JP2012100983A - Walking support device - Google Patents

Abstract

A power-less walking support device that can efficiently support walking motion is provided.
A walking support device includes a waist link, a thigh link, a lower leg link, and a foot link. A pulley 24 is supported on the thigh link or the lower leg link. The pulley 24 is located in front of the rotation axis of the knee joint. One end of a string-like elastic member (spring 50 and wire 54) is connected to the waist link in front of the rotational axis of the thigh link with respect to the waist link, is hung on the pulley in the middle, and the other end is a foot against the lower leg link. It is connected to the foot link behind the rotation axis of the link.
[Selection] Figure 1

Description

  The present invention relates to a walking assist device that is attached to a user's leg and assists the movement of the leg.

  The wearable walking support device typically has a multi-link articulated structure that is worn along the legs. Since the link mechanism is compared to a skeleton arranged outside the user, this type of support device is sometimes called an exo skeleton type. This type of support device assists the walking motion by assisting the user's muscular strength by swinging the link in synchronization with the walking motion of the user. As long as there is a type that includes an actuator for swinging the link and a power source, the walking support device also has a type that swings the link using the elastic energy of an elastic body such as a spring. The type using elastic energy cannot be expected to have a strong auxiliary force, but has an advantage of not requiring a power source. Patent Document 1 discloses an example of a walking support device having an actuator, and Non-Patent Document 1 discloses an example of a walking support device that uses elastic energy.

US Pat. No. 7,190,141

"Exotendons for assistance of human locomotion", van den Bogert, A. J., BioMedical Engineering OnLine, 2003.2 (1), p. 17.

  The technology disclosed in the present specification relates to a power-less exoskeleton type walking support device using an elastic body. Therefore, hereinafter, a powerless walking support device using an elastic body is referred to as a “walking support device” or simply a support device.

  The center of gravity moves up and down during walking. The walking support device has a multi-link structure arranged along the legs, and the elastic body is arranged so that elastic energy is stored with the momentum when the center of gravity is lowered. The walking support device suppresses excessive reduction of the user's center of gravity during walking motion, and at the same time stores energy in the elastic body, and uses the stored elastic energy as auxiliary force when raising the center of gravity. The walking support device disclosed in this specification provides a walking support device that can devise the arrangement of the link structure and the elastic body and can support walking motion more efficiently.

  The novel walking support device disclosed in the present specification is a single elastic member that swings the thigh around the hip joint pitch axis, swings the lower leg around the knee joint rotation axis (pitch axis), and the ankle pitch axis. At the same time assists the swinging of the legs. The “pitch axis” is well known in the technical field of robots and means an axis extending to the side of the human body.

  One embodiment of the walking support device disclosed in the present specification includes a waist link, a thigh link, a crus link, and a foot link. The waist link is attached to the user's waist. The thigh link is disposed along the user's thigh. The lower leg link is arranged along the lower leg of the user. The foot link is attached to the user's foot. The thigh link is rotatably connected to the waist link, and the crus link is rotatably connected to the thigh link. The foot link is rotatably connected to the lower leg link.

  The support device further includes a pulley and an elastic string. The pulley is supported by a column extending from the thigh link or the crus link, and is located in front of the rotation axis of the knee joint. One end of the string-like elastic member is connected to the waist link in front of the rotation axis of the thigh link with respect to the waist link, is hung on the pulley in the middle, and the other end is behind the rotation axis of the foot link to the lower leg link. Connected to the foot link. Here, “front” means the front of the user when the user wearing the support device takes an upright posture. “Back” means the rear of the user when the user wearing the support device takes an upright posture. The cord-like elastic member may typically be a wire and a spring connected in series.

  In general walking movements, the legs land with the legs almost stretched, then the knees bend (lower waist position), then the knees extend (waist position rises), and the legs leave. . In the above support device, when the user's knee bends after the landing of the foot (when the waist position is lowered), the elastic elastic body is stretched and elastic energy is stored by the geometric arrangement of the pulley and the elastic elastic body. . The stored elastic energy is converted into a force (auxiliary force) that raises the waist before the foot leaves. As will be described in detail later, the auxiliary force is composed of three component forces: a moment to lower the toes, a force to stretch the knee, and a force to push the back forward. Any component force (moment) is a force necessary for the walking motion before takeoff. This support device exhibits the above three component forces with a single string-like elastic body.

  In a further aspect of the support device disclosed in the present specification, at least one of the connection position of the waist link and the string-like elastic member, the connection position of the foot link and the string-like elastic member, and the position of the pulley is the user's front-rear direction. It is preferable that the adjustment is possible. By providing these adjustment functions, the support device can be adapted to individual users.

  The technology disclosed in this specification provides a power-less walking support device that can efficiently support walking motion.

It is a side view of a support device. It is a top view of a waist link. It is a figure explaining the auxiliary power which a support device exhibits. It is a figure explaining the adjustment function of an assistance apparatus.

  A walking support device 100 (support device 100) of an embodiment will be described with reference to the drawings. In FIGS. 3 and 4, some of the reference numerals shown in FIG. 1 are omitted for easy understanding of the drawings. The support device 100 includes a waist link 10 that is worn on the user's waist, a foot link 40 that is fixed to the user's foot, a thigh link 20 that connects the waist link 10 and the foot link 40, and a crus link 30. It has a multi-link multi-joint structure. In the figure, only the thigh link 20, the lower leg link 30, and the foot link 40 arranged on the right leg are shown, but these links are also arranged on the left leg. Hereinafter, only the right leg link group will be described, but the same applies to the left leg link group.

  As shown in FIG. 2, the waist link 10 is substantially U-shaped and extends around the user's back to the front side of the user. The waist link 10 has a backrest 10a, and the waist link 10 is firmly fixed to the user's waist and back. The foot link 40 is fixed to the user's foot like a shoe.

  One end of the thigh link 20 is rotatably connected to the waist link 10 at a position coaxial with a rotation axis extending in the pitch axis direction of the hip joint. Reference numeral 12 represents a connection joint. In the present embodiment, reference numeral 12 also means the rotational axis of the thigh link 20 with respect to the waist link 10. The other end of the thigh link is rotatably connected to one end of the crus link 30 at a position coaxial with the rotation axis of the knee joint. Reference numeral 22 represents a rotary joint of the thigh link 20 and the crus link 30, and also represents a rotation axis. The other end of the lower leg link 30 is rotatably connected to the foot link 40 at a position coaxial with a rotation axis extending in the pitch axis direction of the ankle joint. Reference numeral 32 represents a connection joint. In this embodiment, the reference numeral 32 also means the rotation axis of the foot link 40 with respect to the crus link 30. Since the waist link 10 and the foot link 40 are fixed to the user, the positions of the thigh link 20 and the crus link 30 are uniquely regulated without being fixed to the user. However, for further stability, the thigh link 20 and the lower leg link 30 may be fixed to the user's thigh and lower leg using a belt, respectively. The pitch axis corresponds to the Y axis shown in the figure. The X axis and Z axis shown in the figure correspond to the roll axis and the yaw axis, respectively. The X axis also corresponds to the front-rear direction of the user.

  The lower end of the thigh link 20 extends forward of the joint 22, and a pulley 24 is disposed at the tip thereof. In other words, the pulley 24 is supported by a support column extending from the lower end of the thigh link 20 and is positioned in front of the rotation shaft 22 of the knee joint. A wire 54 described later is wound around the pulley 24. A portion between the rotary joint 22 and the pulley 24 in FIG. 1 corresponds to a “post”.

  A slide terminal 14 is attached to the front end of the waist link 10 and in front of the rotary joint 12 (rotation axis 12). The slide terminal 14 is configured to be movable in the front-rear direction of the user. One end of a spring 50 is attached to the slide terminal 14. A wire 54 is attached to the other end of the spring 50. The wire 54 extends along the leg and is hung on the pulley 24 in the middle, and the other end of the wire 54 is connected to the foot link 40 via the slide terminal 42. The slide terminal 42 is attached to the foot link 40 behind the rotary joint 32 (the rotation axis of the foot link 40). The slide terminal 42 can also move in the front-rear direction of the user. The spring 50 and the wire 54 correspond to an example of a string-like elastic member. One end of the string-like elastic member is connected to the waist link 10 in front of the rotation axis 12, and is hung on the pulley 24 in the middle, and the other end is connected to the foot link 40 in the rear of the rotation axis 32. Yes. The spring 50 and the wire 54 are also arranged on the left leg link group.

  The function of the support apparatus 100 will be described. Since the support device 100 has the multi-link multi-joint structure described above, it always swings along the user's leg. More specifically, the thigh link 20 swings according to the movement of the user's thigh, and the lower leg link 30 swings according to the movement of the user's lower leg. The spring 50 always applies a tension T to the wire 54. In the walking motion, after the foot has landed, when the user's waist falls and the knee moves forward, the spring 50 extends and the tension T increases. Then, as shown in FIG. 3, a clockwise moment M <b> 1 acts on the waist link 10 around the rotary joint 12. A force F that pushes the rotary joint 22 backward acts on the pulley 24. A clockwise moment M <b> 2 acts on the foot link 40 around the rotary joint 32. The moment M1 pushes the user's back forward via the waist link 10. The force F acts in the direction of extending the knee. The moment M2 acts in a direction to lower the toes downward. These forces act to stretch the knee and push the body forward before taking off while walking. The link group of the support device is arranged on the left and right legs, and supports the user's walking motion for each step.

  In the support device 100, a single string-like elastic body (spring 50 and wire 54) extends from the waist to the foot via the pulley 24. With the above-described layout of the string-like elastic body, the support device 100 simultaneously generates a moment M1 for pushing the body forward, a force F for extending the knee, and a moment M2 for pushing the toe down, thereby efficiently assisting the walking motion.

  Other functions of the support device 100 will be described. A load sensor 52 is attached between the spring 50 and the wire 54. The load sensor 52 measures the tension T. By measuring the tension T, the assist force applied to the user by the support device 100 can be measured.

  As indicated by an arrow a in FIG. 4, the slide terminal 14 can move in the front-rear direction and is fixed at an arbitrary position. As indicated by reference sign c in FIG. 4, the slide terminal 42 is also movable in the front-rear direction and is fixed at an arbitrary position. The pulley 24 is also movable in the front-rear direction as indicated by the arrow b, and is fixed at an arbitrary position. By adjusting the positions of the slide terminals 14 and 42 and the pulley 24, the magnitude of the assist force can be adjusted according to the characteristics of the user.

  A symbol L in FIG. 4 indicates a distance between the rotation axis 32 and the wire 54. As the knee bends, the tension T changes and the distance L also changes. Accordingly, the magnitude of the moment M2 acting on the foot link 40 is a function of the tension T and the distance L. The moment M2 can also be expressed as a function of the hip joint angle, the knee angle, and the ankle joint angle around the pitch axis. The same applies to the moment M1 and the force F. Using these functions, the strength of the spring 50 and the position of the slide terminal 14 and the like can be determined so that the assist force applied to the user is optimized.

  In the support device 100 of the embodiment, the pulley 24 is supported by the thigh link 20. The pulley 24 only needs to be positioned in front of the rotation axis 22 between the thigh link 20 and the crus link 30 and may be supported by the crus link 30.

  In the above description, it should be noted that “front” and “rear” mean “front” and “rear” when the user takes an upright posture.

  The link structure of the support device is such that the rotational axis between the waist link and the thigh link is substantially the same as the pitch axis of the user's hip joint, and the rotational axis between the thigh link and the crus link is approximately the same as the knee joint pitch axis of the user. In addition, the rotation axis between the lower leg link and the foot link may be configured to substantially coincide with the pitch axis of the user's ankle joint. In other words, the thigh link is rotatably connected to the waist link so as to have a rotation axis that substantially matches the pitch axis of the hip joint, and the crus link has a rotation axis that substantially matches the pitch axis of the knee joint. The foot link may be connected to the lower leg link so as to have a rotation axis that substantially matches the pitch axis of the ankle joint. The physical connection position between the waist link and the thigh link is not limited to the position coaxial with the pitch axis of the hip joint. It should be noted that the rotational axis of the thigh link relative to the waist link may generally coincide with the hip pitch axis. For example, the upper end of the thigh link has an arc-shaped rib when viewed from the side (pitch axis direction), and the thigh link is a waist link by a mechanism in which the rib slides with respect to the waist link along the arc. It may be connected to. In such a structure, the rotational axis of the thigh link coincides with the center of the arc, but the thigh link is physically connected to the waist link by an arc-shaped rib, and the center of the arc is physically There is no connection. The same applies to the connection structure of the thigh link and the crus link and the connection structure of the crus link and the foot link.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

10: waist link 10a: backrest 12, 22, 32: rotation joint (rotation axis)
14, 42: Slide terminal 20: Thigh link 24: Pulley 30: Lower leg link 40: Foot link 50: Spring 52: Load sensor 54: Wire 100: Walking support device

Claims (3)

A walking support device for assisting a user's walking motion,
A waist link to be worn on the user's waist;
A thigh link that is rotatably coupled to the waist link and is disposed along the thigh;
A thigh link that is rotatably connected to the thigh link and is disposed along the thigh,
A leg link that is rotatably connected to the lower leg link and is attached to the user's foot;
A pulley that is supported by a strut extending from the thigh link or the lower thigh link, and located forward of the rotation axis of the knee joint;
One end is connected to the waist link in front of the rotation axis of the thigh link with respect to the waist link, and is hung on the pulley in the middle, and the other end is connected to the foot link behind the rotation axis of the foot link to the lower leg link. A string-like elastic member,
A walking support device characterized by comprising:   The walking support device according to claim 1, wherein the string-like elastic member includes a wire and a spring connected in series.   The connection position between the waist link and the string-like elastic member, the connection position between the foot link and the string-like elastic member, and the position of the pulley can be adjusted in the front-rear direction of the user. 2. The walking support device according to 2.

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