the posture is P3 can be determined.
Specifically, when the center of gravity position is located in the first area A1, the first sitting posture P1, when the center of gravity position is located in the second area A2, the second seating posture P2, and the center of gravity position is the third area A3. Is determined as the third sitting posture P3.
Further, the posture can be similarly determined even when the number of pressure sensors 21 is five or more. Note that the number of postures as the determination result is not limited to 3, and may be 2 or 4 or more.

In the above embodiment, an example in which the present invention is applied to an office chair has been described. However, the present invention is not limited to an office chair, but can be applied to various seats such as a vehicle seat and a spectator seat.

DESCRIPTION OF SYMBOLS 1 Chair 11 Seating part 11a Resin frame 11b Pad material 11c Skin material 12 Backrest part 13 Support | pillar 14 Leg part 15 Through-hole 20 Sensor part 21 Pressure sensor 21a 1st pressure sensor 21b 2nd pressure sensor 21c 3rd pressure sensor 21d 4th pressure Sensor 22 First transmission unit 23 Second transmission unit 24 Connection unit 30 Controller 31 Processor 32 Memory 33 Communication interface 35 Center of gravity position calculation unit 36 Posture determination unit 37 Target range setting unit 40 Operation terminal 41 Processor 42 Memory 43 Communication interface 44 Touch panel Display 50 Operation screen 50M Menu display icon 51 Operation information display area 51A Posture image display area 51B First icon 51C Second icon 51T Timer display area 52 Center of gravity locus display area 53A Weight Trajectory 53B Center of gravity locus 54 Target range 55 Posture determination result display area 56A First posture image 56B Second posture image 56C Third posture image 56D Fourth posture image 56E Fifth posture image 57 Determination result specifying frame A Center of gravity position detection range A1 First 1 area A2 2nd area A3 3rd area C1 1st boundary C2 2nd boundary E1 front end E2 rear end G center of gravity P1 1st sitting posture P2 2nd sitting posture P3 3rd sitting posture U seated person U1 upper body U2 Buttocks U3 Lumbar Spine

Claims (10)

1. A seating part that supports the hips of the seated person,
   Three or more pressure sensors provided in the seating portion;
   Based on the measurement results of the three or more pressure sensors, a center-of-gravity position calculation unit that calculates the position of the center of gravity of the seated person in the seating unit;
   A chair comprising: a posture determination unit that determines the posture of the seated person based on which of a plurality of areas set in the seated part the gravity center position of the seated person is located.
2. The chair according to claim 1, wherein the three or more pressure sensors are arranged so that a figure connecting the three or more pressure sensors as apexes forms a two-dimensional plane.
3. The chair according to claim 1, wherein a boundary between the plurality of areas is between a front end portion and a rear end portion of the three or more pressure sensors.
4. The plurality of areas include a first area, a second area, and a third area provided in order from the front between the front end portion and the rear end portion,
   When the center of gravity position is in the first area, the posture determination unit has a first sitting posture in which the posture of the seated person is seated on the front portion of the seating portion with the upper body standing upright. The chair according to claim 3, wherein the chair is determined to be.
5. The posture determination unit, when the position of the center of gravity is in the second area, is a second sitting in which the posture of the seated person is seated on the front portion of the seating portion with the upper body tilted backward. The chair according to claim 4, wherein the chair is determined to be in a posture.
6. In the third seating posture in which the posture determination unit is seated at the rear portion of the seating portion in a state where the upper body stands up when the center of gravity position is in the third area. The chair according to claim 5, wherein the chair is determined to be present.
7. 6. The distance between the first boundary, which is a boundary between the first area and the second area, and the rear end is at least four times the distance between the first boundary and the front end. The chair described in.
8. The chair according to claim 6, wherein a second boundary, which is a boundary between the second area and the third area, is located substantially at the center between the front end portion and the rear end portion.
9. A target range setting unit that sets a target range of the center of gravity position of the seated person based on a locus of the center of gravity position of the seated person in the seating part calculated by the center of gravity position calculating unit when the seated person is in a target posture Further comprising
   The said posture determination part determines whether the said seated person is the said target posture based on whether the said gravity center position of the said seated person is in the said target range. Chair.
10. A step of calculating a center of gravity position of a seated person in the seating part based on a measurement result of three or more pressure sensors provided in the seating part;
    The control device includes a step of determining the posture of the seated person based on which of the plurality of areas set in the seating portion the gravity center position of the seated person is located. Posture determination method.

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