Robot Arm Mechanism

Abstract

To provide a robot arm mechanism that achieves a large movable area of a serial link and high output of a parallel link simultaneously.SOLUTION: A robot arm mechanism (100) is formed by coupling a first parallel manipulator (100A) and a second parallel manipulator (100B) via a bar (160) and a joint member (170). The joint member (170) slides along the bar (160). By maintaining a constant length of an arm (140) of the first parallel manipulator and an arm (150) of the second parallel manipulator, positions and attitudes of a base (110), a first plate (120) and a second plate (130), which are components of the robot arm mechanism, are fixed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a robot arm mechanism. [Background technology]

[0002] There are two main types of methods for constructing a manipulator, which is a major component of a robot arm mechanism: serial link and parallel link. In a serial link, each link is arranged in series, and the joints connecting each link have degrees of rotational freedom, resulting in a large range of motion. In contrast, in a parallel link, each link is connected in parallel between the base and end plate, allowing the output of each link to be added together, resulting in a large output. In other words, a serial link can achieve a larger range of motion than a parallel link, and a parallel link can achieve a larger output than a serial link. For this reason, a serial link is chosen when range of motion is more important than output, and a parallel link is chosen when output is more important than range of motion.

[0003] For example, Patent Document 1 discloses a robot arm mechanism that uses a parallel link. This robot arm mechanism is configured as a medical position and posture transmission mechanism that uses the parallel link as a lever. FIG. 37 is a perspective view of the position and attitude transmission mechanism 1 disclosed in Patent Document 1. The position and attitude transmission mechanism 1 includes a manipulator 2, a first link member 15 in the form of a rigid round bar, and a second ring member 16 that is fixed.

[0004] The manipulator 2 includes an arm 3, an end effector 4, a movable end plate 6, a base member 8, and a fixed base plate 11. A first link member 15 is connected to the end plate 6 and the base member 8 via universal joints 24. The end effector 4 is attached to the underside of the base member 8. The arm 3 is connected at both ends to the end plate 6 and the base plate 11 via ball joints 14. The arm 3 is made up of six links 12a-12f, each of which is configured as a linear actuator. By controlling the expansion and contraction of each of the links 12a-12f, the end plate 6 can be made to assume a desired position and posture, and the position and posture of the end plate 6 are transmitted to the end effector 4 via a first link member 15.

[0005] A ring-shaped slider 21 is fitted into the first link member 15 , and the second ring member 16 supports the slider 21 and thus the first link member 15 via a universal joint 27 . Three wires 25 are stretched around the first link member 15 between the end plate 6 and the base end member 8 in parallel to the first link member 15 .

[0006] In the position and attitude transmission mechanism 1 having the above-described structure, the motion input from the arm 3 is ultimately output to the end effector 4. Specifically, the input from the arm 3 causes the end plate 6 to linearly displace in three mutually perpendicular axes (the Z axis extending in the longitudinal direction of the first link member 15, and the X and Y axes perpendicular to the Z axis) and to rotate about these three axes. These six degrees of freedom of motion are transmitted to the base end member 8. For example, when the end plate 6 linearly displaces in the X axis direction, the universal joint 27 rotates about the Y axis, causing the base end member 8 to linearly displace in the opposite direction to the X axis direction; and when the end plate 6 linearly displaces in the Y axis direction, the universal joint 27 rotates about the X axis, causing the base end member 8 to linearly displace in the opposite direction to the Y axis direction.

[0007] In this way, the six degrees of freedom of movement of the end plate 6 appear as six degrees of freedom of movement of the base end member 8 , and the movement of the base end member 8 is transmitted to the end effector 4 attached to the base end member 8 . [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-254876 Summary of the Invention [Problem to be solved by the invention]

[0009] The position and attitude transmission mechanism 1 described above uses a general parallel link, and therefore a relatively high output can be expected, but the drawback of parallel links, namely a small range of motion, remains. Previous robot arm mechanisms such as the position and attitude transmission mechanism 1 tended to prioritize either range of motion or output power, sacrificing the other, but recent robot arm mechanisms are being required to have a high level of both range of motion and output power, for example, when applying a robot arm mechanism to a walking assistance mechanism for humans.

[0010] The present invention has been made in consideration of the problems with conventional robot arm mechanisms as described above, and has as its object to provide a robot arm mechanism that combines the large range of motion of a serial link with the high output of a parallel link. [Means for solving the problem]

[0011] In order to achieve this object, the present invention provides a robot arm mechanism comprising a base member, a first member, a second member located on the same side of the base member as the first member, N (N is an integer of 2 or more) first connecting members that can be extended or retracted to a desired length, N (N is an integer of 2 or more) second connecting members that can be extended or retracted to a desired length, a bar, and a joint member, wherein the first connecting member connects the base member and the first member, and the base member, the first member, and the first connecting member constitute a first parallel manipulator, and the second connecting member connects the base member and the second member, and the base member and the first connecting member constitute a first parallel manipulator. The base member, the second member, and the second connecting member constitute a second parallel manipulator, and when the lengths of the first connecting member and the second connecting member are maintained constant, the positions and attitudes of the base member, the first member, and the second member are fixed, and the joint member connects the bar to the second member so that the bar can slide relative to the second member in the length direction of the bar and so that the bar can rotate in all directions relative to the second member, and one end of the bar is connected to the first member so that it can rotate in all directions.

[0012] In the above robot arm mechanism, for example, it is preferable that N is 3, and the first connecting member and the second connecting member are connected to the base member and one of the first member and the second member so as to be rotatable in all directions, and are connected to the other of the base member and the first member and the second member with one rotational degree of freedom. In the above robot arm mechanism, for example, it is preferable that N is 6, and that the first connecting member and the second connecting member are connected to the base member so as to be rotatable in all directions, and are connected to the first member and the second member, respectively, so as to be rotatable in all directions.

[0013] In the above robot arm mechanism, for example, it is preferable that N is 2, and the first connecting member and the second connecting member are connected to the base member with one rotational degree of freedom, and are connected to the first member and the second member with one rotational degree of freedom, respectively. When N is 3, it is preferable that the first connecting member and the second connecting member are connected to the base member via a universal joint and to the first member and the second member via a hinge joint, respectively.

[0014] When N is 6, it is preferable that the first connecting member and the second connecting member are connected to the base member via a universal joint, and are connected to the first member and the second member, respectively, via universal joints. When N is 2, it is preferable that the first connecting member and the second connecting member are connected to the base member via a hinge joint and to the first member and the second member via a hinge joint, respectively.

[0015] The universal joint may comprise, for example, a rod end having a first portion and a cylindrical second portion continuous with the first portion; a holder having a base portion, a first wall portion standing upright on the base portion, and a second wall portion standing upright on the base portion parallel to the first wall portion at a position spaced apart from the first wall portion, wherein the second portion of the rod end is connected to the base member so as to be rotatable about an axial center line of the second portion, and the base portion of the holder is connected to each of the first connecting members and the front portion so as to be rotatable about an axis perpendicular to the base portion. The rod end is connected to each of the second connecting members, and the first portion of the rod end is connected to both the first wall portion and the second wall portion so as to be rotatable around a rotation axis perpendicular to the axial center line of the second portion, the spacing between the first wall portion and the second wall portion is such that the rod end is rotatable around the rotation axis, and a recessed area is formed on the inner surface of at least one of the first wall portion and the second wall portion to form a space between it and a vertical surface, and the recessed area is formed to include the tops of the first wall portion and the second wall portion.

[0016] The recessed region is formed, for example, by forming a slope on the inner surface. The recessed region may be formed by forming an arcuate surface on the inner surface. Alternatively, the inclined surface or the arcuate surface can be formed as a thin portion having a smaller thickness than other portions.

[0017] The inclined surface or the arcuate surface may be formed by bending the inner surface. The inclined surface may be composed of a plurality of inclined surfaces each having a different inclination angle. It is preferable that the inclined surface starts at a position between the rotation axis and one end of the first wall portion or the second wall portion in the width direction, and ends at the other end of the first wall portion or the second wall portion in the width direction.

[0018] The inclination angle of the inclined surface is preferably within the range of 5 to 45 degrees. It is preferable that a portion where the thickness is smallest in the height direction of the first wall portion and the second wall portion is formed between the height of the rotation shaft and the apex of the first wall portion or the second wall portion. It is preferable that the corners of the inclined surface are formed in a curved shape. It is preferable that a corner portion of the first wall portion or the second wall portion located below the inclined surface is formed into a curved shape.

[0019] It is preferable that the recessed region is formed on one side of the first wall portion in the width direction around the rotation axis, and on the other side of the second wall portion in the width direction around the rotation axis. For example, a linear actuator is attached to each of the first connecting members and each of the second connecting members, and each of the first connecting members and each of the second connecting members expands and contracts via this linear actuator.

[0020] For example, the second member may be a ring-shaped member having a circular opening, the joint member may be a first ring member and a second ring member, the bar may be fitted into the first ring member so as to be slidable relative to the first ring member, the first ring member may be fitted inside the second ring member, and the second ring member may be rotatable relative to the first ring member around any direction perpendicular to the longitudinal direction of the bar, and the second ring member may be fitted inside the second member, and the second ring member may be rotatable relative to the second member around a direction perpendicular to the longitudinal direction of the bar and also perpendicular to the any direction.

[0021] In addition to the robot arm mechanism described above, the present invention provides a walking assistance mechanism that utilizes this robot arm mechanism. The walking assistance mechanism includes four robot arm mechanisms, a base, and a mechanism for adjusting the lengths of the first and second connecting members of each of the four robot arm mechanisms. Control means and the four robot arm mechanisms are disposed at positions relative to the base such that the walking assistance mechanisms can stand on their own. The four robot arm mechanisms are preferably arranged so as to be located at the four vertices of a rectangle relative to the base.

[0022] Preferably, the other end of the bar of each of the four robot arm mechanisms is fitted with a caster. This walking assist mechanism includes, for example, a recognition means for recognizing a situation ahead of the walking assist mechanism, a means for digitizing the situation ahead recognized by the recognition means, and a means for determining an appropriate value for each length of the second connecting member or the first connecting member and the second connecting member for the digitized situation ahead. and the control means The length of the second connecting member or the length of the first connecting member and the second connecting member is adjusted based on the appropriate value. do.

[0023] This walking assist mechanism includes, for example, a recognition means for recognizing a situation ahead of the walking assist mechanism, a recognition means for converting the situation ahead recognized by the recognition means into a numerical value, and a recognition means for converting the situation ahead into a numerical value. Caster movement The apparatus may comprise a means for determining an optimum value of the casters, a driving means for driving each of the casters, and a control means for controlling the driving means based on the optimum value.

[0024] This walking assistance mechanism can include, for example, casters attached to the other end of the bar of each of the four robot arm mechanisms, a drive means for driving each of the casters, a position capture means for capturing the current position of the walking assistance mechanism, a database that stores a map, a search means for reading the map from the database and searching for a route from the current position to a destination indicated by the user, and a control means for controlling the operation of at least one of the drive means for driving each of the casters and the first connecting member and the second connecting member based on the route.

[0025] This walking assistance mechanism may include, for example, an input means for inputting an action selected by the user, a means for calculating an appropriate value for each length of the second connecting member or the first connecting member and the second connecting member corresponding to the selected action, and a control means for controlling the length of each of the first connecting member and the second connecting member based on the appropriate value. The recognition means may be, for example, an imaging means for imaging the situation ahead or a distance meter for measuring the distance to an object ahead. [Effects of the Invention]

[0026] According to the robot arm mechanism of the present invention, by controlling the extension and contraction of the first and second connecting members, the lengths of the first and second connecting members can be set to desired values, thereby uniquely determining the positions and orientations of the base member, the first member, and the second member, and by maintaining the lengths of the first and second connecting members constant, the positions and orientations of the base member, the first member, and the second member can be fixed. Furthermore, by controlling the extension and contraction of the lengths of the first and second connecting members, the joint member slides along the bar, making it possible to realize a desired leverage ratio and, ultimately, a desired swing width.

[0027] Furthermore, since the robot arm mechanism according to the present invention has a composite structure of a parallel link and a serial link, it is possible to realize both the large range of motion that is the advantage of a serial link and the high output that is the advantage of a parallel link. From the above points, the robot arm mechanism according to the present invention has a high level of functionality as a lever mechanism, and is ideal for mechanisms that apply the principle of leverage, such as walking assistance mechanisms. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a perspective view showing a schematic structure of a robot arm mechanism according to a first embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view showing the structure of a joint member according to the first embodiment of the present invention. [Figure 3] FIG. 1 is an exploded perspective view illustrating the concept of a robot arm mechanism according to a first embodiment of the present invention. [Figure 4] FIG. 1 is a conceptual perspective view illustrating the function of a robot arm mechanism according to a first embodiment of the present invention. [Figure 5A] 1A to 1C are perspective views showing the behavior of the robot arm mechanism according to the first embodiment when the leverage ratio R is changed to various values. [Figure 5B] 1A to 1C are perspective views showing the behavior of the robot arm mechanism according to the first embodiment when the leverage ratio R is changed to various values. [Figure 5C] 1A to 1C are perspective views showing the behavior of the robot arm mechanism according to the first embodiment when the leverage ratio R is changed to various values.

[0029] [Figure 6] FIG. 1 is a perspective view of a universal joint used in a robot arm mechanism according to a first embodiment of the present invention. [Figure 7] FIG. 7 is a vertical cross-sectional view of the universal joint shown in FIG. 6. [Figure 8] 7 is a perspective view showing only a second wall portion of the universal joint shown in FIG. 6. FIG. [Figure 9]9 is a vertical cross-sectional view of the second wall portion taken along line AA in FIG. 8. [Figure 10] FIG. 4 is a perspective view showing the operation of the universal joint according to the first embodiment of the present invention. [Figure 11] FIG. 4 is a perspective view showing the operation of the universal joint according to the first embodiment of the present invention. [Figure 12] FIG. 4 is a perspective view showing the operation of the universal joint according to the first embodiment of the present invention.

[0030] [Figure 13] FIG. 4 is a perspective view showing the operation of the universal joint according to the first embodiment of the present invention. [Figure 14] FIG. 4 is a perspective view showing the operation of the universal joint according to the first embodiment of the present invention. [Figure 15] FIG. 10 is a perspective view of a second wall portion of a universal joint according to a modified example of the universal joint of the first embodiment of the present invention. [Figure 16] FIG. 16 is a front view of the universal joint according to the modified example shown in FIG. [Figure 17] FIG. 16 is a vertical cross-sectional view of a first modified example of the second wall portion of the universal joint according to the modified example shown in FIG.

[0031] [Figure 18] FIG. 16 is a vertical cross-sectional view of a second modified example of the second wall portion of the universal joint according to the modified example shown in FIG. [Figure 19] FIG. 16 is a vertical cross-sectional view of a third modified example of the second wall portion of the universal joint according to the modified example shown in FIG. [Figure 20] FIG. 10 is a conceptual perspective view of a walking assist mechanism according to a third embodiment of the present invention.

[0032] [Figure 21] FIG. 11 is a perspective view showing the standing-up operation of one robot arm mechanism in a walking assist mechanism according to a third embodiment of the present invention. [Figure 22]FIG. 11 is a perspective view showing the standing-up operation of one robot arm mechanism in a walking assist mechanism according to a third embodiment of the present invention. [Figure 23] FIG. 11 is a perspective view showing the standing-up operation of one robot arm mechanism in a walking assist mechanism according to a third embodiment of the present invention. [Figure 24] FIG. 11 is a perspective view showing an operation of a walking assist mechanism according to a third embodiment of the present invention when assisting a user in standing up.

[0033] [Figure 25] FIG. 11 is a perspective view showing an operation of a walking assist mechanism according to a third embodiment of the present invention when assisting a user in standing up. [Figure 26] FIG. 11 is a perspective view showing an operation of a walking assist mechanism according to a third embodiment of the present invention when assisting a user in standing up. [Figure 27] FIG. 11 is a perspective view showing an operation of a walking assist mechanism according to a third embodiment of the present invention when assisting a user in standing up. [Figure 28] FIG. 11 is a perspective view showing an operation in which a walking assist mechanism according to a third embodiment of the present invention assists a user in climbing up a step.

[0034] [Figure 29] FIG. 11 is a perspective view showing an operation in which a walking assist mechanism according to a third embodiment of the present invention assists a user in climbing up a step. [Figure 30] FIG. 13 is a partial block diagram of a walking assist mechanism according to a first modified example of the third embodiment of the present invention. [Figure 31] FIG. 13 is a partial block diagram of a walking assist mechanism according to a second modified example of the third embodiment of the present invention. [Figure 32] FIG. 13 is a partial block diagram of a walking assist mechanism according to a third modified example of the third embodiment of the present invention.

[0035] [Figure 33] FIG. 11 is a partial block diagram of a walking assist mechanism according to a fourth modified example of the third embodiment of the present invention. [Figure 34]FIG. 13 is a partial block diagram of a walking assist mechanism according to a fifth modified example of the third embodiment of the present invention. [Figure 35] FIG. 13 is a partial block diagram of a walking assist mechanism according to a sixth modified example of the third embodiment of the present invention. [Figure 36] FIG. 13 is a partial block diagram of a walking assist mechanism according to a seventh modified example of the third embodiment of the present invention. [Figure 37] FIG. 1 is a perspective view of a conventional position and attitude transmission mechanism; DETAILED DESCRIPTION OF THE INVENTION

[0036] (First embodiment) FIG. 1 is a perspective view showing a schematic structure of a robot arm mechanism 100 according to a first embodiment of the present invention. The robot arm mechanism 100 of this embodiment is composed of a base 110, a first plate 120, a second plate 130, three first connecting members 140, three second connecting members 150, a bar 160, and a joint member 170.

[0037] The base 110 and the first plate 120 are each a circular flat plate-like member, and the second plate 130 is a ring-like member having a circular opening in the center, as will be described later. The base 110 and the first plate 120 are connected via three first connecting members 140 . The three first connecting members 140 are arranged at positions on the circumference of the base 110 and the first plate 120 at equal circumferential angles (ie, positions where the circumferential angle is 120 degrees).

[0038] Each of the three first connecting members 140 is made up of two bars 141a, 141b and a linear actuator 142 connecting these two bars 141a, 141b. Generally, the linear actuator 142 includes an electric motor, a ball screw, and a speed reduction mechanism, and the ball screw converts the rotational motion of the electric motor into linear motion, which is then output after being reduced in speed by the speed reduction mechanism to an appropriate speed. The direction and speed of the linear motion can be adjusted by controlling the rotation direction and speed of the electric motor.

[0039] In this way, by controlling the operation of the linear actuator 142, one of the two bars 141a, 141b can be linearly displaced relative to the other in the length direction. By displacing one of the two bars 141a, 141b in a direction away from the other, the overall length of each first connecting member 140 can be increased, and by displacing one of the two bars 141a, 141b in a direction toward the other, the overall length of each first connecting member 140 can be decreased. In other words, the linear actuator 142 can extend or contract each of the first connecting members 140 to a desired length, and once the position of each first connecting member 140 relative to the base 110 is determined, the orientation of each first connecting member 140 is determined, or alternatively, once the orientation of each first connecting member 140 is determined, the position of each first connecting member 140 relative to the base 110 is determined.

[0040] The second plate 130 is disposed on the same side of the base 110 as the first plate 120 , and furthermore, the second plate 130 is disposed at a position farther away from the base 110 than the first plate 120 . The base 110 and the second plate 130 are connected via three second connecting members 150 . The three second connecting members 150 are arranged at positions on the circumference of the base 110 and the second plate 130 at equal circumferential angles (ie, positions where the circumferential angle is 120 degrees).

[0041] Similar to the first connecting member 140, each of the three second connecting members 150 is composed of two bars 151 a, 151 b and a linear actuator 152 connecting these two bars 151 a, 151 b. Similar to the first connecting member 140, each of the second connecting members 150 can be extended or contracted to a desired length by controlling the operation of the linear actuator 152, and once the position of each second connecting member 150 relative to the base 110 is determined, the attitude of each second connecting member 150 is determined, or alternatively, once the attitude of each second connecting member 150 is determined, the position of each second connecting member 150 relative to the base 110 is determined.

[0042] One end of the bar 160 (the upper end in FIG. 1) is connected to the first plate 120 via a universal joint 122. Therefore, the first plate 120 and the bar 160 can rotate relative to each other in any direction. The other end of the bar 160 (the lower end in FIG. 1) constitutes an end effector 161 . Furthermore, the bar 160 is connected at one point between both ends to the second plate 130 via a joint member 170. As will be described later, by connecting the bar 160 to the second plate 130 via the joint member 170, the bar 160 can rotate relative to the second plate 130 in any direction within the movable range of the joint member 170, and can also slide relative to the second plate 130 in the longitudinal direction of the bar 160.

[0043] FIG. 2 is a perspective view showing the structure of the joint member 170. As shown in FIG. As shown in FIG. 2, the joint member 170 is made up of a first ring member 171 and a second ring member 172. The first ring member 171 is fitted to the bar 160, and the first ring member 171 is rotatable around the bar 160 around the axial centerline of the bar 160, and the bar 160 and the first ring member 171 are slidable relative to each other in the longitudinal direction of the bar 160.

[0044] First ring member 171 is disposed inside the circular opening of second ring member 172. First ring member 171 and second ring member 172 are connected via joints 173 at two positions where any diameter of first ring member 171 intersects with the circumference, and second ring member 172 is rotatable relative to first ring member 171 about joints 173 within a range that does not interfere with bar 160. In other words, second ring member 172 is configured to be rotatable relative to first ring member 171 about any direction perpendicular to the longitudinal direction of bar 160 (the direction in which any diameter of first ring member 171 extends).

[0045] The second ring member 172 is disposed inside the circular opening of the ring-shaped second plate 130. The second ring member 172 and the second plate 130 are connected to each other via joints 174 at two positions where the diameter of the second ring member 172, which is perpendicular to any diameter of the first ring member 171 described above, intersects with the circumference, and the second ring member 172 is rotatable about the joints 174 relative to the second plate 130 within a range where it does not interfere with the bar 160. The rotation axis of the first ring member 171 is perpendicular to the length of the bar 160 , and the rotation axis of the second ring member 172 is perpendicular to both the length of the bar 160 and the rotation axis of the first ring member 171 .

[0046] In this way, the joint member 170 allows the bar 160 to rotate and slide relative to the second plate 130, and achieves both a gimbal function and a sliding function. FIG. 3 is an exploded perspective view showing the concept of a robot arm mechanism 100 according to this embodiment. In the robot arm mechanism 100, as shown in FIG. 3, a base 110, a first plate 120, and three first connecting members 140 constitute a first parallel manipulator 100A, and further, a base 110, a second plate 130, and three second connecting members 150 constitute a second parallel manipulator 100B.

[0047] The robot arm mechanism 100 is formed by combining a first parallel manipulator (parallel link) 100A and a second parallel manipulator 100B that share a base 110, a bar 160, and a joint member 170. In this way, the robot arm mechanism 100 includes two parallel manipulators 100A and 100B, and has a composite structure in which the first parallel manipulator 100A and the second parallel manipulator 100B are in a serial positional relationship.

[0048] In this way, in the robot arm mechanism 100 consisting of two parallel manipulators 100A and 100B, once the lengths of the first connecting member 140 and the second connecting member 150 are determined, the positions and postures of the base 110, the first plate 120, and the second plate 130 are uniquely determined, and if the lengths of the first connecting member 140 and the second connecting member 150 are maintained constant, the positions and postures of the base 110, the first plate 120, and the second plate 130 are fixed. To achieve this, the first connecting member 140 and the second connecting member 150 must be connected to the base 110 so that they can rotate in all directions, and must also be connected to the first plate 120 and the second plate 130 with one degree of rotational freedom, respectively.

[0049] To satisfy this condition, in the robot arm mechanism 100 of this embodiment, the first connecting member 140 and the second connecting member 150 are connected to the base 110 via universal joints 111 and 112, respectively, and are connected to the first plate 120 and the second plate 130 via hinge joints 121 and 131, respectively. The robot arm mechanism 100 having the above structure operates as follows.

[0050] FIG. 4 is a conceptual perspective view showing the function of the robot arm mechanism 100. In the robot arm mechanism 100 according to this embodiment, the bar 160 is connected to the first plate 120 via a ball joint 122 and is connected to the second plate 130 via a joint member 170 . Each of the first connecting members 140 and each of the second connecting members 150 can be extended or retracted to a desired length. As the length of each of the first connecting members 140 and each of the second connecting members 150 changes, the second plate 130 slides or rotates along the bar 160, and the relative position of the second plate 130 with respect to the first plate 120 changes.

[0051] As shown in the walking assistance mechanism described below, the robot arm mechanism 100 can be configured as a mechanism that functions as a lever. Specifically, as shown in Fig. 4, universal joint 122 connecting bar 160 and first plate 120 functions as a force point, joint member 170 connecting bar 160 and second plate 130 functions as a fulcrum, and end effector 161 at the tip of bar 160 functions as a point of action.

[0052] Here, the leverage is defined as follows: Leverage ratio R=D1 / D2 D1 = distance between the joint member 170 (fulcrum) and the end effector 161 (point of action) D2 = distance between joint member 170 (fulcrum) and universal joint 122 (force point)

[0053] For example, if the end effector 161 at the tip of the bar 160 is placed on the ground and the end effector 161 as the point of application is set as a fixed point, when the length of each second connecting member 150 is extended or shortened, the joint member 170 functioning as a fulcrum moves up and down together with the second plate 130. In other words, the distances D1 and D2 change, and consequently the leverage ratio R changes. As described above, in the robot arm mechanism 100 according to this embodiment, by changing the length of either or both of the first connecting member 140 and the second connecting member 150 via the linear actuators 142, 152, the joint member 170 slides along the bar 160, and the leverage ratio R changes accordingly. This change in the leverage ratio R can be applied to mechanisms for various purposes. For example, as will be described later, it can be applied to a walking assistance mechanism that assists humans in walking.

[0054] 5A, 5B, and 5C are perspective views showing the behavior of the robot arm mechanism 100 when the leverage ratio R is changed to various values. In the state shown in FIG. 5A, the joint member (fulcrum) 170 is closer to the universal joint (point of force) 122 than the end effector (point of application) 161. That is, the distance D1 is relatively large and the distance D2 is relatively small. In the state shown in FIG. 5B, the joint member (fulcrum) 170 is located approximately midway between the end effector (point of application) 161 and the universal joint (point of force) 122, with the distance D1 being smaller than the distance D1 in FIG. 5A and the distance D2 being larger than the distance D2 in FIG. 5A. In the state shown in FIG. 5C, the joint member (fulcrum) 170 is closer to the end effector (point of application) 161 than the universal joint (point of force) 122. That is, the distance D1 is smaller than the distance D1 in FIG. 5B and the distance D2 is larger than the distance D2 in FIG. 5B.

[0055] Therefore, when the leverage ratios in FIGS. 5A, 5B, and 5C are R1, R2, and R3, respectively, the magnitude relationship between R1, R2, and R3 is as follows: R1>R2>R3 The magnitude of the leverage R is directly related to the magnitude of the swing width. The swing refers to the circular arc movement of the bar 160 around the joint member (fulcrum) 170 in response to the expansion and contraction of the first connecting member 140 and the second connecting member 150. When the bar 160 performs the circular arc movement, the end effector (point of action) 161 also performs the circular arc movement. The swing width refers to the horizontal component of the displacement of the end effector (point of action) 161 when the end effector (point of action) 161 performs the circular arc movement.

[0056] The walking assist mechanism described below operates based on the swing of the robot arm mechanism 100 as a basic movement. 4, when the point of force is displaced, the point of application is displaced around the fulcrum in accordance with the amount of displacement. In this case, the larger the leverage ratio R, the larger the amount of displacement of the point of application. Therefore, as shown in FIGS. 5A, 5B, and 5C, if the swing widths when the leverage R is R1, R2, and R3 are S1, S2, and S3, respectively, the magnitude relationship between S1, S2, and S3 is as follows: S1>S2>S3

[0057] In this way, in the robot arm mechanism 100 according to this embodiment, by controlling the extension and contraction of the first connecting member 140 and the second connecting member 150, it is possible to slide the joint member (fulcrum) 170 along the bar 160 and change the leverage ratio R to various values. Therefore, the robot arm mechanism 100 can be used as a lever mechanism and applied to, for example, a walking assistance mechanism, which will be described later. The robot arm mechanism 100 according to this embodiment can provide the following effects.

[0058] According to the robot arm mechanism 100 of this embodiment, the lengths of the first connecting member 140 and the second connecting member 150 can be set to desired values ​​by controlling the extension and contraction of the first connecting member 140 and the second connecting member 150. This allows the joint member (fulcrum) 170 to slide along the bar 160, making it possible to achieve a desired value of leverage ratio R, and ultimately a desired swing width. In particular, it is possible to change the leverage ratio R without changing the position of the end effector 161. By making the leverage ratio R variable, it becomes possible to adjust the range of motion of the end effector 161 and the overall rigidity of the robot arm mechanism 100.

[0059] Furthermore, since the robot arm mechanism 100 has a composite structure of a parallel link and a serial link, it can achieve both the advantage of a serial link, which is a large range of motion, and the advantage of a parallel link, which is a high output. From the above points, the robot arm mechanism 100 according to this embodiment has a high level of functionality as a lever mechanism, and is ideal for mechanisms that apply the principle of a lever, such as a walking assistance mechanism, which will be described later. The robot arm mechanism 100 according to this embodiment is not limited to the above structure, and various modifications are possible.

[0060] The robot arm mechanism 100 according to this embodiment is configured to include three first connecting members 140 and three second connecting members 150. The reason why the number of each of the first connecting members 140 and the second connecting members 150 is three is that, as mentioned above, this is one of the conditions for ensuring that the position and posture of the base 110, the first plate 120, and the second plate 130 are uniquely determined depending on the length of each of the first connecting members 140 and the second connecting members 150. Instead of setting the number of each of the first connecting members 140 and the second connecting members 150 to three, it is also possible to set the number of each to six. Even if the number of each is six, it is possible to uniquely determine the positions and orientations of the base 110, the first plate 120, and the second plate 130 depending on the respective lengths of the first connecting members 140 and the second connecting members 150, and to fix the positions and orientations of the base 110, the first plate 120, and the second plate 130 by maintaining the respective lengths of the first connecting members 140 and the second connecting members 150 constant.

[0061] When the number of each of the first connecting members 140 and the second connecting members 150 is six, the first connecting members 140 and the second connecting members 150 need to be connected to the base 110 so as to be rotatable in all directions, and also connected to the first plate 120 and the second plate 130 so as to be rotatable in all directions, respectively. To satisfy this condition, for example, the first connecting member 140 and the second connecting member 150 are connected to the base 110 via universal joints 111 and 112, respectively, and are connected to the first plate 120 and the second plate 130 via universal joints, respectively.

[0062] It is also possible to set the number of each of the first connecting members 140 and the second connecting members 150 to two. In this case, the first connecting member 140 and the second connecting member 150 must be connected to the base 110 with one rotational degree of freedom, and must also be connected to the first plate 120 and the second plate 130 with one rotational degree of freedom, respectively. To satisfy this condition, for example, the first connecting member 140 and the second connecting member 150 are each connected to the base 110 via a hinge joint, and are also each connected to the first plate 120 and the second plate 130 via a hinge joint. In this embodiment, the base 110 and the first plate 120 are each configured as a circular member, but the shape is not limited to a circle. Any shape can be selected, such as a square or other rectangle, a triangle, an ellipse or other shape including a curve, or a shape combining straight lines and curves.

[0063] (Second embodiment) In the robot arm mechanism 100 according to the first embodiment, the base 110 and each first connecting member 140 are connected via a universal joint 111, and the base 110 and each second connecting member 150 are connected via a universal joint 112. These universal joints 111 and 112 may be commercially available general-purpose products, but the maximum swing angle of a general-purpose universal joint is approximately 40 degrees. The greater the overall range of motion of the robot arm mechanism 100, the more effective its operation, and this requires a larger swing angle for the universal joint. The swing angle refers to the rotation angle when the output shaft oscillates and rotates.

[0064] In the robot arm mechanism according to the second embodiment, a universal joint 200, which will be described later, is used instead of the general-purpose universal joints 111 and 112. This universal joint can achieve a minimum swing angle of 90 degrees, and can realize a larger swing angle than a general-purpose universal joint. FIG. 6 is a perspective view of a universal joint 200 used in a robot arm mechanism according to this embodiment, and FIG. 7 is a vertical cross-sectional view of the universal joint 200. As shown in FIG.

[0065] As shown in FIGS. 6 and 7, the universal joint 200 includes a rod end 210 and a holder 220. The rod end 210 is composed of a first portion 211 having a shape similar to a cylinder, and a second portion 212 having a cylindrical shape extending from a point on the circumference of the first portion 211 in the radial direction of the first portion 211 . The holder 220 is composed of a base portion 221, a first wall portion 222 standing upright on the base portion 221, and a second wall portion 223 standing upright on the base portion 221 parallel to the first wall portion 222 at a position spaced apart from the first wall portion 222 and having the same height as the first wall portion 222.

[0066] The second portion 212 of the rod end 210 is connected to the first part 231 via a bearing 230A so as to be rotatable about an axial center line Y1 of the second portion 212. Although not shown, the base 110 is coupled to the first part 231. The base portion 221 of the holder 220 is connected to the second part 232 via a bearing 230B so as to be rotatable about an axis Y2 parallel to the height direction of the first wall portion 222 and the second wall portion 223, i.e., an axis Y2 perpendicular to a rotation axis X of the first part 211, which will be described later. The first connecting member 140 or the second connecting member 150 is connected to the second part 232.

[0067] The first portion 211 of the rod end 210 is connected to both the first wall portion 222 and the second wall portion 223 via a cylindrical shaft 224 so as to be rotatable around a rotation axis X (see Figure 6; in Figure 7, the axis is perpendicular to the paper surface of Figure 7) that is perpendicular to the plane defined by the first wall portion 222 and the second wall portion 223. The distance between the first wall portion 222 and the second wall portion 223 is set to a distance that does not interfere with the second portion 212 of the rod end 210 when the rod end 210 rotates around the rotation axis X. FIG. 8 is a perspective view showing only the second wall portion 223, and FIG. 9 is a vertical cross-sectional view of the second wall portion 223 taken along line AA in FIG.

[0068] As shown in FIG. 8, an inner surface 241S of the second wall portion 223 (the surface facing the first wall portion 222) has a recessed region 240 (see FIG. 9) that forms a space (gap) between the inner surface 241S of the second wall portion 223 and a vertical plane including the inner surface 241S of the second wall portion 223. 8 and 9, the recessed region 240 is formed as a thin portion having a smaller thickness than other portions. Specifically, the recessed region 240 is formed by providing an inclined surface 241 on the inner surface 241S of the second wall portion 223.

[0069] 9, the inclined surface 241 has a starting point 241A at a position on the inner surface 241S between one end 223A of the second wall portion 223 in the width direction H and the rotation axis X of the shaft 224, and an ending point 241B at a point on the surface of the other end 223B of the second wall portion 223 in the width direction H, and is formed by linearly decreasing the thickness of the second wall portion 223 from the end 223A to the end 223B of the second wall portion 223 in the horizontal direction H. In this way, the inclined surface 241 forms an inclination angle with the vertical plane.

[0070] The starting point 241A of the inclined surface 241 is set between the end 223A of the second wall portion 223 and the rotation axis X of the shaft 224 in order to set a large contact range of the second part 212 of the rod end 210 with the inclined surface 241 and ensure that the second part 212 of the rod end 210 comes into contact with the second wall portion 223. The recessed region 240 is formed to include the top of the second wall portion 223. That is, the recessed region 240 or the inclined surface 241 has a height from the top of the second wall portion 223 to the rotation axis X of the shaft 224 in the height direction of the second wall portion 223. The recessed region 240 is formed to include the top of the second wall portion 223 , allowing the second portion 212 of the rod end 210 to contact the recessed region 240 .

[0071] FIG. 9 shows an example of the dimensions of the second wall portion 223. Width of the second wall portion 223 (length in the horizontal direction H)=40 mm The thickness of the second wall portion 223 (the length in the direction perpendicular to the horizontal direction H) is 9 mm. Diameter of the hole for fitting the shaft 224 = 10 mm Distance between rotation axis X and starting point 241A of inclined surface 241 = 7 mm Distance between the inner surface 241S and the end point 241B of the inclined surface 241 = 4.5 mm 8 and 9, the inclination angle of the inclined surface 241 of the second wall portion 223 is approximately 10 degrees. The inclination angle of the inclined surface 241 can be set within a range of 5 degrees to 45 degrees. However, if the inclination angle is increased, it is necessary to increase the thickness of the second wall portion 223 in accordance with the inclination angle.

[0072] 10 to 14 are perspective views showing the operation of the universal joint 200 in this embodiment. How the universal joint 200 moves will be described below with reference to FIGS. 10 and 11, the rod end 210 (and the first component 231) rotates within the space between the first wall portion 222 and the second wall portion 223 around the rotation axis X of the shaft 224. Specifically, it rotates within a range of approximately 180 degrees between a first limit position shown in Fig. 10 (a position where the second portion 212 of the rod end 210 abuts on the base portion 221) and a second limit position shown in Fig. 11 (a position opposite to the first limit position).

[0073] 11, the first part 231 continues to rotate about the axial center line Y1 relative to the rod end 210, and the second part 232 continues to rotate about the axis Y2 relative to the rod end 210, but the second part 212 of the rod end 210 does not rotate about the axial center line Y1. In other words, the swing angle is 0 degrees. 12 to 14, the rod end 210 rotates around the axial center line Y1 while twisting, that is, it moves with a swing angle.

[0074] First, as shown in Figure 12, while the first part 231 rotates around the axial center line Y1 relative to the rod end 210 and the second part 232 rotates around the axis Y2 relative to the rod end 210, the rod end 210 moves in the direction of arrow R, i.e., tilts toward the second wall portion 223, and the second part 212 of the rod end 210 comes into contact with the inclined surface 241 formed on the inner surface 241S of the second wall portion 223. As shown in FIG. 13, while the first part 231 and the second part 232 continue to rotate, the rod end 210 slides along the inclined surface 241 from the start point 241A of the inclined surface 241 toward the end point 241B.

[0075] Next, when the rod end 210 passes the end point 241B of the inclined surface 241, the rod end 210 falls into the space between the first wall portion 222 and the second wall portion 223, as shown in FIG. This state is the same as the state shown in Figure 10, but in the operation shown in Figure 10, the rod end 210 falls down while the swing angle remains at 0 degrees. In contrast, in the operation shown in Figures 12 to 14, the rod end 210 falls down after achieving a swing angle of approximately 90 degrees. Thus, while conventional universal joints could only achieve a swing angle of approximately 40 degrees, universal joint 200 of this embodiment can achieve a swing angle of approximately 90 degrees. The inclination angle of slope 241 in this embodiment is approximately 10 degrees, and by setting the inclination angle of slope 241 even larger, it is possible to further increase the swing angle.

[0076] The universal joint 200 in this embodiment is not limited to the above structure, and various modifications are possible. FIG. 15 is a perspective view of a second wall portion 223 of a universal joint 300 according to a modified example of universal joint 200, and FIG. As shown in FIG. 15, the corners (peripheral edges) of the inclined surface 241 and the corners of the inner surface 241S of the second wall portion 223 below the inclined surface 241 are all formed in a curved shape.

[0077] By making at least the corners of the inclined surface 241 curved in this manner, the rod end 210 can slide more smoothly on the inclined surface 241, thereby increasing the speed and efficiency of the operation of the universal joint 300. Furthermore, by forming the corners of the inner surface 241S of the second wall portion 223 below the inclined surface 241 into a curved shape, the tilting action of the rod end 210 shown in FIG. 14 can be made smoother. Furthermore, as shown in Figures 15 and 16, a portion 223C where the thickness is smallest in the height direction of the second wall portion 223 is formed between the height of the rotation axis X and the vertex of the second wall portion 223, and the corner portions of this portion 223C can also be formed into a curved shape.

[0078] By forming the portion 223C, the swing angle of the rod end 210 can be further increased, and by forming the corner of the portion 223C into a curved shape, the movement of the rod end 210 can be made smoother. 8 and 15, the inclined surface 241 is formed only on one side of the second wall portion 223 (one side centered on the rotation axis X in the width direction of the second wall portion 223, the left side of the rotation axis X in FIGS. 8 and 15), but it is also possible to form an inclined surface similar to the inclined surface 241 on the first wall portion 222. When an inclined surface similar to the inclined surface 241 is formed on the first wall portion 222, the inclined surface of the first wall portion 222 is formed diagonally opposite the inclined surface 241 of the second wall portion 223. That is, when the inclined surface 241 of the second wall portion 223 is formed on the left side of the rotation axis X as shown in FIGS. 8 and 15, the inclined surface of the first wall portion 222 is formed on the right side of the rotation axis X.

[0079] By forming an inclined surface at an angle between the first wall portion 222 and the second wall portion 223 in this manner, the range in which the rod end 210 can rotate around the rotation axis X with a large swing angle can be maximized. In the above embodiment, the recessed region 240 or the inclined surface 241 is formed by linearly reducing the thickness of the second wall portion 223, but the method of forming the recessed region 240 or the inclined surface 241 is not limited to this. FIG. 17 is a vertical cross-sectional view of a first modified example of the second wall portion 223. As shown in FIG. As shown in Figure 17, instead of linearly reducing the thickness of the second wall portion 223, it is also possible to form a slope 241 by bending the second wall portion 223, which has a constant thickness, and inclining the inner surface 241S of the second wall portion 223 with respect to a vertical plane.

[0080] Furthermore, the formation of the recessed region 240 is not limited to the formation of the slope 241 . FIG. 18 is a vertical cross-sectional view of a second modified example of the second wall portion 223. As shown in FIG. As shown in FIG. 18, instead of the inclined surface 241, an inclined surface made up of a plurality of inclined surfaces 241A, 241B, and 241C (three in FIG. 18) having different inclination angles may be used.

[0081] Inclined surfaces 241A, 241B, and 241C are formed in this order from the rotation axis X toward the end 223B of the second wall portion 223. The length components of the three inclined surfaces 241A, 241B, and 241C in the horizontal direction H are identical to one another, but the inclination angles with respect to the horizontal direction H are different from one another. The inclination angle G1 of the inclined surface 241A is smaller than the inclination angle G2 of the inclined surface 241B, and the inclination angle G2 of the inclined surface 241B is smaller than the inclination angle G3 of the inclined surface 241C. G1 <G2<G3 In this way, by providing a plurality of inclined surfaces, the operation of the rod end 210 can be made more varied.

[0082] FIG. 19 is a vertical cross-sectional view of a third modified example of the second wall portion 223. As shown in FIG. As shown in FIG. 19, instead of the inclined surface 241, an arc-shaped surface 242 can be formed. By forming the arc-shaped surface 242, the same effect as when the inclined surface 241 is formed can be obtained. Although FIG. 19 shows the arcuate surface 242 that is concave toward the first wall portion 222, it is also possible to form an arcuate surface that is convex toward the first wall portion 222.

[0083] (Third embodiment) The third embodiment of the present invention relates to a walking assistance mechanism that applies the robot arm mechanism according to the first or second embodiment. FIG. 20 is a conceptual perspective view of a walking assist mechanism 400 according to this embodiment. As shown in FIG. 16, the walking assistance mechanism 400 is composed of a base 410, first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D attached facing downward to the base 410, and a controller 430 that controls the operation of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D.

[0084] Base 410 is a U-shaped, flat member. Specifically, base 410 is composed of a linear front portion 410A, a right side portion 410B extending horizontally from one end of front portion 410A and perpendicular to front portion 410A, and a left side portion 410C extending horizontally from the other end of front portion 410A and perpendicular to front portion 410A in the same direction as right side portion 410B. Right side portion 410B and left side portion 410C are the same length.

[0085] The first robot arm mechanism 420A is attached to one end of the front section 410A (the intersection of the front section 410A and the right section 410B), the second robot arm mechanism 420B is attached to the other end of the front section 410A (the intersection of the front section 410A and the left section 410C), the third robot arm mechanism 420C is attached to the tip of the right section 410B, and the fourth robot arm mechanism 420D is attached to the tip of the left section 410C. In other words, the first to fourth robot arm mechanisms 420A, 420B, 420C, 420D are arranged so as to be located at the four vertices of a rectangle such as a rectangle or a square. The structure and operation of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D are the same as the robot arm mechanism 100 according to the first embodiment or the robot arm mechanism according to the second embodiment.

[0086] The controller 430 is attached near one end of the front part 410A (the intersection of the front part 410A and the right part 410B). As will be described later, the user of the walking assist mechanism 400 can adjust the operation of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D, specifically, the lengths of the first connecting member 140 and the second connecting member 150, via the controller 430. The height of the base 410 is set so that the user can place their hands on the base 410 whether they are sitting or standing.

[0087] 21 to 23 are perspective views showing the erection operation of one robot arm mechanism 100. In Figures 1, 3, 4, and 5A to 5C, the first connecting member 140 and the second connecting member 150 are each conceptually shown as a single rod-shaped member, but in Figures 21 to 23, the first connecting member 140 and the second connecting member 150 are each shown in a form that is actually used. In order to improve the mobility of the walking assist mechanism 400, casters are attached to the end effector 161. The robot arm mechanism 100 is configured such that once the lengths of the first connecting member 140 and the second connecting member 150 are determined, the position and posture of each member, i.e., the base 110, the first plate 120, the second plate 130, the first connecting member 140, and the second connecting member 150, are uniquely determined.

[0088] In the walking assist mechanism 400, the bar 160 is always maintained in an upright or nearly upright state. The end effector 161 is always in contact with the ground. Therefore, in the standing-up motion described below, the end effector 161 acts as a fixed point. In the standing-up motion described below, the end effectors 161 of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D are always in contact with the ground. First, the lengths of the first connecting member 140 and the second connecting member 150 are adjusted so that the robot arm mechanism 100 assumes the posture shown in FIG.

[0089] Next, as shown in Figure 22, the lengths of the first connecting member 140 and the second connecting member 150 are controlled so that the height of the universal joint 122 (or the second plate 130) from the ground is increased. At this stage, the height of the base 110 from the ground is higher than the height of the base 110 from the ground in Figure 21. Furthermore, as shown in Figure 23, the lengths of the first connecting member 140 and the second connecting member 150 are controlled so that the height of the universal joint 122 from the ground is higher than the height in Figure 22. At this stage, the height of the base 110 from the ground is higher than the original height of the base 110 from the ground in Figure 21.

[0090] As described above, by controlling the lengths of the first connecting member 140 and the second connecting member 150, the height of the base 110 from the ground can be increased while the end effector 161 remains in contact with the ground. The standing-up assisting operation of the walking assist mechanism 400, which assists the user in standing up from a sitting position, is based on the standing-up operation of the robot arm mechanism 100 described above. 24 to 27 are perspective views showing the operation of the walking assist mechanism 400 when assisting the standing-up motion of the user 500. Hereinafter, with reference to FIGS. 24 to 27, the standing-up assist operation of the walking assist mechanism 400 that assists the standing-up motion when the user 500 stands up from the chair 501 will be described.

[0091] 24, it is assumed that user 500 is sitting on chair 501 with both hands placed on front portion 410A of base 410. User 500's right hand is placed on controller 430 and is ready to operate controller 430. The user 500 adjusts the lengths of the first connecting member 140 and the second connecting member 150 via the controller 430, and moves the bases 110 of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D upward, as shown in Fig. 25. As a result, the base 410 begins to lift. Because the user 500 places both hands on the front portion 410A of the base 410, the user is supported by the base 410 that is beginning to lift, and the user 500 can begin to stand up with less effort than if he or she were standing up on his or her own.

[0092] The postures of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D shown in FIG. 25 correspond to the posture of the robot arm mechanism 100 shown in FIG. When the user 500 operates the controller 430 to further shorten the length of the first connecting member 140 without changing the length of the second connecting member 150, an operation similar to the transition from the state shown in Fig. 21 to the state shown in Fig. 22 occurs, and the bases 110 of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D move further upward as shown in Fig. 26, and as a result, the base 410 is further raised. The user 500 is supported by the base 410 that is rising, and the user 500 can continue the operation of standing up.

[0093] The postures of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D shown in FIG. 26 correspond to the posture of the robot arm mechanism 100 shown in FIG. When the user 500 operates the controller 430 to further shorten the length of the first connecting member 140 without changing the length of the second connecting member 150, an operation similar to the transition from the state shown in Fig. 22 to the state shown in Fig. 23 occurs, and the bases 110 of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D move further upward as shown in Fig. 27, with the result that the base 410 is further raised. As a result, the user 500 is supported by the base 410 that is rising, and the user 500 can stand up completely.

[0094] The postures of the first to fourth robot arm mechanisms 420A, 420B, 420C, and 420D shown in FIG. 27 correspond to the posture of the robot arm mechanism 100 shown in FIG. When the user 500 sits in the chair 501, the walking assist mechanism 400 performs the series of operations described above in reverse. Generally, sitting down in a chair places a greater strain on the legs than standing up from the chair. For this reason, the walking assist mechanism 400 is also useful when the user 500 sits in the chair 501. As described above, the walking assist mechanism 400 according to this embodiment assists the user 500, who is sitting in the chair 501, in standing up from the chair 501 or in sitting down in the chair 501, and the user 500 can stand up or sit down with less effort than if he or she were to stand up or sit down on his or her own. The walking assist mechanism 400 is particularly suitable for the user 500 who has a knee disorder.

[0095] The above-described standing-up assisting operation of the walking assist mechanism 400 is one example of an operation that the walking assist mechanism 400 can perform, and the walking assist mechanism 400 is also capable of operations other than the standing-up assisting operation. When the user 500 walks, the walking assist mechanism 400 does not perform any particular assisting action. Casters are attached to the end effector 161 of the walking assist mechanism 400, so the user 500 can walk while being supported by the walking assist mechanism 400.

[0096] 28 and 29 are perspective views showing the operation of the walking assist mechanism 400 when assisting the user 500 in climbing up a step. Hereinafter, with reference to FIGS. 28 and 29, the assisting operation of the walking assist mechanism 400 that assists the user 500 in climbing up a step will be described. As shown in FIG. 28, it is assumed that the user 500 has reached a step 502 together with the walking assist mechanism 400. When the user 500 reaches the step 502, the user 500 controls the lengths of the first connecting member 140 and the second connecting member 150 via the controller 430, and sets the end effector 161 of the first robot arm mechanism 420A to rise from the ground to a height slightly higher than the step 502.

[0097] Next, the end effector 161 of the first robot arm mechanism 420A is advanced so that the end effector 161 is positioned above the step 502. Thereafter, the end effector 161 of the first robot arm mechanism 420A is lowered so that the end effector 161 touches the step 502. Next, as shown in Fig. 29, the user 500 causes the second robot arm mechanism 420B to perform the same operation as that performed by the first robot arm mechanism 420A via the controller 430. As a result, the end effectors 161 of the two robot arm mechanisms 420A and 420B located at the front of the walking assist mechanism 400 both land on the step 502, as shown in Fig. 29.

[0098] After the two robot arm mechanisms 420A, 420B located at the front touch down on the step 502, the two robot arm mechanisms 420A, 420B extend all of the first connecting members 140 and the second connecting members 150. This causes the user 500, who is holding the base 410, to be lifted up. Next, user 500 lifts third robotic arm mechanism 420C and then fourth robotic arm mechanism 420D via controller 430 and places them on step 502.

[0099] As a result, the end effectors 161 of all of the robot arm mechanisms 420A to 420D of the walking assist mechanism 400 are all placed on the step 502. As described above, when the walking assistance mechanism 400 climbs the step 502, the robot arm mechanisms 420A and 420B located at the front climb the step 502 one by one in sequence, and after the two front robot arm mechanisms 420A and 420B have climbed the step 502, the rear robot arm mechanisms 420C and 420D climb the step 502 one by one in sequence.

[0100] When the second robot arm mechanism 420B, which is the second to climb the step 502, the third robot arm mechanism 420C, which is the third to climb the step 502, or the fourth robot arm mechanism 420D, which is the last to climb the step 502, climbs the step 502, the base 410 is also lifted upward. Because the user 500 is supported by the base 410, the user 500 can climb the step 502 with less strain than if he or she were to climb the step 502 by himself or herself. The walking assist mechanism 400 can also perform an assisting operation when descending a step 502. When ascending the step 502, an operation of lifting the end effector 161 up to the top of the step 502 is first performed, but when descending the step 502, an operation of lowering the end effector 161 from the step 502 to the ground is first performed. The subsequent operations are simply the reverse of the operations when ascending the step 502, and the basic concept is the same.

[0101] The basic concept of the above-mentioned assisting motion for standing up, assisting motion for climbing steps, and other assisting motions is the same. First, the trajectory of the toe (end effector 161) relative to the base 110 is determined. Next, the movements of the first connecting member 140 and the second connecting member 150 are determined so as to follow the trajectory. Specifically, it is as follows: First, the position of the toe (end effector 161) and the posture of the first connecting member 140 corresponding to the movement desired by the user 500 are determined. Once the position of the toe (end effector 161) and the posture of the bar 160 are determined, the length of the first connecting member 140 and the position and posture of the first plate 120 are determined.

[0102] Next, determine the leverage ratio R. Since the position and orientation of the first plate 120 are already determined, once the leverage ratio R is determined, the position and orientation of the second plate 130 are determined. In this way, once the position of the toe (end effector 161), the posture of the first connecting member 140, and the leverage ratio R are determined, the lengths of the first connecting member 140 and the second connecting member 150 are determined. By determining the time series of the position of the toe (end effector 161), the posture of the first connecting member 140, and the value of the leverage ratio R by trial and error, under the condition that they fall within the range of motion of the linear-type actuators 142, 152 and there is no interference between the parts, the lengths of the first connecting member 140 and the second connecting member 150 can be determined time-series. The walking assist mechanism 400 according to this embodiment is not limited to the above-described structure, and various modifications are possible. Modifications of this embodiment are listed below.

[0103] (First Modification) FIG. 30 is a partial block diagram of a walking assist mechanism 400A according to a first modified example. The walking assist mechanism 400A is configured by adding a recognition unit 510, an analysis unit 511, a database 512, and a control unit 513 to the walking assist mechanism 400. The recognition means 510 has a function of recognizing the situation ahead in the planned direction of travel of the walking assist mechanism 400A. Specifically, the recognition means 510 includes, for example, one or both of a camera that captures images of the situation ahead of the walking assist mechanism 400A and a distance meter that measures the distance to an object ahead of the walking assist mechanism 400A.

[0104] If there are stairs, slopes, uneven surfaces, traffic lights, escalators, or the like in front of the walking assist mechanism 400A, the camera captures images of these, and the distance meter measures the distance to these. The analysis means 511 analyzes the situation ahead recognized by the recognition means 510 and quantifies the situation ahead. For example, if the recognition means 510 recognizes that there are stairs ahead, the analysis means 511 extracts numerical values ​​such as the number of steps and the height of each step. If there is a slope ahead, the analysis means 511 extracts the slope's inclination angle, and if there is a traffic light ahead, the analysis means 511 extracts the color of the traffic light, etc. The database 512 stores appropriate values ​​for the lengths of the first connecting member 140 and the second connecting member 150 for various situations. These appropriate values ​​are determined in advance through field tests, etc. For example, if the height of one step of a staircase ahead is known by the analysis means 511, appropriate values ​​indicating how the lengths of the first connecting member 140 and the second connecting member 150 should be controlled to climb the staircase are stored in the database 512.

[0105] The control means 513 reads from the database 512 the optimum value corresponding to the situation ahead that has been digitized by the analysis means 511, and controls the length of one or both of the first connecting member 140 and the second connecting member 150 based on the optimum value that has been read. For example, if the height of one step of the stairs ahead is 25 cm, control is performed so that each end effector 161 of each of the first to fourth robot arm mechanisms 420A-420D is raised to a height of 25 cm in the step-up operation shown in Figures 28 and 29.

[0106] According to the walking assist mechanism 400A of the first modification, the control means 513 automatically sets the lengths of the first connecting member 140 and the second connecting member 150 to optimal values ​​in accordance with the forward situation grasped by the recognition means 510 and the analysis means 511. This eliminates the need for the user 500 to adjust the lengths of the first connecting member 140 and the second connecting member 150 of each of the first to fourth robot arm mechanisms 420A-420D via the controller 430. In this way, the walking assist mechanism 400A relieves the user 500 from the burden of operating the walking assist mechanism, dramatically improving the practicality of the walking assist mechanism.

[0107] (Second Modification) FIG. 31 is a partial block diagram of a walking assist mechanism 400B according to a second modified example. Compared to walking assist mechanism 400A according to the first modified example, walking assist mechanism 400B according to the second modified example includes calculation means 514 instead of database 512. Except for this point, walking assist mechanism 400B according to this modified example has the same structure as walking assist mechanism 400A. The calculation means 514 calculates appropriate values ​​for the lengths of the first connecting member 140 and the second connecting member 150 based on the numerical values ​​quantified by the analysis means 511. The control means 513 controls the lengths of one or both of the first connecting member 140 and the second connecting member 150 based on the appropriate values ​​calculated by the calculation means 514.

[0108] In this way, in the walking assist mechanism 400B, instead of the control means 513 reading the optimum value from the database 512, the calculation means 514 directly calculates the optimum value. The walking assist mechanism 400B according to this modification can also achieve the same effects as the walking assist mechanism 400A according to the first modification. As is clear from this modification and the first modification, the database 512 or the calculation means 514 can be used as a means for determining the appropriate values ​​for the lengths of the first connecting member 140 and the second connecting member 150 for the quantified forward situation.

[0109] (Third Modification) FIG. 32 is a partial block diagram of a walking assist mechanism 400C according to a third modified example. Casters are attached to the end effectors 161 of the first to fourth robot arm mechanisms 420A-420D in the walking assistance mechanism 400C of this modified example, and each of the first to fourth robot arm mechanisms 420A-420D is equipped with a motor 515 as a drive means for driving the caster. The database 512 stores data on the movements of the casters according to the situation ahead of the walking assist mechanism 400C.

[0110] For example, assume that the recognition means 510 recognizes that there is a left curve ahead of the walking assist mechanism 400C, and the analysis means 511 quantifies the degree of curvature of the left curve (such as the radius of the left curve and the road width). When the walking assist mechanism 400C turns left, the casters of the second robot arm mechanism 420B and the fourth robot arm mechanism 420D located on the inside wheel rotate slower than the casters of the first robot arm mechanism 420A and the third robot arm mechanism 420C located on the outside wheel, i.e., by reducing the number of rotations, it becomes easier to turn left. In this way, data on the degree of deceleration of the casters on the inside wheel according to the magnitude of the curve is stored in the database 512. The control means 513 reads data corresponding to the situation ahead from the database 512 based on the numerical values ​​calculated by the analysis means 511, and controls each motor 515 based on the read data, thereby controlling each caster to perform an operation according to the situation ahead.

[0111] As described above, according to the walking assist mechanism 400C of this modification, when there is a curve ahead of the walking assist mechanism 400C, the casters can be operated according to the size of the curve. Therefore, the user 500 does not need to operate the robot arm mechanisms 420A-420D themselves, and the walking assist mechanism 400C automatically travels according to the curve, so the user 500 can receive walking assistance from the walking assist mechanism 400C even when turning a curve. Alternatively, even if there are obstacles, grooves, holes, etc. in front of the walking assistance mechanism 400C, the user 500 does not need to operate each robot arm mechanism 420A-420D himself / herself, and the walking assistance mechanism 400C automatically avoids the obstacles, grooves, etc. and moves forward.

[0112] (Fourth Modification) FIG. 33 is a partial block diagram of a walking assist mechanism 400D according to a fourth modified example. Compared to walking assist mechanism 400C according to the third modified example, walking assist mechanism 400D according to the fourth modified example includes calculation means 514 instead of database 512. Except for this point, walking assist mechanism 400D according to this modified example has the same structure as walking assist mechanism 400C.

[0113] The calculation means 514 calculates the optimum values ​​for the movements of the casters of the first to fourth robot arm mechanisms 420A-420D based on the numerical values ​​quantified by the analysis means 511. The control means 513 controls the motors 515 based on the optimum values ​​calculated by the calculation means 514. In this way, in the walking assist mechanism 400D, instead of the control means 513 reading data from the database 512, the calculation means 514 directly calculates the optimum value. The walking assist mechanism 400D according to this modification can also achieve the same effects as the walking assist mechanism 400C according to the third modification.

[0114] (Fifth Modification) FIG. 34 is a partial block diagram of a walking assist mechanism 400E according to a fifth modified example. In the walking assistance mechanism 400E of this modified example, as in the third modified example, casters are attached to the end effectors 161 of each of the first to fourth robot arm mechanisms 420A-420D, and each of the first to fourth robot arm mechanisms 420A-420D is equipped with a motor 515 as a drive means for driving the caster.

[0115] As shown in FIG. 34, the walking assist mechanism 400E further includes a position capture means 516 that captures the current position of the walking assist mechanism 400E, a database 512 that stores a map 517, a search means 518, and a control means 513. The position acquisition means 516 is configured by a GPS (Global Positioning System) and identifies the current position of the walking assist mechanism 400E. The walking assist mechanism 400E is equipped with an input means (not shown) through which the user 500 inputs a destination. The input means is, for example, a keyboard or a voice recognition device. When the user 500 inputs a destination into the input means, the search means 518 reads the map 517 from the database 512 and searches for a route from the current position to the destination indicated by the user 500.

[0116] An example of a route searched by the search means 518 is given below. (1) Continue going straight ahead for 300m. (2) Turn right at the intersection 300m ahead. (3) Go straight for 200m and turn left at the end. (4) Cross the main road at the traffic light (cross when the light turns green). (5) Go straight for 150m, turn right, and go straight for 200m to reach your destination. The control means 513 controls the linear actuators 142 and 152 and the motor 515 according to the route searched by the search means 518 . As described above, with the walking assistance mechanism 400E according to this modified example, once the user 500 inputs the destination, the search means 518 searches for the route to the destination, and the control means 513 automatically controls the walking assistance mechanism 400E to continue to assist the user 500 in walking to the destination, thereby reducing the burden on the user 500 until they reach the destination.

[0117] In particular, even if the user 500 does not know the location of the destination, the search means 518 identifies the route to the destination, so the user 500 can reach the destination by walking in the direction indicated by the walking assistance mechanism 400E. In this modification, a screen (not shown) can be provided on the base 410 to display the route to the destination. Alternatively, a speaker (not shown) can be provided on the base 410 to provide audio information about the situation ahead and the progress of the vehicle. This is particularly useful for users 500 who are visually impaired.

[0118] (Sixth Modification) FIG. 35 is a partial block diagram of a walking assist mechanism 400F according to a sixth modified example. The walking assist mechanism 400F is additionally equipped with an input means 519, a database 512, and a control means 513 compared to the walking assist mechanism 400. As described above, the walking assist mechanism 400 assists the user 500 with various movements of the user 500, such as when the user 500 stands up (FIGS. 24 to 27) and when the user 500 climbs steps (FIGS. 28 and 29).

[0119] When the user 500 receives movement assistance from the walking assist mechanism 400, it is necessary for the user 500 to control the extension and contraction of the first connecting member 140 and the second connecting member 150 via the controller 430 in accordance with each movement. However, since the control of the extension and contraction of the first connecting member 140 and the second connecting member 150 differs depending on the movement, it is a great burden for the user 500 to accurately control the extension and contraction of the first connecting member 140 and the second connecting member 150 according to the movement. In view of this, the walking assist mechanism 400F is configured so that when the user 500 selects any one of a plurality of actions, the selected action is automatically executed.

[0120] In the walking assist mechanism 400F, a number is assigned to each of a plurality of actions. For example, the standing-up assist action is assigned the number 1, and the step-up assist action is assigned the number 2. The user 500 inputs the number corresponding to the action he or she has selected into the input means 519. The input means 519 is configured, for example, with a numeric keypad on a keyboard. The database 512 stores the process of controlling the extension and contraction of the first connecting member 140 and the second connecting member 150 for each of a plurality of operations. The control means 513 reads out from the database 512 the control process for the operation corresponding to the number input to the input means 519, and controls the operation of the linear actuators 142, 152 and the motor 515 in accordance with the read out control process. As described above, with the walking assist mechanism 400F, the user 500 simply selects the desired motion assistance, and the walking assist mechanism 400F automatically performs that motion assistance. Therefore, the user 500 does not need to accurately control the extension and contraction of the first connecting member 140 and the second connecting member 150 in accordance with the motion, which increases the convenience of the walking assist mechanism for the user 500.

[0121] (Seventh Modification) FIG. 36 is a partial block diagram of a walking assist mechanism 400G according to a seventh modified example. Compared to walking assist mechanism 400F according to the sixth modified example, walking assist mechanism 400G according to the seventh modified example includes calculation means 514 instead of database 512. Except for this point, walking assist mechanism 400G according to this modified example has the same structure as walking assist mechanism 400F.

[0122] The calculation means 514 calculates the extension / contraction control process of the first connecting member 140 and the second connecting member 150 corresponding to the number (the operation assistance selected by the user 500) input via the input means 519. The control means 513 controls the operation of the linear actuators 142, 152 and the motor 515 based on the value calculated by the calculation means 514. In this way, in the walking assist mechanism 400G, instead of the control means 513 reading data from the database 512, the calculation means 514 directly calculates the expansion / contraction control process. The walking assist mechanism 400G according to this modification can also achieve the same effects as the walking assist mechanism 400F according to the sixth modification. [Explanation of symbols]

[0123] 100 Robot arm mechanism according to the first embodiment of the present invention 110 base 120 First Plate 130 Second Plate 140 First connecting member 150 Second connecting member 160 bars 170 Joint material 200 universal joint 210 rod end 220 Holder 240 recessed area 241 Slope 300 Universal joint (variant) 400 Walking Assistance Mechanism 410 Base 420A, 420B, 420C, 420D First to fourth robot arm mechanisms 430 Controller

Claims

1. A base member; A first member; a second member located on the same side of the base member as the first member; N (N is an integer of 2 or more) first connecting members that can be extended or contracted to a desired length; N (N is an integer of 2 or more) second connecting members that can be extended or contracted to a desired length; Bar and A joint member; A robot arm mechanism comprising: the first connecting member connects the base member and the first member, and the base member, the first member, and the first connecting member constitute a first parallel manipulator; the second connecting member connects the base member and the second member, and the base member, the second member, and the second connecting member constitute a second parallel manipulator; When the lengths of the first connecting member and the second connecting member are kept constant, the positions and postures of the base member, the first member, and the second member are fixed; the joint member connects the bar to the second member so that the bar can slide relative to the second member in the length direction of the bar and so that the bar can rotate in all directions relative to the second member; A robot arm mechanism in which one end of the bar is connected to the first member so as to be rotatable in all directions.

2. N is 3; 2. The robot arm mechanism according to claim 1, wherein the first connecting member and the second connecting member are connected to one of the base member and the first member and the second member so as to be rotatable in all directions, and are connected to the other of the base member and the first member and the second member with one rotational degree of freedom.

3. N is 6, 2. The robot arm mechanism of claim 1, wherein the first connecting member and the second connecting member are connected to the base member so as to be rotatable in all directions, and are connected to the first member and the second member, respectively, so as to be rotatable in all directions.

4. N is 2, 2. The robot arm mechanism of claim 1, wherein the first connecting member and the second connecting member are connected to the base member with one rotational degree of freedom, and are connected to the first member and the second member with one rotational degree of freedom, respectively.

5. 3. The robot arm mechanism according to claim 2, wherein the first connecting member and the second connecting member are connected to the base member via a universal joint and to the first member and the second member via a hinge joint, respectively.

6. 4. The robot arm mechanism according to claim 3, wherein the first connecting member and the second connecting member are connected to the base member via universal joints, and are connected to the first member and the second member via universal joints, respectively.

7. 5. The robot arm mechanism of claim 4, wherein the first connecting member and the second connecting member are connected to the base member via a hinge joint and to the first member and the second member via a hinge joint, respectively.

8. The universal joint is a rod end including a first portion and a cylindrical second portion continuous with the first portion; a holder including a base portion, a first wall portion standing upright on the base portion, and a second wall portion standing upright on the base portion at a position spaced apart from the first wall portion and parallel to the first wall portion; Equipped with the second portion of the rod end is connected to the base member so as to be rotatable about an axial centerline of the second portion, the base portion of the holder is connected to each of the first connecting members and each of the second connecting members so as to be rotatable about an axis perpendicular to the base portion; the first portion of the rod end is connected to both the first wall portion and the second wall portion so as to be rotatable about a rotation axis perpendicular to an axial center line of the second portion, a distance between the first wall portion and the second wall portion such that the rod end is rotatable around the rotation axis; a recessed region that forms a space between an inner surface of at least one of the first wall portion and the second wall portion and a vertical surface; 7. The robot arm mechanism according to claim 5, wherein the recessed area is formed to include the tops of the first wall portion and the second wall portion.

9. 9. The robot arm mechanism according to claim 8, wherein the recessed area is formed by forming a slope on the inner surface.

10. 9. The robot arm mechanism according to claim 8, wherein the recessed area is formed by forming an arcuate surface on the inner surface.

11. 11. The robot arm mechanism according to claim 9, wherein the inclined surface or the arcuate surface is formed as a thin portion having a thickness smaller than that of other portions.

12. 11. The robot arm mechanism according to claim 9, wherein the inclined surface or the arcuate surface is formed by bending the inner surface.

13. 13. The robot arm mechanism according to claim 9, wherein the inclined surface is made up of a plurality of inclined surfaces each having a different inclination angle.

14. 14. The robot arm mechanism according to claim 9, wherein the inclined surface has a starting point at a position between the rotation axis and one end of the first wall portion or the second wall portion in the width direction, and an end point at the other end of the first wall portion or the second wall portion in the width direction.

15. 15. The robot arm mechanism according to claim 9, wherein the inclination angle of the inclined surface is within a range of 5 degrees to 45 degrees.

16. 16. The robot arm mechanism according to claim 8, wherein a portion where the thickness is smallest in the height direction of the first wall portion and the second wall portion is formed between the height of the rotation shaft and a vertex of the first wall portion or the second wall portion.

17. 17. The robot arm mechanism according to claim 9, wherein corners of the inclined surface are formed into a curved shape.

18. 18. The robot arm mechanism according to claim 9, wherein a corner of the first wall portion or the second wall portion located below the inclined surface is formed into a curved shape.

19. 19. The robot arm mechanism according to claim 8, wherein the recessed areas are formed on one side of the first wall portion in the width direction around the rotation axis and on the other side of the second wall portion in the width direction around the rotation axis.

20. 20. A robot arm mechanism as described in any one of claims 1 to 19, characterized in that a linear actuator is attached to each of the first connecting members and each of the second connecting members, and each of the first connecting members and each of the second connecting members extends and contracts via this linear actuator.

21. the second member is a ring-shaped member having a circular opening; The joint member is a first ring member; a second ring member; It consists of the bar is fitted into the first ring member so as to be slidable relative to the first ring member; the first ring member is fitted inside the second ring member, and the second ring member is rotatable relative to the first ring member in any direction perpendicular to the longitudinal direction of the bar; 21. The robot arm mechanism of claim 1, wherein the second ring member is fitted inside the second member, and the second ring member is rotatable relative to the second member around a direction perpendicular to the length direction of the bar and perpendicular to the arbitrary direction.

22. four robotic arm mechanisms according to any one of claims 1 to 21; With the base, a control means for adjusting the length of each of the first and second connecting members of each of the four robot arm mechanisms; A walking assistance mechanism comprising: The four robot arm mechanisms are arranged at positions relative to the base so that the walking assistance mechanisms can stand on their own.

23. 23. The walking assist mechanism according to claim 22, wherein the four robot arm mechanisms are arranged so as to be positioned at four vertices of a rectangle relative to the base.

24. 24. The walking assist mechanism according to claim 22 or 23, wherein a caster is attached to the other end of the bar of each of the four robot arm mechanisms.

25. a recognition means for recognizing a situation ahead of the walking assist mechanism; a means for digitizing the forward situation recognized by the recognition means and determining an appropriate value for each length of the second connecting member or the first connecting member and the second connecting member for the digitized forward situation; Equipped with 25. The walking assist mechanism according to claim 22, wherein the control means adjusts the length of the second connecting member or the length of the first connecting member and the second connecting member based on the appropriate value.

26. a recognition means for recognizing a situation ahead of the walking assist mechanism; a means for digitizing the forward situation recognized by the recognition means and determining an appropriate value for the movement of the caster with respect to the digitized forward situation; a driving means for driving each of the casters; a control means for controlling the driving means based on the appropriate value; 25. The walking assist mechanism of claim 24, comprising:

27. a caster attached to the other end of the bar of each of the four robotic arm mechanisms; a driving means for driving each of the casters; a position capture means for capturing a current position of the walking assist mechanism; A database storing the map; a search means for reading the map from the database and searching for a route from the current position to a destination indicated by the user; a control means for controlling the operation of at least one of a driving means for driving each of the casters and a first connecting member and a second connecting member based on the travel distance; 27. The walking assist mechanism according to claim 22, comprising:

28. an input means for inputting a user-selected action; a means for determining an appropriate value of each length of the second connecting member or the first connecting member and the second connecting member corresponding to the selected operation; a control means for controlling the lengths of the first connecting member and the second connecting member based on the appropriate value; 28. The walking assist mechanism according to claim 22, comprising:

29. 27. The walking assist mechanism according to claim 25, wherein the recognition means is an imaging means for imaging the situation ahead.

30. 27. A walking assistance mechanism according to claim 25 or 26, wherein the recognition means is a distance meter that measures the distance to an object ahead.

Images