JP2010210368A - Sitting-state analyzer and sitting-state analysis method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sitting-state analyzer and a sitting-state analysis method capable of performing analysis from which the influence due to foreign matters is removed, when analyzing sitting state. <P>SOLUTION: When a region having a different pressing force as much as a prescribed amount or more relative to a template is detected, a region which is different as much as a prescribed amount or more and a corresponding region corresponding to the region are removed from the distribution of a pressing force. For example, when a sitting person is seated with foreign matters stored in a buttock pocket, the buttock pocket storing the foreign matters is treated as a region which is different, as much as the prescribed amount or more, and is removed from the distribution of the pressing force, together with the corresponding region corresponding thereto. The sitting-state from which the influence due to the foreign matters is removed can be analyzed, by analyzing the sitting-state, based on the distribution of the pressing force to which this processing is applied. Furthermore, since the corresponding region corresponding to the different region is also removed from the distribution of the pressing force, influence due to removal of the buttock pocket is also corrected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a seat capable of analyzing a seated state of a seated person, and more particularly to a seat capable of analyzing whether a foreign object is interposed between a seated person and a chair when analyzing the seated state. .

  2. Description of the Related Art Conventionally, a technique for detecting a pressure of a seated person by providing a sensor for detecting pressure on a seat surface of a chair has been used in various fields. For example, Patent Literature 1 discloses a technique for determining a seated bone interval of a seated person using outputs from a plurality of pressure sensor elements provided on a seat. The technique disclosed in Patent Document 1 is used to control the operation of an airbag when the airbag is operated for a passenger such as an automobile. Moreover, in patent document 2, the sensor sheet which detects body pressure distribution is provided in the back surface of a chair in addition to a seat surface. The technique disclosed in Patent Document 2 is used to determine the gender, seating posture, body shape, and the like of the seated person based on the output from the sensor seat.

JP 2002-5761 A JP 2003-111646 A

  Generally, clothes such as trousers and skirts are provided with pockets in the buttock. And a wallet, a mobile phone, etc. are often stored in the buttocks pocket. When a seated person sits in a state where an object harder than human skin (hereinafter referred to as a foreign object) such as a wallet or a mobile phone is stored in the buttock pocket, the foreign object stored in the buttock pocket strongly presses the seat surface. The distribution of the pressing force is considered to be different from the case where no foreign matter is stored in the pocket. That is, in the techniques disclosed in Patent Document 1 and Patent Document 2, if a seated person sits with foreign matter stored in the buttocks pocket, the calculation of the seat bone distance and the determination of the seated person's sex, sitting posture, body shape, etc. are correct. May not be done.

  An object of the present invention is to provide a seating state analysis apparatus and an analysis method capable of performing analysis while eliminating the influence of a foreign object when analyzing a seating state.

  In order to achieve this object, the invention according to claim 1 is provided on a seating surface that comes into contact with a seated person at the time of sitting, and a pressing force distribution detector that detects a distribution of pressing force received by the seating contact surface; The template storage unit that stores the template of the detection result of the pressing force distribution detection unit, and the detection result of the pressing force distribution detection unit and the template stored in the template storage unit, the pressing force is A comparison detection unit that detects a region different from the template by a predetermined amount or more, and a predetermined amount from the detection result of the pressing force distribution detection unit when the comparison detection unit detects a region different from the predetermined amount or more by the comparison detection unit. An area excluding unit excluding the above different areas and corresponding areas corresponding to areas different from the predetermined amount or more, and the pressing force distribution detection performed by the area excluding unit. Based on the component of the detection result, characterized in that it comprises a seating state analysis unit for analyzing the seating state.

  Here, the sitting state means not only the posture when sitting, but also the state of the seated person (gender, height, weight, etc.). The seating surface means not only the surface of the seating surface but also the inside of the seating surface. In other words, the pressing force distribution detection unit may be provided on the surface of the seating surface and directly contact the seated person, or may be embedded inside the seating surface to contact the seated person via the surface of the seating surface. Also good. In short, the pressing force distribution detector may be provided on the seating surface so that the distribution of the pressing force received by the seating surface can be detected.

  According to a second aspect of the present invention, in the first aspect of the present invention, the seating azimuth line that bisects the distribution of the pressing force along the seating direction facing the seated person based on the detection result of the pressing force distribution detection unit. And the corresponding region is a region that is symmetric with respect to the region different from the predetermined amount with respect to the seating direction line.

  According to a third aspect of the present invention, in the invention according to the second aspect, the seating direction determining unit divides the detection region of the pressing force distribution detection unit into a plurality of belt-like regions whose longitudinal directions are parallel to each other. A splitting unit, a barycentric position determining unit that determines the barycentric position of the pressing force distribution for one band-like region, and a seating direction line that determines a sitting direction line by performing predetermined processing based on the barycentric position And a determining unit.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the comparison detection unit is configured to determine a correspondence between a detection result of the pressing force distribution detection unit and the template. A difference detection unit that detects a region where the detection result of the pressure detection unit differs from the template by a predetermined amount or more by taking a difference between the detection result of the pressing force distribution detection unit and the template; It is characterized by having.

  The invention according to claim 5 is the invention according to claim 4, wherein the correspondence determining unit determines the correspondence between the detection result of the pressing force distribution detecting unit and the template. The outline is used.

  According to a sixth aspect of the present invention, in the fifth aspect of the invention, the correspondence determining unit determines the correspondence between the detection result of the pressing force distribution detecting unit and the template, and the contour line behind the heel portion. It is characterized by using only.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the template storage unit further detects a region different from the predetermined amount by the comparison detection unit, The detection result of the pressing force distribution detector is stored as the template in association with the personal information of the seated person.

  The invention according to claim 8 includes a pressing force distribution detecting step for detecting a distribution of pressing force received by a seating surface that contacts a seated person at the time of sitting, a template acquiring step for acquiring a template of the pressing force distribution, By comparing the detection result of the pressing force distribution detection step with the template, a comparison detecting step for detecting a region where the pressing force differs by a predetermined amount or more with respect to the template, and the comparison detecting step to increase the predetermined amount or more. When a different area is detected, an area excluding step of excluding an area different from the predetermined amount from the detection result of the pressing force distribution detection step and a corresponding area corresponding to an area different from the predetermined amount, A seating posture analysis step of analyzing the seating posture based on the detection result of the pressing force distribution detection step processed by the region exclusion step. To.

  According to a ninth aspect of the present invention, in the eighth aspect of the present invention, the seating azimuth line that bisects the distribution of the pressing force along the seating direction facing the seated person based on the detection result of the pressing force distribution detection step. And the corresponding region is a region in a position symmetrical to the region different from the predetermined amount with respect to the seating direction line.

  According to a tenth aspect of the present invention, in the invention according to the ninth aspect, the seating azimuth line determining step divides the detection result of the pressing force distribution detecting step into a plurality of belt-like regions whose longitudinal directions are parallel to each other. A dividing step, a center of gravity position determining step of determining the center of gravity position of the pressing force distribution for one band-like region, and a seating direction line for determining a seating direction line by performing predetermined processing based on the center of gravity position; And a determining step.

  The invention according to claim 11 is the invention according to any one of claims 8 to 10, wherein the comparison detection step is a correspondence that determines a correspondence between a detection result of the pressing force distribution detection step and the template. A difference detection step of detecting a region where the detection result of the pressure detection step differs from the template by a predetermined amount or more by taking a difference between the detection result of the pressing force distribution detection step and the template; It is characterized by having.

  According to a twelfth aspect of the present invention, in the invention according to the eleventh aspect, when the correspondence determining step determines the correspondence between the detection result of the pressing force distribution detector and the template, the distribution of the pressing force is determined. The outline is used.

  According to a thirteenth aspect of the present invention, in the invention according to the twelfth aspect, in the correspondence determining step, when determining the correspondence between the detection result of the pressing force distribution detection unit and the template, a contour line behind the heel portion It is characterized by using only.

  In the invention of claim 14, in the invention of any one of claims 8 to 13, when the comparison detection step does not detect a region different by a predetermined amount or more, the detection result of the pressing force distribution detection step And a template storing step of storing as a template in association with the personal information of the seated person.

  According to the first aspect of the present invention, when a region whose pressing force is different from the template by a predetermined amount or more is detected, a region different from the predetermined amount and a corresponding region corresponding to a region different from the predetermined amount or more Are excluded from the detection result of the pressing force distribution detector. For example, when a seated person sits in a state where foreign matter is stored in the buttock pocket, the shape of the foreign matter and its hardness are different from the shape of the human body and the human skin, so the distribution of the pressing force around the buttock pocket is This is different from the distribution of pressing force when no foreign matter is present in the buttock pocket. As a result, the buttock pocket in which the foreign matter is stored is regarded as a region where the pressing force is different from the template by a predetermined amount or more, and is excluded from the detection result of the pressing force distribution detection unit together with the corresponding region. Since the seating state analysis unit analyzes the seating state based on the detection result of the pressing force distribution detection unit processed by the region exclusion unit, it is possible to analyze the seating state without the influence of the foreign matter. Furthermore, since the corresponding region corresponding to the region where the pressing force is different from the template by a predetermined amount or more is also excluded from the detection result of the pressing force distribution detection unit, the detection result of the pressing force distribution detection unit in the seating state analysis Also, the influence of excluding the region where the pressing force is different from the template by a predetermined amount or more is corrected.

  In the invention according to claim 2, the corresponding region is a region that is in a symmetrical position with a region in which the pressing force is different from the template by a predetermined amount or more with respect to the seating direction line. The seating azimuth line is a line that bisects the distribution of the pressing force along the seating azimuth facing the seated person. Accordingly, by excluding a region where the pressing force is different from the template by a predetermined amount or more with respect to the sitting azimuth line, the pressing force is applied to the template from the detection result of the pressing force distribution detection unit. Thus, it is possible to more accurately correct the influence excluding areas that differ by a predetermined amount or more. Therefore, the sitting state can be analyzed more accurately.

  In the invention according to claim 3, the seating direction line is obtained by performing a predetermined process based on the position of the center of gravity in the belt-like region. Therefore, the seating direction line can be accurately obtained even if the seating direction changes. As a result, it is possible to accurately determine a region in a symmetrical position with a region where the pressing force differs by a predetermined amount or more with respect to the template with reference to the seating direction line.

  In the invention according to claim 4, the correspondence between the detection result of the pressing force distribution detector and the template is determined. Even if it is difficult to make a simple comparison because the distribution of the pressing force differs between the detection result of the pressing force distribution detection unit and the template, for example, the seating position and the direction facing the seating are different. Thus, it is possible to accurately compare the detection result of the pressing force distribution detector with the template.

  According to the fifth aspect of the present invention, the correspondence between the detection result of the pressing force distribution detector and the template is determined using the contour line of the pressing force distribution. Since the processing is simplified by using the contour line, the correspondence between the detection result of the pressing force distribution detection unit and the template is easily determined.

  In the invention according to claim 6, the correspondence between the detection result of the pressing force distribution detection unit and the template is determined using the contour line behind the buttock. The shape of the contour line behind the buttocks is less dependent on the seating state than the distribution of the pressing force that strongly depends on the seating state such as how to put on the weight of the seated person. Therefore, by using the contour line behind the buttock, the correspondence between the detection result of the pressing force distribution detection unit and the template is more accurately determined.

  In the invention according to claim 7, when a region where the pressing force is different from the template by a predetermined amount or more is not detected, that is, when no foreign matter is present, the detection result of the pressing force distribution detection unit is the personal information of the seated person. Correlated and stored as a template. Therefore, the template corresponding to the individual seated person is stored, so that the comparison between the detection result of the pressing force distribution detection unit and the template becomes more accurate.

  In the invention according to claim 8, when a region where the pressing force is different from the template by a predetermined amount or more is detected, a region different from the predetermined amount and a corresponding region corresponding to a region different from the predetermined amount or more Are excluded from the detection result of the pressing force distribution detection step. As a result, when foreign matter is stored in the buttock pocket, the buttock pocket becomes a region where the pressing force differs by a predetermined amount or more with respect to the template, and is excluded from the detection result of the pressing force distribution detection step together with the corresponding corresponding region. The Since the seating state analysis unit analyzes the seating state based on the detection result of the pressing force distribution detection process processed by the region exclusion unit, it is possible to analyze the seating state excluding the influence of the foreign matter. Furthermore, since the corresponding region corresponding to the region where the pressing force differs by a predetermined amount or more with respect to the template is also excluded from the detection result of the pressing force distribution detection step, the detection result of the pressing force distribution detection unit in the seating state analysis Also, the influence of excluding the region where the pressing force is different from the template by a predetermined amount or more is corrected.

  In the invention according to claim 9, the corresponding region is a region which is symmetrical to a region where the pressing force differs by a predetermined amount or more with respect to the template with respect to the seating direction line. The seating azimuth line is a line that bisects the distribution of the pressing force along the seating azimuth facing the seated person. Therefore, by excluding a region where the pressing force is different from the template by a predetermined amount or more with respect to the sitting azimuth line, the pressing force is applied to the template from the detection result of the pressing force distribution detection process. Thus, it is possible to more accurately correct the influence excluding areas that differ by a predetermined amount or more. Therefore, the sitting state can be analyzed more accurately.

  In the invention according to claim 10, the seating direction line is obtained by performing a predetermined process based on the position of the center of gravity in the belt-like region. Therefore, the seating direction line can be accurately obtained even if the seating direction changes. As a result, it is possible to accurately determine a region where the pressing force is different from the template by a predetermined amount or more and a region at a symmetrical position with respect to the seating direction line.

  In the invention described in claim 11, the correspondence between the detection result of the pressing force distribution detection step and the template is determined. Even if it is difficult to make a simple comparison because the distribution of the pressing force differs between the detection result of the pressing force distribution detection process and the template, such as when the seating position and the direction facing when sitting are different, for example, by determining the correspondence Thus, it is possible to accurately compare the detection result of the pressing force distribution detection step with the template.

  In the invention described in claim 12, the correspondence between the detection result of the pressing force distribution detecting step and the template is determined using the contour line of the pressing force distribution. Since the processing is simplified by using the contour line of the pressing force distribution, the correspondence between the detection result of the pressing force distribution detecting step and the template is easily determined.

  In the invention according to claim 13, the correspondence between the detection result of the pressing force distribution detection step and the template is determined using the contour line behind the buttocks. As described above, the shape of the buttock rear contour line always tends to be a shape that is substantially symmetrical with respect to the seating direction line. Therefore, by using the contour line behind the buttocks, the correspondence between the detection result of the pressing force distribution detection step and the template is determined more accurately.

  In the invention described in claim 14, when a region where the pressing force is different from the template by a predetermined amount or more is not detected, that is, when no foreign matter is present, the detection result of the pressing force distribution detecting step is the personal information of the seated person. Correlated and stored as a template. Therefore, by storing the template corresponding to the individual seated person, the comparison between the detection result of the pressing force distribution detection step and the template becomes more accurate.

1 is a schematic diagram of a seating state analysis apparatus 1 according to an embodiment of the present invention. FIG. 2 is a block diagram showing a control circuit configuration of the seating state analyzer 1. The figure which shows an example of seat surface pressure data img1 and back surface pressure data img2. The figure which shows the template used by a template comparison process. The figure which shows the correspondence table of personal information and a personal template. The flowchart explaining the main process in embodiment of this invention. The figure which shows an example of the seat surface pressure data img3 and back surface pressure data img4 when a foreign material exists in a buttocks. The flowchart explaining the process which concerns on the area | region exclusion process in embodiment of this invention. The flowchart explaining the process which concerns on the template comparison process in embodiment of this invention. The flowchart explaining the process which concerns on the seating direction line determination process in embodiment of this invention. The figure explaining the outline | summary of the process performed with respect to seating surface pressure data in a seating azimuth | direction determination process. The flowchart explaining the process which concerns on the seating state analysis process in embodiment of this invention. The figure which shows an example of the seat surface pressure data img5 from which the area | region where a foreign material intervenes was excluded.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Overview Description of the Present Invention>
FIG. 1 is a schematic diagram of a seating state analyzing apparatus 1 and a chair 2 in which the sitting state analyzing apparatus 1 according to an embodiment of the present invention is installed. The seating state analysis device 1 displays a pressure sensor 20 disposed on the surface of the chair 2, a control unit 30 that executes a series of processes related to the seating state analysis, a result of the seating state analysis by the control unit 30, and the like. Display unit 40 and an input unit 50 for receiving input from a seated person. The chair 2 includes a seating portion 3 that a seated person's buttocks contact when seated on the chair 2, a chair support leg 4 that supports the seating portion 3, and a backrest portion that contacts the seated person's back when seated on the chair 2. And 5. The pressure sensor 20 includes a seating surface pressure sensor 21 and a back surface pressure sensor 22. The seating surface pressure sensor 21 is provided on the surface of the seating unit 3 in order to detect the pressing force received by the seating unit 3. The back pressure sensor 22 is provided on the surface of the backrest portion 5 in order to detect the pressing force received by the backrest portion 5. Here, the seating surface pressure sensor 21 may be embedded in the seat portion 3. The same applies to the back pressure sensor 22. In addition, even if the pressure sensor 20 has selectively either the seat surface pressure sensor 21 provided in the seating part 3 or the back surface pressure sensor 22 provided in the backrest part 5, it is intended by the present invention. By the way. In short, it is only necessary that the pressure sensor 20 be provided somewhere on the seating surface (including the seating portion 3 and the backrest portion 5) that the seated person contacts when seated on the chair 2. Moreover, in FIG. 1, although the pressure sensor 20, the control part 30, the display part 40, and the input part 50 which are the components of the seating state analysis apparatus 1 are described separately, these may be comprised integrally. . Furthermore, the seating state analysis device 1 may be built in the chair 2 and may be integrally configured as a chair system capable of analyzing the seating state.

<Explanation of Block Diagram of the Present Invention>
FIG. 2 is a block diagram illustrating an electrical configuration of the seating state analysis apparatus 1 according to the embodiment of the present invention. As described above, the seating state analysis apparatus 1 includes the pressure sensor 20, the control unit 30, the display unit 40, and the input unit 50. The control unit 30 includes a CPU 31, ROM 32, RAM 33, interface 34, image forming circuit 35, storage device 36, and interface 37.

  The CPU 31 transmits and receives signals to and from the ROM 32, RAM 33, interface 34, image forming circuit 35, storage device 36, and interface 37, and performs various calculations and processing. The ROM 32 stores various programs and parameters for controlling the sitting state analysis apparatus 1. The RAM 33 temporarily stores a program processed by the CPU 31 and data processed by the CPU 31 in its address space.

  The interface 34 receives a control signal from the CPU 31 and transmits the control signal to the pressure sensor 20. The interface 34 receives a pressure signal from the pressure sensor 20 and transmits the pressure signal to the CPU 31. The interface 37 receives a control signal from the CPU 31 and transmits the control signal to the input unit 50. Further, the interface 37 receives an input signal from the input unit 50 and transmits the input signal to the CPU 31.

  The image forming circuit 35 forms an image signal corresponding to the control signal transmitted from the CPU 31 and transmits the image signal to the display unit 40. The image forming circuit 35 has a VRAM (not shown) as a temporary storage area for image display.

  The storage device 36 stores the personal information of the seated person and a template used in a template comparison process described later. Details of the personal information of the seated person and the template will be described later. The storage device 36 is configured by a non-volatile storage medium whose storage contents can be rewritten, such as an HDD or a flash ROM.

  The pressure sensor 20 detects the distribution of the pressing force applied to the pressure sensor 20 and generates a pressure signal. Specifically, the seat pressure sensor 21 generates a seat pressure signal, and the back pressure sensor 22 generates a back pressure signal. The generated seating surface pressure signal and back surface pressure signal are transmitted to the CPU 31 via the interface 34 and then temporarily stored in the RAM 33 as seating surface pressure data and back surface pressure data. The pressure sensor 20 has a plurality of pressure sensitive units arranged in a matrix. The pressure sensor 20 can be configured by various methods such as a pressure sensitive resistance method, a capacitance method, and an electromagnetic induction method. In this embodiment, as an example, a pressure distribution sheet such as LLSENSOR (registered trademark) manufactured by Shiroku Corporation using an electromagnetic induction method is used.

FIG. 3 is a diagram for explaining the seating surface pressure data and the back surface pressure data temporarily stored in the RAM 33. As an example of the case where no foreign matter is present in the buttocks, the seating surface pressure data img1 is shown in FIG. 3 (a), and the back pressure data img2 is shown in FIG. 3 (b). Here, the seating surface pressure sensor 21 provided in the seating part 3 is comprised of a pressure sensitive part of m rows × n columns. That is, the seating surface pressure data can be handled as image data having m rows × n columns of pixels, like the seating surface pressure data img1 shown in FIG. Here, in FIG. 3A, the horizontal direction corresponds to the x direction and the vertical direction corresponds to the y direction. Therefore, as shown in FIG. 3A, the seating surface pressure data has coordinates (x ₀ , y ₀ ) in the lower left and coordinates (x _n−1 , y _m−1 ) in the upper right. At this time, the seating surface pressure sensor 21 is arranged with the upper side in the y direction closer to the backrest 5 side so that the collar portion is on the upper side in the y direction in the seated state. Also, the back pressure data can be handled as image data in the same manner as the seat pressure data.

  The display unit 40 displays an image according to the image signal from the image forming circuit 35. The display unit 40 includes a CRT monitor, a liquid crystal monitor, and the like.

  The input unit 50 is configured to operate the seating state analysis apparatus 1 and receives an input from a seated person. The input content received by the input unit 50 is transmitted to the CPU 31 as an input signal via the interface 37.

<Description of Information Stored in Storage Device 36>
The information stored in the storage device 36 will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram showing templates used in template comparison processing to be described later. The template stored in the storage device 36 has the same data format as the seating surface pressure data described above. As is clear from a comparison between FIG. 4 and FIG. 3A, the template is in a region pressed by the seated person's buttocks (hereinafter referred to as a buttocks region) in the distribution of the pressing force included in the seating surface pressure data. The distribution of the pressing force is stored. There are two reasons why only the buttocks region is used as a template. (1) Since there are many pockets in the buttocks, there is a high possibility that foreign matter is present. (2) Since the position of the thigh (position with respect to the buttocks region, distance between the left and right thighs) varies greatly depending on the sitting posture, it is difficult to use a template including the thigh. FIG. 4A shows an example of a shared template used in common in a template comparison process to be described later. FIG. 4B and FIG. 4C show examples of personal templates used corresponding to individual seated persons in the template comparison process described later. The shared template of FIG. 4A can be created in advance using, for example, seating surface pressure data generated when a standard body type seater sits without a foreign object.

  FIG. 5 is a diagram showing a correspondence table that associates personal information of a seated person with an ID number of a personal template. This correspondence table includes personal information such as name, height, weight, date of birth, etc. that can identify an individual, and an ID number of a personal template created from the individual's seat pressure data. Of course, the information included in the correspondence table is not limited to the content described above, and any information that can identify an individual may be included.

<Description of the flow of the present invention>
FIG. 6 is a flowchart for explaining main processing performed by the CPU 31. In step S <b> 1, the CPU 31 transmits a control signal for causing the pressure sensor 20 to generate a seating surface pressure signal and a back surface pressure signal to the pressure sensor 20 via the interface 34. The pressure sensor 20 transmits the generated seating surface pressure signal and back surface pressure signal to the CPU 31 via the interface 34. The CPU 31 temporarily stores the seat surface pressure signal and the back surface pressure signal from the pressure sensor 20 in the RAM 33 as the seat surface pressure data and the back surface pressure data. Thereafter, the CPU 31 shifts the processing to step S2. The above-described step S1 is an example of the pressing force detection step in the present invention.

  In step S <b> 2, the CPU 31 executes an area exclusion process for excluding an area where a foreign object is present and an area corresponding to the area where the foreign object is present from the seating surface pressure data. Hereinafter, this region exclusion process will be described with reference to FIGS.

  FIG. 7 is a diagram illustrating the seating surface pressure data and the back surface pressure data temporarily stored in the RAM 33, as in FIG. However, unlike FIGS. 3 (a) and 3 (b), as an example of the case where foreign matter is present in the buttocks, the seating surface pressure data img3 is shown in FIG. 5 (a), and the back pressure data img4 is shown in FIG. ) Respectively. Usually, since the human body is soft, the portion that contacts the seating surface is deformed when sitting, and as a result, the distribution of the pressing force changes continuously. That is, the position where the most load is applied appears as a local peak, and the pressing force continuously decreases as the distance from the local peak increases (see local peaks LP1 and LP2 in FIG. 3). The foreign object shape and its hardness are different from the human body shape and human body hardness, and the foreign object is generally harder with respect to the hardness. Therefore, when a foreign object is present in the buttocks, the amount of deformation of the foreign object when contacting the seating surface is smaller than that of a human body. Therefore, the distribution of the pressing force in the region where the foreign matter is present is clearly different from the distribution of the pressing force in the region where the foreign matter is not present. On the other hand, the back pressure data img4 shows the distribution of the pressing force substantially the same as the back pressure data img2 because no foreign matter is interposed between the back and the back pressure sensor 22. In this embodiment, the processing when foreign matter is present in the buttocks is exemplified, but when foreign matter is present on the back, that is, the region where foreign matter is present is present in the back pressure data img4 instead of the seating surface pressure data img3. Even in this case, the same processing can be performed.

  FIG. 8 is a flowchart for explaining the area exclusion process performed by the CPU 31. In step SA1, the CPU 31 executes a template comparison process for determining a region where foreign matter is present. Hereinafter, the template comparison process will be described in detail with reference to FIG. The template comparison process shown in FIG. 9 is an example of the comparison detection unit and the comparison detection process in the present invention.

  FIG. 9 is a flowchart for explaining the template comparison process performed by the CPU 31. In step SB1, the CPU 31 receives an input signal generated from the input unit 50 input by the seated person. This input signal includes information that can identify an individual such as the name, weight, height, date of birth, etc. of the seated person. The CPU 31 temporarily stores this input signal in the RAM 33 as personal information. Thereafter, the CPU 31 shifts the processing to step SB2.

  In step SB <b> 2, the CPU 31 determines whether or not a personal template corresponding to the individual seated person is stored in the storage device 36. Specifically, the CPU 31 compares the personal information temporarily stored in the RAM 33 with the personal information included in the correspondence table (see FIG. 5) stored in the storage device 36. When determination of step SB2 is affirmative (Y), CPU31 transfers a process to step SB3. Or when judgment of step SB2 is negative (N), CPU31 transfers a process to step SB4.

  In step SB3, the CPU 31 refers to the ID number of the personal template included in the correspondence table, and reads the corresponding personal template (see FIG. 4B and FIG. 4C) from the storage device 36. For example, when the date of birth included in the personal information temporarily stored in the RAM 33 is May 24, 1973, the ID number of the corresponding personal template is “001” from FIG. The CPU reads the personal template (see FIG. 4B) with the ID number “001” from the storage device 36. The CPU 31 temporarily stores this personal template in the RAM 33 as a comparison template. Thereafter, the CPU 31 shifts the processing to step SB5.

  In step SB 4, the personal template corresponding to the personal information temporarily stored in the RAM 33 is not stored in the storage device 36. Therefore, the CPU 31 reads the shared template (FIG. 4A) from the storage device 36. The CPU 31 temporarily stores this shared template in the RAM 33 as a comparison template. Thereafter, the CPU 31 shifts the processing to step SB5.

  In step SB5, the CPU 31 determines a region (pressed region) where the pressing force is generated by the seating in the seating surface pressure data. Since the distribution of the pressing force generated by the seating changes continuously, the CPU 31 regards an area where the pressing force is a predetermined value or more as a pressed area. This predetermined value may be a threshold value determined in advance through experiments or the like, or may be obtained each time. When obtained each time, as an example, the mode value in the histogram of the pressing force is defined as the pressing force that becomes the background, that is, the pressing force outside the pressed region. Assuming that the pressing force as the background follows a normal distribution, the pressure-sensitive portion having a pressing force with a value obtained by adding “3σ”, which is three times the dispersion σ, to the pressing force as the background is It can be regarded as a contour line. A region surrounded by the contour line of the non-pressed region, that is, a pressure-sensitive portion having a pressing force equal to or greater than a value obtained by adding “3σ” to the pressing force serving as the background is a pressed region. After the pressed area is determined, the CPU 31 proceeds to step SB6.

  In step SB6, the CPU 31 determines the buttocks area from the pressed area. Specifically, the CPU 31 determines a pressed region that is located on the upper side in the y direction of the seating surface pressure data and has a substantially elliptical shape as the buttocks region. The CPU 31 extracts only the buttocks area from the seating surface pressure data and temporarily stores them in the RAM 33 as the buttocks data. Thereafter, the CPU 31 shifts the processing to step SB7.

  In step SB7, the CPU 31 determines a buttock rear outline by performing predetermined line-symmetric processing based on the buttock data temporarily stored in the RAM 33. Specifically, assuming that the contour of the buttock region is a collection of coordinates according to a line-symmetric function, the CPU 31 fits the contour of the buttock region located on the uppermost y-axis to the line-symmetric function (fitting is performed. ) To determine the buttock rear outline. As this line symmetric function, for example, an even function such as a parabolic function, a hyperbolic function, a cosine function, or a function represented by a linear combination thereof is used. Desirably, a function represented by a linear combination of a plurality of even functions is used, and fitting using the least square method may be performed using a coefficient when the plurality of even functions are linearly combined as a variable. The shape of the seated person's buttocks rear contour line is less dependent on the seating state than the pressing force distribution compared to the distribution of the pressing force that strongly depends on the seating state (how the load is applied when sitting). Therefore, by performing fitting with a line-symmetric function, the shape of the buttock rear contour line in the buttock data is determined without depending much on the seating state as compared with fitting with respect to the distribution of the pressing force. Note that the processing in step SB7 is also performed for the comparison template temporarily stored in the RAM 33. Thereafter, the CPU 31 shifts the processing to step SB8.

  In step SB8, the CPU 31 determines whether or not the collar data temporarily stored in the RAM 33 in step SB6 matches the comparison template temporarily stored in the RAM 33. Specifically, it is determined whether or not the shape of the buttock rear outline in the buttock data determined in step SB7 matches the shape of the buttock rear outline in the comparison template. Here, “match” does not mean that they are exactly the same. It is sufficient that the difference is equal to or less than a predetermined allowable amount. When determination of step SB8 is affirmation (Y), CPU31 transfers a process to step SB10. Alternatively, if the determination in step SB8 is negative (N), the CPU 31 proceeds to step SB9.

  In step SB9, the CPU 31 modifies the comparison template temporarily stored in the RAM 33. The deformation here means deformation of the shape on the coordinates. As an example, the deformation of the shape is achieved by performing primary conversion (translation, rotation, enlargement / reduction) on the comparison template. Of course, a modification including a higher-order term of the second or higher order may be used. Thereafter, the CPU 31 shifts the processing to step SB8. That is, the process in step SB9 is repeated until the shape of the buttock rear outline in the buttock data matches the shape of the buttock rear outline in the comparison template (the determination in step SB8 is affirmative (Y)).

  In step SB10, the CPU 31 calculates a difference between the heel part data temporarily stored in the RAM 33 in step SB9 and the comparison template temporarily stored in the RAM 33. Specifically, the pressing force of the pressure-sensitive part having the same coordinates in the comparison template is subtracted from the pressing force of the pressure-sensitive part in the buttock data. Here, the pressing force generated by the seating changes according to the weight of the seated person. Therefore, for example, when the shared template is used as a comparison template in step SB4, the distribution of the pressing force in the buttock data may not match the distribution of the pressing force in the comparison template. Therefore, the CPU 31 multiplies the pressing force of the comparison template by a predetermined coefficient to match the distribution of the pressing force in the buttock data with the distribution of the pressing force in the comparison template. As this predetermined coefficient, as an example, the value of the ratio between the median in the histogram created from the pressing force of the pressure-sensitive part included in the buttock data and the median in the histogram created from the pressing force of the comparison template Is used. The heel data from which the comparison template is subtracted is temporarily stored in the RAM 33 as residual data. Thereafter, the CPU 41 shifts the processing to step SB11.

  In step SB11, the CPU 41 determines whether or not there is a region where the pressing force of the seating surface pressure data differs by a predetermined amount or more with respect to the pressing force of the comparison template. Specifically, the CPU 31 takes the absolute value of the pressing force in the pressure-sensitive portion included in the residual data stored in the RAM 33 in step SB10, and determines whether there is a region where the absolute value is equal to or greater than a predetermined amount. to decide. The predetermined amount of the absolute value of the residual is determined in advance using, for example, residual data when no foreign matter is present in the buttock. As an example, for example, a method of obtaining an average value and variance in a histogram of the absolute value of the residual pressure, and determining a value obtained by adding three times the variance to the average value as a predetermined amount of the absolute value of the residual Is used. When determination of step SB11 is affirmative (Y), CPU31 transfers a process to step SB12. Or when judgment of step SB11 is negative (N), CPU31 transfers a process to step SB13.

  In step SB12, the CPU 31 sets the mask flag of the pressure-sensitive portion of the seating surface pressure data corresponding to a region where the absolute value of the residual is equal to or greater than a predetermined amount in the residual data to ON. The pressure-sensitive portion whose mask flag is set to ON is regarded as a region in which foreign matter is present (foreign matter region) and is not used for subsequent processing. Thereafter, the CPU 31 ends a series of template comparison processes and shifts the process to step SA2 (see FIG. 8).

  When the determination in step SB11 is negative (N), the seating surface pressure data temporarily stored in the RAM 33 does not include a region where foreign matter is present. Therefore, in step SB13, the CPU 31 determines whether or not to update the personal template stored in the storage device 36 using the buttock data. This determination is performed, for example, according to the following flow. (1) The occupant inputs whether or not to update the personal template using the input unit 50, (2) the CPU 31 receives an input signal generated from the input unit 50 by the input, and (3) the input signal Based on the above, the CPU 31 determines whether or not to update the personal template. Alternatively, whether or not to update may be set in advance by the seated person, and the determination in step SB13 may be performed using the setting. If the determination in step SB13 is affirmative (Y), the CPU 31 shifts the process to SB14. Alternatively, if the determination in step SB13 is negative (N), the CPU 31 ends a series of template comparison processes, and proceeds to step SA2 (see FIG. 8).

  In step SB14, the CPU 31 associates the personal information temporarily stored in the RAM 33 with the buttocks data temporarily stored in the RAM 33 and stores them in the storage device 36. Here, if the determination in step SB2 is negative (N), that is, if the shared template is used as a comparison template, the CPU 31 assigns an ID number to the buttock data. The hip data assigned with the ID number is stored in the storage device 36 as a new personal template. Further, the CPU 31 adds the personal information temporarily stored in the RAM 33 to the correspondence table stored in the storage device 36 together with the ID number assigned to the buttock data. On the other hand, if the determination in step SB2 is affirmative (Y), that is, if the personal template is used as a comparison template, the CPU 31 overwrites the personal template stored in the storage device 36 with the buttocks data. To do. Thereafter, the CPU 31 ends a series of template comparison processes and shifts the process to step SA2 (see FIG. 8).

  In step SA2, the CPU 31 executes a seating direction line determination process in order to determine a seating direction line of the seating surface pressure data. FIG. 10 is a flowchart for explaining the seating direction determination process performed by the CPU 31. FIG. 11 is a diagram illustrating an outline of processing performed on the seating surface pressure data. Here, the sitting direction line represents a line that bisects the distribution of the pressing force along the direction (sitting direction) in which the seated person faces in the state where the seated person is seated on the chair 2. For example, in the seating surface pressure data img3 in FIG. 7A, the seating direction line SD3 is substantially parallel to the y direction, which means that the seated person is seated on the seating portion 3 in the y direction. . Further, if the seated person is seated on the seat portion 3 so as to be inclined with respect to the y direction, the seating direction line is inclined with respect to the y direction. Hereinafter, the seating direction determination process will be described in detail with reference to FIGS. 10 and 11. Note that the seating orientation line determination process shown in FIG. 10 is an example of a seating orientation line determination unit and a seating orientation line determination step in the present invention.

  In step SC1, the CPU 31 performs the same process as in step SB5 (see FIG. 9). That is, the CPU 31 determines the pressed area. The area surrounded by the curves BD1, BD2, and BD3 in FIG. 11A indicates an area determined as a pressed area by the process in step SC1. After the pressed area is determined, the CPU 31 proceeds to step SC2.

  In step SC2, the CPU 31 determines a buttock rear outline by performing a predetermined line-symmetric process based on the pressed area determined in step SC1. Specifically, the CPU 31 determines the buttocks rear contour line by fitting the contour of the pressed area located on the uppermost side of the y-axis with a line-symmetric function. Since the fitting with this line symmetric function has already been described in step SB7 (see FIG. 9), the details are omitted here. A curve CTR shown in FIG. 11B is a buttock rear outline determined by the process in step SC2. Thereafter, the CPU 31 shifts the processing to step SC3.

  The determination of the buttock rear outline means that the position of the buttock of the seated person is determined. The shape of the buttock rear contour line is substantially line symmetric with respect to the seating direction line. Therefore, in step SC3, the CPU 31 determines a symmetrical line of the buttock rear contour line based on the buttock rear contour line determined in step SC2. Specifically, the symmetric line of the above-described line symmetric function is the symmetric line of the buttock rear outline. The CPU 31 temporarily stores this symmetry line in the RAM 33 as a temporary seating direction line that bisects the distribution of the pressing force. By determining the provisional seating direction line, the seating direction line can be registered to some extent. A straight line TSD shown in FIG. 11C is a temporary seating direction line TSD determined by the process in step SA3. Thereafter, the CPU 31 shifts the processing to step SC4.

  In step SC4, the CPU 31 divides the seating surface pressure data into a plurality of band-like regions. The plurality of belt-like regions are set so that the longitudinal direction is orthogonal to the above-described temporary seating direction line or temporary seating direction line candidate (see step SC13 described later). Specifically, the CPU 31 calculates the inclination of a temporary seating azimuth line temporarily stored in the RAM 33 or a straight line orthogonal to the temporary seating azimuth line candidate. Then, the CPU 31 arranges eight orthogonal straight lines at equal intervals so that the bearing surface pressure data is divided into nine belt-like regions. Each area delimited by the straight lines arranged at equal intervals is a band-shaped area. A plurality of regions ST shown in FIG. 11D are a plurality of band-like regions determined by the process in step SC4. Thereafter, the CPU 31 shifts the processing to step SA5. The process performed in step SC4 is an example of the dividing unit and the dividing process in the present invention.

  In step SC5, the CPU 31 determines whether or not there is a pressure-sensitive portion in which the mask flag is set to ON in step SB12 (see FIG. 9) in the band-like region. If the determination in step SC5 is affirmative (Y), CPU 31 advances the process to step SC6. Alternatively, if the determination in step SC5 is negative (N), the CPU 31 moves the process to step SC7.

  In step SC6, the CPU 31 determines the position of the center of gravity of the pressing force distribution in the belt-like region. Specifically, the same processing as the method for obtaining the center of gravity of the mass system is performed on the pressure-sensitive parts included in the individual band-like regions, except for the pressure-sensitive parts whose mask flag is turned on in step SB12. By not using the pressing force in the area where the foreign matter is present, the position of the center of gravity can be accurately determined without being affected by the foreign matter. The method will be described in detail below.

The position vector for the pressure sensitive part located at the coordinates (x _i , y _j ) included in the band-like area from the coordinates (x _min , y _min ) of the pressure-sensitive part where the x coordinate and y coordinate in the belt-like area are minimum r _t and the pressing force at the pressure-sensitive portion located at the coordinates (x _i , y _j ) are respectively expressed as p _t . The center-of-gravity position R _c of the belt-like region is determined by using the pressure-sensitive portion included in the belt-like region.

Is determined. However, “P” is the sum of the pressing forces of the pressure-sensitive part included in the belt-like region, that is,

It is. Thereafter, the CPU 31 shifts the processing to step SC8.

  In step SC7, the CPU 31 determines the barycentric position in the band-like region. At this time, since there is no pressure-sensitive portion whose mask flag is turned on in step SB11, the center-of-gravity position is determined using all the pressure-sensitive portions included in the band-like region. Note that the method of determining the center of gravity position is the same as in step SC6 described above. A point indicated by an asterisk in FIG. 11 (e) is the center-of-gravity position in each band-like region ST determined by the process in step SC6 or step SC7. Thereafter, the CPU 31 shifts the processing to step SC8. In addition, the process performed by step SC6 and step SC7 is an example of the gravity center position determination part and gravity center position determination process in a claim.

  In step SC8, the CPU 31 determines the seating azimuth line from the barycentric position in the band-like region determined in step SC6 or step SC7. Specifically, the CPU 31 determines the seating direction line by fitting the barycentric position in the belt-like region using a predetermined function, for example, a linear function. In other words, the slope and intercept of the linear function are determined by the method of least squares using individual centroid positions as samples. This sitting azimuth line is temporarily stored in the RAM 33. Since the longitudinal direction of the belt-like region is orthogonal to the temporary seating azimuth line, the individual gravity center positions tend to be located in the vicinity of the temporary seating azimuth line. Since the seating azimuth line is determined based on the position of the center of gravity, the seating azimuth line can be accurately determined even when the seating azimuth is inclined with respect to the front-rear direction. Further, since the seating azimuth line is determined based on the position of the center of gravity, the distribution of the pressing force is substantially symmetric with respect to the seating azimuth line. A straight line SD shown in FIG. 11F is a seating direction line determined by the process in step SC8. Thereafter, the CPU 31 shifts the processing to step SC9. The process performed in step SC8 is an example of a seating direction line determination unit and a seating direction line determination step in the claims.

  In step SC9, the CPU 31 determines the deviation amount of the center of gravity position in the belt-like region with respect to the seating direction line. Specifically, the CPU 31 obtains the sum of squares of the distance from the center of gravity position in the belt-like region to the seating direction line, and regards the sum of squares as the deviation amount of the center of gravity position. The deviation amount of the center of gravity position is temporarily stored in the RAM 33 in association with the seating direction line temporarily stored in the RAM 33. Thereafter, the CPU 31 shifts the processing to step SC10.

  In step SC10, the CPU 31 determines whether or not the deviation amount of the center of gravity position of the sitting azimuth line temporarily stored in the RAM 33 is smaller than the deviation amount (minimum deviation amount) of the center of gravity position of the best sitting azimuth line stored in the RAM 33. Judging. Here, the best seating azimuth line means a seating azimuth line that minimizes the deviation amount of the center of gravity position. If the determination in step SC10 is affirmative (Y), or if the best seating direction line is not yet stored in the RAM 33 because the processing in step SC8 and step SC9 has been performed for the first time, the CPU 31 proceeds to step SC11. To do. Alternatively, when the determination at step SC10 is negative (N), the CPU 31 proceeds to step SC12.

  In step SC11, the CPU 31 temporarily stores the seating direction line temporarily stored in the RAM 33 in the RAM 33 as a new best seating direction line. That is, the best seating direction line temporarily stored in the RAM 33 before step SC11 is updated in step SC11. At this time, the deviation amount of the center of gravity position temporarily stored in the RAM 33 in step SC9 is also temporarily stored in the RAM 33 as the minimum deviation amount in association with the best seating direction line. Thereafter, the CPU 31 shifts the processing to step SC12.

  In the seating azimuth line determination process shown in FIG. 10, the processes from step SC4 to step SC13 are repeatedly executed to more accurately determine the best seating azimuth line. Therefore, in step SC12, CPU 31 determines whether or not the processing in steps SC4 to SC13 has been repeated a predetermined number of times. The predetermined number of repetitions is set such that the processes in steps SC4 to SC13 are performed over a range of ± 30 ° around the temporary sitting direction line determined in step SC3, for example. If the determination in step SC12 is affirmative (Y), the CPU 31 ends a series of sitting azimuth line determination processes, and proceeds to step SA3 (see FIG. 8). Alternatively, if the determination in step SC12 is negative (N), the CPU 31 proceeds to step SC13.

  In step SC13, the CPU 31 creates a temporary seating direction line candidate by moving the temporary seating direction line by a predetermined angle. The predetermined angle is set to 1 °, for example, but may be changed as appropriate in consideration of the processing speed and the accuracy of the best seating direction line. A straight line TSDC shown in FIG. 11 (g) is a temporary seating direction line candidate determined by the process in step SC13. Thereafter, the CPU 31 shifts the processing to step SC4.

  With reference to FIG. 8 again, the flow of region exclusion processing will be described. In step SA3, the CPU 31 uses the seating azimuth line as a reference, and the mask flag of the pressure-sensitive part that exists in a line-symmetric position with the area where the foreign matter is present, that is, the pressure-sensitive part in which the mask flag is set to ON in step SA2. Set to ON. Thereafter, the CPU 31 ends the series of area exclusion processing, and proceeds to step S3 (see FIG. 6).

  In step S3, the CPU 31 performs seating state analysis processing using the seating surface pressure data and the back surface pressure data. Hereinafter, the seating state analysis process will be described with reference to FIG.

  FIG. 12 is a flowchart for explaining a seating state analysis process performed by the CPU 31. In the flowchart shown in FIG. 12, as an example of the seating state analysis process, a process for determining whether or not the seated person is in the back muscle direction (steps SD1 to SD7) and a process for determining whether or not the seated person is in the right and left seating balance (steps). SD8 to step SD16). The seating state analysis process shown in FIG. 12 is an example of a seating state analysis unit and a seating state analysis process in the claims.

  In steps SD1 to SD7, the seated person is informed of whether or not the seated person is seated in a state where the back muscles are straight, that is, whether or not the back muscle direction is good. Sitting in a state where the back muscles are bent may place a burden on the waist of the seated person and cause back pain and the like. That is, the seated person can maintain a comfortable and healthy sitting posture by knowing whether or not the spine direction is good.

  In step SD1, the CPU 31 performs the above-described seating direction line determination process (see FIG. 10). Since the mask flag of the pressure-sensitive part at the above-described symmetrical position is turned on (see step SA3 in FIG. 8), the best seating direction line can be determined more accurately by performing the seating direction line determination process again. . Thereafter, the CPU 31 shifts the processing to step SD2.

  In step SD2, the CPU 31 performs the same processing as that in step SC4 on the back pressure data. However, the back pressure data does not have a characteristic shape such as the back ridge shape in the seat pressure data. Therefore, unlike the seating surface pressure data, the temporary seating direction line is not defined in the backside pressure data. Therefore, the CPU 31 divides the back pressure data into a plurality of band-like regions whose longitudinal direction is parallel to the x direction. Thereafter, the CPU 31 shifts the processing to step SD3.

  In step SD3, the CPU 31 determines the position of the center of gravity in the belt-like region by performing the same process as the method of obtaining the center of gravity of the mass system using all the pressure sensitive parts included in the back pressure data. Since this process is the same as step SC7 (see FIG. 10), the details are omitted here. Thereafter, the CPU 31 shifts the processing to step SD4.

  In step SD4, the CPU 31 performs the same process as in step SC8 on the back pressure data. That is, the CPU 31 determines the back orientation line by fitting the barycentric position in the belt-like region using a predetermined function, for example, a linear function. Here, the back bearing line is a symmetrical line in which the distribution of the pressing force generated by sitting on the chair 2 is bilaterally symmetric, like the above-described sitting bearing line. However, since the back bearing line is different from the sitting bearing line described above in that it is determined with respect to the back pressure data, this name is used to distinguish it from the sitting bearing line. This back bearing line is temporarily stored in the RAM 33. Thereafter, the CPU 31 shifts the processing to step SD5.

  In step SD5, the CPU 31 determines whether or not the inclination of the best seating azimuth line matches the inclination of the back azimuth line. The slope of the best seating orientation line indicates the seating orientation. The inclination of the back bearing line indicates the direction of the back muscle of the seated person. Therefore, when the inclination of the best sitting azimuth line and the inclination of the back azimuth line coincide with each other, the posture of the seated person's back muscles and the seating direction are aligned, and thus it is considered that the posture is light on the body. On the other hand, when the inclination of the best sitting azimuth line and the inclination of the back azimuth line do not match, the seated person's back muscles and the seating direction are misaligned, which is considered to be a posture with a heavy burden on the body. If the determination in step SD5 is affirmative (Y), the CPU 31 shifts the processing to step SD6. Or when judgment of step SD5 is negative (N), CPU31 transfers a process to step SD7.

  In step SD6, the CPU 31 transmits a control signal to the image forming circuit 35 in order to notify the seated person that the direction of the back muscles is in a state where the load on the body is small. The image forming circuit 35 forms an image signal corresponding to the control signal from the CPU 31 and transmits the image signal to the display unit 40. Then, the display unit 40 displays the “back muscle direction OK” according to the image signal from the image forming circuit 35. Thereafter, the CPU 31 shifts the processing to step SD8.

  In step SD7, the CPU 31 transmits a control signal to the image forming circuit 35 in order to notify the seated person that the direction of the back muscles is in a state where the load on the body is heavy. The image forming circuit 35 forms an image signal corresponding to the control signal from the CPU 31 and transmits the image signal to the display unit 40. Then, the display unit 40 displays the “back muscle direction NG” according to the image signal from the image forming circuit 35. Thereafter, the CPU 31 shifts the processing to step SD8.

  In step SD8 to step SB16, the seated person is notified of whether the seated person's right / left sitting balance is good or bad. When the right and left seating balance is not uniform, that is, when the seated person's load is biased to the left or right, there is a possibility of giving a burden to the seated person's waist and causing back pain or the like. That is, the seated person can maintain a comfortable and healthy sitting posture by knowing whether the right and left sitting balance is good or bad.

  In step SD8, the CPU 31 performs the same treatment as in step SC1 described above. That is, the CPU 31 determines the pressed area in the seating surface pressure data. Thereafter, the CPU 31 shifts the process to SD9.

  In step SD9, the CPU 31 performs the same process as in step SB6 described above. That is, the CPU 31 determines the buttocks area from the pressed area. Thereafter, the CPU 31 shifts the processing to step SD10.

  In step SD10, the CPU 31 determines whether or not there is a pressure-sensitive part in which the mask flag is set to ON in the buttocks area. If the determination in step SD10 is affirmative (Y), the CPU 31 shifts the processing to step SD11. Or when judgment of step SD10 is negative (N), CPU31 transfers a process to step SD12.

  In step SD11, the CPU 31 determines the position of the local peak of the pressing force in the buttocks region. In step SD11, there are MSK1 and MSK2, which are areas in which the mask flag is set to ON, as in the bearing surface pressure data img5 shown in FIG. If no foreign substance is present, the position of the local peak of the pressing force is included in the area where the mask flag is set to ON, and the position of the local peak cannot be determined accurately. Therefore, the CPU 31 determines the position of the local peak of the pressing force by performing fitting on the distribution of the pressing force using a function such as a two-dimensional Gaussian. By the processing in step SD11, the position of the local peak of the pressing force can be accurately determined even if there is a region where the mask flag is ON. The local peak position coordinates and the pressing force at the local peak position are temporarily stored in the RAM 33. Thereafter, the CPU 31 shifts the processing to step SD13.

  In step SD12, the CPU 31 determines the position of the local peak of the pressing force in the buttocks region. In step SD12, there is no region where the mask flag is set to ON as in the seating surface pressure data img1 shown in FIG. Therefore, the CPU 31 regards the positions LP1 and LP2 at which the value of the pressing force is maximum as local peak positions. Since the process of step SD12 does not require a complicated calculation like the process of step SD11, the position of the local peak of the pressing force can be determined quickly. The position of the local peak and the pressing force at the position of the local peak are temporarily stored in the RAM 33. Thereafter, the CPU 31 shifts the processing to step SD13.

  When the seated person's load is equally applied to the left and right, the position of the local peak exists on both the left and right sides of the best seating direction line. Therefore, in step SD13, the CPU 31 determines whether or not the position of the local peak exists on both the left and right sides of the best seating direction line. If the determination in step SD13 is affirmative (Y), the CPU 31 shifts the processing to step SD14. Or when judgment of step SD13 is negative (N), CPU31 transfers a process to step SD16.

  When the seated person's load is applied equally to the left and right, substantially the same amount of pressing force is applied to the positions of the left and right local peaks. Therefore, in step SD14, the CPU 31 determines whether or not the pressing forces at the left and right local peak positions are substantially the same. If the determination in step SD14 is affirmative (Y), the CPU 31 proceeds to step SD15. Or when judgment of step SD14 is negative (N), CPU31 transfers a process to step SD16.

In step SD15, the CPU 31 transmits a control signal to the image forming circuit 35 in order to notify the seated person that the left-right balance of the load of the seated person is equal. The image forming circuit 35 forms an image signal corresponding to the control signal from the CPU 31 and transmits the image signal to the display unit 40. Then, the display unit 40 displays “left and right seating balance OK” in accordance with the image signal from the image forming circuit 35. Thereafter, the CPU 31 ends the main process after returning the process to the main process. In step SD16, the CPU 31 informs the seated person that the left-right balance of the load on the seated person is not uniform. A control signal is transmitted to. The image forming circuit 35 forms an image signal corresponding to the control signal from the CPU 31 and transmits the image signal to the display unit 40. Then, the display unit 40 displays “left and right sitting balance NG” in accordance with the image signal from the image forming circuit 35. Thereafter, the CPU 31 ends the main process after returning the process to the main process.

<Modification>
The present invention is not limited to the embodiments described so far, and various modifications and changes can be made without departing from the spirit of the present invention. An example of the modification will be described below.

  In the above-described embodiment, the region exclusion process shown in FIG. 8 is performed on the seating surface pressure data. This is because, in many cases, there is a pocket in the buttocks, and there is a high possibility that foreign matter is stored in the pocket. However, the region exclusion process may be performed on the back pressure data. When the region exclusion process is performed on the back pressure data, the process of determining the buttock rear outline (see step SC2 in FIG. 10) cannot be applied to the back pressure data. Therefore, instead of step SC2, a process of dividing each longitudinal direction into a plurality of band-like regions parallel to the x direction (see step SD2 in FIG. 12) may be performed.

  In the above-described embodiment, as an example of the seating state analysis process, a process for determining whether or not the seated person is in the back muscle direction (steps SD1 to SD7) and a process for determining whether or not the seated person is in the right and left seating balance (steps SD8 to SD8). Step SD16). Since the present invention is characterized in that the analysis can be performed without the influence of foreign matter, the contents of the seating state analysis process are not limited to the above-described embodiment. For example, as in the technique described in Patent Document 1, an analysis for determining the ischial interval may be performed as the seating state analysis process.

  In the above-described embodiment, the analysis result of the sitting state is displayed on the display unit 40 (see FIG. 12). However, the display unit 40 is an example of a configuration for notifying the seated person of the analysis result of the seating state, and may report the analysis result of the seating state by voice or the like, for example. Furthermore, since the present invention is characterized in that it is possible to analyze without the influence of foreign matter, the configuration for notifying the seated person of the analysis result of the sitting state is merely an example of a method of using the analysis result of the sitting state. Yes, not mandatory. Therefore, for example, the chair is deformed so as to correct the posture of the seated person using the analysis result, and it is used for controlling the airbag as in the technique described in Patent Document 2. Even if it is used, it is intended by the present invention.

  In the above-described embodiment, acquisition of personal information is performed by the input unit 50 receiving input from a seated person (see step SB1 in FIG. 9). However, the method for acquiring the personal method is not limited to this. For example, personal information such as height and weight is stored in the correspondence table shown in FIG. Therefore, personal information may be acquired by determining the weight of the seated person from the seating surface pressure data and the backside pressure data. Alternatively, personal information may be acquired by determining the height of the seated person based on the range in which the pressing force is distributed in the seating surface pressure data and the back surface pressure data. In short, any acquisition method may be used as long as information for identifying an individual can be acquired.

  In the above-described embodiment, only the buttocks area included in the seating surface pressure data is used as a template because of the high possibility of foreign matter and the difficulty of using data including the thigh. However, other data may be used as a template. For example, the pressing force generated by the left and right thighs may be used as a template. In this case, since the position of the thigh (position with respect to the buttocks region, distance between the left and right thighs) varies greatly depending on the sitting posture, the left and right thighs are used as different templates, and the template comparison shown in FIG. The processing may be performed separately for the left and right thighs. Further, if the buttocks region and the thigh are used as templates, the buttocks region is preferably a template different from the thighs. Also in this case, the template comparison process is performed separately. Of course, back pressure data may be used as a template.

In the above-described embodiment, the mask flag of the pressure-sensitive portion that is in a position symmetrical to the pressure-sensitive portion in which the mask flag is set to ON in step SA3 in FIG. (See step SA3 in FIG. 8). The purpose of this process is to correct the influence of removing the area where foreign matter is present from the seating surface pressure data. Accordingly, any processing may be performed instead as long as the influence of removing the region where the foreign substance is present from the seating surface pressure data is corrected. As an example, if the seated person is seated so that the midpoint in the x direction is the center of gravity, the coordinates (x _i , y _j ) of the seating surface pressure data are excluded as the region where the foreign matter is present, The coordinates (x _{ni −1} , y _j ) of the seating surface pressure data at a symmetric position with respect to “x = (n−1) / 2” (intermediate point in the x direction) may be excluded. Since the complicated processing as in the above-described embodiment is not required, the influence of easily removing the region where the foreign matter is present from the seating surface pressure data is corrected.

DESCRIPTION OF SYMBOLS 1 Seating state analysis apparatus 2 Chair 3 Seating part 4 Chair support leg 5 Backrest part 20 Pressure sensor 21 Seat surface pressure sensor 22 Back surface pressure sensor 30 Control part 31 CPU
32 ROM
33 RAM
34 Interface 35 Image forming circuit 40 Display unit 50 Input unit img1, img3, img5 Seat pressure data img2, img4 Back pressure data

Claims (14)

A pressing force distribution detector provided on a seating surface that comes into contact with a seated person when seated, and detects a distribution of pressing force received by the seating contact surface;
A template storage unit for storing a template of a detection result of the pressing force distribution detection unit;
A comparison detection unit for detecting a region in which the pressing force differs by a predetermined amount or more with respect to the template by comparing the detection result of the pressing force distribution detection unit and the template stored in the template storage unit;
When the comparison detection unit detects a region different from the predetermined amount or more, a correspondence corresponding to a region different from the predetermined amount and a region different from the predetermined amount is detected from the detection result of the pressing force distribution detection unit. An area exclusion unit that excludes areas;
A seating state analysis unit that analyzes a seating state based on a detection result of the pressing force distribution detection unit that has been processed by the region exclusion unit;
A seating state analyzing apparatus comprising: Based on the detection result of the pressing force distribution detection unit, further comprises a sitting direction line determination unit that determines a sitting direction line that bisects the distribution of the pressing force along the sitting direction that the seated person faces.
The corresponding region is a region in a symmetrical position with a region different from the predetermined amount with respect to the seating direction line.
The seating state analyzing apparatus according to claim 1. The seating direction line determination unit
A dividing unit that divides the detection region of the pressing force distribution detection unit into a plurality of strip-like regions whose longitudinal directions are parallel to each other;
A center-of-gravity position determining unit that determines a center-of-gravity position of the pressing force distribution for one of the band-like regions;
A seating azimuth line determination unit that determines a seating azimuth line by performing predetermined processing based on the position of the center of gravity;
The seating state analyzing apparatus according to claim 2. The comparison detection unit
A correspondence determining unit for determining a correspondence between the detection result of the pressing force distribution detecting unit and the template;
A difference detection unit for detecting a region where the detection result of the pressure detection unit differs from the template by a predetermined amount or more by taking a difference between the detection result of the pressing force distribution detection unit and the template;
The seating state analyzing apparatus according to any one of claims 1 to 3, wherein The correspondence determining unit uses a contour of the distribution of the pressing force when determining the correspondence between the detection result of the pressing force distribution detecting unit and the template.
The seating state analyzing apparatus according to claim 4. The correspondence determination unit uses only the contour line behind the buttock when determining the correspondence between the detection result of the pressing force distribution detection unit and the template.
The seating state analyzing apparatus according to claim 5. The template storage unit further stores the detection result of the pressing force distribution detection unit in association with the personal information of the seated person as the template when the comparison detection unit does not detect a region different from the predetermined amount or more.
The sitting state analyzing apparatus according to any one of claims 1 to 6. A pressing force distribution detection step for detecting the distribution of the pressing force received by the seating surface that contacts the seated person at the time of sitting;
A template acquisition step of acquiring a template of the distribution of the pressing force;
By comparing the detection result of the pressing force distribution detecting step with the template, a comparison detecting step of detecting a region where the pressing force is different from the template by a predetermined amount or more,
When a region different from the predetermined amount is detected by the comparison detection step, a region different from the predetermined amount from the detection result of the pressing force distribution detection step, and a corresponding region corresponding to a region different from the predetermined amount Region exclusion process to exclude
A seating posture analysis step of analyzing a seating posture based on the detection result of the pressing force distribution detection step processed by the region exclusion step;
A seating state analysis method comprising: Based on the detection result of the pressing force distribution detection step, further comprising a seating direction line determination step for determining a seating direction line that bisects the distribution of the pressing force along the seating direction facing the seated person,
The corresponding region is a region in a symmetrical position with a region different from the predetermined amount with respect to the seating direction line.
The seating state analysis method according to claim 8. The seating orientation line determination step includes
A division step of dividing the detection result of the pressing force distribution detection step into a plurality of strip-like regions whose longitudinal directions are parallel to each other;
A center-of-gravity position determination step for determining the center-of-gravity position of the pressing force distribution for one of the band-shaped regions;
A seating azimuth line determination step of determining a seating azimuth line by performing a predetermined process based on the position of the center of gravity.
The seating state analysis method according to claim 9. The comparative detection step includes
A correspondence determination step for determining a correspondence between the detection result of the pressing force distribution detection step and the template;
A difference detection step of detecting a region where the detection result of the pressure detection step differs from the template by a predetermined amount or more by taking a difference between the detection result of the pressing force distribution detection step and the template;
The seating state analysis method according to any one of claims 8 to 10, characterized by comprising: The correspondence determining step uses a contour line of the distribution of the pressing force when determining the correspondence between the detection result of the pressing force distribution detection unit and the template.
The seating state analysis method according to claim 11. The correspondence determination step uses only the contour line behind the buttock when determining the correspondence between the detection result of the pressing force distribution detection unit and the template.
The seating state analysis method according to claim 12. A template storage step of storing the detection result of the pressing force distribution detection step as the template in association with the personal information of the seated person when the comparison detection step is different from the predetermined amount but is not detected;
The seating state analysis method according to any one of claims 8 to 13, wherein the seating state analysis method is performed.