JP2002301124A - Walking assisting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a decline in muscle power and correct a walking form by promoting motion by assisting motion such as walking of a user with weakened muscle power of the legs. SOLUTION: This walking assisting device has the first electric actuator 12 for extending and bending the hip joint of a user, the second electric actuator 13 for extending and bending the knee joint of a user, and a back pack 11 mounted on the back of a user in which a power source 29 for the first and the second electric actuators 12 and 13 and a control means 26 is accommodated. The control means 26 calculates the necessary torque for the hip joint and the knee joint required in each motion mode based on the output of an angle sensor and a gyro sensor for a joint and generates the torque obtained by subtracting the threshold value TV previously set according to the state of a user from the necessary torque in the first and second electric actuators 12 and 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention promotes exercise by assisting walking, climbing up and down stairs, standing up from a sitting position, sitting up from a standing position, etc., for an elderly or injured person with weak muscles. The present invention relates to a walking assist device for suppressing muscle weakness and correcting a gait form.

[0002]

2. Description of the Related Art Such a walking assist device is disclosed in Japanese Unexamined Patent Publication No.
These are known from JP-A-15035 and JP-A-59-115036. This walking assist device has hydraulic actuators attached to the user's hip, knee, and ankle joints, and operates these hydraulic actuators to generate joint torque that extends and bends each joint. It is designed to assist exercise such as walking.

[0003]

As shown in FIG. 8, in the normal range of human activity, 20% to 30% of the maximum voluntary muscle strength
It is known that when more muscle strength is used, the maximum muscle strength increases, but when less muscle strength is used, the maximum muscle strength decreases. The sudden decline in muscle strength of a bedridden old man is caused by the fact that the muscle strength is no longer used. Therefore, users who can no longer walk on their own will use the walking assist device to perform walking training, thereby actively using the muscles of the lower limbs to prevent muscular weakness and increase muscular strength, as well as correct gait. The form can be recovered.

However, in the above-mentioned conventional apparatus, since the walking assist device generates most of the joint torque necessary for walking, the muscular strength of the lower limb of the user is appropriately used to prevent muscular strength reduction and increase muscular strength. There was a problem that cannot be achieved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and assists a user who has weak muscles of the lower limbs, such as walking, to promote such exercises, thereby suppressing muscle weakness and improving gait form. The purpose of this is to correct.

[0006]

According to the first aspect of the present invention, a first electric actuator for extending and bending a hip joint of a user and a knee joint of the user are provided. A second electric actuator for extending and bending, an angle sensor for detecting angles of a hip joint and a knee joint, a gyro sensor for detecting an angle of a user's torso with respect to a vertical direction, and power and control of the first and second electric actuators A backpack that houses the means and is mounted on the back of the user, wherein the control means calculates the required torque of the hip joint and the knee joint required in each exercise mode based on the outputs of the angle sensor and the gyro sensor. The first and second electric actuators calculate the torque obtained by subtracting a predetermined threshold from the required torque according to the state of the user. Walking assist device is proposed which is characterized in that generating the.

According to the above configuration, the first electric actuator for extending and bending the hip joint of the user and the second electric actuator for extending and bending the knee joint of the user are provided, and the hip joint required in each exercise mode is provided. And the first and second electric actuators generate a torque obtained by subtracting a preset threshold value according to the user's condition from the required torque of the knee joint, so that the torque less than the threshold value is generated by the user's own muscle strength, Only the torque exceeding the threshold can be generated in the first and second electric actuators. As a result, the user exercises by using his / her own muscle power appropriately, so that the user can not only reduce the muscle power due to the nonuse of the muscle power but also increase the muscle power, and can also increase the first and second electric power. By assisting the movement with the torque generated by the actuator, it is possible to correct the gait form of the user.

According to the invention described in claim 2,
In addition to the configuration of claim 1, a walking assist device is proposed, wherein the threshold value is variable.

According to the above configuration, since the threshold value is variable, the threshold value is changed according to the user's muscular strength, physical condition, fatigue level, proficiency level, etc., so that the muscular strength can be appropriately adjusted according to the user's condition. And exercise can be performed, thereby making it possible to further enhance the effect of preventing a decrease in muscle strength and the effect of increasing muscle strength while minimizing the burden on the user.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 7 show an embodiment of the present invention. FIG. 1 is a diagram showing a use state of a walking assist device, FIG. 2 is a first partial view of an exploded perspective view of the walking assist device, and FIG. 3 is a second partial view of an exploded perspective view of the walking assist device, FIG. 4 is a block diagram of a control system, FIG. 5 is an explanatory diagram of a walking mode and a stepping over mode, and FIG. 6 is a graph showing changes in hip joint torque in each mode. FIG. 7 is a graph showing changes in knee joint torque in each mode.

As shown in FIGS. 1 to 3, the walking assist device according to the present embodiment includes a backpack 11 that a user carries on his back.
A pair of left and right first electric actuators 12 and 12 for applying torque to the left and right hip joints, and a pair of left and right second electric actuators 13 and 1 for applying torque to the left and right knee joints
3, an abdominal band 14 made of a soft resin detachably attached to the abdomen of the user, and an upper leg pad made of a soft resin divided into two parts before and after detachably attached to the left and right thighs of the user Fifteen
f, 15r, and a lower leg pad 16 made of a soft resin divided into two parts before and after detachably attached to the left and right shin parts of the user.
f, 16r, and two suspension belts 17, connected from the front of the abdominal band 14 to the rear of the abdominal band 14 via the shoulder of the user.
17 are provided. FIG. 3 shows an upper leg pad 15 for the left leg.
Although f and 15r and lower leg pads 16f and 16r are shown, those for the right leg (not shown) have the same symmetric structure.

The first link 18 and the reinforcing member 19 are bolted so as to sandwich the respective outer and inner surfaces of the left and right sides of the abdominal band 14. At the lower end of the first link 18
The second link 20, which is flexibly connected via the electric actuator 12, is bolted to the outside of the rear upper leg support 15r. At this time, the first link 18 and the second link 18
The pivot of the link 20, ie the first electric actuator 1
2 is located outside the hip joint of the user.

An outer third link 21 and an inner third link 2 are provided outside and inside the rear upper leg rest 15r, respectively.
2 is bolted and the rear lower leg rest 16
An outer fourth link 23 and an inner fourth link 24 are bolted to the outside and inside of r, respectively. The lower end of the outer third link 21 and the upper end of the outer fourth link 23
Flexibly connected via an electric actuator 13,
The lower end of the inner third link 22 and the upper end of the inner fourth link 24 are flexibly connected via a hinge 25. At this time, both third links 21 and 22 and both fourth links 2
3, 24 pivots, ie the second electric actuator 13
And hinges 25 are located outside and inside the knee joint of the user.

Inside the backpack 11, which is detachably attached to the suspension belts 17, 17, there are first electric actuators 12, 12, and second electric actuators 13, 1,
An electronic control unit 26 for controlling the operation of the actuator 3, an indicator 27 for indicating the state of the torque generated by each of the actuators 12, 12, 13 and 13, and a motor for driving each of the actuators 12, 12; Motor driver 28 and its motor and electronic control unit 2
And a power supply 29 (for example, a Ni-Zn battery) for supplying power to the power supply 6.

The first electric actuators 12, 12 and the second electric actuators 13, 13 have a common structure and are composed of a DC motor and a speed reducer.
The casing is bolted to the lower end of the first link 18 and its output shaft is bolted to the second link 2.
Connected to the top of 0. Therefore, by driving the first electric actuator 12, a torque for relatively rotating the first link 18 and the second link 20 is generated, and the hip joint of the user can be extended and bent. The casing of the second electric actuator 13 is bolted to the lower end of the outer third link 21, and the output shaft is connected to the upper end of the outer fourth link 23 by a bolt 35.
Accordingly, by driving the second electric actuator 13, a torque for relatively rotating the outer third link 21 and the outer fourth link 23 is generated, and the knee joint of the user is extended and extended.
Can be bent.

The maximum movable angle of the hip joint is 120 ° for bending (bending forward) and 45 ° for extension (bending backward). The maximum movable angle of the knee joint is 120 ° for flexion (bending backward) and 0 ° for extension (bending forward).

As shown in FIG. 4, the electronic control unit 26
Includes a pair of angle sensors 37, 37 for detecting the angle of the left and right hip joints (ie, the angle formed by the first link 18 and the second link 20), and the angle of the left and right knee joints (ie, the outside third link 21 and the outside link). A signal from a pair of angle sensors 38, 38 for detecting the angle formed by the fourth link 23), a signal from a gyro sensor 39 for detecting the angle of the torso of the user with respect to the vertical direction, and a threshold described later. A signal from the threshold setting means 40 to be set is input. The electronic control unit 26 performs arithmetic processing on each of the signals, and outputs the four electric actuators 12, 1 via a motor driver 28.
2; control the operation of 13 and 13 and operate the indicator 27 to operate the four electric actuators 1;
2, 12, 13 and 13 indicate the state of the torque generated.

FIGS. 6 and 7 show various motion modes,
That is, the flat-land walking mode (see FIG. 5A) and 5 cm,
15cm, 25cm step over mode of each step (Fig. 5
(Refer to (B))) shows the required torque of the hip joint and the knee joint required when performing (1). Positive torque is torque when the joint is extended, and negative torque is torque when the joint is bent. A threshold TV is set for each of the torque at the time of extension and the torque at the time of flexion of the joint, and the threshold TV is arbitrarily set by the threshold setting means 40 according to the user's muscular strength, physical condition, degree of fatigue, proficiency, and the like. It is possible. The first and second electric actuators 12, 12; 13, 13 do not generate assist torque in a region where the required torque is equal to or less than the threshold TV, and generate the assist torque in a region where the required torque exceeds the threshold TV. The amount of assist torque generation is controlled such that the sum of the torque and the assist torque matches the required torque.

More specifically, the left and right hip joint angles detected by the angle sensors 37, 37, the left and right knee joint angles detected by the angle sensors 38, 38, and the vertical direction detected by the gyro sensor 39 are used as references. Based on the angle of the user's torso and the angle, angular velocity and angular acceleration of the user's torso, upper and lower legs based on the vertical direction, the hip and knee joint needs at that time Calculate the torque. If the required torque is equal to or less than a preset threshold TV, the first and second electric actuators 12, 12; 1
The exercises 3 and 13 do not generate assist torque, and exercise by the muscle strength of the user is performed. When the required torque exceeds the threshold value TV, the first and second electric actuators 12, 12, 13 and 13 generate assist torque corresponding to the excess.

As described above, when performing various modes of movement such as walking on a flat ground or climbing over a step, the total amount of torque required for performing the movement is determined by the first and second electric actuators 1.
2,12; 13,13 is not generated, but only torque exceeding a preset threshold is generated according to the state of the user, so that the user exercises using his / her own muscle power appropriately. Thus, it is possible to prevent a decrease in muscle strength and increase muscle strength. In addition, assisting the exercise with the assist torque generated by the first and second electric actuators 12, 12, 13 and 13 can help the user to recover a correct gait form.

In particular, since the threshold value TV can be set arbitrarily, when the user's muscular strength is strong, when the physical condition is good,
When the degree of fatigue is low, the threshold TV is set to be high when the level of proficiency is high, and when the muscular strength of the user is weak, when the physical condition is poor, when the degree of fatigue is high, and when the level of proficiency is low, the threshold TV is set.
By setting to a low value, it is possible to obtain the maximum muscle strength maintaining effect or the maximum muscle strength effect while minimizing the burden on the user.

Although the embodiments of the present invention have been described in detail above, various design changes can be made in the present invention without departing from the gist thereof.

For example, the threshold TV of the hip joint torque and the knee joint torque, the threshold TV of the positive side (progressive side) torque and the negative side (flexion side) torque, or the torque of the right joint and the left joint torque Need not match, and they can all be set arbitrarily.

The threshold value T during the exercise in the predetermined mode
Instead of keeping V constant, the threshold TV may be varied for each part of the movement.

[0026]

As described above, according to the first aspect of the present invention, the first electric actuator for extending and bending the hip joint of the user and the second electric actuator for extending and bending the knee joint of the user. The first and second electric actuators generate torques obtained by subtracting a preset threshold value according to the state of the user from the required torques of the hip and knee joints required in each exercise mode.
The torque below the threshold is generated by the user's own muscle strength,
Only the torque exceeding the threshold can be generated in the first and second electric actuators. As a result, the user exercises by using his / her own muscle power appropriately, so that the user can not only reduce the muscle power due to the nonuse of the muscle power but also increase the muscle power, and can also increase the first and second electric power. By assisting the movement with the torque generated by the actuator, it is possible to correct the gait form of the user.

According to the second aspect of the present invention,
Since the threshold value is variable, by changing the threshold value according to the user's muscular strength, physical condition, fatigue level, proficiency level, etc., it is possible to exercise appropriately using the muscular strength according to the state of the user. This makes it possible to further enhance the effect of preventing muscle strength reduction and the effect of increasing muscle strength while minimizing the burden on the user.

[Brief description of the drawings]

FIG. 1 is a diagram showing a use state of a walking assist device.

FIG. 2 is a first partial view of an exploded perspective view of the walking assist device.

FIG. 3 is a second partial view of an exploded perspective view of the walking assist device.

FIG. 4 is a block diagram of a control system.

FIG. 5 is an explanatory diagram of a walking mode and a stepping over mode.

FIG. 6 is a graph showing changes in hip joint torque in each mode.

FIG. 7 is a graph showing changes in knee joint torque in each mode.

FIG. 8 is a graph showing the relationship between the amount of muscle strength used and the change in muscle strength.

[Explanation of symbols]

 Reference Signs List 11 backpack 12 first electric actuator 13 second electric actuator 26 electronic control unit (control means) 29 power supply 38 angle sensor 39 gyro sensor TV threshold

Claims (2)

[Claims] 1. A first method for extending and bending a user's hip joint.
An electric actuator (12), a second electric actuator (13) for extending and bending the user's knee joint, and an angle sensor (3) for detecting angles of the hip joint and the knee joint.
7, 38), a gyro sensor (39) for detecting the angle of the body of the user with respect to the vertical direction, and a power supply (29) and control means (26) for the first and second electric actuators (12, 13). And a backpack (11) mounted on the back of the user, and the control means (26) includes the angle sensor (37, 3).
8) and the output of the gyro sensor (39), the required torque of the hip joint and the knee joint required in each exercise mode is calculated, and a threshold (TV) preset in accordance with the state of the user is calculated from the required torque. ) Is subtracted from the first and second electric actuators (12, 1).
3) A walking assistance device characterized in that it is generated. 2. The walking assist device according to claim 1, wherein the threshold value (TV) is variable.