JP6928939B2 - Posture identification system, posture identification method, and posture identification program - Google Patents

Description

The present invention, the posture identifying system, posture specifying method, and a posture identifying program.

In recent years, with the widespread use of devices equipped with acceleration sensors (smart phones, etc.), various techniques for detecting human movements using acceleration sensors have been proposed. For example, as so-called apps for smartphones, various apps such as a pedometer using the output of an accelerometer, a push-up and squat counter, and a golf swing judgment have been released.

Further, Patent Document 1 discloses a technique of detecting a bending / stretching state of a human elbow or knee lying on a bed or the like by using an acceleration sensor. Specifically, using the first acceleration sensor attached to the subject's torso and the second acceleration sensor attached to the subject's wrist or ankle, the angle of rotation and the length of the hand with the trunk as the axis of rotation are used. The rotation angle with the vertical direction as the rotation axis is detected, and it is determined whether the combination of these rotation angles is a state that is normally possible or impossible for a person lying on a bed or the like. This makes it possible to detect whether a person lying on a bed or the like is in a normal lying position or a dangerous lying position.

Japanese Unexamined Patent Publication No. 2015-198771

The technique described in Patent Document 1 described above detects a posture state of a person lying on a bed or the like in a lying position, and does not detect a posture state other than the lying position. Further, although the technique described in Patent Document 1 is a technique for detecting a posture state, it is a technique for determining whether the posture is a normal posture or an abnormal posture rather than detecting the posture itself, and rotation with the trunk as the rotation axis. It merely detects the angle and the angle of rotation with the length direction of the hand as the axis of rotation, and determines the normality of the combination.

An object of the present invention is to make it possible to identify the state of the joints of the lower body of a human being in a posture state other than the recumbent position by using a device configuration as simple as possible. Further, more preferably, it is possible to quantitatively evaluate the load applied to a person who takes a posture state other than the lying position, and to make it possible to determine whether or not some of the posture states other than the lying position are in the posture state. Make it possible.

One of the embodiments of the present invention is to output the first acceleration sensor attached to at least one of the left and right thighs of a human, the second acceleration sensor attached to the upper body of the human, and the first acceleration sensor. It is a posture specifying system including a calculation unit for specifying a flexion state of a joint of the lower body of a human using the first acceleration information and the second acceleration information output by the second acceleration sensor.

In the posture identification system configured in this way, the flexion state of the joints of the lower body of a human being is determined by using the first acceleration information output by the first acceleration sensor and the second acceleration information output by the second acceleration sensor. The calculation unit identifies it. In this way, the flexion state of the joints of the lower body of a human being in a posture state other than the lying position such as standing can be roughly grasped by specifying the gravitational acceleration applied to the thigh and the gravitational acceleration applied to the upper body. Is. Therefore, as long as it has a simple device configuration of two acceleration sensors and a calculation unit, it is possible to identify the flexion state of the joints of the lower body of a human being in a posture state other than the recumbent position to some extent.

One of the selective aspects of the present invention is a posture specifying system characterized in that the joints of the lower body of the human being whose calculation unit specifies a flexion state are the joints of the hip and knee of the human being. be.

In the posture specifying system configured in this way, the flexion state of the human lower body joints, particularly the human hip and knee joints, is specified. That is, the gravitational acceleration applied to the thigh, the gravitational acceleration applied to the upper body, the flexion state of the hip joint, and the flexion state of the knee joint are specified. It is possible to get an overview of the flexion state of the human hip and knee joints simply by specifying the parameters. That is, it is possible to identify the flexion state of the human hip and knee joints by obtaining the minimum necessary parameters from the accelerometer and performing a simple calculation.

As one of the selective aspects of the present invention, the calculation unit uses the inclination of the thigh specified from the first acceleration information and the inclination of the upper body specified from the second acceleration information. The posture specifying system is characterized in that the flexion angles of the human hip and knee joints are specified.

In the posture identification system configured in this way, the inclination of the thigh is specified from the first acceleration information (gravitational acceleration applied to the thigh) output by the first acceleration sensor, and the second acceleration sensor outputs the second. The inclination of the upper body (trunk) is specified from the acceleration information (gravitational acceleration applied to the upper body), and the calculation unit specifies the flexion angle of the human hip and knee joints using these inclinations. As described above, the flexed state of the joints of the lower body of a human being in a posture state other than the lying position such as a standing position can be roughly grasped by specifying the inclination of the thigh and the inclination of the upper body.

In one of the selective aspects of the present invention, the first acceleration sensor and the second acceleration sensor are acceleration sensors built into different smart phones, and one smart phone is connected to the other smart phone. Accelerometer information is transmitted, and the arithmetic unit built into the one smart phone executes arithmetic processing for identifying the flexion state of the human lower body joint using the acceleration information detected by both smart phones. It is a posture identification system characterized by.

In the posture identification system configured in this way, two acceleration sensors built into different smartphones are used to identify the gravitational acceleration applied to the thigh and the gravitational acceleration applied to the upper body, and one of the smart phones is built-in. The calculation unit executes arithmetic processing using these gravitational accelerations to identify the flexion state of the human lower body joint in a posture state other than the lying position such as standing. Therefore, a posture identification system can be realized with a simple device configuration.

One of the other aspects of the present invention is an operation in which the human crouches based on a first acceleration sensor attached to at least one of the left and right thighs of the human and the first acceleration information output by the first acceleration sensor. It is an operation determination system including a calculation unit for determining whether a person has performed a sitting motion or a sitting motion.

In the motion determination system configured in this way, it is possible to discriminate between the squatting motion and the sitting motion performed by a human using the first acceleration information output by the first acceleration sensor mounted on the thigh. As described above, as long as it has a simple device configuration of one acceleration sensor and a calculation unit, it is possible to discriminate between a squatting motion and a sitting motion in which the flexion states of the joints of the lower body of a human are similar.

The posture identification system and the motion determination system described above include various aspects such as being implemented in a state of being incorporated in another device or being implemented together with other methods. Further, the method embodied in the posture identification system and the motion determination system described above includes various aspects such as being implemented as a part of other methods. Further, the program used in the posture specifying system and the motion determination system described above can also be realized as a computer-readable recording medium or the like on which the program is recorded.

According to the present invention, the state of the joints of the lower body in the standing or sitting position can be specified by the device configuration as simple as possible.

It is a figure which showed the appearance of the posture identification system which concerns on this embodiment schematic. It is a figure which showed schematicly about the electrical structure of the posture specifying system which concerns on this embodiment. It is a figure which shows a specific example of a posture specifying process. It is a figure explaining the flow of the lumbar load identification processing which concerns on 2nd Embodiment. It is a figure explaining the flow of the posture specifying process which concerns on 3rd Embodiment. It is a figure explaining the inclination of an accelerometer while a person shifts from a "standing posture (including a walking posture)" to a "sitting posture" sitting on a chair or the like. The measured value obtained from the accelerometer when a person shifts from a "standing posture (including walking posture)" to a "sitting posture" sitting on a chair, etc., and then from a "sitting posture" to a "standing posture". It is a figure which shows the time-dependent change of an absolute value. It is a figure explaining the inclination of an accelerometer while a person shifts from a "standing posture" to a crouching "crouching posture". The figure which shows the time-dependent change of the absolute value of the measured value obtained from an accelerometer when a person shifts from a "standing posture" to a crouching "crouching posture" and then shifts from a "crouching posture" to a "standing posture". Is.

Hereinafter, the present invention will be described in the following order.
(A) First embodiment:
(B) Second embodiment:
(C) Third embodiment:

(A) First embodiment:
FIG. 1 is a diagram schematically showing the appearance of the system 100 (posture identification system or motion determination system) according to the present embodiment, and FIG. 2 is a diagram schematically showing the electrical configuration of the system 100.

The attitude identification system 100 includes an acceleration sensor 10 as a first acceleration sensor, an acceleration sensor 20 as a second acceleration sensor, a calculation unit 30, and a display unit 40.

The acceleration sensor 10 is attached to the thigh F of the human M. The acceleration sensor 20 is attached to the upper body Bu of the same human M to which the acceleration sensor 10 is attached. Human M's upper body Bu refers to the part of the human M's torso above the waist. The accelerometer 10 is attached to the thigh of the human M by accommodating it in the right pocket of the pants worn by the human M, for example, and the accelerometer 20 is accommodated in the chest pocket of the shirt worn by the human M, for example. As a result, it is attached to the upper body Bu of human M.

In the present embodiment, the acceleration sensor 10 is built in the information processing terminal Sa, and the acceleration sensor 20 is built in the information processing terminal Sb. The information processing terminals Sa and Sb are portable information processing devices such as smartphones and tablet terminals. As the acceleration sensors 10 and 20, an acceleration sensor built in a device other than the information processing terminal may be used, or a single acceleration sensor may be used.

The information processing terminal Sa has a calculation unit 30 such as a microcomputer. The calculation unit 30 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory), and a program stored in the ROM (a posture identification program in the present embodiment) is stored in the RAM. While loading, the CPU executes arithmetic processing based on the program. The calculation unit 30 is not limited to the one built in the information processing terminal Sa, and the one built in the external information processing device may be used.

The information processing terminal Sb has a communication unit 50b capable of communicating with the information processing terminal Sa. The communication unit 50b transmits the output data D2 of the acceleration sensor 20 to the information processing terminal Sa. The communication unit 50a of the information processing terminal Sa receives the data transmitted from the communication unit 50b. The communication unit 50b may transmit the calculation result performed by the calculation unit 30b such as the microcomputer built in the information processing terminal Sb to the information processing terminal Sa based on the output data D2 of the acceleration sensor 20. When a calculation unit built in an external information processing device is used as the calculation unit 30, the information processing terminals Sa and Sb send the output data or calculation of the acceleration sensors 10 and 20 to the information processing device via the communication units 50a and 50b. Send the result.

The acceleration sensors 10 and 20 are acceleration sensors having two or more detection axes for detecting acceleration. In the present embodiment, the acceleration sensor 10 is a three-axis acceleration sensor with detection axes A1x, A1y, and A1z, and the acceleration sensor 20 is a three-axis acceleration sensor with detection axes A2x, A2y, and A2z.

In the acceleration sensors 10 and 20 built into the information processing terminals Sa and Sb, for example, as shown in FIG. 1, the left-right direction of the terminal (the left direction is positive with respect to the terminal) constitutes the detection axes A1x and A2x. The vertical direction (upward direction is positive) of the terminal constitutes the detection axes A1y and A2y, and the front-back direction (front direction is positive) of the terminal constitutes the detection axes A1z and A2z.

The acceleration sensor 10 attached to the thigh F of the human M, for example, orients the directions of each axis as follows. The detection axis A1y is oriented in the direction along the length direction of the thigh of the human M, and the direction toward the knee is positive and the direction toward the waist is negative. The detection axis A1z is oriented along the anteroposterior direction of the thigh so as to be orthogonal to the length direction of the thigh of the human M, the direction toward the front of the thigh is negative, and the direction toward the back of the thigh is negative. Positive.

The acceleration sensor 10 attached to the upper body Bu of the human M, for example, orients the directions of each axis as follows. The detection axis A2y is oriented in the direction along the extending direction of the trunk of the human M, and the direction toward the waist is positive and the direction toward the head is negative. The detection axis A2z is oriented along the anteroposterior direction of the upper body so as to be orthogonal to the length direction of the trunk of the human M, the direction toward the front of the upper body is negative, and the direction toward the rear of the upper body is positive. ..

Hereinafter, a specific example of the posture specifying process performed by the calculation unit 30 by executing the posture specifying program will be described with reference to FIG.

In this process, first, the human M is asked to take a substantially upright posture, and the initial value is acquired (S11). The calculation unit 30 acquires the value of the acceleration output by the acceleration sensors 10 and 20 while the human M is in a substantially upright posture. That is, the initial value G10 (= (G10x, G10y, G10z)) of the acceleration applied to the thigh (mainly the gravitational acceleration) is acquired from the acceleration sensor 10, and the acceleration applied to the trunk of the upper body (mainly the gravitational acceleration). The initial value G20 (= (G20x, G20y, G20z)) is acquired from the acceleration sensor 20. Hereinafter, the human M in this state may be referred to as an initial state.

Then, at an arbitrary moment, a process for identifying the state of the joints of the lower body of the human M is performed. The lower body of the human M refers to a part below the waist of the human M. In the present embodiment, the states of the hip joint and the knee joint are specified as the joints below the waist of the human M.

Specifically, first, at an arbitrary moment, the measured value of the acceleration output by the acceleration sensors 10 and 20 is acquired (S12). That is, the measured value G11 (= (G11x, G11y, G11z)) of the acceleration applied to the thigh (mainly the gravitational acceleration) is acquired from the acceleration sensor 10, and the acceleration applied to the trunk of the upper body (mainly). The measured value G12 (= (G12x, G12y, G12z)) of the gravitational acceleration) is acquired from the acceleration sensor 20.

Next, based on the initial state, the upper body inclination angle θB indicating how much the trunk of the upper body of the human M is tilted and the thigh inclination θL indicating how much the thigh of the human M is tilted are calculated. Calculate (S13). The upper body tilt angle θB and the thigh tilt angle θL can be calculated by the following formula (1) using the initial values G10 and G20 and the measured values G11 and G21, and the thigh tilt angle θL can be calculated by the following formula (1). It can be calculated according to (2).

Next, using the obtained upper body tilt angle θB and thigh tilt angle θL, the waist flexion angle θW and the knee flexion angle θN of the human M are calculated (S14).

The lumbar flexion angle θW can theoretically be considered as the angle formed by the straight line connecting the shoulder and the hip joint and the straight line connecting the hip joint and the knee, and is actually a straight line extending along the extending direction of the trunk. , It can be grasped as an angle formed by a straight line extending along the extending direction of the thigh.

The knee flexion angle θN can theoretically be considered as the angle formed by the straight line connecting the hip joint and the knee and the straight line connecting the knee and the ankle, and in reality, the straight line extending along the extending direction of the thigh and the straight line extending along the extending direction of the thigh. It can be grasped as an angle formed by a straight line extending along the extending direction of the lower leg. As for the lower leg, a straight line extending along the virtual extension direction of the lower leg is used assuming that the knee is perpendicular to the ground.

The waist flexion angle θW can be calculated using the following formula (3), and the knee flexion angle θN can be calculated using the following formula (4). The waist flexion angle θW and the knee flexion angle θN of the human M in the initial state are set to 0 °.

By the above processing, it is possible to identify the state of the joints of the lower body of the human M who takes a posture state other than the recumbent position. Further, when the acceleration sensors 10 and 20 built in the mobile information terminal are used, this can be realized by a simple device configuration. Further, by calculating the upper body tilt angle θB, the thigh tilt angle θL, the waist flexion angle θW, and the knee flexion angle θN using the calculation unit 30 built in the mobile information terminal, this can be realized with a simpler device configuration. can. Further, the information acquired in this way may be displayed on, for example, the display unit 40 of the information processing terminal Sa or the display unit 40b of the information processing terminal Sb. Further, the information processing terminals Sa and Sb may be used to transmit information directly or via a communication network to an external information processing device.

(B) Second embodiment:
Next, the lumbar load specifying system according to the second embodiment will be described. Since the lumbar load specifying system according to the second embodiment has the same device configuration as the posture specifying system 100 according to the first embodiment described above, it will be described using the same reference numerals as the posture specifying system 100.

FIG. 4 is a diagram illustrating a flow of a lumbar load specifying process for realizing the lumbar load specifying method according to the second embodiment.

In this process, first, the input of numerical values related to the height, weight, and weight of the handled object of the human M is accepted via the user interface of the portable information processing terminal. Examples of the user interface of the portable information processing terminal include a keyboard (including a software keyboard), a mouse, and a touch panel.

Next, as in the first embodiment, the initial value G10 of the acceleration applied to the thigh F and the initial value G20 of the acceleration applied to the upper body Bu are acquired (S21). After that, as in the first embodiment, at an arbitrary moment, acquisition of measured values (S22), calculation of upper body tilt angle and thigh tilt angle (S23), and calculation of waist flexion angle and knee flexion angle (S24). Is performed to specify the posture of the human M, and then a process of estimating the load applied to the waist of the human M in the specified posture is performed (S25). Since the process up to specifying the posture of the human M is the same as that of the first embodiment described above, detailed description thereof will be omitted.

After the posture of the human M is specified, the load applied to the lumbar region of the human M by taking the posture is calculated next. The following formula (5) is a formula for estimating the lumbar disc compression force Fc that the posture of the human M gives to the lumbar disc of the human M.

In the above formula (5), Uw is the weight above the L5 (fifth lumbar vertebra) / S1 (sacral) joint, g is the gravitational acceleration (9.8 (m / s ² )), and Rar is the joint of the L5 / S1 joint. The angle of inclination of the surface, Lw is the weight of the object to be handled, Fa is the abdominal pressure, and Fm is the force of the erector spinae muscle that opposes the moment around the L5 / S1 joint together with Fa.

Each variable of the above equation (5) is the height of the human M, the weight of the human M, the weight of the object to be handled, the upper body tilt angle, the upper arm angle, the forearm angle, the thigh angle, the lower leg angle, the waist flexion angle, and the knee flexion angle. It can be calculated using a parameter group composed of each value. In the present embodiment, a configuration in which each value of the weight of the object to be handled, the upper arm angle, the forearm angle and the lower leg angle is not specified in this parameter group is adopted, and the calculation is performed with all of them set to 0. Therefore, in the present embodiment, each variable of the lumbar disc compression force Fc is obtained by the following method using the height of the human M, the weight of the human M, the upper body tilt angle, the thigh angle, the lumbar flexion angle, and the knee flexion angle. Be done. Of course, it is also possible to add a configuration for specifying each value of the weight of the handled object, the upper arm angle, the forearm angle and the lower leg angle, and perform the calculation of the above equation (5) including these values.

First, the weight Uw above the L5 / S1 joint is defined as, for example, the weight above the waist, and for example, as shown in the following formula (6), multiplying the total weight by the ratio of each part of the body. Can be calculated by

In the above formula (6), W is the weight of the human M, Wp1 is the weight of the torso, Wi is the weight of the head, Wh and Wh are the weights from the left and right shoulders to the elbows, and Wg and Wgg are the left and right elbows. Represents the weight of the tip. The numerical value representing the ratio of each part shown in the above formula (6) is an example.

Next, the inclination angle Rar of the joint surface of the L5 / S1 joint can be obtained, for example, by using Anderson's equation shown in the following equation (7).

In the present embodiment, the above-mentioned upper body tilt angle θB is used as the upper body tilt angle Qt shown in the above formula (7), and the above-mentioned knee flexion angle θN is used as the knee flexion angle Qk.

Next, the abdominal pressure Fa is a force that the diaphragm or the like pushes from the ventral side toward the back, and is a force that affects the shape of the spine. The abdominal pressure Fa can be obtained, for example, by using Fisher's formula represented by the following formula (8).

In the formula (8), Rh represents a hip flexion _{angle, M L5 / S1} represents the moment due to the handling of around L5 / S1 joint. As the waist flexion angle Rh, the waist flexion angle θW described above is used. For the moment M _{L5 / S1} , as shown in the following equation (9), the moment from the lumbar region of each part of the body can be obtained, and the total value thereof can be used.

In the above equation (9), Xpp is the coordinate of the x-axis of the body, Wp1 is the weight of the body, Xip is the coordinate of the x-axis of the head, Wi is the weight of the head, and Xhp is the right shoulder to the right elbow. X-axis coordinate of the center of gravity, Xhpp is the x-coordinate coordinate of the left shoulder to the left elbow, Wh is the weight of the part from the shoulder to the elbow, Xgp is the center of gravity coordinate of the x-axis from the right elbow to the right wrist, Xggp is the left The x-axis center of gravity coordinates from the elbow to the left wrist, Wg is the weight of the part from the elbow to the wrist, Xwp is the x-axis center of gravity coordinate of the right hand, and Xwww is the x-axis center of gravity coordinate of the left hand. The x-axis referred to here is an axis extending horizontally and along the front-rear direction in a state where the human M stands upright. The coordinates of the center of gravity of each part can be obtained by using the length of each part obtained as a statistical average value based on the height H of the human M and the angle of each part. The following equations (10) to (17) are examples of equations for obtaining the coordinates of the center of gravity of each part.

In the above equations (10) to (17), Q5 is the upper right arm angle, Q55 is the upper left arm angle, Q6 is the right forearm angle, and Q66 is the left forearm angle. Further, a4 used in the above formulas (10) to (17) is represented by the following formula (18).

Next, the force Fm can be obtained from the equation of the balance between the force due to the handling object and the force supporting it, which is shown in the following equation (19).

In the above formula (19), D represents the moment arm length around L5 / S1 due to abdominal pressure. In the above equation (19), E represents the moment arm length of the erector spinae muscle and is generally approximated by 0.05 (m). The moment arm length D can be calculated using, for example, the Morris equation shown in the following equation (20).

As described above, L5 / S1 as each variable of the above equation (5) using the height of the human M, the weight of the human M, the upper body tilt angle, the thigh angle, the waist flexion angle and the knee flexion angle. The weight Uw above the joint, the inclination angle Rar of the joint surface of the L5 / S1 joint, the abdominal pressure Fa, and the force Fm of the erector spinae muscle that opposes the moment around the L5 / S1 joint together with Fa are obtained. As a result, the lumbar disc compression force Fc represented by the above formula (5) can be obtained. That is, the load applied to the lumbar region can be specified by using the upper body tilt angle θB and the knee flexion angle θN. Further, the information acquired in this way may be displayed on, for example, the display unit 40 of the information processing terminal Sa or the display unit 40b of the information processing terminal Sb. Further, the information processing terminals Sa and Sb may be used to transmit information directly or via a communication network to an external information processing device.

(C) Third embodiment:
Next, the posture specifying system according to the third embodiment will be described. The posture identification system according to the third embodiment has the same device configuration as the posture identification system 100 according to the first embodiment described above, except that the acceleration sensor 20 attached to the upper body Bu is unnecessary. , The same reference numerals as those of the posture specifying system 100 will be described.

FIG. 5 is a diagram illustrating a flow of a posture specifying process for realizing the posture specifying method according to the third embodiment.

In the present embodiment, first, the human M is asked to take a substantially upright posture, and the initial value is acquired (S31). The calculation unit 30 acquires the value of the acceleration output by the acceleration sensor 10 while the human M is in a substantially upright posture. That is, the initial value G10 (= (G10x, G10y, G10z)) of the acceleration (mainly the gravitational acceleration) applied to the thigh F is acquired from the acceleration sensor 10.

Next, continuous acquisition of the measured value of the acceleration output by the acceleration sensor 10 is started (S32). That is, the measured value G11 (= (G11x, G11y, G11z)) of the acceleration (mainly the gravitational acceleration) applied to the thigh F is continuously acquired from the acceleration sensor 10.

FIG. 6 is a diagram for explaining the inclination of the acceleration sensor 10 while the human M shifts from the “standing posture (including the walking posture)” to the “sitting posture” sitting on a chair or the like, and FIG. 7 shows the human M “standing”. Shows the time course of the absolute value of the measured value G11 obtained from the acceleration sensor 10 when the posture is changed from the posture to the sitting posture and then the sitting posture is changed to the standing posture. It is a figure.

FIG. 8 is a diagram illustrating the inclination of the accelerometer 10 while the human M shifts from the “standing posture” to the “crouching posture”, and FIG. 9 is a diagram showing the “crouching posture” in which the human M crouches from the “standing posture”. It is a figure which shows the time-dependent change of the absolute value of the measured value G11 obtained from the acceleration sensor 10 when it shifts to a "crouching posture" and then shifts from a "standing posture".

The measured values G11 shown in FIGS. 7 and 9 are 1 when facing vertically upward, -1 when facing vertically downward, and when facing horizontally with respect to each axis of the acceleration sensor 10. The measured value is standardized by dividing it by the gravitational acceleration (9.8 m / s ^{2) so that it becomes 0.} Further, in FIGS. 7 and 9, the measured value G11 is shown as an absolute value.

As can be seen from FIG. 6, when shifting from the “standing posture” to the “sitting posture”, | G11y | decreases from almost 1 to almost 0, and | G11z | decreases from almost 0 to almost 1. An ascending change occurs.

Further, as can be seen from FIG. 7, even when shifting from the “standing posture” to the “crouching posture”, | G11y | decreases from almost 1 to almost 0, and | G11z | decreases from almost 0 to almost 0. A change that rises toward 1 occurs.

That is, when shifting from the "standing posture" to the "sitting posture" or the "crouching posture", the absolute value of the measured value G11 decreases in the Y-axis direction and increases in the Z-axis direction. Similar changes occur in that the relationships are reversed. From this, it can be determined that | G11z |> | G11y | is a "standing posture", and | G11y |> | G11z | is a "sitting posture" or a "crouching posture".

On the other hand, as can be seen from FIG. 7, when shifting from the “standing posture” to the “crouching posture”, | G11y | decreases from almost 1 to 0 and then rises from 0 to around 0.7. .. This is because, in | G11y | shown in FIG. 8, the positive and negative values are reversed between the time when the value decreases from approximately 1 to 0 and the time when the value increases from 0 to around 0.7. This change does not occur when shifting from the "standing posture" to the "sitting posture". That is, | G11y | in the "sitting posture" is stable at around 0, and | G11y | in the "crouching posture" is once decreased to 0, then immediately rises and is stable at around 0.7.

Based on the above situation, it is determined whether or not a transition from the “standing posture” to the “sitting posture” or the “crouching posture” has occurred using the continuously acquired measured values G11 (S33). Specifically, it is determined whether or not | G11y | decreases and | G11z | increases, causing a change in which the magnitude relationship between | G11y | and | G11z | is reversed. When this change occurs (S33: Yes), it is determined that the transition to the "sitting posture" or the "crouching posture" has occurred, and when this change does not occur (S33: No), the "standing posture" is determined. , And the process of step S33 is repeatedly executed at regular intervals.

When the transition to the “sitting posture” or the “crouching posture” occurs, it is determined whether the transition to the “sitting posture” or the “crouching posture” has occurred (S34). In the discrimination between the "sitting posture" and the "crouching posture", it is determined whether or not the change of | G11y | from approximately 1 to a predetermined value or less and then increasing from 0 to a predetermined value occurs within a predetermined time. do. When this change occurs, it is determined that the transition to the "crouching posture" has occurred (S36), and when this change has not occurred, it is determined that the transition to the "sitting posture" has occurred (S35).

As a predetermined value used in this determination, a value selected from the range of 0.1 to 0.6 can be adopted, and more preferably, a value selected from the range of 0.15 to 0.5 can be adopted. Specifically, for example, 0.2 can be adopted. As the predetermined time, a value selected from the range of 0.8 seconds to 2.0 seconds can be adopted, and more preferably, a value selected from the range of 1.0 seconds to 1.5 seconds can be adopted. Yes, specifically, for example, 1.2 seconds can be adopted.

As the predetermined value, the predetermined value used for the determination at the time of decrease and the predetermined value used for the determination at the time of increase may be different values. Further, the determination may be performed using Ay1 which is not an absolute value. In this case, for example, in step S35, the zero cross of Ay1 is detected, and after the zero cross, a predetermined value whose positive and negative values are different from those before the zero cross is set to Ay1 within a certain time. Judges whether or not is exceeded.

After that, it is determined whether or not a transition from the “sitting posture” or the “crouching posture” to the “standing posture” has occurred (S37). Specifically, it is determined whether or not | G11y | increases and | G11z | decreases in the absolute value of the measured value G11, causing a change in which the magnitude relationship between | G11y | and | G11z | is reversed. do. When this change occurs (S37: Yes), the process returns to step S33 to determine whether or not a transition from the “standing posture” to the “sitting posture” or the “crouching posture” has occurred, and this change occurs. If not (S37: No),
Returning to step S34, the "sitting posture" and the "crouching posture" are discriminated.

According to the posture identification system described above, the human M is in a "sitting posture", a "crouching posture", or a "standing posture" using the acceleration data output by the acceleration sensor attached to the thigh F of the human M. It is possible to easily determine whether or not the posture is taken, and the transition between these postures can be easily detected. Further, the information acquired in this way may be displayed on, for example, the display unit 40 of the information processing terminal Sa or the display unit 40b of the information processing terminal Sb. Further, the information processing terminals Sa and Sb may be used to transmit information directly or via a communication network to an external information processing device.

The present invention is not limited to the above-described embodiments, but includes configurations in which the configurations disclosed in the above-described embodiments are replaced with each other or combinations are changed, known techniques, and the above-described embodiments. It also includes configurations in which the configurations disclosed in the above are replaced with each other or combinations are changed. Further, the technical scope of the present invention is not limited to the above-described embodiment, but extends to the matters described in the claims and their equivalents.

10 ... Accelerometer, 20 ... Accelerometer, 30 ... Calculation unit, 30'... Calculation unit, 40 ... Display unit, 50a ... Communication unit, 50b ... Communication unit, 100 ... System, F ... Thigh, A1x ... Detection axis , A1y ... detection axis, A1z ... detection axis, A2x ... detection axis, A2y ... detection axis, A2z ... detection axis, Bu ... upper body, D2 ... output data, Sa ... information processing terminal, Sb ... information processing terminal

Claims (5)

The first accelerometer attached to at least one of the human left and right thighs,
The second accelerometer worn on the upper body of the human and
A calculation unit that identifies the flexion state of the human lower body joint using the first acceleration information output by the first acceleration sensor and the second acceleration information output by the second acceleration sensor.
With
The first acceleration sensor and the second acceleration sensor are acceleration sensors built into different information processing terminals.
Acceleration information is transmitted from the other information processing terminal to one information processing terminal,
The calculation unit built in one of the information processing terminals identifies the flexion state of the joints of the lower body of the human using the acceleration information detected by both information processing terminals, and also identifies the load on the lumbar region of the human. A posture identification system characterized by executing arithmetic processing. The joints of the lower body of the human whose calculation unit identifies the flexed state are the joints of the hip and knee of the human.
The posture identification system according to claim 1. The calculation unit identifies the flexed state of the lower body of the human body by using the inclination of the thigh specified from the first acceleration information and the inclination of the trunk specified from the second acceleration information. ,
The posture identification system according to claim 1 or 2, wherein the posture identification system is characterized in that. The process of acquiring the first acceleration information from the first acceleration sensor attached to at least one of the left and right thighs of a human being,
The process of acquiring the second acceleration information from the second acceleration sensor mounted on the human upper body, and
The first acceleration sensor and the second acceleration sensor are acceleration sensors built into different information processing terminals.
The process of transmitting acceleration information from the other information processing terminal to one information processing terminal,
Arithmetic unit said one information processing terminal is you built, as well as identify the flexion of the lower body of the joint of the human using the acceleration information detected by both the information processing terminal, the load on the said human waist The process of executing the specified arithmetic processing and
A posture identification method characterized in that it is composed of. A function to acquire the first acceleration information from the first acceleration sensor attached to at least one of the left and right thighs of a human being,
A function to acquire the second acceleration information from the second acceleration sensor mounted on the upper body of the human being, and
The first acceleration sensor and the second acceleration sensor are acceleration sensors built into different information processing terminals.
A function to send acceleration information to one information processing terminal from the other information processing terminal,
Arithmetic unit said one information processing terminal is you built, as well as identify the flexion of the lower body of the joint of the human using the acceleration information detected by both the information processing terminal, the load on the said human waist A function to execute specific arithmetic processing and
Posture identification program to realize the above on a computer.

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