阅读说明：本技术 步行动作辅助装置 (Walking movement assisting device ) 是由 高桥玲 牧原幸伸 泽田祐一 东善之 大畑光司 于 2020-02-25 设计创作，主要内容包括：在本发明的步行动作辅助装置中,大腿相位角算出单元具有最新数据发送处理和保存数据发送处理,所述最新数据发送处理将采样定时S(k)(k为1以上的整数)下的大腿相位角φ(k)发送给步行动作定时算出单元并且将大腿相位角φ(k)保存为基准大腿相位角φc,所述保存数据发送处理代替定时S(k)下的大腿相位角φ(k)而将保存着的基准大腿相位角φc发送给步行动作定时算出单元并且维持基准大腿相位角φc,所述大腿相位角算出单元仅在满足一个定时下的大腿相位角小于在该时间点下保存着的基准大腿相位角且其偏差的绝对值为预定阈值以下的条件的情况下进行所述保存数据发送处理,在其他情况下进行所述最新数据发送处理。(In the walking motion assisting apparatus of the present invention, the thigh phase angle calculating means includes latest data transmission processing for transmitting the thigh phase angle (k) at the sampling timing s (k) (k is an integer of 1 or more) to the walking motion timing calculating means and storing the thigh phase angle (k) as the reference thigh phase angle (c), and stored data transmission processing for transmitting the stored reference thigh phase angle (c) to the walking motion timing calculating means and maintaining the reference thigh phase angle (c) in place of the thigh phase angle (k) at the timing s (k), the thigh phase angle calculating means performs the stored data transmission processing only when a condition that the thigh phase angle at one timing is smaller than the reference thigh phase angle stored at that point in time and the absolute value of the deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, the latest data transmission processing is performed in other cases.)

1. A walking motion assistance device is characterized by comprising:

an actuator that gives an assisting force to a walking motion of a user;

a thigh posture detection unit that detects an angle-related signal related to a hip joint angle that is a back-and-forth swing angle of a thigh of a user at each sampling timing;

a thigh phase angle calculation unit that calculates a thigh phase angle for each sampling timing based on the angle-related signal;

walking motion timing calculation means for calculating a cycle walking motion timing as a percentage of a walking cycle based on the thigh phase angle from the thigh phase angle calculation means;

an assist torque calculation means having an output torque pattern defining a relationship between a periodic walking motion timing and a torque value to be output, the assist torque calculation means calculating a torque value corresponding to a sampling timing by applying the periodic walking motion timing transmitted from the walking motion timing calculation means to the output torque pattern; and

an operation control unit that controls operation of the actuator so that the actuator outputs an assist force of the torque value calculated by the assist torque calculation unit,

the thigh phase angle calculating means has latest data transmission processing of transmitting a thigh phase angle (k) calculated based on an angle-related signal at a k-th sampling timing S (k) in one walking cycle to the walking action timing calculating means as a thigh phase angle at the sampling timing S (k) and storing the thigh phase angle (k) as a reference thigh phase angle (c), where k is an integer of 1 or more, and stored data transmission processing of transmitting the reference thigh phase angle (c) stored at that time point to the walking action timing calculating means as a thigh phase angle at the sampling timing (S (k) in place of the thigh phase angle (k) calculated based on the angle-related signal at the k-th sampling timing S (k) in one walking cycle and continuously storing the reference thigh phase angle (c) stored at that time point, the thigh phase angle calculation unit performs the stored data transmission processing only when a condition that one thigh phase angle calculated based on the angle-related signal at one sampling timing is smaller than a reference thigh phase angle stored at that point in time and an absolute value of a deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and performs the latest data transmission processing in other cases.

2. A walking motion assist device according to claim 1,

the predetermined threshold is set to 1.8 pi.

3. A walking motion assistance device is characterized by comprising:

an actuator that gives an assisting force to a walking motion of a user;

a thigh posture detection unit that detects an angle-related signal related to a hip joint angle that is a back-and-forth swing angle of a thigh of a user at each sampling timing;

a thigh phase angle calculation unit that calculates a thigh phase angle for each sampling timing based on the angle-related signal;

walking motion timing calculation means for calculating a cycle walking motion timing as a percentage of a walking cycle based on the thigh phase angle from the thigh phase angle calculation means;

an assist torque calculation means having an output torque pattern defining a relationship between a periodic walking motion timing and a torque value to be output, the assist torque calculation means calculating a torque value corresponding to a sampling timing by applying the periodic walking motion timing transmitted from the walking motion timing calculation means to the output torque pattern; and

an operation control unit that controls operation of the actuator so that the actuator outputs an assist force of the torque value calculated by the assist torque calculation unit,

the walking operation timing calculation means includes latest data transmission processing of transmitting a periodic walking operation timing t (k) calculated based on an angle-related signal at a k-th sampling timing s (k) in one walking cycle to the assist torque calculation means and storing the periodic walking operation timing t (k) as a periodic walking operation timing of the sampling timing s (k) as a reference periodic walking operation timing Tc, where k is an integer of 1 or more, and stored data transmission processing of transmitting the reference periodic walking operation timing Tc stored at the time point to the assist torque calculation means in place of the periodic walking operation timing t (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle as the periodic walking operation timing of the sampling timing s (k) and continuing to store the same at the time point And a stored reference cycle walking motion timing Tc, wherein the walking motion timing calculation means performs the stored data transmission processing only when a condition that one cycle walking motion timing calculated based on the angle-related signal at one sampling timing is smaller than the reference cycle walking motion timing stored at that point in time and an absolute value of a deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and performs the latest data transmission processing in other cases.

4. A walking motion assist device according to claim 3,

the predetermined threshold value is 90% when the periodic walking operation timing in one walking cycle is 0 to 100%.

5. The walking motion assist device according to any one of claims 1 to 4,

the walking motion timing calculation means has a conversion function that defines a relationship between a thigh phase angle and a periodic walking motion timing in a walking cycle, and calculates the periodic walking motion timing by applying the thigh phase angle transmitted from the thigh phase angle calculation means to the conversion function.

Technical Field

The present invention relates to a walking motion assist device.

Background

As a device for assisting walking or rehabilitation for a person with inconvenience in legs or a person who is paralyzed by stroke or the like, a walking motion assisting device provided with an actuator such as an electric motor for assisting the motion of legs has been proposed (see patent document 1 below).

The walking motion assist device is configured to be attachable to and detachable from a knee-ankle-foot brace, and is capable of applying a walking assist force in a front-rear direction to a lower leg link in the knee-ankle-foot brace.

The walking motion assistance device includes: a housing detachably attached to the knee-ankle-foot brace; the actuator supported by the housing; a drive arm that pushes a lower leg brace in the knee-ankle-foot brace forward and backward using rotational power from the actuator; a thigh posture detection unit that detects a hip joint angle that is a back-and-forth swing angle of a thigh of a user at each sampling timing s (k) (k is an integer of 1 or more); a thigh phase angle calculation unit that calculates a thigh phase angle Φ (k) at a sampling timing s (k) based on the hip joint angle from the thigh posture detection unit; a walking motion timing calculation unit that calculates a walking motion timing T (k) corresponding to a sampling timing S (k) in one walking cycle based on the thigh phase angle φ (k); assist torque calculation means having an output torque pattern defining a relationship between a walking operation timing t (k) in one walking cycle and a torque value p (k) to be output, the assist torque calculation means calculating a torque value p (k) to be output by applying the walking operation timing t (k) to the output torque pattern; and an operation control unit that controls operation of the actuator so that the actuator outputs an assist force of the torque value p (k) calculated by the assist torque calculation unit.

The walking motion assist device described in patent document 1 is effective in that the walking motion timing in one walking cycle is recognized based on the phase angle Φ of the upper leg, not the lower leg which is the target portion to which the walking assist force is applied, and the walking motion timing can be recognized without requiring a complicated configuration as compared with a configuration in which the walking motion timing is recognized based on the motion of the lower leg.

The thigh phase angle calculation means calculates a thigh phase angle Φ (═ Arctan (ω/θ) + pi) based on the hip joint angle θ input from the thigh posture detection means and a hip joint angular velocity ω obtained by differentiating the hip joint angle θ.

Fig. 10 schematically shows a trajectory diagram obtained by plotting a thigh phase angle Φ (walking state) defined by the hip joint angle θ and the hip joint angular velocity ω over one walking cycle.

As shown in FIG. 10, the thigh phase angle φ defined by the hip angle θ and the hip angular velocity ω varies between 0 and 2 π in one walking cycle.

More specifically, when the hip angle θ in a state where the thigh is positioned forward and rearward of the body axis of the user in the vertical direction is "positive" and "negative", respectively, and the hip angular velocity ω in a state where the thigh swings forward and rearward, respectively, is "positive" and "negative", when the thigh phase angle Φ in a state where the hip angle θ is maximized in the "negative" direction and the hip angular velocity ω is "zero" is 0, a period (from a state where the hip angle θ is maximized in the "negative" direction and the hip angular velocity ω is "zero", a sampling timing S (1) in fig. 10) where the thigh swings maximally rearward from a state where the thigh swings maximally rearward (the hip angle θ is maximized in the "negative" direction and the hip angular velocity ω is "zero") to a state where the thigh moves relatively forward in a leg-up (free leg, japanese: comfortable foot) state and matches the body axis of the user (the hip angle θ is "zero" and the hip angular velocity is maximized in the "positive" direction) ") is included Walking area a1 of fig. 10), the thigh phase angle phi changes from 0 to pi/2.

Next, the thigh phase angle Φ changes from pi/2 to pi during a period from a state in which the raised thigh is aligned with the body axis of the user (a state in which the hip joint angle θ is "zero" and the hip joint angular velocity ω is maximum in the "positive" direction) to a state in which the thigh is further swung maximally to the front (a state in which the hip joint angle θ is maximum in the "positive" direction and the hip joint angular velocity ω is "zero") (the walking region a2 in fig. 10).

Further, the thigh phase angle Φ changes from the phase angle to 3 pi/2 during a period (walking region a3 in fig. 10) from a state in which the thigh in the leg-up state swings maximally forward (a state in which the hip joint angle θ is maximized in the "positive" direction and the hip joint angular velocity ω is "zero") to a state in which the thigh in the leg-up state swings relatively rearward while being grounded via heel contact (japanese foot standing) to become a leg standing state (a state in which the hip joint angle θ is "zero" and the hip joint angular velocity ω is maximized in the "negative" direction) and the body axis of the user coincides with the leg.

Further, the thigh phase angle Φ changes from 3 pi/2 to 2 pi during a period (walking region a4 in fig. 10) from a state in which the thigh in the standing-leg state coincides with the body axis of the user (a state in which the hip joint angle θ is "zero" and the hip joint angular velocity ω is maximum in the "negative" direction) to a state in which the thigh swings relatively backward and swings maximum in the backward direction (a state in which the hip joint angle is maximum in the "negative" direction and the hip joint angular velocity is "zero").

In addition, in a user who can perform a normal walking motion, the thigh phase angle Φ increases for each sampling timing, that is, as time passes.

However, in a user with inconvenient legs or a user who is paralyzed due to stroke or the like, there may occur a state where the thigh phase angle Φ (k +1) at one sampling timing S (k +1) is decreased from the thigh phase angle Φ (k) at the previous sampling timing S (k) of the one sampling timing S (k +1), that is, a phenomenon of reverse swing of the thigh in which the thigh is temporarily returned to the side opposite to the direction in which the thigh should swing in the normal walking motion.

When such a situation occurs, in the walking motion assistance device described in patent document 1, the output of the actuator changes abruptly.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6148766

Disclosure of Invention

The present invention has been made in view of the above-described conventional technology, and an object thereof is to provide a walking motion assist device configured to apply a walking assist force to the lower leg in accordance with a periodic walking motion timing identified based on a thigh phase angle, the walking motion assist device being capable of applying the walking assist force as smoothly as possible even when a reverse swing phenomenon occurs in which the user's thigh swings in a direction opposite to a direction in which the user should swing during a normal walking motion during a walking cycle.

In order to achieve the above object, a1 st aspect of the present invention provides a walking motion assistance device including: an actuator that gives an assisting force to a walking motion of a user; a thigh posture detection unit that detects an angle-related signal related to a hip joint angle that is a back-and-forth swing angle of a thigh of a user at each sampling timing; a thigh phase angle calculation unit that calculates a thigh phase angle for each sampling timing based on the angle-related signal; walking motion timing calculation means for calculating a cycle walking motion timing as a percentage of a walking cycle based on the thigh phase angle from the thigh phase angle calculation means; an assist torque calculation means having an output torque pattern defining a relationship between a periodic walking motion timing and a torque value to be output, the assist torque calculation means calculating a torque value corresponding to a sampling timing by applying the periodic walking motion timing transmitted from the walking motion timing calculation means to the output torque pattern; and an operation control unit that controls operation of the actuator so that the actuator outputs an assist force of the torque value calculated by the assist torque calculation unit, wherein the thigh phase angle calculation unit includes a latest data transmission process of transmitting a thigh phase angle phi (k) calculated based on an angle-related signal at a k-th sampling timing s (k) (k is an integer of 1 or more) in one walking cycle to the walking operation timing calculation unit as a thigh phase angle at the sampling timing s (k) and storing the thigh phase angle phi (k) as a reference thigh phase angle phi c, and a stored data transmission process of storing a reference thigh phase angle phi (k) stored at the time point instead of the thigh phase angle phi (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle The phase angle Φ c is transmitted to the walking motion timing calculation means as the thigh phase angle at the sampling timing s (k) and is stored in the reference thigh phase angle Φ c stored at the time point, and the thigh phase angle calculation means performs the stored data transmission processing only when a condition that one thigh phase angle calculated based on the angle-related signal at one sampling timing is smaller than the reference thigh phase angle stored at the time point and the absolute value of the deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and performs the latest data transmission processing in other cases.

According to the walking motion assistance device of claim 1 of the present invention, the thigh phase angle calculation means includes latest data transmission processing of transmitting the thigh phase angle Φ (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle to the walking motion timing calculation means as the thigh phase angle at the sampling timing s (k) and storing the thigh phase angle Φ (k) as the reference thigh phase angle Φ c, and stored data transmission processing of transmitting the reference thigh phase angle Φ c stored at the time point to the walking motion timing calculation means instead of the thigh phase angle (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle as the thigh phase angle at the sampling timing s (k) and continuously storing the reference thigh phase angle Φ stored at the time point to the walking motion timing calculation means And a thigh phase angle Φ c, wherein the thigh phase angle calculation means performs the stored data transmission processing only when a condition that one thigh phase angle calculated based on the angle-related signal at one sampling timing is smaller than the reference thigh phase angle stored at that point in time and an absolute value of a deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and performs the latest data transmission processing in other cases, and therefore, even when an unintended reverse swing phenomenon of the thigh occurs, it is possible to apply the walking assist force as smoothly as possible.

In the 1 st aspect, for example, the predetermined threshold is set to 1.8 pi.

In order to achieve the above object, a2 nd aspect of the present invention provides a walking motion assistance device comprising: an actuator that gives an assisting force to a walking motion of a user; a thigh posture detection unit that detects an angle-related signal related to a hip joint angle that is a back-and-forth swing angle of a thigh of a user at each sampling timing; a thigh phase angle calculation unit that calculates a thigh phase angle for each sampling timing based on the angle-related signal; walking motion timing calculation means for calculating a cycle walking motion timing as a percentage of a walking cycle based on the thigh phase angle from the thigh phase angle calculation means; an assist torque calculation means having an output torque pattern defining a relationship between a periodic walking motion timing and a torque value to be output, the assist torque calculation means calculating a torque value corresponding to a sampling timing by applying the periodic walking motion timing transmitted from the walking motion timing calculation means to the output torque pattern; and an operation control unit that controls operation of the actuator so that the actuator outputs the assist force of the torque value calculated by the assist torque calculation unit, wherein the walking operation timing calculation unit includes a latest data transmission process of transmitting a periodic walking operation timing t (k) calculated based on an angle-related signal at a k-th sampling timing s (k) (k is an integer of 1 or more) in one walking cycle to the assist torque calculation unit as a periodic walking operation timing of the sampling timing s (k) and storing the periodic walking operation timing t (k) as a reference periodic walking operation timing Tc, and a stored data transmission process of transmitting stored data in place of the periodic walking operation timing t (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle The reference cycle walking motion timing Tc stored at this time point is transmitted to the assist torque calculation means as the cycle walking motion timing of the sampling timing s (k) and the reference cycle walking motion timing Tc stored at this time point is stored in succession, and the walking motion timing calculation means performs the stored data transmission processing only when a condition that the one-cycle walking motion timing calculated based on the angle-related signal at one sampling timing is smaller than the reference cycle walking motion timing stored at this time point and the absolute value of the deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and performs the latest data transmission processing in other cases.

In the walking motion assistance device according to claim 2 of the present invention, the walking motion timing calculation means includes latest data transmission processing of transmitting the periodic walking motion timing t (k) calculated based on the angle-related signal at the kth sampling timing s (k) in one walking cycle to the assistance torque calculation means as the periodic walking motion timing of the sampling timing s (k) and storing the periodic walking motion timing t (k) as the reference periodic walking motion timing Tc, and stored data transmission processing of transmitting the reference periodic walking motion timing Tc stored at the time point to the assistance torque calculation means instead of the periodic walking motion timing t (k) calculated based on the angle-related signal at the kth sampling timing s (k) in one walking cycle as the periodic walking motion timing of the sampling timing s (k) And a step of outputting means for continuing to store the reference periodic walking motion timing Tc stored at the time point, wherein the walking motion timing calculation means performs the stored data transmission processing only when a condition that the one-periodic walking motion timing calculated based on the angle-related signal at the one sampling timing is smaller than the reference periodic walking motion timing stored at the time point and an absolute value of a deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and performs the latest data transmission processing in other cases.

In the above-described aspect 2, for example, when the cycle walking operation timing in one walking cycle is set to 0 to 100%, the predetermined threshold value is set to 90%.

In the various configurations of the walking motion assist device according to the present invention, the walking motion timing calculation means has a conversion function that defines a relationship between a thigh phase angle and a periodic walking motion timing in a walking cycle, and the thigh phase angle transmitted from the thigh phase angle calculation means is applied to the conversion function to calculate the periodic walking motion timing.

Drawings

FIG. 1 is a front view of a knee/ankle-foot support to which the walking motion assist device of the present invention can be attached.

Fig. 2 is an enlarged perspective view of a portion II in fig. 1.

Fig. 3 is an exploded perspective view of fig. 2.

Fig. 4 is a longitudinal cross-sectional perspective view of fig. 2.

Fig. 5 is a perspective view of the walking motion assist device according to the embodiment of the present invention as viewed from the front and inward in the width direction of the user, as attached to a knee-ankle-foot brace.

Fig. 6 is an exploded perspective view of the walking motion assist device as viewed from the mounting surface side (the inside in the user's width direction).

Fig. 7 is an exploded perspective view of the walking motion assist device and the knee/ankle/foot brace as viewed from the outside in the width direction of the user.

Fig. 8 is an exploded longitudinal sectional view of the walking motion assist device and the knee-ankle-foot brace.

Fig. 9 is a control block diagram of the walking motion assistance device.

Fig. 10 is a trajectory diagram obtained by plotting the hip joint angle θ and the hip joint angular velocity ω calculated by the control device in the walking movement assistance device over one walking cycle, and shows a state in which the scale (amplitude) of the hip joint angle θ and the scale (amplitude) of the hip joint angular velocity ω are aligned.

Fig. 11 is a graph showing a relationship between sampling timing and the thigh phase angle calculated by the thigh phase angle calculating unit.

Fig. 12 is a trajectory diagram obtained by plotting the hip joint angle θ and the hip joint angular velocity ω calculated by the control device in the walking movement assistance device over one walking cycle, and is a trajectory diagram of the user in which the scale (amplitude) of the hip joint angular velocity ω is 2 times the scale (amplitude) of the hip joint angle θ.

Fig. 13 is a diagram showing a walking posture in one walking cycle in time series.

Fig. 14 is a flowchart of an actuator operation control mode executed by the control device in the walking motion assist device.

Fig. 15 is a flowchart of the transmission process of the thigh phase angle walking operation timing calculation means in the actuator operation control mode.

Detailed Description

Hereinafter, an embodiment of a walking motion assistance device according to the present invention will be described with reference to the drawings.

The walking motion assist device 100 according to the present embodiment provides a walking assist force to a user wearing the knee-ankle-foot brace 1, and can be attached to either the knee-ankle-foot brace for the left leg or the knee-ankle-foot brace for the right leg.

First, the knee-ankle-foot support 1 will be described by taking a knee-ankle-foot support for a left leg as an example.

FIG. 1 shows a front view of a left leg knee ankle foot brace worn on a user's left leg.

The left-leg knee-ankle brace and the right-leg knee-ankle brace are bilaterally symmetric with respect to a central vertical plane passing through a body axis of the user in the vertical direction and extending in the front-rear direction.

The knee-ankle-foot brace 1 is an apparatus worn for walking assistance or rehabilitation by a person who has difficulty in walking or who is paralyzed by stroke or the like, and is customized in accordance with the physical constitution of the user.

As shown in fig. 1, the knee-ankle-foot brace 1 includes a thigh wearing body 11 to be worn on a thigh of a user, a thigh brace 20 extending substantially in the vertical direction in a state of supporting the thigh wearing body 11, a lower leg wearing body 31 to be worn on a lower leg of the user, and a lower leg brace 40 extending substantially in the vertical direction in a state of supporting the lower leg wearing body 31.

The thigh wearing body 11 and the lower leg wearing body 31 may take various forms as long as they can be worn on the thigh and the lower leg of the user, respectively.

In the present embodiment, the thigh wearing body 11 is formed in a tubular shape having a wearing hole of such a size that the thigh of the user can be inserted therein and fits to the thigh.

Similarly, the lower leg wearing body 31 is formed in a tubular shape having a wearing hole into which the lower legs of the user can be inserted and which has a size that fits the lower legs.

In the present embodiment, as shown in fig. 1, the thigh support 20 has a1 st thigh support 20(1) extending substantially in the up-down direction at the outer side of the user's widthwise direction W of the thigh wearing body 11 and a2 nd thigh support 20(2) extending substantially in the up-down direction at the inner side of the user of the thigh wearing body 11.

Similarly, the lower leg link 40 includes a1 st lower leg link 40(1) extending substantially in the vertical direction at the outer side in the user widthwise direction W of the lower leg wearing body 31 and a2 nd lower leg link 40(2) extending substantially in the vertical direction at the inner side in the user widthwise direction W of the lower leg wearing body 31.

Fig. 2 is an enlarged perspective view of a portion II in fig. 1.

Fig. 3 is an exploded perspective view of fig. 2.

In fig. 3, a part of the constituent members is not shown for easy understanding.

Also, the longitudinal cross-sectional perspective view of fig. 2 is shown in fig. 4.

As shown in fig. 1 to 4, the lower leg link 40 is connected to the upper leg link 20 via a link-side pivot connecting portion 50 so as to be swingable about a link-side pivot axis X coaxial with the knee joint of the user.

As described above, in the present embodiment, the thigh link 20 includes the 1 st and 2 nd thigh links 20(1) and 20(2), and the lower leg link 40 includes the 1 st and 2 nd lower leg links 40(1) and 40 (2).

In this case, the upper end portion of the 1 st lower leg link 40(1) is connected to the lower end portion of the 1 st upper leg link 20(1) via a1 st link-side pivotal connection portion 50(1) so as to be swingable about the link-side pivotal axis X, and the upper end portion of the 2 nd lower leg link 40(2) is connected to the lower end portion of the 2 nd upper leg link 20(2) via a2 nd link-side pivotal connection portion 50(2) so as to be swingable about the link-side pivotal axis X.

Specifically, as shown in fig. 2 to 4, the thigh link 20 includes a link main body 21c extending in the vertical direction, and a pair of connecting pieces 21a and 21b fixedly joined to both sides in the user width direction W at the lower end portion of the link main body 21c by pinning, welding, or the like, and the upper end portion of the corresponding lower leg link 40 is interposed between the pair of connecting pieces 21a and 21 b.

The thigh link mounting hole 20a is provided on the pair of connecting pieces 21a, 21b so as to be coaxial with the brace-side pivot axis X, and the lower leg link mounting hole 40a is provided on the lower leg link 40 so as to be coaxial with the brace-side pivot axis X.

The brace-side pivotal coupling portion 50 includes a brace-side coupling 51, and the brace-side coupling 51 is inserted into a brace-side bracket mounting hole formed by the thigh bracket mounting hole 20a and the lower leg bracket mounting hole 40a, so that the corresponding thigh bracket 20 and the corresponding lower leg bracket 40 are coupled to each other so as to be pivotable about a brace-side pivot axis X.

As shown in fig. 2 to 4, the holder-side coupler 51 includes a female screw member 52 and a male screw member 55 that are detachably screwed to each other in the holder-side bracket mounting hole.

The female screw member 52 has a cylindrical portion 53 inserted into the bracket mounting hole on the holder side from one side in the user width direction, and a flange portion 54 extending radially outward from the bracket mounting hole on the holder side from one side in the user width direction of the cylindrical portion 53, and the cylindrical portion 53 is formed with a screw hole opened to a free end side.

On the other hand, the male screw member 55 has a cylindrical portion 56 formed with a male screw screwed into the screw hole from the other side in the user width direction, and a flange portion 57 extending radially outward from the other side in the user width direction of the cylindrical portion 56 with respect to the brace-side bracket mounting hole.

As shown in fig. 2 to 4, in the present embodiment, the female screw member 52 is inserted into the brace-side bracket mounting hole from the thigh side of the user inserted into the thigh wearing body 11, and the male screw member 55 is screwed into the female screw member 52 from the side opposite to the thigh of the user.

In fig. 3 and 4, the reference numeral 54a is a radially outward projection provided on the flange portion 53, and the female screw member 52 is held so as not to be rotatable about the axis relative to the inner connecting piece 21b (i.e., the thigh bracket 20) by engaging with a recess 22 (see fig. 3) formed in the inner connecting piece 21 b.

In the present embodiment, the swing position of the lower leg link 40 around the link-side pivot axis X at the time of maximum extension of the lower leg of the user is set as a swing end of the lower leg link 40 in the forward direction around the link-side pivot axis X with respect to the thigh link 20.

Specifically, as shown in fig. 3, the upper end surface of the lower leg link 40 (the end surface facing the upper leg link 20) is an inclined surface whose radial distance from the link-side pivot axis line X increases as going from one side to the other side about the link-side pivot axis line X, and the lower end surface 25 of the upper leg link 20 (the end surface facing the lower leg link 40) is an inclined surface corresponding to the upper end surface 45 of the lower leg link 40.

With this configuration, when the lower leg is maximally extended, the lower leg link 40 permits only the rotation to one side (the direction in which the lower leg of the user bends with respect to the thigh) with respect to the thigh link 20 about the link-side pivot axis X, and prohibits the rotation to the other side (the direction in which the lower leg of the user extends with respect to the thigh).

In the present embodiment, as shown in fig. 1 to 4, the knee-ankle-foot brace 1 further includes a lock member 70 for inhibiting the rotation of the lower leg link 40 in both directions about the link-side pivot axis X with respect to the thigh link 20.

The lock member 70 is configured to be capable of taking a locked state (a state shown in fig. 2) in which the both brackets 20, 40 are coupled around the thigh bracket 20 and the lower leg bracket 40 to prevent the lower leg bracket 40 from rotating relative to the thigh bracket 20 about the bracket side pivot axis X, and a released state in which the coupling between the thigh bracket 20 and the lower leg bracket 40 is released to allow the lower leg bracket 40 to rotate relative to the thigh bracket 20 about the bracket side pivot axis X.

In the present embodiment, the locking member 70 includes a1 st locking member 70(1) that acts on the 1 st thigh link 20(1) and the 1 st lower leg link 40(1), and a2 nd locking member 70(2) that acts on the 2 nd thigh link 20(2) and the 2 nd lower leg link 40 (2).

In the present embodiment, as shown in fig. 1, the knee-ankle-foot brace 1 further includes a foot rest 60 on which a user places his or her foot.

In this case, the lower end of the lower leg link 40 is connected to the foot link 60.

The walking movement assistance device 100 according to the present embodiment will be described below.

Fig. 5 is a perspective view of the walking motion assistance device 100 attached to the knee/ankle/foot brace 1 for the left leg, as viewed from the front side and the inside in the width direction of the user.

Fig. 6 is an exploded perspective view of the walking motion assistance device 100 as viewed from the installation surface side.

Fig. 7 and 8 are an exploded perspective view and an exploded longitudinal sectional view of the walking motion assistance device 100 and the knee/ankle brace 1, respectively, as viewed from the outside in the user's width direction and from the front.

As shown in fig. 5 to 8, the walking motion assist device 100 includes a case 110 detachably connected to the knee/ankle-foot brace 1, an actuator accommodated in the case 110 and outputting a walking assist force for the lower leg, a driving arm 150 driven to swing by the actuator, a walking motion state detection sensor 170 for detecting a walking motion state in one walking cycle, and a control device 500 for controlling the operation of the actuator.

The housing 110 has a bracket 115 supporting the actuator and a cover 120 surrounding the bracket 115 and the actuator.

The bracket 115 has a vertically extending wall 117 extending substantially vertically in a state where the case 110 is attached to the knee/ankle/foot brace 1, and a horizontally extending wall 119 extending substantially horizontally from the vertically extending wall 117.

The cover 120 has: a lower cover 122, said lower cover 122 forming a mounting surface 112 opposite said 1 st thigh support 20 (1); and an upper cover 125, wherein the upper cover 125 is detachably coupled to the lower cover 122 and cooperates with the lower cover 122 to form a housing space for housing the bracket 115 and the actuator.

In the present embodiment, the bracket 115 is fixed in the housing space of the cover 120 by the vertically extending wall 117 being coupled to the inner surface of the lower cover 122 by fastening members such as bolts.

In the present embodiment, the upper cover 125 includes a1 st upper cover 125a detachably coupled to the lower cover 122 and a2 nd upper cover 125b detachably coupled to the 1 st upper cover 125 a.

In the present embodiment, the electric motor 130 is used as the actuator.

As shown in fig. 6, the electric motor 130 includes a motor main body 132 and an output shaft 135 coupled to the motor main body 132, and is configured to be capable of outputting rotational power in both directions, i.e., a1 st direction about an axis and a2 nd direction about an axis, from the output shaft 135.

In the present embodiment, the motor main body 132 is supported by the bracket 115 in a state of being placed on the horizontally extending wall 119, and the output shaft 135 extends downward from the horizontally extending wall 119.

As shown in fig. 6 and 7, the walking motion assistance device 100 according to the present embodiment further includes a power source 190 of the electric motor 130 such as a battery.

The power source 190 is supported by the vertically extending wall 117 so as to be located above the electric motor 130.

The drive arm 150 is operatively coupled to the output shaft 135, and swings about the drive-side pivot axis Y in the first 1 st direction on one side and the second 2 nd direction on the other side in accordance with the 1 st and 2 nd direction rotation outputs of the output shaft 135.

As shown in fig. 8, in the present embodiment, the driving arm 150 is operatively coupled to the output shaft 135 via a transmission gear mechanism 140.

The transmission gear mechanism 140 includes a drive-side bevel gear 142 supported by the output shaft 135 so as not to be relatively rotatable, and a driven-side bevel gear 144 disposed on the drive-side pivot axis Y in a state of meshing with the drive-side bevel gear 142.

The driven-side bevel gear 144 is disposed closer to the knee-ankle-foot brace 1 than the output shaft 135 in the user width direction W.

The base end of the drive arm 150 is coupled to the driven bevel gear 144, and the drive arm 150 is thereby swung about the drive-side pivot axis Y in accordance with the output of the output shaft 135.

As shown in fig. 8, the lower cover 122 is provided with a contact opening 123, and the driven bevel gear 144 and the base end of the driving arm 150 are coupled to each other through the contact opening 123.

The distal end portion of the drive arm 150 is operatively connected to the 1 st lower leg link 40(1) in a state where the walking motion assistance device 100 is attached to the knee/ankle foot brace 1, and pushes the 1 st lower leg link 40(1) about the brace side pivot axis X in accordance with the swing of the drive arm 150 about the drive side pivot axis Y.

The walking motion assistance device 100 according to this embodiment further includes a rotation sensor 160 that detects the swing position of the drive arm 150.

Specifically, as shown in fig. 8, a shaft 146 to be detected is coupled to the driven-side bevel gear 144 so as to be relatively non-rotatable about a drive-side pivot axis Y, and the rotation sensor 160 is disposed so as to detect a rotation angle of the shaft 146 to be detected about the axis.

The walking motion assist device 100 is detachably attached to the knee/ankle/foot brace 1 at 3 positions, i.e., an upper portion, a lower portion, and an upper-lower intermediate portion.

Specifically, as shown in fig. 6, the walking motion assistance device 100 includes an upper connection mechanism 220, a lower connection mechanism 260, and an intermediate connection mechanism 250.

As shown in fig. 8, the intermediate coupling mechanism 250 includes a ball stud 251 provided in the knee/ankle/foot brace 1, and a receiving recess 258 provided in the walking motion assistance device 100 and into which the ball stud 251 is ball-jointed.

As shown in fig. 8, the ball stud 251 has a shaft portion 252 that is provided to rise coaxially with the brace-side pivot axis X of the knee/ankle-foot brace 1 and extends toward the walking motion assist device 100, and a ball portion 255 that is provided at the tip end portion of the shaft portion 252.

In the present embodiment, the ball stud 251 is provided to the knee/ankle foot brace 1 so as to stand up by the brace-side link 51.

Specifically, as shown in fig. 4 and 8, the ball stud 251 is provided to stand up on the knee/ankle foot brace 1 by being screwed to an inner screw member (in the present embodiment, the female screw member 52) located at the user widthwise inner side of the female screw member 52 and the male screw member 55, instead of an outer screw member (in the present embodiment, the male screw member 55) located at the user widthwise outer side of the female screw member 52 and the male screw member 55 of the brace side connector 51.

The threaded coupling of the ball stud 251 to the internally threaded member can be exhibited by various structures.

For example, a stepped axial hole penetrating in the axial direction may be formed in the ball stud 251. The stepped axis hole has a large diameter hole opened on the side where the ball head 255 is located, a small diameter hole opened on the opposite side of the ball head in the axis direction, and a stepped portion connecting the large diameter hole and the small diameter hole. The ball stud 251 can be coupled to the inner threaded member by fastening a coupling member such as a bolt inserted through the stepped axial hole and screwed to the inner threaded member.

According to this configuration, the ball stud 251 can be easily erected on the conventional knee-ankle-foot brace 1 coaxially with the brace-side pivot axis X.

In the present embodiment, as shown in fig. 8, the housing recess 258 is formed at the base end portion of the drive arm 150.

With this configuration, the user of the walking motion assistance device 100 can be reduced in size in the width direction, and the brace-side pivot axis X and the drive-side pivot axis Y can be reliably positioned coaxially.

As shown in fig. 6, the upper coupling mechanism 220 includes an upper pivot shaft 222 provided on the attachment surface 112 so as to extend inward in the user width direction, and an upper fastening coupling member 225 supported rotatably about the axis on the upper pivot shaft 222.

The upper fastening member 225 includes a bearing portion 227 supported by the upper rotating shaft 222, and a cam portion 229 extending radially outward from the bearing portion 227.

The cam portion 229 is configured such that the radial distance between the outer peripheral surface and the axis of the upper turning shaft 222 increases toward one side with going around the axis of the upper turning shaft 222.

The upper coupling mechanism 220 further includes an upper receiving member 246 provided on the mounting surface 112 at a position separated from the upper rotating shaft 222 in the user front-rear direction by a distance that can be interposed between the upper receiving member and the upper rotating shaft 222 and the 1 st thigh link 20 (1).

In the present embodiment, the upper coupling mechanism 220 includes an upper receiving shaft 247 extending inward in the user width direction from the attachment surface 112, and an elastic roller 248 supported by the upper receiving shaft 247 functions as the upper receiving member 246.

By moving the walking motion assistance device 100 in a direction approaching the knee/ankle foot brace 1 in a state where the upper fastening member 225 is located at the release position around the upper rotation axis 222, the 1 st thigh link 20(1) can be located in a space between the upper fastening member 225 and the upper receiving member 246, and by moving the walking motion assistance device 100A in a direction separating from the knee/ankle foot brace 1 in a state where the 1 st thigh link 20(1) is located in the space, the 1 st thigh link 20(1) can be retracted from the space.

When the upper fastening member 225 is rotated about the upper rotation shaft 222 from the release position to the fastening position in a state where the 1 st thigh link 20(1) is positioned in the space, the cam portion 229 cooperates with the upper receiving member 246 to hold the 1 st thigh link 20(1) in the user front-rear direction, thereby bringing about a state where the upper portion of the walking motion assistance apparatus 100 is coupled to the 1 st thigh link 20 (1).

As shown in fig. 6, in the present embodiment, the upper fastening member 225 further includes an operating arm 230 extending radially outward from the bearing portion 227.

The radial length of the operating arm 230 between the free end and the axis of the upper turning shaft 222 is greater than the radial length between the radially outermost end of the cam portion 229 and the axis of the upper turning shaft 222.

According to this configuration, the upper fastening member 225 can be easily rotated about the upper rotation shaft 222 via the operation arm 230, and when an unintended external force is applied to the 1 st thigh frame 20(1) and the upper portion of the walking motion assistance device 100, it is possible to effectively prevent the upper fastening member 225 from being rotated about the upper rotation shaft 222 via the cam portion 229 and releasing the coupled state of the upper portion of the walking motion assistance device 100 and the 1 st thigh frame 20 (1).

As shown in fig. 6, in the present embodiment, the upper fastening member 225 includes an engaging arm 232 extending radially outward from the bearing 227 at a position inward in the user width direction with respect to the cam portion 229.

The engaging arm 232 is provided on the upper fastening member 225 so as to be positioned further inward in the user's width direction than the 1 st thigh support 20(1) in a state of being positioned in the space between the upper fastening member 225 and the upper receiving member 246.

The engaging arm 232 is provided with an engaging groove 233, and the engaging groove 233 is engaged with a portion of the upper receiving shaft 247 that extends inward in the user width direction than the upper receiving member 246 in a state where the upper fastening member 225 is pivotally operated from the release position to the fastening position about the upper rotational shaft 222 and the cam portion 229 cooperates with the upper receiving member 246 to sandwich the 1 st thigh frame 20(1) in the user front-rear direction, and the engaging groove 233 is engaged with the portion of the upper receiving shaft 247 that extends inward in the user width direction, whereby the upper portion of the walking motion assistance device 100 and the 1 st thigh frame 20(1) can be prevented from being relatively moved in the user width direction against will.

Next, the lower coupling mechanism 260 will be described.

As shown in fig. 5 to 8, in the present embodiment, a swing member 200 swingable around a rotation shaft 205 along the front-rear direction of the user is provided at the distal end portion of the driving arm 150, and the lower coupling mechanism 260 is provided at the swing member 200.

With such a configuration, the relative positions of the upper coupling mechanism 220, the intermediate coupling mechanism 250, and the lower coupling mechanism 260 in the user width direction can be appropriately adjusted, and the walking motion assistance device 100 can be attached to the knee/ankle/foot braces 1 of various shapes customized according to the physique of the user in an appropriate state.

That is, the knee/ankle-foot brace 1 is customized to fit the physical constitution of the user, and the inclination angle and/or the curved shape of the 1 st thigh link 20(1) with respect to the 1 st lower leg link 40(1) in the user width direction W (see fig. 1) differs for each knee/ankle-foot brace 1.

In this regard, by connecting the swing member 200 to the distal end portion of the drive arm 150 so as to be swingable in the user width direction and providing the lower connection mechanism 260 to the swing member 200, the walking motion assistance device 100 can be appropriately attached to various types of knee/ankle-foot braces 1 having different inclination angles and/or curved shapes in the user width direction W of the 1 st thigh brace 20(1) with respect to the 1 st lower leg brace 40 (1).

The lower coupling mechanism 260 has substantially the same structure as the upper coupling mechanism 220.

Specifically, as shown in fig. 6, the lower coupling mechanism 260 includes a lower rotating shaft 262 provided on the swing member 200 so as to extend inward in the user width direction, and a lower fastening coupling member 265 supported rotatably about the axis on the lower rotating shaft 262.

The lower fastening member 265 includes a bearing portion (not shown) supported by the lower rotating shaft 262 and a cam portion (not shown) extending radially outward from the bearing portion.

The cam portion is configured such that the radial distance between the outer peripheral surface and the axis of the lower turning shaft 262 increases toward one side around the axis of the lower turning shaft 262.

As shown in fig. 6, the lower coupling mechanism 260 further includes a lower receiving member 286 supported by the swing member 200 at a position separated from the lower rotation shaft 262 in the user front-rear direction by a distance that can be interposed between the lower leg link 40(1) and the lower rotation shaft 262.

In the present embodiment, the lower coupling mechanism 260 includes a lower receiving shaft 287 provided in the swing member 200 so as to extend inward in the user width direction, and an elastic roller 288 supported by the lower receiving shaft 287 functions as the lower receiving member 286.

By moving the walking motion assistance device 100 in a direction approaching the knee/ankle foot brace 1 in a state where the lower fastening member 265 is located at the release position around the lower rotation shaft 262, the 1 st lower leg link 40(1) can be located in a space between the lower fastening member 265 and the lower receiving member 286, and by moving the walking motion assistance device 100 in a direction separating from the knee/ankle foot brace 1 in a state where the 1 st lower leg link 40(1) is located in the space, the 1 st lower leg link 40(1) can be retracted from the space.

When the lower fastening member 265 is operated to pivot from the release position to the fastening position about the lower pivot shaft 262 in a state where the 1 st lower leg link 40(1) is positioned in the space, the cam portion cooperates with the lower receiving member 286 to hold the 1 st lower leg link 40(1) in the user's front-rear direction, thereby assuming a state where the lower portion of the walking motion assistance apparatus 100 is coupled to the 1 st lower leg link 40 (1).

As shown in fig. 6, in the present embodiment, the lower fastening member 265 further includes an operating arm 270 extending radially outward from the bearing portion.

The operating arm 270 is configured such that the radial length between the free end and the axis of the lower rotating shaft 262 is greater than the radial length between the radially outermost end of the cam portion 269 and the axis of the lower rotating shaft 262.

According to this configuration, the lower fastening member 265 can be easily rotated about the lower rotation shaft 262 via the operation arm 270, and when an unintended external force is applied to the 1 st lower leg link 40(1) and the lower portion of the walking motion assistance device 100, the situation in which the lower fastening member 265 is rotated about the lower rotation shaft 262 via the cam portion to release the coupled state of the lower portion of the walking motion assistance device 100 and the 1 st lower leg link 40(1) can be effectively prevented.

As shown in fig. 6, in the present embodiment, the lower fastening member 265 has an engaging arm 272 extending radially outward from the bearing 267 at a position inward in the user width direction with respect to the cam 269.

The engagement arm 272 is provided on the lower fastening member 265 so as to be positioned further inward in the user width direction than the 1 st lower leg link 40(1) in a state of being positioned in the space between the lower fastening member 265 and the lower receiving member 286.

The engaging arm 272 is provided with an engaging groove 273, and the engaging groove 273 is engaged with a portion of the lower receiving shaft 287 that extends inward in the user width direction than the lower receiving member 286 in a state where the lower fastening member 265 is pivotally operated from the release position to the fastening position about the lower rotational shaft 262 and the cam portion cooperates with the lower receiving member 286 to sandwich the 1 st lower leg link 40(1) in the user front-rear direction, and the inner extending portion of the lower receiving shaft 287 is engaged with the engaging groove 273, whereby the lower portion of the walking motion assistance device 100 and the 1 st lower leg link 40(1) can be prevented from being relatively moved in the user width direction against will.

Next, a control structure of the walking motion assistance device 100 will be described.

Fig. 9 shows a control block diagram of the walking motion assistance device 100.

The walking motion assist device 100 includes a thigh posture detection unit 510 as the walking motion state detection sensor 170, and the control device 500 recognizes a walking state (a periodic walking motion timing) in a walking cycle based on a thigh phase angle Φ, and performs operation control of the electric motor 130 so that the electric motor 130 gives a walking assist force corresponding to the walking state to the lower leg.

That is, the walking motion assist device 100 is configured to detect the motion of the upper leg, which is a region different from the lower leg, instead of the lower leg, which is a region to which the assist force is applied, recognize the walking state in the walking cycle based on the motion of the upper leg, and apply the walking assist force corresponding to the walking state to the lower leg, which is a region to which the assist force is applied.

Specifically, the thigh posture detection unit 510 can detect an angle-related signal related to a hip joint angle that is a back-and-forth swing angle of the user's thigh at each sampling timing.

In addition, as shown in fig. 9, the walking motion assistance device 100 includes a thigh phase angle calculation unit 550 that calculates a thigh phase angle Φ based on the angle-related signal, an assistance torque calculation unit 570 that calculates a torque value to be output in a walking state identified based on the thigh phase angle Φ, and an operation control unit 580 that controls the operation of the actuator.

As shown in fig. 9, the walking motion assisting device 100 according to the present embodiment includes a walking motion timing calculation unit 560, the walking motion timing calculation unit 560 calculates which walking state in one walking cycle the thigh phase angle Φ corresponds to based on the thigh phase angle Φ (that is, a cycle walking motion timing defined as a percentage of the walking cycle), and the assist torque calculation unit 570 is configured to calculate a torque value of the assist force to be output based on the cycle walking motion timing.

The assist torque calculation means 570 is configured to have an output torque pattern defining a relationship between the periodic walking operation timing in one walking cycle and the torque value to be output, and to calculate the torque value to be output by applying the periodic walking operation timing calculated by the walking operation timing calculation means 560 to the output torque pattern.

As shown in fig. 9, in the walking motion assistance device 100 according to the present embodiment, the control device 500 functions as the thigh phase angle calculation means 550, the walking motion timing calculation means 560, the assistance torque calculation means 570, and the operation control means 580.

That is, the control device 500 includes: an arithmetic section including a control arithmetic unit that executes arithmetic processing based on a signal input from the thigh posture detection unit 510, a human operation member, or the like; and a storage unit including a ROM that stores a control program, control data, and the like, a nonvolatile storage unit that stores a set value and the like in a state where the set value and the like are not lost even when the power supply is turned off and that can rewrite the set value and the like, a RAM that temporarily holds data generated in the calculation performed by the calculation unit, and the like.

The thigh posture detecting unit 510 detects the angle-related signal at each predetermined sampling timing determined in advance in one walking cycle.

The thigh posture detection unit 510 may be any device as long as it can directly or indirectly detect the back-and-forth swing angle of the thigh (hip joint angle θ), and may have various types such as a gyro sensor, an acceleration sensor, a rotary encoder, and a sensor for measuring a muscle current and muscle hardness.

In the walking motion assistance device 100 according to the present embodiment, the thigh posture detection means 510 includes a 3-axis angular velocity sensor (gyro sensor) 511 (see fig. 9) capable of detecting a forward and backward swinging angular velocity of the thigh, and the thigh phase angle calculation means 550 is configured to calculate the hip joint angle θ as the forward and backward swinging angle of the thigh by integrating the angular velocity of the thigh detected by the 3-axis angular velocity sensor 511.

The walking motion assistance device 100 according to the present embodiment includes the 3-axis acceleration sensor 515, and the thigh phase angle calculation unit 550 is configured to calculate a hip joint angle (a forward/backward swing angle of the thigh) with reference to the body axis (vertical axis) of the user based on a detection value detected by the 3-axis acceleration sensor 515 when the device is stationary.

Alternatively, the 3-axis acceleration sensor 515 may not be provided.

In this case, the hip joint angle θ (the back-and-forth swing angle of the thigh) calculated by the thigh phase angle calculation unit 550 is the back-and-forth swing angle of the thigh with reference to the time point when the main power supply of the walking motion assistance device 100 is turned on.

Therefore, in this case, the thigh phase angle calculation unit 550 can correct the reference hip joint angle θ (the forward/backward swing angle of the thigh) so as to be the center value of the forward/backward swing angle of the thigh using a high-pass filter.

Alternatively, instead of using a high-pass filter, the thigh phase angle calculation means 550 may detect a deviation between the positive direction maximum value and the negative direction maximum value of the calculated hip joint angle θ (forward/backward swing angle of the thigh), and may correct the reference of the hip joint angle θ (forward/backward swing angle of the thigh) so as to be the center value of the forward/backward swing angle of the thigh based on the deviation.

The angle of the back-and-forth movement of the thigh with respect to the body axis may be detected by a rotary encoder, and the detected value may be used as the hip joint angle θ, but in the present embodiment, the degree of freedom in designing the walking motion assistance device 100 is improved by calculating the hip joint angle based on the angular velocity detected by the 3-axis angular velocity sensor 511.

That is, when the hip joint angle θ (the angle of the front-back movement of the thigh with respect to the body axis) is detected by the rotary encoder, it is necessary to detect the relative movement angle between the trunk-side detector fixed to the trunk and the thigh-side detector fixed to the thigh so as to integrally swing with the thigh, and therefore, it is necessary to attach the both detectors so that the trunk-side detector and the thigh-side detector do not shift in position with respect to the trunk and the thigh, respectively.

On the other hand, the method of calculating the hip joint angle θ based on the angular velocity detected by the 3-axis angular velocity sensor 511 can improve the degree of freedom in designing the walking motion assistance device 100 without being limited to the above.

As described above, in the walking motion assistance device 100 according to the present embodiment, the thigh posture detection unit 510 includes the 3-axis acceleration sensor 515 in addition to the 3-axis angular velocity sensor 511.

In this case, the thigh phase angle calculating unit 550 is configured to calculate a total euler angle by summing up a high frequency component of a1 st euler angle calculated based on the angular velocity data from the 3-axis angular velocity sensor 511 and a low frequency component of a2 nd euler angle calculated based on the acceleration data from the 3-axis acceleration sensor 515, and to calculate a thigh phase angle Φ based on a hip joint angle θ calculated from the total euler angle and a hip joint angular velocity ω calculated from the hip joint angle θ.

Specifically, as shown in fig. 9, the thigh phase angle calculation unit 550 receives angular velocity data based on the sensor coordinate axis from the 3-axis angular velocity sensor 511 at each sampling timing, and converts the angular velocity data into angular velocity data (euler angular velocity) indicating the correlation between the sensor coordinate axis and a global coordinate axis (a spatial coordinate axis based on the vertical direction) using a predetermined conversion expression.

The thigh phase angle calculating unit 550 calculates the 1 st euler angle by integrating the angular velocity data (euler angular velocity).

Preferably, the thigh phase angle calculating unit 500 removes drift of the angular velocity data input from the 3-axis angular velocity sensor 511 with reference to the sensor coordinate axis at each predetermined sampling timing, using the angular velocity data input from the 3-axis angular velocity sensor 511 at rest.

The thigh phase angle calculating means 550 receives acceleration data based on the sensor axis from the 3-axis acceleration sensor 515 via the low-pass filter 520 at each sampling timing, and calculates the 2 nd euler angle indicating the correlation between the sensor axis and the global axis (spatial axis based on the vertical direction) from the acceleration data received via the low-pass filter 520 based on the acceleration data received at rest and the gravitational acceleration.

The thigh phase angle calculating unit 550 calculates the hip joint angle θ based on the total euler angle obtained by summing the high frequency component of the 1 st euler angle obtained via the high pass filter 530 and the low frequency component of the 2 nd euler angle obtained via the low pass filter 535, and a unit vector indicating the orientation of the thigh.

Preferably, the thigh phase angle calculating unit 550 detects a heel strike based on acceleration data from the acceleration sensor 515, and adds the corrected euler angle calculated based on the angular velocity data from the 3-axis angular velocity sensor 511 to the total euler angle when detecting a heel strike, thereby enabling drift removal.

The thigh phase angle phi is calculated by the following algorithm.

The thigh phase angle calculating unit 550 calculates a hip joint angle θ for each sampling timing, and calculates a hip joint angular velocity ω by differentiating the hip joint angle θ.

For example, when calculating the hip joint angle θ (k) at the kth sampling timing s (k) (k is an integer of 1 or more) from the walking cycle reference timing, the thigh phase angle calculating unit 550 differentiates the hip joint angle θ (k) to calculate the hip joint angular velocity ω (k) at the sampling timing s (k).

The walking cycle reference timing may be set to, for example, a timing at which the heel is grounded or a predetermined time has elapsed since the heel is grounded.

The timing of heel strike can be identified by various methods.

For example, when the hip joint angular velocity ω when the thigh is swung forward and backward with respect to the body axis (vertical axis) of the user is positive and negative, respectively, the time point when the calculated hip joint angular velocity ω has traveled the predetermined phase angle Δ α from the timing at which the calculated hip joint angular velocity ω has changed from a positive value to zero may be identified as the heel landing time point.

Alternatively, the walking motion assistance device 100 may be provided with a heel strike detection unit that detects a heel strike, and the thigh phase angle detection unit 550 may recognize the timing detected by the heel strike detection unit as a heel strike time point. The heel strike detection unit may be, for example, a pressure sensor capable of detecting the ground contact of the heel.

Further, when the acceleration sensor 515 is provided as in the walking motion assistance device 100 according to the present embodiment, the acceleration sensor 515 can be used as the heel strike detection means as well.

The thigh phase angle calculating unit 550 calculates a thigh phase angle Φ (k) (═ Arctan (ω (k)/θ (k)) + pi) at the sampling timing s (k) based on the hip angle θ (k) and the hip angular velocity ω (k) at the sampling timing s (k).

Fig. 10 schematically shows a trajectory diagram obtained by plotting a thigh phase angle Φ (walking state) defined by the hip joint angle θ and the hip joint angular velocity ω over one walking cycle.

As shown in FIG. 10, the thigh phase angle φ defined by the hip angle θ and the hip angular velocity ω varies between 0 and 2 π in one walking cycle.

More specifically, when the hip angle θ in a state in which the thigh is positioned forward and rearward of the body axis of the user in the vertical direction is "positive" and "negative", respectively, and the hip angular velocity ω in a state in which the thigh swings forward and rearward, respectively, is "positive" and "negative", respectively, when the thigh phase angle Φ in a state in which the hip angle θ is at a maximum in the "negative" direction and the hip angular velocity ω is "zero" is 0, a walking period (a walking region a1 in fig. 10) from a state in which the thigh swings to the rear side at a maximum (a state in which the hip angle θ is at a maximum in the "negative" direction and the hip angular velocity ω is at "zero", and a sampling timing S (1) in fig. 10) to a state in which the thigh moves to the front side in the leg-up state and coincides with the body axis of the user (a state in which the hip angle θ is at "zero" and the hip angular velocity ω is at a maximum in the "positive" direction ") is reached from the leg-up state The thigh phase angle phi varies from 0 to pi/2.

Next, the thigh phase angle Φ changes from pi/2 to pi during a period from a state in which the raised thigh is aligned with the body axis of the user (a state in which the hip joint angle θ is "zero" and the hip joint angular velocity ω is maximum in the "positive" direction) to a state in which the thigh is further swung maximally to the front (a state in which the hip joint angle θ is maximum in the "positive" direction and the hip joint angular velocity ω is "zero") (the walking region a2 in fig. 10).

Further, the thigh phase angle changes from the phase angle pi to 3 pi/2 during a period from a state in which the thigh in the leg-up state swings maximally forward (a state in which the hip joint angle θ becomes maximum in the "positive" direction and the hip joint angular velocity ω becomes "zero") to a state in which the thigh in the leg-up state swings relatively backward while being grounded via heel-to-heel contact and becomes in the leg-standing state and the body axis of the user coincides (a state in which the hip joint angle θ becomes "zero" and the hip joint angular velocity ω becomes maximum in the "negative" direction) (the walking region a Φ 3 in fig. 10).

Further, the thigh phase angle Φ changes from 3 pi/2 to 2 pi during a period (walking region a4 in fig. 10) from a state in which the thigh in the standing-leg state coincides with the body axis of the user (a state in which the hip joint angle θ is "zero" and the hip joint angular velocity ω is maximum in the "negative" direction) to a state in which the thigh swings relatively backward and swings maximum in the backward direction (a state in which the hip joint angle is maximum in the "negative" direction and the hip joint angular velocity is "zero").

In the present embodiment, the thigh phase angle calculating unit 550 is configured to be able to perform latest data transmission processing of transmitting the thigh phase angle Φ (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle to the walking operation timing calculating unit 560 as the thigh phase angle at the sampling timing s (k) and storing the thigh phase angle Φ (k) as the reference thigh phase angle Φ c, and storing the stored data transmission processing of transmitting the reference thigh phase angle Φ c stored at the time point to the walking operation timing calculating unit 560 as the thigh phase angle at the sampling timing s (k) in place of the thigh phase angle Φ (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle and continuing to store the reference thigh phase angle Φ c at the time point to the walking operation timing calculating unit 560 The stored reference thigh phase angle Φ c, and the thigh phase angle calculation unit 550 is configured to perform the stored data transmission processing only when a condition that one thigh phase angle calculated based on the angle-related signal at one sampling timing is smaller than the reference thigh phase angle stored at that point in time and an absolute value of a deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and to perform the latest data transmission processing in other cases.

This point will be described in detail below.

Fig. 11 shows a graph showing a relationship between sampling timing and the thigh phase angle Φ calculated by the thigh phase angle calculating unit 550 for each sampling timing.

When the motion of the thigh in the walking cycle is normal, as in the walking cycles C2 and C3 of fig. 11, the thigh phase angle Φ calculated by the thigh phase angle calculating unit 550 gradually increases for each sampling timing S as the sampling timing S progresses (that is, as time passes), and the next walking cycle ends at the time point when the thigh phase angle Φ reaches 2 pi, and then the next walking cycle starts.

However, in a user who has inconvenience in legs or a user who is paralyzed by a stroke or the like, there is a possibility that a state in which the thigh phase angle Φ at one sampling timing is smaller than the thigh phase angle Φ at a sampling timing immediately before the one sampling timing, that is, a state in which the thigh is temporarily returned to the side opposite to the direction in which the user should swing during a normal walking motion (hereinafter, referred to as a phenomenon of reverse swing of the thigh).

As described above, the walking motion timing calculation means 560 calculates the cycle walking motion timing T, which is a percentage of the walking cycle, based on the thigh phase angle Φ transmitted from the thigh phase angle calculation means 550, the assist torque calculation means 570 calculates the torque value to be output by the actuator based on the cycle walking motion timing T transmitted from the walking motion timing calculation means 560, and the operation control means 580 controls the operation of the actuator so that the actuator outputs the assist force of the torque value transmitted from the assist torque calculation means 570.

Therefore, when the phenomenon of reverse swing of the thigh occurs, the actuator outputs an assisting force having a torque value different from a torque value to be originally output at the timing, and vibration may be caused in some cases.

In walking cycle C1 of fig. 11, the thigh phase angle Φ calculated by thigh phase angle calculating section 550 gradually increases with time before sampling timing s (a). In this state, the thigh phase angle Φ calculated based on the angle-related signal transmitted from the thigh posture detecting unit 510 at one sampling timing is larger than the reference thigh phase angle Φ c stored in the thigh phase angle calculating unit 550 at that point in time, and the condition for executing the stored data transmission processing is not satisfied.

Therefore, thigh phase angle calculating section 550 executes the latest data transmission processing.

In contrast, the thigh phase angle calculation unit 550 calculates the thigh phase angle Φ (a +1) based on the angle-related signal transmitted from the thigh posture detection unit 510 at the sampling timing S (a +1) in the walking cycle C1 in fig. 11 to be smaller than the reference thigh phase angle Φ C (in this example, Φ (a)) stored in the thigh phase angle calculation unit 550 at that point in time.

In this case, the thigh phase angle calculating unit 550 executes the stored data transmission processing (part a in fig. 11) for transmitting the reference thigh phase angle Φ c (Φ (a) in the example shown in fig. 11) stored at this time point to the walking operation timing calculating unit 560 as the thigh phase angle Φ at the sampling timing S (a + 1).

As described above, the execution conditions of the stored data transmission processing include a condition that one thigh phase angle calculated based on the angle-related signal at one sampling timing is smaller than the reference thigh phase angle stored at that point in time, and the absolute value of the deviation is equal to or smaller than a predetermined threshold value (hereinafter, referred to as "stored data transmission processing" condition 2), which will be described later.

In the 1 st walking cycle C1 shown in fig. 11, the thigh phase angle calculation unit 550 calculates the thigh phase angle Φ (a +2) based on the angle-related signal transmitted from the thigh posture detection unit 510 at the next sampling timing S (a +2) to be smaller than the reference thigh phase angle Φ C (Φ (a) in this example) stored in the thigh phase angle calculation unit 550 at that point in time.

In this case, the thigh phase angle calculating unit 550 executes the stored data transmission processing (part a in fig. 11) for transmitting the reference thigh phase angle Φ c (Φ (a) in the example shown in fig. 11) stored at this time point to the walking operation timing calculating unit 560 as the thigh phase angle Φ at the sampling timing S (a + 2).

On the other hand, the thigh phase angle calculation unit 550 calculates a thigh phase angle Φ (a +3) based on the angle-related signal transmitted from the thigh posture detection unit 510 at the sampling timing S (a +3) in the walking cycle C1 of fig. 11, which is larger than the reference thigh phase angle Φ C (in this example, Φ (a)) stored in the thigh phase angle calculation unit 550 at that point in time, and does not satisfy the condition for executing the stored data transmission processing.

Therefore, the thigh phase angle calculation unit 550 executes the latest data transmission processing of transmitting the thigh phase angle Φ (a +3) as the thigh phase angle Φ of the sampling timing S (a +3) to the walking motion timing calculation unit 560 and saving the thigh phase angle Φ (a +3) as the reference thigh phase angle Φ c.

According to this configuration, even when a reverse swing phenomenon occurs in which the user's thighs swing against will in the opposite direction to the direction in which the user should swing during a normal walking motion during a walking cycle, a walking assist force for returning to the normal walking motion can be effectively applied.

In addition, the situation that the output of the actuator is excessively and rapidly changed due to the contrary inverse swing phenomenon of the thigh can be prevented or reduced as much as possible, and the vibration of the actuator can be effectively prevented or reduced.

Here, the 2 nd condition of the save data transmission process will be described.

The thigh phase angle phi increases from 0 to 2 pi as the sampling timing progresses (i.e., as time passes) in one walking cycle, which ends at the point in time when the thigh phase angle reaches 2 pi.

Then, the next sampling timing becomes the 1 st sampling timing of the next walking cycle, and the thigh phase angle Φ again increases from 0 to 2 π as the sampling timing progresses (i.e., as time passes).

Thus, when switching from one walking cycle to the next, the thigh phase angle decreases from 2 π to 0.

That is, at the time of switching walking cycles, the thigh phase angle calculated by the thigh phase angle calculating means 550 based on the angle-related signal at the first sampling timing of the next walking cycle is substantially reduced by only 2 pi, as compared with the thigh phase angle calculated by the thigh phase angle calculating means 550 based on the angle-related signal at the last sampling timing in one walking cycle.

Therefore, by setting, as the predetermined threshold, a value that is sufficiently smaller than the absolute value of the deviation of the thigh phase angle (i.e., 2 pi) at the time of switching from one walking cycle to the next and larger than the absolute value of the deviation of the thigh phase angle assumed in accordance with the unintended phenomenon of reverse sway of the thigh, it is possible to perform the stored data transmission processing of transmitting the reference thigh phase angle Φ to the walking operation timing calculation unit 560 at the time of occurrence of the phenomenon of reverse sway of the thigh, and to allow switching from one walking cycle to the next.

As long as the condition is satisfied, the predetermined threshold value can be arbitrarily set, and can be set to, for example, 1.8 pi, which is 90% of 2 pi.

In the present embodiment, the walking motion timing calculation means 560 has a phase pattern function for converting the thigh phase angle Φ into a periodic walking motion timing which is a percentage of the walking cycle, and applies the thigh phase angle Φ (k) calculated by the thigh phase angle calculation means 550 based on the angle-related signal from the thigh posture detection means 510 at the sampling timing s (k) or the reference thigh phase angle Φ c held by the thigh phase angle calculation means 550 at that point in time when the phenomenon of inversion swinging of the thigh occurs to the thigh to the phase pattern function to calculate which period walking motion timing t (k) in the walking cycle the sampling timing s k corresponds to (that is, when the entire one walking cycle is 100%, the thigh phase angle phi (k) corresponds to what percentage).

Here, the cycle walking operation timing t (k) is calculated by the following conversion function.

T(k)＝(φ(k)/2π)×100(％)

The assist torque calculation means 570 has an output torque pattern defining the relationship between the periodic walking motion timing and the torque value to be output, and calculates the torque value p (k) to be output at the sampling timing s (k) by applying the periodic walking motion timing transmitted from the walking motion timing calculation means 560 to the output torque pattern.

The output torque pattern is created for each user and stored in the assist torque calculation means 570 in advance.

The operation control unit 580 performs operation control of the actuator (the electric motor 130) so that the actuator (the electric motor 130) outputs the assist force of the torque value calculated by the assist torque calculation unit 570.

In this way, the walking movement assistance device 100 according to the present embodiment is configured to grasp the walking state in the walking cycle (the periodic walking movement timing) based on the phase angle of the thigh (thigh phase angle Φ) different from the calf as the portion to which the walking assistance force is applied, and to output the assistance force corresponding to the walking state to the calf.

Therefore, compared to a configuration in which the walking state (the periodic walking operation timing) is recognized based on the movement of the lower leg which performs a complicated movement during walking, the walking state can be recognized accurately, and the assist force according to the walking state can be output.

In the walking motion assistance device 100 according to the present embodiment, the thigh phase angle calculation unit 550 calculates the thigh phase angle Φ based on the hip joint angle θ and the hip joint angular velocity ω and transmits the thigh phase angle Φ to the walking motion timing calculation unit only when the vector length of a plotted point on a locus diagram defined by the hip joint angle θ and the hip joint angular velocity ω exceeds a predetermined threshold value, and outputs the actuator operation prohibition signal when the vector length is equal to or less than the predetermined threshold value.

Therefore, when the posture of the user wearing the walking exercise assisting device 100 is changed unintentionally, the actuator (the electric motor 130) can be effectively prevented from outputting the walking assisting force even though the walking exercise is not started.

As described above, the walking motion assistance device 100 according to the present embodiment is configured to recognize the walking state in one walking cycle based on the thigh phase angle Φ, and to apply the walking assistance force to the lower leg by the actuator (the electric motor 130).

Therefore, it is possible to provide an accurate walking assisting force even for a user who has hemiplegia due to stroke or the like.

That is, the conventional walking assistance device configured to apply the walking assistance force by an actuator such as an electric motor is configured to detect the operation of the control target portion to which the assistance force is applied by the actuator, and to perform operation control of the actuator based on the detection result.

For example, in a conventional walking assistance device that supplies a walking assistance force to the thighs, operation control of an actuator that applies the walking assistance force to the thighs is performed based on the detection result of the movement of the thighs.

In addition, in the conventional walking assistance device that supplies the walking assistance force to the lower legs, the operation control of the actuator that applies the walking assistance force to the lower legs is performed based on the detection result of the motion of the lower legs.

However, in the case of a patient with hemiplegia due to stroke or the like, the walking motion of the thigh (forward and backward swinging motion around the hip joint) can be performed relatively normally, but the walking motion of the lower leg (forward and backward swinging motion around the knee joint) cannot be performed normally in many cases.

When it is intended to provide such a patient with a walking assistance force to the lower legs, in the conventional walking assistance device described above, the operation of the actuator that provides the walking assistance force to the lower legs is controlled based on the movement of the lower legs that cannot perform a normal walking operation, and there is a possibility that an accurate walking assistance force cannot be provided.

In contrast, as described above, the walking motion assistance device 100 according to the present embodiment is configured to control the operation of the actuator (the electric motor 130) that applies the walking assistance force to the lower legs based on the thigh phase angle Φ.

Therefore, even when the user has hemiplegia due to stroke or the like, it is possible to supply accurate walking assist force to the lower leg.

Preferably, the thigh phase angle calculating unit 550 may be configured to calculate the thigh phase angle Φ (k) by using a normalized hip joint angle θ a (k) and a normalized hip joint angular velocity ω a (k) instead of the hip joint angle θ (k) calculated based on the angle-related signal from the thigh posture detecting unit 510 (hereinafter, also referred to as an unnormalized hip joint angle θ (k)) and the hip joint angular velocity ω (k) obtained by differentiating the unnormalized hip joint angle θ (k) (hereinafter, also referred to as an unnormalized hip joint angular velocity ω (k)).

That is, the thigh phase angle calculating unit 550 may be configured to calculate the normalized hip joint angle θ a (k) by dividing the unnormalized hip joint angle θ (k) by the stored hip joint angle normalization coefficient a, calculate the normalized hip joint angular velocity ω a (k) by dividing the unnormalized hip joint angular velocity ω (k) by the stored hip joint angular velocity normalization coefficient B, and calculate the thigh phase angle Φ (k) ((-Arctan (ω a) (k)/θ a (k)) + pi) by using the normalized hip joint angle θ a (k) and the normalized hip joint angular velocity ω a (k)).

With this configuration, the walking state in the walking cycle (cycle walking operation timing) can be accurately recognized.

Specifically, in fig. 10, for easy understanding, a locus diagram of the thigh phase angle Φ is schematically shown in a state where the scale (amplitude) of the hip angle θ and the scale (amplitude) of the hip angular velocity ω are made to coincide with each other, but actually, the scale (amplitude) of the hip angle θ and the scale (amplitude) of the hip angular velocity ω do not coincide with each other and are different for each user, and more strictly, may be different depending on the walking cycle even in the same user.

Fig. 12 shows a schematic diagram of a trace plot of a user during a step cycle.

In the example shown in fig. 12, the scale (amplitude) of the hip joint angular velocity ω is about 2 times the scale (amplitude) of the hip joint angle θ.

In fig. 10 and 12, S (1) is a sampling timing when the hip joint angle θ becomes maximum in the "positive" direction and the hip joint angular velocity ω becomes "zero", and the sampling timings S (2) to S (12) are sampling timings subsequent to the sampling timing S (1).

The thigh phase angles Φ (2) to Φ (12) are obtained based on the measured values at the sampling timings S (2) to S (12), respectively.

As is apparent from comparison between fig. 10 and 12, fig. 12 shows that, in a region where the absolute value of the hip joint angle θ is large (for example, the sampling timings S (1) to S (3)), the change rate of the thigh phase angle Φ with respect to the elapse of time (that is, the deviation of the thigh phase angle Φ between one sampling timing and the next sampling timing) is large, whereas in a region where the absolute value of the hip joint angle θ is small (for example, the sampling timing S (7) to the sampling timing S (12)), the shift rate of the thigh phase angle Φ with respect to the elapse of time is small, as compared with fig. 10.

As described above, when the thigh phase angle φ (k) at the sampling timing S (k) is expressed by the cycle walking motion timing T (k) defined by a percentage of the walking cycle,

T(k)＝(φ(k)/2π)×100(％)。

therefore, when the scale (amplitude) of the hip joint angle θ and the scale (amplitude) of the hip joint angular velocity ω are different, the change rate of the periodic walking motion timing calculated based on the thigh phase angle Φ greatly varies depending on the swing position of the thigh in one walking cycle (that is, the magnitude of the absolute value of the hip joint angle θ), and as a result, the periodic walking motion timing cannot be accurately recognized, and it is difficult to accurately obtain the torque value to be output by the actuator.

In consideration of this, the normalized hip joint angle θ a (k) can be calculated by dividing the unnormalized hip joint angle θ (k) by the hip joint angle normalization coefficient a, the normalized hip joint angular velocity ω a (k) can be calculated by dividing the unnormalized hip joint angular velocity ω (k) obtained by differentiating the unnormalized hip joint angle θ (k) by the hip joint angular velocity normalization coefficient B, and the thigh phase angle Φ (k) can be calculated by using the normalized hip joint angle θ a (k) and the normalized hip joint angular velocity ω a (k) (-Arctan (ω a) (k)/θ a (k)) + pi).

According to this configuration, it is possible to prevent or reduce a difference in scale (amplitude) between the hip joint angle θ a (k) and the hip joint angular velocity ω a (k) that are the basis for calculating the thigh phase angle Φ (k), and it is possible to accurately recognize the periodic walking motion timing over the walking period.

For example, the thigh phase angle calculating means 550 may be configured to store, as the hip angle normalization coefficient a, a maximum value of absolute values of unnormalized hip joint angles θ obtained based on the angle-related signal from the thigh posture detecting means 510 within a predetermined period, and store, as the hip angular velocity normalization coefficient B, a maximum value of absolute values of unnormalized hip joint angular velocities ω calculated by differentiating the unnormalized hip joint angles θ obtained within the predetermined period.

According to this configuration, the hip joint angle normalization coefficient a and the hip joint angular velocity normalization coefficient B corresponding to "learning" of walking that differs for each user can be obtained, and the accuracy of recognition of the periodic walking motion timing can be improved.

Alternatively, the thigh phase angle calculation unit 550 may be modified so that the manually input hip angle and the manually input hip angular velocity that are input in advance are stored as the hip angle normalization coefficient a and the hip angular velocity normalization coefficient B, respectively.

In this modification, the artificial input hip joint angle and the artificial input hip joint angular velocity can be set for each user based on past walking data of the user.

In the above-described modification, it is preferable that the thigh phase angle calculating means 550 is configured to overwrite and store a maximum value of an absolute value of an unnormalized hip joint angle θ obtained based on the angle-related signal from the thigh posture detecting means 510 for a predetermined period as the hip joint angle normalization coefficient a instead of the human input hip joint angle, and to overwrite and store a maximum value of an absolute value of an unnormalized hip joint angular velocity ω calculated by differentiating the unnormalized hip joint angle θ obtained for the predetermined period as the hip joint angular velocity normalization coefficient B instead of the human input hip joint angular velocity.

The predetermined period may be, for example, a period from a point in time when the main power supply of the walking motion assistance device 100 is turned on to a most recently completed walking cycle of a predetermined number of times (most recently to the present, japanese: immediate).

The predetermined number of times can be set as appropriate as an integer of 1 or more.

Next, the walking assisting force required for the walking operation will be described.

Fig. 13 shows a schematic diagram representing a walking posture in one walking cycle in time series.

As shown in fig. 13, one walking cycle includes: a heel strike period (a period before and after the foot is grounded), X1, the heel strike period X1 including a heel strike time point at which the heel is grounded at a position forward of the body axis (vertical axis) of the user; a leg standing period (period in which the grounded lower leg moves backward relative to the body) X2 in which the leg standing period X2 moves the leg with the heel grounded backward relative to the grounded leg after the heel is grounded; an initial stage X3a of a leg raising period in which X3a raises the lower leg of a standing leg from the end time point of the leg standing period X2; and a later stage X3b of a leg raising period, wherein the later stage X3b of the leg raising period guides the raised calf to the heel by relatively moving the raised calf to the front side.

The walking assistance force includes a force for pushing the lower leg against the upper leg in the extending direction and a force for pushing the lower leg against the upper leg in the bending direction, and the directions of the walking assistance forces required according to the operation timing in the walking cycle are different.

For example, in the heel strike period X1 and the leg stance period X2, a walking assist force in the extension direction is required to rotate the lower leg in the knee extension direction around the knee joint and prevent the knee from bending.

In the initial stage X3a of the leg-raising period, a walking assist force in the bending direction is required to assist the leg-raising by rotating the lower leg in the knee bending direction about the knee joint.

In the latter stage X3b of the leg raising period, a walking assist force for rotating the lower leg in the knee extension direction about the knee joint is required.

The walking assistance force required in any or all of the 4 stages and/or the degree of walking assistance force required in the necessary stage may be different depending on the user and/or the degree of recovery of the user.

In view of this, the output torque pattern is set according to each user and each recovery degree of the user.

Fig. 14 shows a flow of an actuator operation control mode performed by the control device 500 in the walking motion assistance device 100.

The control device 500 starts the actuator operation control mode according to the start signal input.

The start signal is input by a manual operation of a manual operation member such as a start button by a user, for example.

When the actuator operation control mode is activated, the thigh phase angle calculation unit 550 determines whether or not a predetermined number of walking cycles have been completed in step S11.

The number of times the thigh phase angle Φ (k) calculated in "transmission processing of the thigh phase angle walking operation timing calculation means" described later returns to a preset walking cycle reference angle (for example, 0) can be counted, and whether or not the walking cycle of the predetermined number of times is completed can be determined based on whether or not the counted number of times reaches the predetermined number of times.

If yes at step S11, the process proceeds to step S12, and if no at step S11, the process bypasses step S12 and proceeds to step S13.

Immediately after the actuator operation control mode is started, the determination in step S11 is no, and the process proceeds to step S13.

Step S12 will be described later.

In step S13, the thigh phase angle calculation unit 550 calculates an unnormalized hip joint angle θ (k) at one sampling timing S (k) from the thigh posture detection unit 510 based on the angle-related signal at the one sampling timing S (k), and in step S14, calculates an unnormalized hip joint angular velocity ω (k) at the one sampling timing S (k) based on the unnormalized hip joint angle θ (k).

In step S15, the thigh phase angle calculation unit 550 calculates a normalized hip joint angle θ a (k) at the sampling timing S (k) by dividing the unnormalized hip joint angle θ (k) by the stored hip joint angle normalization coefficient a, and calculates a normalized hip joint angular velocity ω a (k) at the sampling timing S (k) by dividing the unnormalized hip joint angular velocity by the stored hip joint angular velocity normalization coefficient B.

The thigh phase angle calculating unit 550 creates a trajectory diagram based on the normalized hip joint angle θ a (k) and the normalized hip joint angular velocity ω a (k) in step S16, and determines whether or not the vector length of the plotted point (the distance between the plotted point and the origin) on the trajectory diagram exceeds a threshold value in step S17.

If no in step S17, the thigh phase angle calculation unit 550 determines that the walking operation is not started, and outputs an actuator operation prohibition signal (step S25).

In this case, the actuator operation control mode returns to step S11.

If yes in step S17, the "transmission process by the thigh phase angle walking operation timing calculation means" is executed.

Fig. 15 shows a flow of "transmission processing by the thigh phase angle walking operation timing calculation means".

The thigh phase angle calculating unit 550 calculates a thigh phase angle Φ (k) based on the hip angle θ (k) and the hip angular velocity ω (k) (in the present embodiment, the normalized hip angle θ a (k) and the normalized hip angular velocity ω a (k)) at the sampling timing S (k) (step S51).

Next, the thigh phase angle calculation unit 550 determines whether or not the thigh phase angle Φ (k) is smaller than the reference thigh phase angle Φ c stored at that time point (step S52).

Here, the initial value of the reference thigh phase angle Φ c is 0, and the stored value is set when the reference thigh phase angle Φ c is overwritten and stored in steps S55, S62, and S67 described below.

If no in step S52, that is, if the thigh phase angle Φ (k) calculated in step S51 is greater than the reference thigh phase angle Φ c, it means that a normal walking motion (that is, a walking motion in which the thigh phase angle Φ increases with the passage of time) is being performed.

In this case, the thigh phase angle calculating means 550 transmits the thigh phase angle Φ (k) calculated based on the angle-related signal at the sampling timing S (k) to the walking operation timing calculating means 560 as the thigh phase angle Φ at the sampling timing S (k) (step S61), overwrites and holds the thigh phase angle Φ (k) with a new reference thigh phase angle Φ c (step S62), and ends the "transmission processing by the thigh phase angle walking operation timing calculating means".

Therefore, in this case, in step S52 of "transmission processing of the thigh phase angle to walking operation timing calculation means" for the next sampling timing S (k +1), it is determined whether or not the thigh phase angle Φ (k +1) calculated based on the angle-related signal at this sampling timing S (k +1) is smaller than the thigh phase angle Φ (k) stored as the reference thigh phase angle Φ c.

If yes in step S52, that is, if the thigh phase angle Φ (k) calculated in step S51 is smaller than the reference thigh phase angle Φ c, it means that a normal walking motion (that is, a walking motion in which the thigh phase angle increases with time) is not performed, and there is a possibility that the phenomenon of reverse swing of the thigh occurs.

In this case, the thigh phase angle calculation unit 550 determines whether or not the absolute value of the deviation between the thigh phase angle Φ (k) and the reference thigh phase angle Φ c is smaller than a predetermined threshold value (step S53).

Step S53 is a step for determining whether the situation in which the thigh phase angle Φ (k) calculated in step S51 is smaller than the reference thigh phase angle Φ c is due to an unintended inversion swing phenomenon of the thigh or due to a change from one walking cycle to the next.

As described above, the predetermined threshold value in step S53 is set to the determination in step S53 of no at the time of the switching of the walking cycle.

The predetermined threshold is, for example, 90% (1.8 pi) of the amplitude of change (2 pi) of the thigh phase angle of the whole walking cycle.

If no in step S53, the thigh phase angle calculation unit 550 determines that the calculated thigh phase angle Φ (k) is smaller than the reference thigh phase angle Φ c due to the switching from one walking cycle to the next walking cycle, and transmits the thigh phase angle Φ (k) calculated based on the angle-related signal at the sampling timing S (k) to the walking operation timing calculation unit 560 as the thigh phase angle at the sampling timing S (k) (step S66), and stores the thigh phase angle Φ (k) as the new reference thigh phase angle Φ c (step S67), and ends the transmission processing of the "thigh phase walking angle operation timing calculation unit".

Therefore, in this case, in step S52 of "transmission processing of the thigh phase angle to walking operation timing calculation means" at the next sampling timing S (k +1), it is determined whether or not the thigh phase angle Φ (k +1) calculated based on the angle-related signal at this sampling timing S (k +1) is smaller than the thigh phase angle Φ (k) stored as the reference thigh phase angle Φ c.

If yes in step S53, the thigh phase angle calculation unit 550 determines that an unintended inversion sway phenomenon of the thigh has occurred, and transmits the reference thigh phase angle Φ c to the walking motion timing calculation unit 560 in place of the thigh phase angle Φ (k) calculated based on the angle-related signal at the sampling timing S (k) (step S54).

In this case, the thigh phase angle calculating means 550 directly stores the reference thigh phase angle Φ c stored at that time point (step S55), and ends the "transmission process by the thigh phase angle walking operation timing calculating means".

Therefore, in this case, in step S52 of "transmission processing of the thigh phase angle to walking operation timing calculation means" at the next sampling timing S (k +1), it is determined whether or not the thigh phase angle Φ (k +1) calculated based on the angle-related signal at the sampling timing S (k +1) is smaller than the reference thigh phase angle Φ c which is continuously held.

When the "transmission processing by the thigh phase angle walking operation timing calculation means" is finished, as shown in fig. 14, the walking operation timing calculation means 560 calculates the periodic walking operation timing t (k) based on the thigh phase angle (k) or reference thigh phase angle (c) transmitted from the thigh phase angle calculation means 550, and transmits the periodic walking operation timing t (k) to the assist torque calculation means 570 (step S19).

The assist torque calculation means 570 applies the periodic walking operation timing t (k) from the walking operation timing calculation means 560 to the stored output torque pattern, and obtains the magnitude and direction of the walking assist force to be output by the actuator at the timing (sampling timing S (k)) and transmits the obtained force to the operation control means 580 (step S20).

The operation control unit 580 controls the operation of the actuator so that the actuator outputs the walking assistance force of the magnitude and direction calculated by the assistance torque calculation unit 570 (step S21).

In step S22, the control device 500 determines whether or not an end signal of the actuator operation control mode has been input, returns to step S11 when no end signal has been input, and ends the control mode when an end signal has been input.

The end signal is input by, for example, a user manually operating a manual operation member such as an end button.

When returning from step S22 to step S11, the thigh phase angle calculation unit 550 determines whether the number of walking cycles counted in step S18 has reached a predetermined number of times, and if yes, it proceeds to step S12.

In step S12, thigh phase angle calculating section 550 overwrites the maximum value of the absolute value of unnormalized hip joint angle θ obtained based on the angle signal from thigh posture detecting section 510 in a predetermined number of walking cycles with the hip joint angle normalization coefficient a, and overwrites the maximum value of the absolute value of unnormalized hip joint angular velocity ω calculated by differentiating unnormalized hip joint angle θ obtained based on the angle signal from thigh posture detecting section in a predetermined number of walking cycles with the hip joint angular velocity normalization coefficient B.

In the present embodiment, the presence or absence of the occurrence of the phenomenon of the back swing of the thigh is determined based on the thigh phase angle as described above, but instead, the presence or absence of the occurrence of the phenomenon of the back swing of the thigh may be determined based on the periodic walking operation timing.

That is, the walking operation timing calculation unit 560 may be configured to include a latest data transmission process of transmitting the periodic walking operation timing t (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle to the assist torque calculation unit 570 as the periodic walking operation timing of the sampling timing s (k), and storing the periodic walking operation timing t (k) as the reference periodic walking operation timing Tc, and a stored data transmission process of transmitting the reference periodic walking operation timing Tc stored at the time point to the assist torque calculation unit 570 instead of the periodic walking operation timing t (k) calculated based on the angle-related signal at the k-th sampling timing s (k) in one walking cycle as the periodic walking operation timing of the sampling timing s (k) And continues to store the reference cycle walking motion timing Tc stored at that point in time, the walking motion timing calculation unit 560 performs the stored data transmission processing only when a condition that the one-cycle walking motion timing calculated based on the angle-related signal at one sampling timing is smaller than the reference cycle walking motion timing stored at that point in time and the absolute value of the deviation thereof is equal to or smaller than a predetermined threshold value is satisfied, and performs the latest data transmission processing in other cases.

With this configuration, as in the case of the present embodiment, even when the phenomenon of the inversion swing of the thigh is generated unintentionally, the walking assisting force can be applied as smoothly as possible.

In this case, when the cycle walking operation timing in one walking cycle is set to 0 to 100%, the predetermined threshold value may be set to 90%, for example.

Description of the reference numerals

100 walking motion assisting device

130 electric motor (actuator)

510 thigh posture detecting unit

550 thigh phase angle calculating unit

560 walking motion timing calculating means

570 assist torque calculating unit

580 working control unit