Frame system and system

Abstract

A frame system according to the present disclosure comprises a first fixed frame, a second fixed frame, a movable frame, and a moving unit. The first fixed frame and the second fixed frame extend in a first direction. The movable frame is supported by the first fixed frame and the second fixed frame and extends in a second direction intersecting the first direction. The first fixed frame includes an endless first belt and a first speed-increasing unit configured to accelerate the movement of the first belt. One end of the movable frame is connected to the first belt, whereby the movable frame is configured to move along the first fixed frame and the second fixed frame in accordance with the movement of the first belt.

Description

Frame system and system

[0001] The present disclosure relates to frame systems and systems.

[0002] In recent years, Body Weight Supported Treadmill Training (BWSTT) has become popular in fields such as rehabilitation, where walking training is performed while at least a portion of the user's body weight is supported. However, the training environment on a treadmill is limited. Therefore, development of a mobile weight support system has been promoted to improve adaptability to various overground walking situations in daily life.

[0003] For example, Non-Patent Document 1 proposes a wire system for supporting a user from four directions. Specifically, the wire system proposed in Non-Patent Document 1 includes a pair of rails. Two carts are arranged on each rail with a gap between them. Each cart moves along the rail. Four cables connect the corresponding cart to a harness worn by the user. As a result, the user is supported by the four cables.

[0004] Furthermore, for example, Non-Patent Document 2 proposes a frame system (universal core frame) for movably supporting a load-bearing device. Specifically, the frame system proposed in Non-Patent Document 2 includes a pair of fixed frames and a movable frame. The movable frame is movably supported by the pair of fixed frames. A mobile unit is attached to the movable frame. The mobile unit is configured to be movable along the movable frame. The load-bearing device is attached to this mobile unit. According to the systems proposed in Non-Patent Document 1 and Non-Patent Document 2, a user can perform walking training even when not on a treadmill.

[0005] International Publication No. 2020 / 246587 Japanese Patent Application Laid-Open No. 2016-061302

[0006] M. Plooij, U. Keller, B. Sterke, S. Komi, H. Vallery, and J. von Zitzewitz, “Design of RYSEN: An Intrinsically Safe and Low-Power Three-Dimensional Overground Body Weight Support,” [Online], IEEE Robot. Autom. Lett., vol. 3, no. 3, pp. 2253-2260, July 2018. [Retrieved September 4, 2023], Internet <URL: http: / / ieeexplore.ieee.org / document / 8307350 / > INTERRIHA Corporation, “Unweighting Device,” [Retrieved September 4, 2023], Internet <URL: https: / / www.irc-web.co.jp / unweightingsystem> A. Takai, T. Teramae, T. Noda, K. Ishihara, J.-i. Furukawa, H. Fujimoto, M. Hatakenaka, N. Fujita, A. Jino, Y. Hiramatsu, I. Miyai, and J. Morimoto, “Development of split-force-controlled body weight support (SF-BWS) robot for gait rehabilitation,” Front. Hum. Neurosci., vol. 17, p. 1197380, July 2023, [Retrieved September 4, 2023], Internet <URL: https: / / www.frontiersin.org / articles / 10.3389 / fnhum.2023.1197380 / full>

[0007] The present inventors have discovered the following problems with conventional systems. The wire system proposed in Non-Patent Document 1 requires a high ceiling because it uses a structure in which the device is suspended from wires in four directions. This makes it difficult to use this wire system in small- to medium-sized facilities with low ceilings. On the other hand, the frame system proposed in Non-Patent Document 2 can be used in facilities with low ceilings. Therefore, adopting such a frame system is preferable for introducing a load-relief system in facilities of any size. However, in this frame system, the wider the range of movement of the mobile unit, the longer the length of the movable frame. The longer the length of the movable frame, the heavier the weight of the movable frame becomes, resulting in a problem of impairing the mobility (ease of movement) of the movable frame. Note that this problem is not limited to load-relief systems. This problem can occur in any situation in which any device other than a load-relief device is used in a frame system.

[0008] In one aspect, the present disclosure has been made in consideration of the above points, and an object of the present disclosure is to provide a technique for increasing the mobility of a movable frame in a frame system.

[0009] In order to solve the above-mentioned problems, the present disclosure employs the following configurations. Note that the following configurations of the invention can be combined as appropriate.

[0010] A frame system according to one aspect of the present disclosure includes a first stationary frame, a second stationary frame, a movable frame, and a moving unit. The first stationary frame extends in a first direction. The first stationary frame includes a first output pulley, a first auxiliary pulley, an endless first belt, and a first speed-increasing unit. The first output pulley is disposed at one end of the first stationary frame. The first auxiliary pulley is disposed at the other end of the first stationary frame. The first belt is stretched between the first output pulley and the first auxiliary pulley. The first speed-increasing unit is configured to receive a driving force input from a first actuator and output the input driving force to the first output pulley, thereby increasing the speed of movement of the first belt. The second stationary frame extends in the first direction and is disposed parallel to the first stationary frame. The movable frame is supported by the first stationary frame and the second stationary frame and extends in a second direction intersecting the first direction. The movable frame has one end connected to the first belt and configured to move along the first fixed frame and the second fixed frame in response to movement of the first belt. The moving unit is supported by the movable frame and configured to move along the movable frame.

[0011] In the frame system according to this configuration, a first speed-increasing unit is provided on the first fixed frame. The first speed-increasing unit increases the speed of movement of the first belt by outputting the driving force of the first actuator to the first output pulley. One end of the movable frame is connected to this first belt. Therefore, the increased speed by the first speed-increasing unit is transmitted to the movable frame via the first belt, thereby facilitating movement of the movable frame in the first direction. Therefore, this configuration can increase the mobility of the movable frame in the frame system. Note that increasing the mobility of the movable frame corresponds to increasing the mobility of the movable unit in the first direction. Any device may be attached to the movable unit.

[0012] In the frame system according to the above aspect, the second stationary frame may include a second output pulley, a second auxiliary pulley, an endless second belt, and a second speed-increasing unit. The second output pulley may be disposed at one end of the second stationary frame. The second auxiliary pulley may be disposed at the other end of the second stationary frame. The second belt may be stretched between the second output pulley and the second auxiliary pulley. The second speed-increasing unit may be configured to receive a driving force from the second actuator and output the driving force input from the second actuator to the second output pulley, thereby increasing the speed of the second belt. The other end of the movable frame may be connected to the second belt. With this configuration, by providing speed-increasing units on both sides of the first stationary frame and the second stationary frame, the speed-increasing force can be transmitted to both ends of the movable frame via the belts. This reduces the generation of rotational loads when transmitting the speed-increasing force from each belt to each end of the movable frame, thereby improving the mobility of the movable frame. In other words, the movable frame can be moved smoothly.

[0013] In the frame system according to the above aspect, the movable frame may include a third output pulley, a third auxiliary pulley, an endless third belt, and a third speed-increasing unit. The third output pulley may be disposed at one of one end and the other end of the movable frame. The third auxiliary pulley may be disposed at the other of the one end and the other end of the movable frame. The third belt may be stretched between the third output pulley and the third auxiliary pulley. The third speed-increasing unit may be configured to receive a driving force input from the third actuator and output the driving force input from the third actuator to the third output pulley, thereby increasing the speed of movement of the third belt. The moving unit may be connected to the third belt. According to this configuration, by providing a speed-increasing unit on the movable frame as well, the mobility of the moving unit in the second direction can be increased.

[0014] In the frame system according to the above aspect, the moving unit may include a base portion having a cavity opening in the vertical direction and configured to supply a plurality of linear structures, including a first linear structure and a second linear structure, from vertically above through the cavity to vertically below, and a rotation unit configured to rotate around the cavity around the vertical direction. The rotation unit may include a first moving portion disposed outside the cavity and configured to rotate around the vertical direction in response to rotation of the rotation unit, and a second moving portion disposed outside the cavity and spaced apart from the first moving portion around the vertical direction and configured to rotate around the vertical direction in response to rotation of the rotation unit while maintaining a positional relationship with the first moving portion. The first moving portion may include a first holding portion configured to hold a first end of a curl formed when the first linear structure hangs vertically downward from the cavity and is then taken up vertically upward, and the first linear structure may hang further vertically downward from the first end. The second moving portion is a second holding portion configured to hold the second end of the curl formed when the second linear structure hangs vertically downward from the cavity and then is handled vertically upward, and the second linear structure may include a second holding portion that hangs further vertically downward from the second end.

[0015] Depending on the device used in the mobile unit, it may be necessary to supply any linear structure, such as a power cable, a communication cable, a Bowden cable, or an air tube, below the mobile unit. In this configuration, a cavity is provided in the base portion, allowing multiple linear structures to be supplied in a concentrated state below the mobile unit. This makes it easier to handle multiple linear structures. Furthermore, if multiple linear structures are supplied in a concentrated state, the linear structures may become entangled, making it difficult to deploy each linear structure while maintaining a separation. In particular, when rotation is allowed, the linear structures may become twisted, making it difficult to separate them. In contrast, in this configuration, the first and second moving units are arranged circumferentially spaced apart in the rotation unit. After forming the curl, the first and second linear structures are held by the first and second moving units and handled so as to hang vertically downward. The separation between the first and second moving units allows the first and second linear structures to be maintained apart. In addition, even when the rotation unit rotates around the vertical direction (i.e., when rotating around the vertical direction), each linear structure has slack for the curled portion, thereby reducing the effect of rotation on the portion hanging down from each moving section. In other words, the curled portion acts on the winding of the rotation, so that the portion of each linear structure beyond each moving section can rotate while maintaining a spaced apart state without being affected by the winding. Therefore, with this configuration, multiple linear structures can be supplied below the moving unit in a spaced apart state, and even when they rotate around the vertical direction, this spaced apart state can be maintained. Note that the linear structures may be any linear object that can be wired or piped. The linear structures may be, for example, cables, tubes, etc. The types of cables and tubes may be selected appropriately depending on the embodiment.

[0016] In the frame system according to the above aspect, the rotation unit may further include a central portion supported by the base portion for rotation around a vertical axis, a hollow portion opening in the vertical direction and communicating with the cavity of the base portion, a first arm extending vertically downward or at an angle from the central portion, connecting the central portion and the first moving portion, and a second arm extending vertically downward or at an angle from the central portion, connecting the central portion and the second moving portion. The moving portion is provided with a holding portion for holding the linear structure. Therefore, a load caused by the linear structure acts on the moving portion. In this configuration, the moving portion is positioned below the rotating portion (central portion). This allows the other portion to act as a stopper when the other portion shifts to one side. Furthermore, the Yajirobe effect can enhance rotation stability.

[0017] In the frame system according to the above aspect, the moving unit may include a base portion having a cavity opening in the vertical direction and configured to supply the linear structure vertically downward through the cavity from above, and a rotation unit configured to rotate around the cavity in the vertical direction. The rotation unit may include a moving portion disposed outside the cavity and configured to rotate around the vertical direction in response to rotation of the rotation unit. The moving portion may include a holding portion configured to hold the end of a curl formed when the linear structure hangs vertically downward from the cavity and is then wound vertically upward, and the linear structure may further hang vertically downward from the holding portion. In this configuration, the curled portion acts on the winding of the rotation, allowing the portion of the linear structure beyond the moving portion to rotate without being affected by the winding. This allows even linear structures that are difficult to twist to rotate.

[0018] In the frame system according to the above aspect, the first actuator may be a variable stiffness actuator. With this configuration, impedance control in the first direction is possible.

[0019] In the frame system according to the above aspect, the variable stiffness actuator may be configured with a pair of artificial muscles. Artificial muscles can continuously output a relatively large force with low energy. Therefore, with this configuration, it is possible to reduce energy consumption when maintaining a state. Furthermore, the more the artificial muscles contract, the weaker their force becomes. Therefore, with this configuration, the output decreases when the movable frame reaches the end, and the force hitting the end can be weakened.

[0020] In the frame system according to the above aspect, each artificial muscle may include a wire for inputting a driving force to the first speed-up unit, a stopper configured to transmit the driving force to the wire when the artificial muscle contracts in the direction of pulling the wire, and an elastic member configured to maintain tension in the wire when the artificial muscle relaxes and the stopper is released. In this configuration, when the wire is stretched, the stopper acts to stop the wire from moving. On the other hand, when the wire is pulled back, the stopper is released, allowing the wire to move freely and maintaining tension in the wire by the elastic member. This allows the movable frame to be freely moved manually within a certain range. In other words, the frame system can set a range within which the frame can be freely moved in the first direction.

[0021] In the frame system according to the above aspect, each artificial muscle may be a fluid pressure artificial muscle. With this configuration, the system can be easily constructed.

[0022] When a configuration in which the second speed-increasing unit is provided on the second fixed frame is adopted, the second actuator may also be configured in the same manner as the first actuator. That is, in one example, the second actuator may be a variable stiffness actuator. In one example, the variable stiffness actuator of the second actuator may be composed of a pair of artificial muscles. In one example, each artificial muscle of the second actuator may be configured to include the above-mentioned wire, stopper, and elastic member. In one example, each artificial muscle of the second actuator may be a fluid pressure artificial muscle.

[0023] In the frame system according to the above aspect, when a configuration is adopted in which a third speed-up unit is provided on the movable frame, the third actuator may be a variable stiffness actuator. With this configuration, impedance control in the second direction is possible. The third actuator may also be configured in the same manner as the first actuator. That is, in one example, the variable stiffness actuator of the third actuator may be configured with a pair of artificial muscles. In one example, each artificial muscle of the third actuator may be configured to include the wire, stopper, and elastic member. In one example, each artificial muscle of the third actuator may be a fluid pressure artificial muscle.

[0024] In the frame system according to the above aspect, a load-relieving device may be attached to the moving unit. With this configuration, the mobility of the movable frame can be increased in situations where the load-relieving device is used.

[0025] In the frame system according to the above aspect, a load-relieving device may be attached to the moving unit. Additionally, the moving unit may include a base portion having a cavity that opens in the vertical direction and is configured to supply a plurality of linear structures, including the first linear structure and the second linear structure, of the load-relieving device from vertically above through the cavity to vertically below, and a rotation unit configured to rotate around the cavity in the vertical direction. The rotation unit may include a first moving portion disposed outside the cavity and configured to rotate around the vertical direction in response to rotation of the rotation unit, and a second moving portion disposed outside the cavity and spaced apart from the first moving portion in the vertical direction, and configured to rotate around the vertical direction in response to rotation of the rotation unit while maintaining a positional relationship with the first moving portion. The first moving unit may be a first holding unit configured to be formed when the first linear structure hangs vertically downward from the cavity and then is routed vertically upward, the first linear structure including a first holding unit that hangs further vertically downward from a first end toward one of the left and right sides of a user of the load-relief device. The second moving unit may be a second holding unit configured to hold a second end of a curl formed when the second linear structure hangs vertically downward from the cavity and then is routed vertically upward, the second linear structure including a second holding unit that hangs further vertically downward from the second end toward the other of the left and right sides of the user. With this configuration, the multiple linear structures of the load-relief device can be supplied to the user in a spaced-apart state, and the spaced-apart state can be maintained even when rotated around the vertical direction. Note that each of the linear bodies of the load-relief device may be a cable supporting each of the left and right sides of the user.

[0026] In the frame system according to the above aspect, a robot arm may be attached to the movement unit. With this configuration, the mobility of the movable frame can be improved in situations where the robot arm is used.

[0027] In the frame system according to the above aspect, a robot arm may be attached to the moving unit. Additionally, the movable frame may include a third output pulley, a third auxiliary pulley, an endless third belt, and a third speed-increasing unit. The third output pulley may be disposed at one of one end and the other end of the movable frame. The third auxiliary pulley may be disposed at the other of the one end and the other end of the movable frame. The third belt may be stretched between the third output pulley and the third auxiliary pulley. The third speed-increasing unit may be configured to receive a driving force input by the third actuator and output the driving force input from the third actuator to the third output pulley, thereby increasing the speed of movement of the third belt. The moving unit may be connected to the third belt. This configuration can enhance the mobility of the robot arm in the first and second directions.

[0028] In the frame system according to the above aspect, the robot arm may be attached to the moving unit via a balancer. From the viewpoint of convenience, it is preferable that the robot arm be moved vertically upward when moving and lowered vertically downward when in use. With this configuration, the balancer facilitates this vertical movement, thereby improving convenience.

[0029] Furthermore, in one aspect of the present disclosure, a system may be configured using a plurality of frame systems each according to any one of the above aspects. For example, a system according to one aspect of the present disclosure may include a first frame system disposed in a first space and a second frame system disposed in a second space adjacent to the first space. Each frame system may include a first stationary frame, a second stationary frame, a movable frame, and a moving unit. The first stationary frame of each frame system may extend in a first direction. The first stationary frame of each frame system may include a first output pulley, a first auxiliary pulley, an endless first belt, and a first speed-increasing unit. In each frame system, the first output pulley may be disposed at one end of the first stationary frame. The first auxiliary pulley may be disposed at the other end of the first stationary frame. The first belt may be stretched between the first output pulley and the first auxiliary pulley. The first speed-increasing unit may be configured to receive a driving force input by a first actuator and output the input driving force to the first output pulley, thereby increasing the speed of movement of the first belt. The second fixed frame of each frame system may extend in a first direction and may be arranged parallel to the first fixed frame. The movable frame of each frame system may be supported by the first fixed frame and the second fixed frame and may extend in a second direction intersecting the first direction. The movable frame of each frame system may have one end connected to the first belt and configured to move along the first fixed frame and the second fixed frame in response to movement of the first belt. The moving unit of each frame system may be supported by the movable frame and configured to move along the movable frame. The first frame system and the second frame system may be arranged at a distance such that a load-relieving device can be attached to the moving unit of both the first frame system and the second frame system at or near the boundary between the first space and the second space. This configuration can increase the mobility of the movable frame of each frame system. Furthermore, by arranging the first frame system and the second frame system at the above distance, the load-relieving device can be used continuously in the first space and the second space.

[0030] In the system according to the above aspect, the first space and the second space may be selected arbitrarily. In one example, one of the first space and the second space may be a bathroom. According to this example, the weight-relieving device can be used in the bathroom. This is expected to reduce the burden on the caregiver in the bathroom.

[0031] According to the present disclosure, a technique for increasing the mobility of a movable frame in a frame system can be provided.

[0032] FIG. 1 schematically illustrates an example of a frame system according to an embodiment. FIG. 2A schematically illustrates an example of a first fixed frame according to an embodiment. FIG. 2B schematically illustrates an example of a side view of the first fixed frame (second fixed frame) according to an embodiment. FIG. 2C is a diagram for explaining impedance control by a speed-increasing unit of a fixed frame according to an embodiment. FIG. 3 schematically illustrates an example of a movable frame according to an embodiment. FIG. 4A is a perspective view schematically illustrating an example of a support portion of a movable frame and a first fixed frame according to an embodiment. FIG. 4B is a partial cross-sectional view schematically illustrating an example of a support portion of a movable frame and a first fixed frame according to an embodiment. FIG. 4C is a partial cross-sectional view schematically illustrating an example of a support portion of a movable frame and a second fixed frame according to an embodiment. FIG. 5A is a perspective view schematically illustrating an example of a moving unit according to an embodiment. FIG. 5B is a partial cross-sectional view schematically illustrating an example of a moving unit according to an embodiment. FIG. 6 schematically illustrates an example of a general configuration of an artificial muscle according to an embodiment. FIG. 7 schematically illustrates an example of a hardware configuration of a control device according to an embodiment. FIG. 8 schematically shows an example of the software configuration of a control device according to an embodiment. FIG. 9 is a flowchart showing an example of a processing procedure of a control device according to an embodiment. FIG. 10 schematically shows an example of a frame (first fixed frame, second fixed frame, and movable frame) according to another embodiment. FIG. 11A schematically shows an example of another situation in which the frame system of the present disclosure is used. FIG. 11B is a perspective view schematically showing an example of handling a linear structure in a mobile unit of the present disclosure. FIG. 11C is a partial cross-sectional view schematically showing an example of handling a linear structure in a mobile unit of the present disclosure. FIG. 12 schematically shows an example of another situation in which the frame system of the present disclosure is used. FIG. 13 schematically shows an example of another situation in which the frame system of the present disclosure is used. FIG. 14 is a flowchart showing another example of a processing procedure of a control device of the present disclosure. FIG. 15 schematically shows an example of a system of the present disclosure. FIG. 16A schematically shows an example of a situation in which a user of a load-relief device moves from a first space to a second space in the system of the present disclosure.Fig. 16B schematically shows an example of a scene in which a user of a load-relieving device moves from a first space to a second space in the system of the present disclosure. Fig. 17 schematically shows an example of a general configuration of an artificial muscle according to another embodiment. Fig. 18 schematically shows an example of force control according to the present disclosure. Fig. 19A shows the results of a first experimental example. Fig. 19B shows the results of the first experimental example. Fig. 20A shows the results of a second experimental example. Fig. 20B shows the results of the second experimental example.

[0033] An embodiment according to one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described below with reference to the drawings. However, the present embodiment described below is merely an example of the present invention in all respects. Needless to say, various improvements and modifications can be made without departing from the scope of the present invention. In other words, when implementing the present invention, specific configurations according to the embodiment may be adopted as appropriate. Attributes such as the shape, material, and structure of each component described in the present embodiment may be changed as appropriate depending on the embodiment. Note that while data appearing in the present embodiment is described in natural language, more specifically, it is specified using computer-recognizable pseudo-language, commands, parameters, machine language, etc.

[0034] §1 Configuration Example Fig. 1 shows a schematic diagram of an example of a frame system ST according to this embodiment. The frame system ST according to this embodiment includes a first fixed frame 10, a second fixed frame 20, a movable frame 30, and a moving unit 40.

[0035] In one example, the first fixing frame 10 extends in a first direction (x direction) and is formed with a substantially rectangular cross section. The second fixing frame 20 also extends in the first direction (x direction) and is formed with a substantially rectangular cross section. The second fixing frame 20 is arranged in parallel to the first fixing frame 10. The length of each fixing frame (10, 20) may be determined appropriately depending on the embodiment. In the example of FIG. 1 , the first fixing frame 10 and the second fixing frame 20 have substantially the same length. However, the length of each fixing frame (10, 20) is not limited to this example, and one of the first fixing frame 10 and the second fixing frame 20 may be longer than the other. The material of each fixing frame (10, 20) may be selected appropriately depending on the embodiment.

[0036] The movable frame 30 extends in a second direction (y direction) intersecting the first direction and has a generally rectangular cross section. The movable frame 30 is supported by the first fixed frame 10 and the second fixed frame 20 so as to be movable along the first fixed frame 10 and the second fixed frame 20 (i.e., in the first direction). The length of the movable frame 30 may be determined appropriately depending on the embodiment. The moving unit 40 is supported by the movable frame 30. The moving unit 40 is configured to move along the movable frame 30. The materials of the movable frame 30 and the moving unit 40 may be selected appropriately depending on the embodiment. In one example of this embodiment, a load-relieving device 60 may be attached to the moving unit 40. FIG. 1 illustrates an example of a scenario in which the frame system ST of the present disclosure is used together with the load-relieving device 60.

[0037] The first fixed frame 10 and the second fixed frame 20 may be fixed as appropriate. In the example of FIG. 1 , the frame system ST further includes four support columns (first support column 55, second support column 56, third support column 57, and fourth support column 58). Each of the support columns 55 to 58 is configured as a tension type and is fixed by being sandwiched between the floor and the ceiling. Each end of the first fixed frame 10 is fixed as appropriate near the ceiling of each of the first support column 55 and the second support column 56. Similarly, each end of the second fixed frame 20 is fixed as appropriate near the ceiling of each of the third support column 57 and the fourth support column 58. As a result, the first fixed frame 10 and the second fixed frame 20 are fixed at approximately the same height.

[0038] In the example of FIG. 1 , the frame system ST further includes a third fixed frame 51 and a fourth fixed frame 52. The third fixed frame 51 and the fourth fixed frame 52 each extend in the second direction (y direction) and have a generally rectangular cross section. The lengths of the third fixed frame 51 and the fourth fixed frame 52 are approximately the same as that of the movable frame 30. The third fixed frame 51 spans between the second support column 56 and the third support column 57 at approximately the same height as the first fixed frame 10 and the second fixed frame 20. Each end of the third fixed frame 51 is fixed to the second support column 56 and the third support column 57, respectively. As a result, the third fixed frame 51 connects one end of the first fixed frame 10 and one end of the second fixed frame 20 to each other. Similarly, the fourth fixed frame 52 spans between the first support column 55 and the fourth support column 58 at approximately the same height as the first fixed frame 10 and the second fixed frame 20. Each end of the fourth fixing frame 52 is fixed to the first support column 55 and the fourth support column 58, respectively. In this way, the fourth fixing frame 52 fixes the other ends of the first fixing frame 10 and the second fixing frame 20. By fixing the respective ends of the first fixing frame 10 and the second fixing frame 20 to each other using the third fixing frame 51 and the fourth fixing frame 52, it is possible to prevent the first fixing frame 10 and the second fixing frame 20 from expanding in the second direction.

[0039] In each figure, for convenience of explanation, the first direction is indicated as the "x direction," the second direction is indicated as the "y direction," and the vertical direction is indicated as the "z direction." However, the correspondence between the directions is merely an example and may be changed as appropriate depending on the embodiment. For example, the relationship between the first direction and the second direction may be reversed (for example, the first direction may be the y direction and the second direction may be the x direction). It is preferable that the first direction and the second direction are horizontal, but as long as the movable frame 30 is movable, the first direction and the second direction may be inclined with respect to the vertical direction.

[0040] Furthermore, the parallel arrangement of the first fixed frame 10 and the second fixed frame 20 is preferably configured by the first fixed frame 10 and the second fixed frame 20 being parallel to each other. However, as long as the movable frame 30 is movable, the parallel arrangement is not limited to this example, and may also include the first fixed frame 10 and the second fixed frame 20 being arranged at an angle.

[0041] Furthermore, the intersection of the first direction and the second direction is preferably configured by the first direction and the second direction being perpendicular to each other (i.e., the angle at which the first direction and the second direction intersect is a right angle). However, as long as the movable frame 30 is movable, the intersection of the first direction and the second direction is not limited to this example and may include the first direction and the second direction intersecting at an acute angle or an obtuse angle.

[0042] [First Fixed Frame / Second Fixed Frame] Fig. 2A schematically shows an example of the first fixed frame 10 according to this embodiment. Fig. 2B schematically shows an example of the first fixed frame 10 (second fixed frame 20) according to this embodiment as viewed from the side. In this example, the first fixed frame 10 includes a first output pulley 11, a first auxiliary pulley 12, an endless first belt 13, and a first speed-increasing unit 14.

[0043] The first output pulley 11 is disposed at one end 101 of the first fixed frame 10. The first auxiliary pulley 12 is disposed at the other end 102 of the first fixed frame 10. The diameters of the first output pulley 11 and the first auxiliary pulley 12 may be determined appropriately depending on the embodiment. In one example, the diameters of the first output pulley 11 and the first auxiliary pulley 12 may be the same. Also, in the example of FIG. 1 , the first output pulley 11 may be housed in a housing 140 together with the first speed-up unit 14, and the first auxiliary pulley 12 may be housed in a housing 121. Each housing (121, 140) may be omitted.

[0044] The first belt 13 is wound between the first output pulley 11 and the first auxiliary pulley 12. In the example shown in FIGS. 2A and 2B , the first belt 13 is exposed between the housings (121, 140). A tensioner 131 that presses the first belt 13 from below is provided near the exit of the housing 121 of the first auxiliary pulley 12. A pair of tensioners (132, 133) are provided above and below the exit of the housing 140 of the first output pulley 11. These tensioners 131 to 133 maintain the tension of the first belt 13 wound between the first output pulley 11 and the first auxiliary pulley 12. However, the method of maintaining the tension of the first belt 13 is not limited to this example and may be changed as appropriate depending on the embodiment. Furthermore, the state of the first belt 13 is not limited to this example and may be selected as appropriate depending on the embodiment. In another example, the first belt 13 may be entirely enclosed or entirely exposed. In this embodiment, the first belt 13 is disposed on the outer side of the first fixed frame 10 (specifically, on the side opposite to the side on which the movable frame 30 is disposed). The location of this first belt 13 may be changed as appropriate depending on the embodiment.

[0045] Note that the ends (101, 102) merely indicate the range over which the first belt 13 is wound, and the first fixed frame 10 may have a shape that extends further from each end (101, 102). That is, arranging the first output pulley 11 at one end 101 may mean arranging the first output pulley 11 on one end side with respect to the first auxiliary pulley 12. Arranging the first auxiliary pulley 12 at the other end 102 may mean arranging the first auxiliary pulley 12 on the other end side with respect to the first output pulley 11. The first output pulley 11 and the first auxiliary pulley 12 may be arranged near each end of the first fixed frame 10, or may be arranged away from each end. The relationship between the one end 101 and the other end 102 may be reversed. In one example, the axes of the first output pulley 11 and the first auxiliary pulley 12 face in the second direction. As a result, the first output pulley 11 and the first auxiliary pulley 12 are arranged to rotate around the second direction, thereby moving the first belt 13 in the first direction.

[0046] The first speed-up unit 14 is configured to receive a driving force input from the first actuator 15 and output the input driving force to the first output pulley 11, thereby increasing the speed of movement of the first belt 13. In the present embodiment, the first actuator 15 is configured with a pair of artificial muscles (151, 152). The first actuator 15 configured as such is an example of a variable stiffness actuator. The type of each artificial muscle (151, 152) may be selected appropriately depending on the embodiment. In one example, each artificial muscle (151, 152) may be a fluid pressure artificial muscle. The fluid may be either a gas or a liquid. The fluid may be selected appropriately from, for example, air, oil, water, etc. As a typical example, each artificial muscle (151, 152) may be a pneumatic artificial muscle. In another example, each artificial muscle (151, 152) may be an artificial muscle other than a fluid pressure artificial muscle, such as a polymer actuator or a dielectric actuator. The arrangement of the artificial muscles (151, 152) may be determined appropriately depending on the embodiment. In the example of Fig. 1, the first speed increasing unit 14 is provided on the second support column 56 side. Accordingly, the artificial muscles (151, 152) may be arranged on the second support column 56.

[0047] In this embodiment, the first speed-increasing unit 14 includes a first input pulley 141 and an endless first speed-increasing belt 143. The first input pulley 141 includes a coaxial first drive gear 142. That is, the first input pulley 141 and the first drive gear 142 are configured as two-stage pulleys. The first input pulley 141 is arranged to face the same direction as the first output pulley 11. Similarly, the first output pulley 11 includes a coaxial first driven gear 111. That is, the first output pulley 11 and the first driven gear 111 are also configured as two-stage pulleys.

[0048] The first drive gear 142 is disposed opposite the first driven gear 111. The first speed-increasing belt 143 is wound around the first drive gear 142 and the first driven gear 111. As long as the first speed-increasing belt 143 can be wound around the first drive gear 142 and the first driven gear 111, the positional relationship between the first drive gear 142 and the first driven gear 111 is not limited to this example and may be changed as appropriate depending on the embodiment. On the other hand, the positional relationship between the first input pulley 141 and the first output pulley 11 may be arbitrary. The first input pulley 141 may or may not face the first output pulley 11. A pair of tensioners (148, 149) are provided above and below the first drive gear 142 and the first driven gear 111. These tensioners (148, 149) maintain the tension of the first speed-increasing belt 143. The method for maintaining the tension of the first speed-increasing belt 143 is not limited to this example and may be changed as appropriate depending on the embodiment.

[0049] The diameter of the first drive gear 142 is larger than the diameter of the first driven gear 111. Other diameter relationships may be determined appropriately depending on the embodiment. In one example, the diameter of the first driven gear 111 may be smaller than the diameter of the first output pulley 11. The diameter of the first drive gear 142 may be larger than the diameter of the first input pulley 141. Of the pair of artificial muscles (151, 152), the wire of one artificial muscle is wound around the first input pulley 141 in one direction, and its end is fixed to the first input pulley 141. In this way, one artificial muscle is configured to rotationally drive the first input pulley 141 in one direction via the wire. Meanwhile, the wire of the other artificial muscle is wound around the first input pulley 141 in the other direction, and its end is fixed to the first input pulley 141. In this way, the other artificial muscle is configured to rotationally drive the first input pulley 141 in the other direction via the wire.

[0050] That is, in the first speed-increasing unit 14 according to the present embodiment, the input of driving force by the pair of artificial muscles (151, 152) is received by the first input pulley 141. The driving force input to the first input pulley 141 is output to the first output pulley 11 via the first speed-increasing belt 143. At this time, the rotation of the first input pulley 141 is accelerated according to the ratio between the first drive gear 142 and the first driven gear 111, and then transmitted to the first output pulley 11. In this way, the first speed-increasing unit 14 accelerates the movement of the first belt 13.

[0051] The movable frame 30 is configured to move along the first fixed frame 10 and the second fixed frame 20 in response to movement of the first belt 13 by connecting one end 301 of the movable frame 30 to the first belt 13. The method of connecting the movable frame 30 and the first belt 13 is not particularly limited and may be selected appropriately depending on the embodiment. In this embodiment, the one end 301 of the movable frame 30 is connected to the first belt 13 via a coupling unit 36.

[0052] In this embodiment, the second fixed frame 20 is configured in the same manner as the first fixed frame 10. That is, the second fixed frame 20 includes a second output pulley 21, a second auxiliary pulley 22, an endless second belt 23, and a second speed-increasing unit 24.

[0053] The second output pulley 21 is disposed at one end 201 of the second fixed frame 20. The second auxiliary pulley 22 is disposed at the other end 202 of the second fixed frame 20. The diameters of the second output pulley 21 and the second auxiliary pulley 22 may be the same. The second output pulley 21 may be housed in a housing 240 together with the second speed-increasing unit 24, and the second auxiliary pulley 22 may be housed in a housing 221. Each housing (221, 240) may be omitted.

[0054] The second belt 23 is wound between the second output pulley 21 and the second auxiliary pulley 22. In the example of FIG. 2B , the second belt 23 is exposed between the housings (221, 240). A tensioner 231 that presses the second belt 23 from below is provided near the exit of the housing 221 of the second auxiliary pulley 22. Furthermore, a pair of tensioners (232, 233) are provided, one above the other, near the exit of the housing 240 of the second output pulley 21. These tensioners 231 to 233 maintain the tension of the second belt 23 wound between the second output pulley 21 and the second auxiliary pulley 22. However, the method of maintaining the tension of the second belt 23 is not limited to this example and may be changed as appropriate depending on the embodiment. Furthermore, the state of the second belt 23 is not limited to this example and may be selected as appropriate depending on the embodiment. In another example, the second belt 23 may be entirely enclosed or entirely exposed. In this embodiment, the second belt 23 is disposed on the outer side of the second fixed frame 20 (specifically, on the side opposite to the side on which the movable frame 30 is disposed). The location of this second belt 23 may be changed as appropriate depending on the embodiment.

[0055] Note that the ends (201, 202) merely indicate the range over which the second belt 23 is wound, and the second stationary frame 20 may have a shape that extends further from the ends (201, 202). The second output pulley 21 and the second auxiliary pulley 22 may be disposed near each end of the second stationary frame 20, or may be disposed away from each end. The relationship between the one end 201 and the other end 202 may be reversed. In one example, the axes of the second output pulley 21 and the second auxiliary pulley 22 face the second direction. As a result, the second output pulley 21 and the second auxiliary pulley 22 are disposed so that they rotate around the second direction to move the second belt 23 in the first direction. Furthermore, in the example of FIG. 1 , one end 101 of the first stationary frame 10 faces one end 201 of the second stationary frame 20, and the other end 102 of the first stationary frame 10 faces the other end 202 of the second stationary frame 20. However, the positional relationship between the ends is not limited to this example. In another example, one end 101 of the first fixing frame 10 may face the other end 202 of the second fixing frame 20, and the other end 102 of the first fixing frame 10 may face the one end 201 of the second fixing frame 20.

[0056] The second speed-up unit 24 is configured to receive a driving force input from the second actuator 25 and output the input driving force to the second output pulley 21, thereby increasing the speed of movement of the second belt 23. In the present embodiment, the second actuator 25 is configured with a pair of artificial muscles (251, 252). The second actuator 25 is an example of a variable stiffness actuator. The type of each artificial muscle (251, 252) may be selected appropriately depending on the embodiment. In one example, each artificial muscle (251, 252) may be a fluid pressure artificial muscle. Fluid pressure artificial muscles may include hybrid artificial muscles configured to be able to output other driving forces, such as electricity, in addition to fluid pressure. In another example, each artificial muscle (251, 252) may be an artificial muscle other than a fluid pressure artificial muscle. The arrangement of each artificial muscle (251, 252) may be determined appropriately depending on the embodiment. In the example of FIG. 1 , the second speed-up unit 24 is provided on the third support 57 side. Accordingly, each artificial muscle (251, 252) may be arranged on the third strut 57.

[0057] In this embodiment, the second speed-increasing unit 24 includes a second input pulley 241 and an endless second speed-increasing belt 243. The second input pulley 241 includes a coaxial second drive gear 242. The second input pulley 241 is arranged to face the same direction as the second output pulley 21. Similarly, the second output pulley 21 includes a coaxial second driven gear 211. The second drive gear 242 is arranged to face the second driven gear 211. The second speed-increasing belt 243 is stretched between the second drive gear 242 and the second driven gear 211. As long as the second speed-increasing belt 243 can be stretched between them, the positional relationship between the second drive gear 242 and the second driven gear 211 is not limited to this example and may be changed as appropriate depending on the embodiment. On the other hand, the positional relationship between the second input pulley 241 and the second output pulley 21 may be arbitrary. A pair of tensioners (248, 249) are provided above and below between the second drive gear 242 and the second driven gear 211. These tensioners (248, 249) maintain the tension of the second speed-up belt 243. Note that the method for maintaining the tension of the second speed-up belt 243 is not limited to this example, and may be changed as appropriate depending on the embodiment.

[0058] The diameter of the second drive gear 242 is larger than the diameter of the second driven gear 211. Other diameter relationships may be determined appropriately depending on the embodiment. In one example, the diameter of the second driven gear 211 may be smaller than the diameter of the second output pulley 21. The diameter of the second drive gear 242 may be larger than the diameter of the second input pulley 241. Of the pair of artificial muscles (251, 252), the wire of one artificial muscle is wound around the second input pulley 241 from one direction, with its end fixed to the second input pulley 241. Meanwhile, the wire of the other artificial muscle is wound around the second input pulley 241 from the other direction, with its end fixed to the second input pulley 241. In this way, the second speed-up unit 24 increases the speed of movement of the second belt 23 in a manner similar to that of the first speed-up unit 14.

[0059] The movable frame 30 is configured to move along the first fixed frame 10 and the second fixed frame 20 in accordance with the movement of the second belt 23 by connecting the other end 302 of the movable frame 30 to the second belt 23. The method of connecting the movable frame 30 and the second belt 23 is not particularly limited and may be selected appropriately depending on the embodiment. In this embodiment, the other end 302 of the movable frame 30 is connected to the second belt 23 via a coupling unit 37.

[0060] (Impedance Control) In this embodiment, the pair of artificial muscles (151, 152) are driven in an antagonistic manner. That is, one of the pair of artificial muscles (151, 152) is connected to rotate and drive the first input pulley 141 in one direction, and the other artificial muscle is connected to rotate and drive the first input pulley 141 in the other direction. When no other forces act on the movable frame 30, the position of the movable frame 30 is maintained at a balanced position for the pair of artificial muscles (151, 152). When the movable frame 30 is shifted from this balanced position, one of the pair of artificial muscles (151, 152) contracts and the other artificial muscle stretches. When the movable frame 30 is shifted in the opposite direction, one artificial muscle stretches and the other artificial muscle contracts. This generates a driving force (hereinafter also referred to as a restoring force) in a direction that returns the movable frame 30 to the balanced position. From this point of view, each of the pair of artificial muscles (151, 152) can be considered as a pair of springs (SP1, SP2) connected to each other. The position at which the driving forces are balanced can be considered as the balance point BP of the springs (SP1, SP2). The same is true for the pair of artificial muscles (251, 252) in the second fixed frame 20. Note that each speed-up unit (14, 24) can shift the position of the balance point BP from the position of the movable frame 30, thereby moving the movable frame 30 in that direction.

[0061] In this embodiment, the pair of artificial muscles (151, 152) of the first actuator 15 is an example of a variable stiffness actuator. Similarly, the pair of artificial muscles (251, 252) of the second actuator 25 is also an example of a variable stiffness actuator. A variable stiffness actuator is an actuator whose stiffness can be changed. By configuring each actuator (15, 25) as a variable stiffness actuator, impedance control of each belt (13, 23) by each speed-up unit (14, 24) is possible. By enabling impedance control of at least one of the first belt 13 and the second belt 23, impedance control in a first direction is possible.

[0062] 2C is a diagram for explaining impedance control by each speed-up unit (14, 24) of each fixed frame (10, 20) according to this embodiment. The horizontal axis of the diagram represents the contraction rate of one of the pair of artificial muscles (151, 152) (251, 252). Because there is a relationship in which when one artificial muscle extends, the other artificial muscle contracts (i.e., the pair of artificial muscles are driven in an antagonistic manner), the other artificial muscle is shown inverted. The resultant force F3 of the driving force F1 of one artificial muscle and the driving force F2 of the other artificial muscle is the driving force output from each actuator (15, 25). The point TO where the resultant force F3 becomes 0 corresponds to the equilibrium point BP. The slope of the resultant force F3 corresponds to the rigidity of each actuator (15, 25).

[0063] The rigidity of the artificial muscles can be changed as appropriate. When fluid pressure artificial muscles are used for the artificial muscles (151, 152) (251, 252), the rigidity of each artificial muscle (151, 152) (251, 252) can be increased by increasing the fluid pressure within each artificial muscle (151, 152) (251, 252). This makes it possible to increase the slope of the resultant force F3 with respect to the contraction rate, as shown in FIG. 2C . In other words, by stiffening each spring (SP1, SP2), it is possible to increase the restoring force that occurs when the movable frame 30 deviates from the equilibrium point BP. Conversely, by decreasing the fluid pressure, it is possible to decrease the rigidity of each artificial muscle (151, 152) (251, 252). This makes it possible to decrease the slope of the resultant force F3 with respect to the contraction rate. In other words, by softening each spring (SP1, SP2), it is possible to reduce the restoring force that occurs when the movable frame 30 deviates from the equilibrium point BP. In this embodiment, changing the stiffness of each actuator (15, 25) in this way enables impedance control in the first direction. Note that the example of FIG. 2C assumes a situation in which a pair of artificial muscles (151, 152) (251, 252) are antagonistic, with one artificial muscle fully contracted and the other artificial muscle not contracting at all. However, the antagonistic state of the pair of artificial muscles (151, 152) (251, 252) is not limited to this example and may be determined appropriately depending on the embodiment. In the example of FIG. 2C, the antagonistic state may be changed so that at least one of the pair of driving forces (F1, F2) is shifted along the horizontal axis.

[0064] 3 schematically shows an example of the movable frame 30 according to this embodiment. In this embodiment, the movable frame 30 also has a configuration similar to that of the first fixed frame 10. That is, the movable frame 30 includes a third output pulley 31, a third auxiliary pulley 32, an endless third belt 33, and a third speed-increasing unit 34.

[0065] The third output pulley 31 is disposed at one of the one end 301 and the other end 302 of the movable frame 30. The third auxiliary pulley 32 is disposed at the other of the one end 301 and the other end 302 of the movable frame 30. The diameters of the third output pulley 31 and the third auxiliary pulley 32 may be the same. The third output pulley 31 may be housed in a housing 340 together with the third speed-increasing unit 34, and the third auxiliary pulley 32 may be housed in a housing 321. Each housing (321, 340) may be omitted.

[0066] The third belt 33 is wound between the third output pulley 31 and the third auxiliary pulley 32. In the example shown in FIG. 3 , the third belt 33 is exposed between the housings (321, 340). A tensioner 331 that presses the third belt 33 from below is provided near the exit of the housing 321 of the third auxiliary pulley 32. Furthermore, a pair of tensioners (332, 333) are provided, one above the other, near the exit of the housing 340 of the third output pulley 31. These tensioners 331 to 333 maintain the tension of the third belt 33 wound between the third output pulley 31 and the third auxiliary pulley 32. However, the method of maintaining the tension of the third belt 33 is not limited to this example and may be changed as appropriate depending on the embodiment. Furthermore, the state of the third belt 33 is not limited to this example and may be selected as appropriate depending on the embodiment. In another example, the third belt 33 may be entirely enclosed or entirely exposed. In the example of FIG. 3, the third belt 33 is partially omitted.

[0067] The movable frame 30 may have a shape that extends further from each end (301, 302). One end 301 of the movable frame 30 is supported by the first fixed frame 10, and the other end 302 is supported by the second fixed frame 20. The portions supported by each fixed frame (10, 20) and the portions where the pulleys (31, 32) are arranged may overlap or be separated. The third output pulley 31 and the third auxiliary pulley 32 may be arranged near each end of the movable frame 30, or separated from each end. Similarly, the movable frame 30 may be supported by each fixed frame (10, 20) near each end or separated from each end. The ends (301, 302) may broadly refer to the supported portions of each fixed frame (10, 20) and the portions where the pulleys (31, 32) are arranged. In one example, the axes of the third output pulley 31 and the third auxiliary pulley 32 face in the first direction. As a result, the third output pulley 31 and the third auxiliary pulley 32 are arranged so that they rotate around the first direction to move the third belt 33 in the second direction. In the example of FIG. 3 , the third output pulley 31 is arranged at the other end 302 of the movable frame 30, and the third auxiliary pulley 32 is arranged at the one end 301. However, the arrangement of the third output pulley 31 and the third auxiliary pulley 32 is not limited to this example. The third output pulley 31 may be arranged at the one end 301, and the third auxiliary pulley 32 may be arranged at the other end 302. That is, the third output pulley 31 may be arranged at one of the one end 301 and the other end 302 of the movable frame 30, and the third auxiliary pulley 32 may be arranged at the other of the one end 301 and the other end 302 of the movable frame 30.

[0068] The third speed-up unit 34 is configured to receive a driving force input from the third actuator 35 and output the input driving force to the third output pulley 31, thereby increasing the speed of movement of the third belt 33. In this embodiment, the third actuator 35 is composed of a pair of artificial muscles (351, 352). The third actuator 35 is an example of a variable stiffness actuator. The type of each artificial muscle (351, 352) may be selected appropriately depending on the embodiment. In one example, the each artificial muscle (351, 352) may be a fluid pressure artificial muscle. In another example, the each artificial muscle (351, 352) may be an artificial muscle other than a fluid pressure artificial muscle. The arrangement of the each artificial muscle (351, 352) may be determined appropriately depending on the embodiment. In the example of FIGS. 1 and 3 , the each artificial muscle (351, 352) is arranged on the upper part and one end 301 side of the movable frame 30. The wires of each artificial muscle (351, 352) extend from here and are input to the third speed-increasing unit 34.

[0069] In this embodiment, the third speed-increasing unit 34 includes a third input pulley 341 and an endless third speed-increasing belt 343. The third input pulley 341 includes a coaxial third drive gear 342. The third input pulley 341 is arranged to face the same direction as the third output pulley 31. Similarly, the third output pulley 31 includes a coaxial third driven gear 311. The third drive gear 342 is arranged to face the third driven gear 311. The third speed-increasing belt 343 is stretched between the third drive gear 342 and the third driven gear 311. As long as the third speed-increasing belt 343 can be stretched between them, the positional relationship between the third drive gear 342 and the third driven gear 311 is not limited to this example and may be changed as appropriate depending on the embodiment. On the other hand, the positional relationship between the third input pulley 341 and the third output pulley 31 may be arbitrary. A pair of tensioners (348, 349) are provided above and below between the third drive gear 342 and the third driven gear 311. These tensioners (348, 349) maintain the tension of the third speed-up belt 343. Note that the method for maintaining the tension of the third speed-up belt 343 is not limited to this example, and may be changed as appropriate depending on the embodiment.

[0070] The diameter of the third drive gear 342 is larger than the diameter of the third driven gear 311. Other diameter relationships may be determined appropriately depending on the embodiment. For example, the diameter of the third driven gear 311 may be smaller than the diameter of the third output pulley 31. The diameter of the third drive gear 342 may be larger than the diameter of the third input pulley 341. Of the pair of artificial muscles (351, 352), the wire of one artificial muscle is wound around the third input pulley 341 from one direction, and its end is fixed to the third input pulley 341. Meanwhile, the wire of the other artificial muscle is wound around the third input pulley 341 from the other direction, and its end is fixed to the third input pulley 341. In this way, the third speed-up unit 34 increases the speed of movement of the third belt 33 in a manner similar to that of the first speed-up unit 14, etc.

[0071] The moving unit 40 is supported by the movable frame 30 and connected to the third belt 33. As a result, the moving unit 40 is configured to move along the movable frame 30 in accordance with the movement of the third belt 33. The method of connecting the moving unit 40 and the third belt 33 is not particularly limited and may be selected appropriately depending on the embodiment. An example of a method of connecting the moving unit 40 will be described later.

[0072] In this embodiment, the pair of artificial muscles (351, 352) of the third actuator 35 is an example of a variable stiffness actuator. The pair of artificial muscles (351, 352) acts in the same manner as the pair of artificial muscles (151, 152). Therefore, in this embodiment, impedance control in the second direction is possible using the third speed-up unit 34 of the movable frame 30, as in the first direction. By increasing the stiffness of each artificial muscle (351, 352), the moving unit 40 can be rigidly supported in the second direction, and the restoring force generated when the moving unit 40 deviates from the equilibrium point in the second direction can be increased. On the other hand, by decreasing the stiffness of each artificial muscle (351, 352), the moving unit 40 can be flexibly supported in the second direction, and the restoring force generated when the moving unit 40 deviates from the equilibrium point in the second direction can be reduced. The stiffness in the first and second directions may be controlled as appropriate.

[0073] In this embodiment, endless belts are used for each of the belts (13, 23, 33) and each of the speed-increasing belts (143, 243, 343). The endless belts may be produced by any method. In one example, the belts may be formed to be endless from the beginning. In another example, the endless belt may be formed by connecting the ends of a single belt. Furthermore, the shape of the belt is not particularly limited as long as it can achieve its respective purpose, and may be selected appropriately depending on the embodiment. In one example, the belts may include a general belt, a chain, and a wire.

[0074] (Supporting Portions) Fig. 4A is a perspective view schematically showing an example of the supporting portions of the movable frame 30 and the first fixed frame 10 according to this embodiment. Fig. 4B is a partial cross-sectional view schematically showing an example of the supporting portions of the movable frame 30 and the first fixed frame 10 (second fixed frame 20) according to this embodiment. Note that in Fig. 4B, the upper periphery of the first belt 13 is omitted.

[0075] In this embodiment, one end 301 of the movable frame 30 is supported by the first fixed frame 10 and connected to the first belt 13 via a connecting unit 36. The configuration of the connecting unit 36 ​​may be determined appropriately depending on the embodiment. In one example, the connecting unit 36 ​​includes a pair of first members 360, a second member 361, a slide unit 362, a third member 363, a fourth member 364, and a fifth member 365. Each first member 360 is formed in a flat plate shape. The pair of first members 360 are fixed to the lower side of the movable frame 30 in a state in which the one end 301 of the movable frame 30 is sandwiched between them. Each first member 360 extends slightly downward from the movable frame 30 and is fixed to one end of the second member 361. In this way, the pair of first members 360 connects the one end 301 of the movable frame 30 to the second member 361.

[0076] In this embodiment, the first belt 13 is disposed on the outer side of the first fixed frame 10 (i.e., the side opposite the movable frame 30). Accordingly, the second member 361 is formed in a flat plate shape and extends from one end 301 of the movable frame 30, passing under the first fixed frame 10, toward the outer side of the first fixed frame 10. The other end of the second member 361 is connected to a fourth member 364 via a flat plate-shaped third member 363. One end of the third member 363 is fixed to the other end of the second member 361, and the other end of the third member 363 is fixed to one end of the fourth member 364. The fourth member 364 is formed in a flat plate shape and extends from the other end of the third member 363, passing under the first belt 13 (lower periphery), to a position slightly outside the first belt 13. The other end of the fourth member 364 is fixed to a flat plate-shaped fifth member 365, with the first belt 13 sandwiched therebetween. As a result, one end 301 of the movable frame 30 is connected to the first belt 13 .

[0077] Furthermore, in this embodiment, the first fixing frame 10 has an internal space 190 with a generally rectangular cross section at its lower side, and this internal space 190 communicates with an external space via a groove 193 provided at the lower end of the first fixing frame 10. Each edge (191, 192) located in the width direction (second direction) of the groove 193 is bent inward, making the width of the groove 193 narrower than the width of the internal space 190. The internal space 190 and each edge (191, 192) form a linear guide. The slide unit 362 enters the internal space 190 from the underside of the first fixing frame 10 through the groove 193 and is supported by the first fixing frame 10 by being hooked onto each edge (191, 192), and slides using each edge (191, 192) as a track.

[0078] In one example, the slide unit 362 includes a base 3620, a pair of vertical wheels (3621, 3622), and a pair of horizontal wheels (3623, 3624). The lower end of the base 3620 is fixed to the second member 361. The length of the base 3620 in the width direction (the left-right direction in FIG. 4B ) is shorter than the groove 193, so that the base 3620 extends upward from the second member 361 and enters the internal space 190.

[0079] In the internal space 190, a pair of vertical wheels (3621, 3622) are rotatably connected to the base 3620 via axles in the width direction. The distance between the pair of vertical wheels (3621, 3622) (the length in the left-right direction in FIG. 4B ) is approximately the same as or wider than the width direction of the groove 193, allowing the slide unit 362 to hook onto each edge (191, 192). The thickness of each vertical wheel (3621, 3622) is approximately the same as or narrower than the width of the bent portion (track) of each edge (191, 192). The vertical wheels (3621, 3622) rotate using the upper ends of the edges (191, 192) as tracks, allowing the movable frame 30 to slide along the first fixed frame 10 via the slide unit 362.

[0080] Additionally, in the internal space 190, a pair of horizontal wheels (3623, 3624) are rotatably connected to the base 3620 in the width direction so as not to interfere with the vertical wheels (3621, 3622). The horizontal wheel 3623 is disposed near the inner wall surface on the edge 191 side of the first fixed frame 10. Meanwhile, the horizontal wheel 3624 is disposed near the inner wall surface on the edge 192 side of the first fixed frame 10. The pair of horizontal wheels (3623, 3624) abut against the inner wall surfaces in their respective directions, thereby being able to bear axial loads on the axes of the pair of vertical wheels (3621, 3622) that serve as guides. This allows the movable frame 30 to slide smoothly.

[0081] The configuration of the slide unit 362 may be modified as appropriate depending on the embodiment. For example, the number and arrangement of the vertical wheels (3621, 3622) and horizontal wheels (3623, 3624) are not limited to the example shown in FIG. 4B and may be modified as appropriate depending on the embodiment. Furthermore, for example, if a gap is formed between the base 3620 and the upper end surface of the internal space 190, one or more vertical wheels may be attached to the base 3620 to fill this gap. This allows the pair of vertical wheels (3621, 3622) to bear radial loads on their axes, thereby enabling the movable frame 30 to slide more smoothly. In this embodiment, the slide unit 362 supports one end 301 of the movable frame 30 on the first fixed frame 10 at approximately the same height as the first fixed frame 10.

[0082] FIG. 4C is a partial cross-sectional view schematically illustrating an example of the support portions of the movable frame 30 and the second fixed frame 20 according to this embodiment. Note that the upper periphery of the second belt 23 is omitted in FIG. 4C . In this embodiment, the other end 302 of the movable frame 30 is supported by the second fixed frame 20 and connected to the second belt 23 via a connecting unit 37. The configuration of the connecting unit 37 may be determined appropriately depending on the embodiment. In one example, the connecting unit 37 may have a configuration similar to that of the connecting unit 36. That is, the connecting unit 37 includes a pair of first members 370, a second member 371, a slide unit 372, a third member 373, a fourth member 374, and a fifth member 375. The pair of first members 370 connect the other end 302 of the movable frame 30 to the second member 371.

[0083] In this embodiment, the second belt 23 is disposed on the outer side of the second fixed frame 20 (i.e., the opposite side from the movable frame 30). Accordingly, the second member 371 extends from the other end 302 of the movable frame 30, passing under the second fixed frame 20, toward the outer side of the second fixed frame 20. The other end of the second member 371 is connected to the fourth member 374 via the third member 373. The fourth member 374 extends from the other end of the third member 373, passing under the second belt 23 (lower circumference), to a position slightly outside the second belt 23. The fourth member 374 is fixed to the fifth member 375 with the second belt 23 sandwiched therebetween. As a result, the other end 302 of the movable frame 30 is connected to the second belt 23.

[0084] Furthermore, in this embodiment, the second fixing frame 20 has an internal space 290 with a generally rectangular cross section at its lower side, and this internal space 290 communicates with an external space via a groove 293 provided at the lower end of the second fixing frame 20. Each edge (291, 292) located in the width direction of the groove 293 is bent inward, making the width of the groove 293 narrower than the width of the internal space 290. The slide unit 372 enters the internal space 290 from the underside of the second fixing frame 20 through the groove 293 and is supported by the second fixing frame 20 by being hooked onto each edge (291, 292), and is configured to slide using each edge (291, 292) as a track.

[0085] In one example, the slide unit 372 includes a base 3720, a pair of vertical wheels (3721, 3722), and a pair of horizontal wheels (3723, 3724). The lower end of the base 3720 is fixed to the second member 371. The length of the base 3720 in the width direction is shorter than the groove 293, so that the base 3720 extends upward from the second member 371 and enters the internal space 290.

[0086] In the internal space 290, a pair of vertical wheels (3721, 3722) are rotatably connected to the base 3720 in the width direction via a shaft. The pair of vertical wheels (3721, 3722) are configured similarly to the pair of vertical wheels (3621, 3622). The slide unit 372 is hooked onto each edge (291, 292) by the pair of vertical wheels (3721, 3722). The vertical wheels (3721, 3722) rotate using the upper ends of the edges (291, 292) as tracks, allowing the movable frame 30 to slide along the second fixed frame 20 via the slide unit 372.

[0087] Additionally, in the internal space 290, a pair of horizontal wheels (3723, 3724) are rotatably connected to the base 3720 in the width direction so as not to interfere with the vertical wheels (3721, 3722). The horizontal wheel 3723 is disposed near the inner wall surface on the edge 291 side of the second fixed frame 20. Meanwhile, the horizontal wheel 3724 is disposed near the inner wall surface on the edge 292 side of the second fixed frame 20. The pair of horizontal wheels (3723, 3724) abut against the inner wall surfaces in their respective directions, thereby being able to bear axial loads on the axes of the pair of vertical wheels (3721, 3722) that serve as guides. This allows the movable frame 30 to slide smoothly.

[0088] The configuration of the slide unit 372 may be modified as appropriate depending on the embodiment. For example, the number and arrangement of the vertical wheels (3721, 3722) and horizontal wheels (3723, 3724) are not limited to the example shown in FIG. 4C and may be modified as appropriate depending on the embodiment. Furthermore, for example, if a gap is formed between the base 3720 and the upper end surface of the internal space 290, one or more vertical wheels may be attached to the base 3720 to fill this gap. This allows the pair of vertical wheels (3721, 3722) to bear radial loads on their axes, thereby enabling the movable frame 30 to slide more smoothly. Other components of the coupling unit 37 may be configured similarly to the components of the coupling unit 36. In this embodiment, the slide unit 372 supports the other end 302 of the movable frame 30 on the second fixed frame 20 at approximately the same height as the second fixed frame 20.

[0089] 5A and 5B are a perspective view and a partial cross-sectional view, respectively, illustrating an example of the moving unit 40 according to this embodiment. In this embodiment, the moving unit 40 includes a pair of base units (41, 42), a rotation unit 43, a slide unit 45, and a connecting unit 46.

[0090] The pair of base portions (41, 42) are an example of a base portion of the present disclosure. The pair of base portions (41, 42) have cavities (410, 420) that open in the vertical direction. The rotation unit 43 is configured to rotate around the periphery of the cavities (410, 420) in the vertical direction. Rotation around the vertical direction corresponds to rotation around the vertical direction as the rotation axis. Note that the rotation axis may be tilted from the vertical direction depending on the sway of the movement unit 40, etc. Rotation around the vertical direction may include rotation around such a rotation axis tilted from the vertical direction. The rotation unit 43 includes a first movement portion 434 and a second movement portion 435. The first movement portion 434 is disposed outside the cavities (410, 420) and configured to rotate around the vertical direction in response to rotation of the rotation unit 43. The first movement portion 434 includes a first holding portion 436. The second moving part 435 is disposed outside the cavities (410, 420) and spaced apart from the first moving part 434 in the vertical direction, and is configured to rotate and move in the vertical direction in response to rotation of the rotation unit 43 while maintaining its positional relationship with the first moving part 434. The second moving part 435 includes a second holding part 437. Such a rotation unit 43 may be configured appropriately depending on the embodiment.

[0091] In one example, the rotation unit 43 further includes a central portion 431, a first arm portion 432, and a second arm portion 433. In this embodiment, each of the portions 431 to 435 of the rotation unit 43 is formed in a flat plate shape and has a bent shape at each arm portion (432, 433). The central portion 431 is supported by a pair of base portions (41, 42) so as to be rotatable around the vertical direction. In this embodiment, the upper base portion 41 is formed in a cylindrical shape. The lower base portion 42 has a circular shape with a larger diameter than the upper base portion 41, and has a shape in which the diameter remains constant as it moves downward, then decreases once, and then increases again. The central portion 431 is supported by the pair of base portions (41, 42) by being rotatably sandwiched between the upper base portion 41 and the lower base portion 42. The central portion 431 also has a hollow portion 430 that opens in the vertical direction. The hollow portion 430 communicates with the cavities (410, 420) of the pair of base portions (41, 42).

[0092] A thrust bearing may be disposed between the central portion 431 and the lower base portion 42. The thrust bearing can support the axial load on the rotation shaft of the rotating unit 43. This allows the rotating unit 43 to rotate smoothly. A hollow shaft may be provided in the central portion 431, and a radial bearing may be disposed on the hollow shaft. The radial bearing also allows the rotating unit 43 to rotate smoothly.

[0093] In the example of FIG. 5B , the first arm 432 has a shape that extends obliquely vertically downward from the central portion 431. The first arm 432 is configured to connect the central portion 431 and the first moving portion 434. Note that the extending direction of the first arm 432 is not limited to this example. In another example, the first arm 432 may have a shape that extends vertically downward from the central portion 431. Similarly, the second arm 433 has a shape that extends obliquely vertically downward from the central portion 431. The second arm 433 is configured to connect the central portion 431 and the second moving portion 435. The extending direction of the second arm 433 is not limited to this example. In another example, the second arm 433 may have a shape that extends vertically downward from the central portion 431. Furthermore, the extending shape of each arm (432, 433) may include an at least partially curved shape. In this embodiment, the first moving portion 434 and the second moving portion 435 are connected via the central portion 431 and each arm portion (432, 433) and are configured to rotate in response to the rotation of the central portion 431. This allows the first moving portion 434 and the second moving portion 435 to rotate while maintaining a state of being spaced apart in the vertical direction. The positional relationship between the first moving portion 434 and the second moving portion 435 is not particularly limited and may be determined appropriately depending on the embodiment. In one example, the first moving portion 434 and the second moving portion 435 may be arranged to be spaced apart at a positional relationship of 180 degrees in the circumferential direction.

[0094] In this embodiment, the movable frame 30 has a U-shaped groove 385 on its upper side. The upper end of the groove 385 is open (open). An L-shaped bracket 38 is attached to the side wall of the upper side of the movable frame 30, opposite the third belt 33. One or more linear structures of devices to be attached to the mobile unit 40 can be placed in the groove 385 and the bracket 38. The type of linear structure is not particularly limited and may be selected appropriately depending on the embodiment. The linear structure may include cables, tubes, harnesses, other wired or piped objects, or combinations of these. Examples of cables include Bowden cables, power cables, signal lines, and communication cables. Examples of tubes include air tubes.

[0095] The upper base portion 41 is provided with a pair of guide portions (441, 442). The guide portion 441 extends from the side wall of the upper base portion 41 on the groove 385 side toward the movable frame 30 and is configured to draw a linear structure placed in the groove 385 toward the upper base portion 41. The guide portion 442 extends from the side wall of the upper base portion 41 on the bracket 38 side toward the movable frame 30 and is configured to draw a linear structure placed on the bracket 38 toward the upper base portion 41. The pair of base portions (41, 42) are configured to supply one or more linear structures drawn in by the pair of guide portions (441, 442) vertically downward through the cavities (410, 420) from above. In this embodiment, one or more linear structures are supplied from above to below the moving unit 40 by passing through the cavity 410 of the upper base portion 41, the hollow portion 430 of the central portion 431, and the cavity 420 of the lower base portion 42 in this order. Note that the pair of guide portions (441, 442) may be omitted. In this case, the one or more linear structures may be directly drawn into the pair of base portions (41, 42).

[0096] In one example, a plurality of linear structures may be supplied vertically below the moving unit 40 by a pair of base portions (41, 42). In this case, the plurality of linear structures may include a first linear structure and a second linear structure. The first holding portion 436 of the first moving portion 434 may be configured to hold a first end of a curl formed when the first linear structure hangs vertically downward from the cavities (410, 420) and then is wound vertically upward. The first linear structure may hang further vertically downward from the first end. Similarly, the second holding portion 437 of the second moving portion 435 may be configured to hold a second end of a curl formed when the second linear structure hangs vertically downward from the cavities (410, 420) and then is wound vertically upward. The second linear structure may hang further vertically downward from the second end. The configuration of each of the holding parts (436, 437) is not particularly limited as long as it is capable of holding (restraining) a linear structure, and may be appropriately selected depending on the embodiment. Each of the holding parts (436, 437) may be configured, for example, by a bolt that holds a wire.

[0097] In this embodiment, the cavities (410, 420) are provided in the pair of base portions (41, 42), allowing multiple linear structures to be supplied in a concentrated state below the moving unit 40. This makes it easier to handle multiple linear structures. Furthermore, in the rotating unit 43, the first moving portion 434 and the second moving portion 435 are arranged spaced apart in the circumferential direction. After forming a curl, the first linear structure and the second linear structure are held by the first moving portion 434 and the second moving portion 435 and handled so as to hang down vertically downward. Since the first moving portion 434 and the second moving portion 435 are spaced apart, the first linear structure and the second linear structure can be maintained spaced apart. In addition, even when the rotating unit 43 rotates vertically, each linear structure has a slack corresponding to the curled portion (i.e., the curled portion is unwound by rotation), so the portions hanging down from the moving portions (434, 435) can rotate while maintaining a spaced apart state. Therefore, according to this embodiment, a plurality of linear structures can be supplied below the moving unit 40 in a spaced-apart state, and the spaced-apart state can be maintained even when the linear structures rotate around the vertical direction.

[0098] Furthermore, in this embodiment, each moving part (434, 435) is disposed below the rotating part (central part 431) of the rotation unit 43. This allows one of the pair of moving parts (434, 435) to function as a stopper when the other part shifts. For example, if the rotation unit 43 shifts toward the first moving part 434, the inner walls of the second arm part 433 and the second moving part 435 come into contact with the lower base part 42, thereby preventing the rotation unit 43 from shifting. In addition, the "Yajirobe" effect can increase the stability of the rotation of the rotation unit 43.

[0099] 1 , 3 and 5A , in one example of this embodiment, a load-relieving device 60 may be attached to the mobile unit 40. The load-relieving device 60 includes a pair of artificial muscles (601, 602), a pair of wires (603, 604), and a pair of attachments (606, 607). One of the pair of wires (603, 604) is an example of a first linear structure of the load-relieving device 60, and the other is an example of a second linear structure of the load-relieving device 60.

[0100] A user W of this load-relief device 60 wears a pair of attachments (606, 607) on the left and right. The artificial muscle 601 transmits a load-relief force to the attachment 606 via a wire 603. The artificial muscle 602 transmits a load-relief force to the attachment 607 via a wire 604. This allows the load-relief device 60 to relieve at least part of the weight of the user W. As with the artificial muscles (151, 152), the type of the artificial muscles (601, 602) is not particularly limited and may be selected appropriately depending on the embodiment. In a typical example, the artificial muscles (601, 602) may be pneumatic artificial muscles. The wires (603, 604) may be, for example, Bowden cables.

[0101] The drive source of the load-relieving device 60 may be selected appropriately depending on the embodiment. In one example, when each artificial muscle (601, 602) is a pneumatic artificial muscle, the load-relieving device 60 may include a compressor and an air valve. The compressor may be connected to the air valve, and the air pressure inside the pneumatic artificial muscle may be adjusted by opening and closing the air valve. The load-relieving device 60 may further include a control device configured to control the operation of each artificial muscle (601, 602). The compressor, air valve, and control device may be appropriately arranged to drive the pair of artificial muscles (601, 602). In this case, the control device can adjust the load-relieving force of each artificial muscle (601, 602) by controlling the opening and closing of the air valve. The configuration of the load-relieving device 60 is not particularly limited and may be selected appropriately depending on the embodiment. For example, a known configuration such as that described in Patent Document 1 may be adopted for the load-relieving device 60. The type of each artificial muscle (601, 602) may be selected arbitrarily.

[0102] In this embodiment, the routing of the moving unit 40 and the rotating unit 43 described above may be adopted for the pair of wires (603, 604) in this load-relieving device 60. In one example, the pair of artificial muscles (601, 602) may be arranged at the upper end of the one end 301 side of the movable frame 30, similar to the third actuator 35. The wires (603, 604) extending from the artificial muscles (601, 602) are extended toward the other end 302 within the groove 385 and bracket 38 on the upper end side of the movable frame 30, and then folded back and routed toward the moving unit 40. This makes it possible to secure the payout portion of each wire (603, 604) for movement of the moving unit 40 on the upper end side of the movable frame 30. In the example of FIG. 5B , the wire 603 is arranged in the bracket 38, and the wire 604 is arranged in the groove 385. 5B, cable bearings (CB1, CB2) may be attached to portions of the wires (603, 604) routed around the upper end of the movable frame 30 in order to improve followability to the movement of the moving unit 40. Each guide portion (441, 442) may be configured to pull in a linear structure from the tip of each cable bearing (CB1, CB2).

[0103] The pair of wires (603, 604) may be routed toward the moving unit 40 and then drawn toward the upper base portion 41 via the pair of guide portions (441, 442). After being drawn toward the upper base portion 41, the pair of wires (603, 604) may pass through the cavity 410 of the upper base portion 41, the hollow portion 430 of the central portion 431, and the cavity 420 of the lower base portion 42, in that order, and be supplied below the moving unit 40.

[0104] One of the pair of wires (603, 604) may hang vertically downward from the cavity 420 and then be routed vertically upward to form a curl, and the end of the curl formed on the one wire may be held by the first holding portion 436 of the first moving portion 434. This curled end is an example of a first end. One of the wires may hang further vertically downward from the curled end toward either the left or right side of the user W of the unloading device 60. Similarly, the other wire may hang vertically downward from the cavity 420 and then be routed vertically upward to form a curl, and the end of the curl formed on the other wire may be held by the second holding portion 437 of the second moving portion 435. This curled end is an example of a second end. The other wire may hang further vertically downward from the curled end toward the other of the left or right side of the user W of the unloading device 60.

[0105] In the examples of FIGS. 3 and 5A , the wire 603 hangs vertically downward from the cavity 420 and then is routed vertically upward, forming a curl 6031, and the end of the formed curl 6031 is held by the first holding portion 436. The wire 603 further hangs vertically downward from the end of the curl 6031 and is connected to the wearing device 606 on the right side of the user W. Meanwhile, the wire 604 hangs vertically downward from the cavity 420 and is routed vertically upward, forming a curl 6041, and the end of the formed curl 6041 is held by the second holding portion 437. The wire 604 further hangs vertically downward from the end of the curl 6041 and is connected to the wearing device 607 on the left side of the user W. Each holding portion (436, 437) may hold the end of the curled portion of each wire (603, 604) while maintaining the curls (6031, 6041). In this embodiment, the pair of wires (603, 604) of the weight-relieving device 60 are supplied to the user W in a spaced-apart state, and the spaced-apart state can be maintained even when the user W rotates around the vertical direction. Therefore, even when the user W rotates, the wearing state of each wearing device (606, 607) can be maintained. This improves the wearability of the weight-relieving device 60.

[0106] Hanging (hanging down) vertically means hanging down at a lower position in the vertical direction. Hanging (hanging down) vertically may include at least a portion extending linearly downward in the vertical direction, hanging at an angle in the vertical direction, hanging in a curved manner in the vertical direction, etc. The hanging shape of the linear structure is not particularly limited. Wrapping vertically upward means wrapping so as to raise the position in the vertical direction. Wrapping vertically may include at least a portion extending linearly upward in the vertical direction, extending at an angle in the vertical direction, extending in a curved manner in the vertical direction, etc. The shape of the linear structure wrapped vertically upward is not particularly limited. Wrapping vertically upward may include a portion hanging down vertically. Furthermore, as long as the curled portion constitutes an excess portion for rotation of the rotation unit 43, its shape is not limited to the shapes exemplified in FIGS. 1 , 3 , and 5A and may be modified as appropriate depending on the embodiment. In one example, the curled portion may have a shape that is wound multiple times.

[0107] (Coupling Portion) In this embodiment, the third belt 33 is disposed on the outer side of the movable frame 30 (the right side in FIG. 5B ). Accordingly, the connecting portion 46 includes a first member 461 and a second member 462. One end of the first member 461 is fixed to the upper end of the upper base portion 41. The first member 461 is formed in a flat plate shape and extends from the upper base portion 41, passing under the third belt 33, to a position slightly outside the third belt 33. The other end of the first member 461 is fixed to the flat plate-shaped second member 462 with the third belt 33 sandwiched therebetween. In this way, the moving unit 40 is connected to the third belt 33.

[0108] Furthermore, in this embodiment, the movable frame 30, like the first fixed frame 10, has an internal space 390 with a generally rectangular cross section at its lower side. A partition is provided between this internal space 390 and the groove 385 on the upper side, thereby preventing the internal space 390 from communicating with the groove 385. Meanwhile, the internal space 390 communicates with the external space via a groove 393 provided at the lower end of the movable frame 30. The edges (391, 392) of the groove 393 in the width direction are bent inward, making the width of the groove 393 narrower than the width of the internal space 390. The slide unit 45 enters the internal space 390 from the lower side of the movable frame 30 through the groove 393 and is supported by the movable frame 30 by being hooked onto the edges (391, 392), while sliding along the edges (391, 392) as tracks.

[0109] In one example, the slide unit 45 may be configured similarly to the slide units (362, 372) described above. That is, the slide unit 45 includes a base 450, a pair of vertical wheels (451, 452), and a pair of horizontal wheels (453, 454). The lower end of the base 450 is fixed to the upper end of the upper base portion 41. The length of the base 450 in the width direction is shorter than the groove 393, so that the base 450 extends upward from the upper base portion 41 and enters the internal space 390.

[0110] In the internal space 390, a pair of vertical wheels (451, 452) are rotatably connected to the base 450 via a shaft in the width direction. The pair of vertical wheels (451, 452) may be configured similarly to the pair of vertical wheels (3621, 3622) (3721, 3722). The slide unit 45 is hooked onto each edge (391, 392) by the pair of vertical wheels (451, 452). The vertical wheels (451, 452) rotate and move using the upper ends of the edges (391, 392) as tracks, allowing the moving unit 40 to slide along the movable frame 30 via the slide unit 45.

[0111] Additionally, in the internal space 390, a pair of horizontal wheels (453, 454) are rotatably connected to the base 450 in the width direction so as not to interfere with the vertical wheels (451, 452). The horizontal wheel 453 is disposed near the inner wall surface on the edge 391 side of the movable frame 30. Meanwhile, the horizontal wheel 454 is disposed near the inner wall surface on the edge 392 side of the movable frame 30. The pair of horizontal wheels (453, 454) abut against the inner wall surfaces in their respective directions, thereby being able to bear axial loads on the axes of the pair of vertical wheels (451, 452) that act as guides. This allows the moving unit 40 to slide smoothly.

[0112] The configuration of the slide unit 45 may be modified as appropriate depending on the embodiment. For example, the bottom view and arrangement of the vertical wheels (451, 452) and horizontal wheels (453, 454) are not limited to the example shown in FIG. 5B and may be modified as appropriate depending on the embodiment. Furthermore, for example, if a gap is formed between the base 450 and the upper end surface of the internal space 390, one or more vertical wheels may be attached to the base 450 to fill this gap. This allows the radial load on the axes of the pair of vertical wheels (451, 452) to be received, thereby enabling the moving unit 40 to slide more smoothly. In this embodiment, the moving unit 40 is supported on the moving frame 30 below the moving frame 30 by the slide unit 45.

[0113] [Artificial Muscle] FIG. 6 schematically shows an example of the overall configuration of an artificial muscle 500 according to this embodiment. The example in FIG. 6 assumes a situation in which pneumatic artificial muscle is used as the artificial muscle 500. The artificial muscle 500 according to this embodiment includes a chamber 501, a pair of ends (502, 503), a pipe cylinder 504, a wire 505, a stopper 506, and an elastic member 507. The chamber 501 is made of a flexible material. The chamber 501 is filled with compressed air, and the air pressure is converted into tension in the artificial muscle 500. The pair of ends (502, 503) seal the chamber 501 from the outside. A supply port 509 is provided in the lower end 503, and the supply port 509 is connected to an air valve. The air valve is connected to a compressor. When the air valve is opened, compressed air is supplied into the chamber 501 via the supply port 509. The pipe cylinder 504 is connected to the end 502 so that the atmospheric pressure in the pipe cylinder 504 and the air pressure in the chamber 501 are sealed.

[0114] The wire 505 extends from the lower end inside the pipe cylinder 504 to the outside via the upper end 502. The wire 505 is used to output driving force to the outside. The stopper 506 is configured to transmit driving force to the wire 505 when the artificial muscle 500 contracts in the direction of pulling the wire 505. In one example, the stopper 506 is attached to the end 502 side of the wire 505 and is formed larger than the through-hole of the wire 505. When the artificial muscle 500 contracts in the direction of pulling the wire 505, the stopper 506 engages the underside of the end 502, thereby transmitting the contractile force of the artificial muscle 500 to the wire 505. The elastic member 507 is configured to maintain the tension of the wire 505 when the artificial muscle 500 relaxes and the stopper 506 is released. The type of elastic member 507 is not particularly limited and may be selected appropriately depending on the embodiment. The elastic member 507 may be, for example, a spring. The configuration of the artificial muscle 500 may be changed as appropriate depending on the embodiment. Other known configurations of the artificial muscle 500 may be adopted, for example, as described in Patent Document 2. For example, the portion of the wire 505 that is exposed from the end 502 may be covered with a sleeve or the like. Furthermore, the artificial muscle 500 may be configured so that the contraction rate can be measured by any method, such as a scaler and encoder.

[0115] In the above embodiment, the artificial muscles 500 in FIG. 6 may be used as the artificial muscles (151, 152) of the first actuator 15. In this case, the artificial muscles 500 in the above description may be replaced with the artificial muscles (151, 152). The driving force of the artificial muscles (151, 152) is input to the first speed-up unit 14 via a wire 505. Similarly, the artificial muscles 500 in FIG. 6 may be used as the artificial muscles (251, 252) of the second actuator 25. In this case, the artificial muscles 500 in the above description may be replaced with the artificial muscles (251, 252). The driving force of the artificial muscles (251, 252) is input to the second speed-up unit 24 via a wire 505. The artificial muscles 500 in FIG. 6 may be used as the artificial muscles (351, 352) of the third actuator 35. The artificial muscle 500 in the above description may be replaced with each of the artificial muscles (351, 352). The driving force of each of the artificial muscles (351, 352) is input to the third speed-increasing unit 34 via a wire 505.

[0116] In this artificial muscle 500, when the wire 505 is stretched, the movement of the wire 505 is stopped by the action of the stopper 506. On the other hand, when the wire is pulled back, the stopper 506 is released, allowing the wire 505 to move freely, and the tension of the wire 505 is maintained by the elastic member 507. This allows the wire 505 to be moved freely by hand within a certain range. By using the artificial muscles 500 as the artificial muscles (151, 152) of the first actuator 15, it is possible to set the range in which the movable frame 30 can move freely in the first direction. The same applies when the artificial muscles 500 are used as the artificial muscles (251, 252) of the second actuator 25. Furthermore, by using the artificial muscles 500 as the artificial muscles (351, 352) of the third actuator 35, it is possible to set the range in which the moving unit 40 can move freely in the second direction. The artificial muscles 500 may also be used for the artificial muscles (601, 602) of the load-relieving device 60.

[0117] [Controller] As shown in Fig. 1, in this embodiment, a controller 70 is used to control the operation of each of the actuators (15, 25, 35). The controller 70 is one or more computers configured to control the operation of each of the actuators (15, 25, 35). In one example, a different computer may be used as the controller 70 for each of the actuators (15, 25, 35). In another example, the same computer may be used as the controller 70 for at least two combinations of the three actuators (15, 25, 35).

[0118] The control device 70 may appropriately control the operation of each actuator (15, 25, 35). Controlling may include directly controlling each actuator (15, 25, 35) and indirectly controlling each actuator (15, 25, 35) via an external device such as a controller. The control device 70 may be directly or indirectly connected to each actuator (15, 25, 35). Indirect connection means connection via an external device such as another computer.

[0119] Furthermore, the operation criteria for each of the actuators (15, 25, 35) may be determined as appropriate depending on the embodiment. The control device 70 may acquire information, determine the operation of each of the actuators (15, 25, 35) based on the acquired information, and control each of the actuators (15, 25, 35) to perform the determined operation.

[0120] In one example, the sensor SE may be used to observe an object (e.g., a user W of the load-relieving device 60, etc.) related to the mobile unit 40. The type of sensor SE may be selected appropriately depending on the observation content. The control device 70 may be directly or indirectly connected to the sensor SE. The control device 70 may acquire observation data (measurement data) of the object from the sensor SE and analyze the acquired observation data as appropriate. The control device 70 may control the operation of each actuator (15, 25, 35) depending on the obtained analysis results.

[0121] As a specific example, in the case where the above-described weight-relieving device 60 is used, the control device 70 may measure the position of the user W using the sensor SE. Then, the control device 70 may control the operation of each actuator (15, 25, 35) according to the position measurement result. In this case, a sensor capable of measuring the position, such as an image sensor (camera), may be used as the sensor SE. The sensor SE may be held by the user W, or may be arranged so as to observe the user W from outside.

[0122] The method for driving each actuator (15, 25, 35) may be selected as appropriate depending on the type of each actuator (15, 25, 35), etc. As a typical example, when the artificial muscle 500 (pneumatic artificial muscle) shown in FIG. 6 is used for each actuator (15, 35, 35), the control device 70 may be connected to an air valve. The control device 70 can control the driving force of each actuator (15, 25, 35) by controlling the opening and closing of the air valve.

[0123] (Hardware Configuration) Fig. 7 schematically shows an example of the hardware configuration of the control device 70 according to this embodiment. In the example shown in Fig. 7, the control device 70 according to this embodiment is a computer to which a control unit 71, a storage unit 72, an external interface 73, an input device 74, an output device 75, and a drive 76 are electrically connected.

[0124] The control unit 71 includes a hardware processor such as a central processing unit (CPU), a random access memory (RAM), and a read-only memory (ROM), and is configured to execute information processing based on programs and various data. The control unit 71 (CPU) is an example of a processor resource.

[0125] The storage unit 72 may be configured, for example, with a hard disk drive, a solid state drive, a semiconductor memory, or the like. The storage unit 72 (and RAM, ROM) are examples of memory resources. In this embodiment, the storage unit 72 stores various information such as a program 87. The program 87 is a program for causing the control device 70 to execute information processing (see FIG. 9 , etc., described below) related to the control of each actuator (15, 25, 35). The program 87 includes a series of instructions for the information processing.

[0126] The external interface 73 may be, for example, a Universal Serial Bus (USB) port, a dedicated port, or the like, and is configured to connect to an external device via a wired or wireless connection. The external interface 73 may include, for example, a communication interface such as a wired Local Area Network (LAN) module or a wireless LAN module. The type and number of external interfaces 73 may be selected arbitrarily. In this embodiment, the control device 70 may be connected to each of the actuators (15, 25, 35) and the sensor SE.

[0127] The input device 74 is a device for inputting, for example, a mouse, a keyboard, an operator, etc. The output device 75 is a device for outputting, for example, a display, a speaker, etc. An operator can operate the control device 70 by using the input device 74 and the output device 75. The input device 74 and the output device 75 may be integrated into one device, for example, a touch panel display, etc.

[0128] The drive 76 is a device for reading various information, such as a program, stored in a storage medium 97. The program 87 may be stored in the storage medium 97 instead of or together with the storage unit 72. The storage medium 97 is configured to store various information (such as the stored program) by electrical, magnetic, optical, mechanical, or chemical action so that a machine such as a computer can read the information. The control device 70 may obtain the program 87 from the storage medium 97. The storage medium 97 may be a disk-type storage medium such as a CD or DVD, or a non-disk-type storage medium such as a semiconductor memory (e.g., a flash memory). The type of the drive 76 may be selected appropriately depending on the type of the storage medium 97.

[0129] Note that, with regard to the specific hardware configuration of the control device 70, components may be omitted, replaced, or added as appropriate depending on the embodiment. For example, the control unit 71 may include multiple hardware processors. The type of hardware processor is not particularly limited and may be selected as appropriate depending on the embodiment. The storage unit 72 may be configured with RAM and ROM included in the control unit 71. At least one of the external interface 73, the input device 74, the output device 75, and the drive 76 may be omitted. The control device 70 may be configured with multiple computers. In this case, the hardware configurations of the computers may or may not be the same. Furthermore, the control device 70 may be an information processing device designed specifically for the service provided, as well as a general-purpose PC (Personal Computer), a tablet PC, a mobile terminal (including a smartphone), etc.

[0130] (Software Configuration) Fig. 8 schematically shows an example of the software configuration of the control device 70 according to this embodiment. The control unit 71 of the control device 70 loads a program 87 stored in the storage unit 72 into RAM and executes instructions included in the program 87 using the CPU. As a result, the control device 70 according to this embodiment operates as a computer including an information acquisition unit 711 and a drive unit 712 as software modules. That is, in this embodiment, each software module of the control device 70 is realized by the control unit 71 (CPU).

[0131] The information acquisition unit 711 is configured to acquire information. The acquired information is not particularly limited and may be appropriately selected depending on the embodiment. For example, the acquired information may be observation data of the sensor SE, analysis results of the observation data, input data via the input device 74, etc. The drive unit 712 is configured to control the operation of each actuator (15, 25, 35) according to the acquired information.

[0132] Each software module of the control device 70 will be described in detail in the operation example below. In this embodiment, an example is described in which each software module of the control device 70 is implemented by a general-purpose CPU. However, some or all of the above software modules may be implemented by one or more dedicated processors. Each of the above modules may be implemented as a hardware module. Furthermore, with regard to the software configuration of the control device 70, software modules may be omitted, replaced, or added as appropriate depending on the embodiment.

[0133] §2 Operation Example FIG. 9 is a flowchart showing an example of the processing procedure of the control device 70 according to this embodiment. The processing procedure of the control device 70 described below is an example of a control method (information processing method). However, the processing procedure described below is merely an example, and each step may be modified as much as possible. Furthermore, steps may be omitted, replaced, or added to the processing procedure below as appropriate depending on the embodiment. Note that the example of FIG. 9 assumes a situation in which a frame system ST is used for the above-mentioned load-relieving device 60, and a configuration is adopted in which the operation of each actuator (15, 25, 35) is controlled according to the position of the user W of the load-relieving device 60.

[0134] In step S101, the control unit 71 operates as the information acquisition unit 711 and acquires measurement data of the position of the user W from the sensor SE. As long as the position of the user W can be identified, the type of sensor SE and the type of measurement data are not particularly limited and may be selected appropriately depending on the embodiment. The data acquired by the sensor SE may be the measurement data itself, or the measurement data may be obtained by performing any information processing (analysis processing) on ​​the data acquired by the sensor SE. In one example, the sensor SE may be an image sensor (camera). The image sensor may be appropriately positioned to capture an image of the range within which the mobile unit 40 can move. The control unit 71 may acquire a captured image from the image sensor and perform an analysis processing to detect the user W from the captured image, thereby acquiring a measurement result (measurement data) of the position of the user W. After acquiring the position measurement result, the control unit 71 proceeds to the next step S102.

[0135] In step S102, the control unit 71 operates as a drive unit 712 and controls the operation of each actuator (15, 25, 35) according to the measured position of the user W. In this embodiment, the effect of acceleration by each actuator (15, 25, 35) can be changed by setting the equilibrium position (equilibrium point BP, point TO) of each artificial muscle (151, 152) (251, 252) (351, 352) relative to the position of the user W.

[0136] In one example, the control unit 71 may drive the actuators (15, 25, 35) so that the equilibrium position of each artificial muscle (151, 152) (251, 252) (351, 352) follows the measured position of the user W. In other words, the equilibrium position of each artificial muscle (151, 152) (251, 252) (351, 352) may be set to be the same as the position of the user W. This makes it possible to cause the movable frame 30 and the moving unit 40 to follow the position of the user W while reducing the load acting on the user W from the movable frame 30 and the moving unit 40.

[0137] In another example, the control unit 71 may drive each actuator (15, 25, 35) so as to displace the balance position of each artificial muscle (151, 152) (251, 252) (351, 352) in the guiding direction from the measured position of the user W. The direction in which the balance position is shifted relative to the position of the user W corresponds to the guide direction. Furthermore, the amount by which the balance position is shifted relative to the position of the user W corresponds to the value obtained by dividing the guide force by the spring constant. The guide direction (target) and guide force may be specified by any method, such as input by an operator. In this way, by using the load acting on the user W from the movable frame 30 and the moving unit 40 to guide the user W, the weight of the movable frame 30 and the moving unit 40 is less likely to act as a load, and the guide force can improve the mobility of the user W.

[0138] The control unit 71 can move the position of balance while maintaining rigidity by increasing the force of one of the pair of artificial muscles (151, 152) (251, 252) (351, 352) and decreasing the force of the other artificial muscle. The control unit 71 can also increase the force supporting the user W by increasing the rigidity of each artificial muscle (151, 152) (251, 252) (351, 352). On the other hand, the control unit 71 can decrease the force supporting the user W by decreasing the rigidity of each artificial muscle (151, 152) (251, 252) (351, 352). After controlling the operation of each actuator (15, 25, 35), the control unit 71 proceeds to the next step S103.

[0139] In step S103, the control unit 71 determines whether to terminate the control of each actuator (15, 25, 35). The determination criteria may be set arbitrarily. In one example, after the control device 70 is started and a control start operation is performed via the input device 74, the control unit 71 may determine not to terminate the control of each actuator (15, 25, 35) until an instruction to terminate is given. On the other hand, when an instruction to terminate is given (e.g., a user operation via the input device 74), the control unit 71 may determine to terminate the control of each actuator (15, 25, 35). If it is determined not to terminate the control, the control unit 71 returns to step S101 and executes the process again from step S101. On the other hand, if it is determined to terminate the control, the control unit 71 terminates the processing procedure of the control device 70 according to this operation example.

[0140] §3 Features As described above, in this embodiment, the first stationary frame 10 is provided with the first speed-increasing unit 14. The first speed-increasing unit 14 can increase the movement speed of the first belt 13 by outputting the driving force of the first actuator 15 to the first output pulley 11. The movable frame 30 is connected to this first belt 13. Therefore, the speed-increasing effect of the first speed-increasing unit 14 can be transmitted to the movable frame 30 via the first belt 13, thereby improving the mobility of the movable frame 30. In step S102, the speed-increasing effect of the first speed-increasing unit 14 is used in a tracking or guiding manner, making it difficult for the load of the movable frame 30 to act as a load and facilitating the movement of the movable frame 30 in the first direction. Therefore, this embodiment can improve the mobility of the movable frame 30 in the frame system ST. In one example of this embodiment, the mobility of the movable frame 30 can be improved when using the load-relieving device 60.

[0141] Furthermore, in this embodiment, by providing the second speed-up unit 24 also on the second fixed frame 20, it is possible to transmit the speed-up force via the belts (13, 23) to both ends (301, 302) of the movable frame 30. This makes it possible to suppress the generation of load in the rotational direction when transmitting the speed-up force from each belt (13, 23) to each end (301, 302) of the movable frame 30, and as a result, it is possible to improve the mobility of the movable frame 30.

[0142] In addition, in this embodiment, by providing the third speed increasing unit 34 also on the movable frame 30, the mobility of the moving unit 40 in the second direction can be increased.

[0143] Furthermore, in this embodiment, impedance control in the first direction is possible by using a variable stiffness actuator as the first actuator 15. The same applies when a variable stiffness actuator is used as the second actuator 25. Impedance control in the second direction is possible by using a variable stiffness actuator as the third actuator 35.

[0144] Furthermore, in this embodiment, the first actuator 15 is composed of a pair of artificial muscles (151, 152). Artificial muscles can continuously output a relatively large force with low energy. Therefore, energy consumption when maintaining a state in the first direction can be reduced. Furthermore, the more an artificial muscle contracts, the weaker its force becomes. Therefore, the output decreases when the movable frame 30 reaches the end, and the force with which the movable frame 30 hits the end can be reduced. The same applies when the second actuator 25 is composed of a pair of artificial muscles (251, 252). By configuring the third actuator 35 with a pair of artificial muscles (351, 352), energy consumption when maintaining a state in the second direction can be reduced. Furthermore, the force with which the moving unit 40 hits the end can be reduced.

[0145] Furthermore, the output of fluid-pressure artificial muscles can be easily adjusted. Therefore, in this embodiment, by using fluid-pressure artificial muscles for each of the artificial muscles (151, 152), it is possible to easily build a system. The same applies when fluid-pressure artificial muscles are used for each of the artificial muscles (251, 252) (351, 352).

[0146] §4 Modifications Although the embodiments of the present invention have been described above in detail, the above description is merely an example of the present invention in every respect. Various improvements or modifications may be made to the above embodiments as appropriate. For example, the following modifications are possible. Note that, in the following, the same reference numerals are used for components similar to those in the above embodiments, and descriptions of the same points as in the above embodiments are omitted as appropriate. The following modifications can be combined as appropriate.

[0147] <4.1> In the above embodiment, the method of supporting the first fixed frame 10 and the second fixed frame 20 may be changed as appropriate. The pillars 55 to 58 may have a form other than a tension type. The number of pillars does not have to be limited to four. Furthermore, instead of being supported by the pillars 55 to 58, the first fixed frame 10 and the second fixed frame 20 may be suspended from the ceiling by any method, such as a suspension device. The pillars 55 to 58 may be omitted.

[0148] Furthermore, in the above embodiment, each fixed frame (10, 20, 51, 52) may be further supported horizontally inward from the outside (the side opposite to the side where the movable frame 30 is arranged). For example, the first fixed frame 10 may be supported horizontally toward the second fixed frame 20. This makes it possible to suppress lateral shaking of each fixed frame (10, 20, 51, 52).

[0149] In the above embodiment, at least one of the third fixing frame 51 and the fourth fixing frame 52 may be omitted. In the above embodiment, the first fixing frame 10 and the second fixing frame 20 may be connected to each other by a method other than the third fixing frame 51 and the fourth fixing frame 52. This may reinforce the support of the first fixing frame 10 and the second fixing frame 20.

[0150] Furthermore, in the above embodiment, the first fixed frame 10, the second fixed frame 20, and the movable frame 30 are supported at approximately the same height. However, this height relationship is not limited to this example and may be changed as appropriate depending on the embodiment. In another example, the first fixed frame 10 and the second fixed frame 20 may be positioned higher and the movable frame 30 may be positioned lower. In another example, the first fixed frame 10 and the second fixed frame 20 may be positioned lower and the movable frame 30 may be positioned higher. In another example, one of the first fixed frame 10 and the second fixed frame 20 may be positioned higher and the other lower, with the movable frame 30 positioned therebetween. The support relationship between the frames (10, 20, 30) may be changed as appropriate depending on the embodiment.

[0151] In the above embodiment, the first fixed frame 10, the second fixed frame 20, and the movable frame 30 are supported at their respective ends. However, the supporting locations do not have to be limited to the ends and may be changed as appropriate depending on the embodiment. The first fixed frame 10 and the second fixed frame 20 may be supported at positions spaced apart from their respective ends. The first fixed frame 10 and the second fixed frame 20 may also support the movable frame 30 at positions spaced apart from their respective ends.

[0152] <4.2> In the above embodiment, the first holding unit 436 (first moving unit 434) may hold two or more linear structures as first linear structures. The second holding unit 437 (second moving unit 435) may hold two or more linear structures as second linear structures. The multiple linear structures supplied via the pair of base units (41, 42) may include linear structures other than the linear structures handled as the first linear structure and the second linear structure (i.e., linear structures not held by the first holding unit 436 and the second holding unit 437).

[0153] In the above embodiment, the load-relieving device 60 may include linear structures other than the pair of wires (603, 604), such as a power cable, a communication cable, etc. When the load-relieving device 60 includes a plurality of linear structures, one or more of the plurality of linear structures may be routed as a first linear structure, and one or more of the remaining linear structures may be routed as a second linear structure.

[0154] <4.3> In the above embodiment, the rotation unit 43 includes two moving units (434, 435). However, the number of moving units provided in the rotation unit 43 is not limited to two and may be one, three, or more. When three or more moving units are provided, the moving units may be appropriately arranged depending on the embodiment. Typically, the three or more moving units may be arranged at equal intervals around the vertical direction (circumferential direction). The three or more moving units may each include a holding unit. Accordingly, the linear structure may be held in a curled shape by each of the three or more holding units. That is, a third or subsequent moving unit, holding unit, and linear structure may be present. Alternatively, one of the first moving unit 434 and the second moving unit 435 may be omitted.

[0155] In the above embodiment, the rotation unit 43 may be provided with at least one moving unit. Accordingly, the rotation unit 43 may include a moving unit disposed outside the cavity (410, 420) and configured to rotate about the vertical direction in response to the rotation of the rotation unit 43. The moving unit may include a holding unit. The holding unit may be configured to hold the end of a curl formed when the linear structure hangs vertically downward from the cavity (410, 420) and then is wound vertically upward. The linear structure may hang further vertically downward from this end. The holding unit may hold one or more linear structures. The held linear structures may have properties that make them resistant to twisting. With this configuration, the curled portion is unwound by the rotation, allowing the portion of the linear structure beyond the holding unit to rotate and move without being affected by the rotation of the rotation unit 43. This allows even linear structures that are resistant to twisting to rotate and move about the vertical direction.

[0156] Furthermore, in the above embodiment, the rotation unit 43 may be configured to rotate around the cavity of the base portion in the vertical direction, and the structure of the rotation unit 43 may be modified as appropriate. In the rotation unit 43, the central portion 431 and the arm portions (432, 433) may be omitted. The moving portions (434, 435) may be rotatably supported by a structure other than the central portion 431 and the arm portions (432, 433). In another example, a guide may be provided around the outer peripheral wall of the base portion in the circumferential direction, and the moving portions (434, 435) may be configured to rotate around this guide in the circumferential direction while maintaining a distance therebetween. In the above embodiment, the cavities (410, 420) of the pair of base portions (41, 42) and the hollow portion 430 of the central portion 431 form the passage of the linear structure in the moving unit 40. By omitting the central portion 431, the hollow portion 430 may be omitted from the passage of the linear structure.

[0157] In addition, in the above embodiment, the relationship between the pair of base portions (41, 42) and the rotation unit 43 may be changed as appropriate. The base portion does not need to be divided into upper and lower portions. The rotation unit 43 may be rotatably supported above or below the base portion as appropriate. The rotation unit 43 may be omitted. The configuration of the moving unit 40 may be changed as appropriate depending on the embodiment.

[0158] In the above embodiment, the moving unit 40 is supported below the movable frame 30. However, the positional relationship between the moving unit 40 and the movable frame 30 is not limited to this example and may be changed as appropriate depending on the embodiment. The moving unit 40 may be supported at approximately the same height as the movable frame 30 or above the movable frame 30.

[0159] <4.4> In the above embodiment, the type of each actuator (15, 25, 35) may be selected as appropriate. In one example, a fluid pressure artificial muscle may be used for at least one of the three actuators (15, 25, 35). In one example, an artificial muscle other than a fluid pressure artificial muscle, such as a polymer actuator or a dielectric actuator, may be used for at least one of the three actuators (15, 25, 35). In one example, when any type of artificial muscle (e.g., an artificial muscle other than a pneumatic one) is used for at least one of the three actuators (15, 25, 35), the artificial muscle may include the wire 505, stopper 506, and elastic member 507 shown in FIG. 6 above, or may include other configurations. In one example, at least one of the three actuators (15, 25, 35) may be configured with a pair of artificial muscles. However, the number of artificial muscles used in an actuator is not limited to this example and may be selected as appropriate depending on the embodiment.

[0160] In one example, at least one of the three actuators (15, 25, 35) may be a variable stiffness actuator other than an artificial muscle, such as an actuator including a spring, a mechanism for changing the stiffness (spring constant) of the spring, and a motor. Impedance control in the first direction may be performed by providing a speed-up unit (14, 24) in at least one of the first fixed frame 10 and the second fixed frame 20 and using a variable stiffness actuator as the actuator (15, 25) that inputs driving force to the speed-up unit (14, 24). Also, in one example, at least one of the three actuators (15, 25, 35) may be an actuator other than a variable stiffness actuator, such as an actuator including a spring and a motor, a series elastic actuator, a piezoelectric actuator, or a motor.

[0161] The configuration of each speed-increasing unit (14, 24, 34) is not particularly limited as long as it can output the driving force of each actuator (15, 25, 35) to each output pulley (11, 21, 31). The configuration of each speed-increasing unit (14, 24, 34) may be changed as appropriate depending on the type of actuator (15, 25, 35). In one example, in at least one of the three speed-increasing units (14, 24, 34), the driving force of the actuator (15, 25, 35) may be directly input to the driven gear (111, 211, 311). In one example, in at least one of the three speed-increasing units (14, 24, 34), the actuator (15, 25, 35) may be configured by a motor, and the input pulley (141, 241, 341) or the output pulley (11, 21, 31) may be driven by this motor.

[0162] In one example, at least one of the three actuators (15, 25, 35) may be an actuator capable of backdriving. In this embodiment, the diameters of the driven gears (111, 211, 311) provided on the output pulleys (11, 21, 31) are smaller than the diameters of the drive gears (142, 242, 342) provided on the input pulleys (141, 241, 341). Therefore, even if a small force is applied to the belts (13, 23, 33), a large force can be applied to the actuators (15, 25, 35). Therefore, even if an actuator that is difficult to backdrive is used for at least one of the three actuators (15, 25, 35), it is possible to backdrive this actuator with a relatively small force. In other words, providing a speed-up unit (14, 24, 34) in at least one of the first fixed frame 10, the second fixed frame 20, and the movable frame 30 can improve backdrivability in that direction. Therefore, a strain wave gear device may be used for at least one of the three actuators (15, 25, 35). Although strain wave gear devices are difficult to backdrive, the effect of the speed-increasing unit described above can ensure backdrivability in the strain wave gear device. At the same time, using a strain wave gear device can make the actuators more compact.

[0163] In one example, a freely movable range may be formed in at least one of the three actuators (15, 25, 35) by a configuration other than the configuration shown in FIG. 6 . For example, a clutch may be provided on the input pulley (141, 241, 341) in at least one of the three speed-up units (14, 24, 34). In this configuration, the clutch allows the drive force of the actuators (15, 25, 35) to be connected or disconnected. By disengaging the clutch, the actuators (15, 25, 35) can be disconnected, thereby allowing the belts (13, 23, 33) to move freely.

[0164] When an artificial muscle is used in at least one of the three actuators (15, 25, 35), the drive range of the artificial muscle may be changed by employing this clutch configuration.

[0165] In one example, an encoder may be attached to the input pulley (141, 241, 341) in at least one of the three speed-increasing units (14, 24, 34), and the angle of the input pulley (141, 241, 341) may be measured by this encoder. When a clutch configuration is not employed, the position of the driving point corresponds to the amount of rotation of the input pulley (141, 241, 341) (i.e., the amount of drive of the artificial muscle), and therefore the position of the driving point can be estimated from the measured angle. In the first fixed frame 10 and the second fixed frame 20, the driving point is the position of the movable frame 30, and in the movable frame 30, the driving point is the position of the moving unit 40.

[0166] On the other hand, when a clutch configuration is employed, disengaging the clutch causes the drive amount of the artificial muscle to no longer correspond to the movement of the drive point, making it difficult to identify the position of the drive point using the angle of the input pulley (141, 241, 341). Therefore, in another example, when a clutch configuration is employed in at least one of the three speed-up units (14, 24, 34), an encoder may be attached to the output pulley (11, 21, 31) corresponding to the input pulley (141, 241, 341) that employs the clutch. This encoder may measure the angle of the output pulley (11, 21, 31), and the position of the drive point may be estimated from the measured angle. In this way, the frame system ST may be configured to adjust the drive range of the artificial muscle by switching the clutch on and off while estimating the position of the drive point. The drive range of the artificial muscle is limited. Therefore, if the length of at least one of the first direction frame (first fixed frame 10 and second fixed frame 20) and the second direction frame (movable frame 30) is long, it may not be possible to cover the entire range of that frame as the drive range of the artificial muscle. In contrast, by adopting this configuration, the drive range of the artificial muscle can be changed, and therefore, even if the frame is long, the drive range of the artificial muscle can cover the entire frame.

[0167] In one example, a brake for suppressing movement may be provided on at least one of the movable frame 30 and the moving unit 40. The brake may be provided, for example, on at least one of the output pulleys (11, 21, 31), the auxiliary pulleys (12, 22, 32), and the slide units (362, 372, 45). The type of brake is not particularly limited and may be selected appropriately depending on the embodiment. In this embodiment, increasing the rigidity of each actuator (15, 25, 35) stiffens the driving point, thereby achieving an effect similar to that of a brake. On the other hand, providing a brake can further suppress movement as needed. For example, if excessive force acts on the belt (13, 23, 33), the brake can suppress the movement of the belt (13, 23, 33). This reduces the load on the speed-up units (14, 24, 34).

[0168] <4.5> In the above embodiment, the first fixed frame 10 supports the movable frame 30 via the slide unit 362. The second fixed frame 20 supports the movable frame 30 via the slide unit 372. The movable frame 30 supports the moving unit 40 via the slide unit 45. However, the support method is not limited to this example and may be changed as appropriate depending on the embodiment. The configuration of the slide units (362, 372, 45) may be changed as appropriate depending on the embodiment. A support method other than the slide unit may be adopted for at least one of these. In another example, in at least one of the three slide units (362, 372, 45), the horizontal wheels may be disposed in the grooves (193, 293, 393). The horizontal wheels may be slightly smaller than the grooves (193, 293, 393). The horizontal wheels can bear an axial load by abutting against the edge portions (191, 192), (291, 292), and (391, 392). The horizontal wheels may be attached to the slide units (362, 372, 45) via elastic members (e.g., springs). In another example, in the above embodiment, at least one of the horizontal wheels (3623, 3624, 3723, 3724, 453, 454) may be attached to the slide units (362, 372, 45) via elastic members (e.g., springs).

[0169] In the above embodiment, the movable frame 30 is connected to the first belt 13 by the fourth member 364 and the fifth member 365. The movable frame 30 is connected to the second belt 23 by the fourth member 374 and the fifth member 375. The moving unit 40 is connected to the third belt 33 by the connecting portion 46. However, the connecting method is not limited to this example and may be changed as appropriate depending on the embodiment. The configuration of the connecting member may be changed as appropriate depending on the embodiment.

[0170] <4.6> In the movable frame 30 according to the above embodiment, the third speed-increasing unit 34 may be omitted. In this case, the third output pulley 31 and the third auxiliary pulley 32 may simply be referred to as pulleys. Even when the third speed-increasing unit 34 is omitted, the movable frame 30 may include the third belt 33, and the moving unit 40 may be connected to the third belt 33.

[0171] In the above embodiment, the third output pulley 31, the third auxiliary pulley 32, the third belt 33, and the third speed-increasing unit 34 may be omitted. Accordingly, the connection between the moving unit 40 and the third belt 33 may also be omitted. In one example, the movable frame 30 may be used simply as a rail for the moving unit 40.

[0172] <4.7> In the second fixed frame 20 according to the above embodiment, the second speed-increasing unit 24 may be omitted. In this case, the second output pulley 21 and the second auxiliary pulley 22 may simply be referred to as pulleys. Even when the second speed-increasing unit 24 is omitted, the second fixed frame 20 may include the second belt 23, and the movable frame 30 may be connected to the second belt 23.

[0173] In the above embodiment, the second output pulley 21, the second auxiliary pulley 22, the second belt 23, and the second speed-increasing unit 24 may be omitted. Accordingly, the connection between the movable frame 30 and the second belt 23 may also be omitted. In one example, the second fixed frame 20 may be used simply as a rail for the movable frame 30.

[0174] <4.8> In the above embodiment, the first auxiliary pulley 12 is a driven pulley. However, the first auxiliary pulley 12 is not limited to this example. In another example, the first fixed frame 10 may be provided with a speed-up unit separate from the first speed-up unit 14, and the driving force of the actuator may be output to the first auxiliary pulley 12 by the speed-up unit. In this way, the first auxiliary pulley 12 may operate in the same manner as the first output pulley 11.

[0175] The same applies to the second fixed frame 20 and the movable frame 30. That is, in another example, the second fixed frame 20 may be provided with a speed-up unit separate from the second speed-up unit 24, and the driving force of the actuator may be output to the second auxiliary pulley 22 by the speed-up unit. In this way, the second auxiliary pulley 22 may operate in the same manner as the second output pulley 21.

[0176] In another example, the movable frame 30 may be provided with a speed-up unit separate from the third speed-up unit 34, and the driving force of the actuator may be output to the third auxiliary pulley 32 by the speed-up unit. As a result, the third auxiliary pulley 32 may operate in the same manner as the third output pulley 31.

[0177] <4.9> In the above embodiment, an encoder may be attached to each of the output pulleys (11, 21, 31) and auxiliary pulleys (12, 22, 32) in at least one of the first fixed frame 10, the second fixed frame 20, and the movable frame 30. Each encoder may measure the angle of each of the output pulleys (11, 21, 31) and auxiliary pulleys (12, 22, 32). The control device 70 may use each angle to estimate the force acting on the driving point. The control device 70 may also use each angle to correct the position of the driving point. As described above, in the first fixed frame 10 and the second fixed frame 20, the driving point is the position of the movable frame 30, and in the movable frame 30, the driving point is the position of the movement unit 40.

[0178] FIG. 10 schematically shows an example of frames (first fixed frame 10, second fixed frame 20, and movable frame 30) according to this modified example. An output pulley 591 corresponds to each of the output pulleys (11, 21, 31), and an auxiliary pulley 592 corresponds to each of the auxiliary pulleys (12, 22, 32). An endless belt 593 corresponds to each of the belts (13, 23, 33). The configuration of FIG. 10 may be employed for at least one of the first fixed frame 10, second fixed frame 20, and movable frame 30. Note that FIG. 10 assumes a situation in which a driving point DP (connection point) is provided on the lower circumference of the belt 593.

[0179] In one example, the encoder EN1 may be provided on the output pulley 591, and the encoder EN2 may be provided on the auxiliary pulley 592. The type of each encoder (EN1, EN2) is not particularly limited and may be selected appropriately depending on the embodiment. The encoders (EN1, EN2) may be appropriately disposed on the rotation shaft, side surface, etc. of each pulley (591, 592). As long as the rotation angle of each pulley (591, 592) can be measured, the location of the encoders (EN1, EN2) is not particularly limited and may be appropriately determined depending on the embodiment.

[0180] The control device 70 may acquire measurement results of the rotation angles of the pulleys (591, 592) directly or indirectly from the encoders (EN1, EN2). The control device 70 may calculate the amount of extension (stretching) of the upper connecting portion PT1 of the belt 593 between the output pulley 591 and the auxiliary pulley 592 based on the difference between the measured rotation angles of the output pulley 591 and the auxiliary pulley 592. The spring constant of the upper connecting portion PT1 may be measured in advance. Taking into account the influence of the tensioner, this spring constant may be approximated by a nonlinear function. The control device 70 may estimate the force acting on the driving point DP by multiplying the calculated amount of extension by the previously measured spring constant. The control device 70 may use the estimated force for feedback control of the driving point DP. Thus, the control device 70 may control the driving point DP with or without using other sensors.

[0181] The control device 70 may also calculate the distance between the pulley and the driving point DP in the no-load state, based on the rotation angle of the pulley that is opposite to the direction of action of the estimated force. This distance corresponds to the position of the driving point DP in the no-load state. The distance between the pulley and the driving point DP corresponds to the length of the lower portion of the belt 593 between the pulley and the driving point DP. The example of FIG. 10 assumes a situation in which the estimated force is directed toward the output pulley 591. In this case, the control device 70 may calculate the length of the lower portion of the belt 593 between the auxiliary pulley 592 and the driving point DP in the no-load state, based on the measured rotation angle of the auxiliary pulley 592. Because the belt 593 is not stretched in the no-load state, the control device 70 may uniformly determine the length of the lower portion of the belt 593 in the no-load state, based on the measured rotation angle of the pulley. As in the force estimation scenario described above, the spring constant of this lower portion of the belt 593 may also be measured in advance. The spring constant may be approximated by, for example, a function. The control device 70 may estimate the spring constant of the lower bridge portion from the calculated length of this portion. The control device 70 may then calculate the amount of deviation of the position of the driving point DP by dividing the estimated force value by the estimated spring constant value. The control device 70 may correct the position of the driving point DP by shifting the position of the driving point DP by the calculated amount of deviation in the direction of action of the estimated force. The corrected position may be used to control the position of the driving point DP.

[0182] An inexpensive encoder can be used to measure the pulley angle. Therefore, this configuration allows for a relatively inexpensive method to improve the accuracy of force and position control of the driving point DP. If the driving point DP (connection point) is located on the upper circumference of the belt 593, the upper connection portion in the force estimation process may be replaced with the lower connection portion, and the lower connection portion in the position correction process may be replaced with the upper connection portion.

[0183] <4.10> In the above embodiment, the configuration of the mobile unit 40 is not particularly limited as long as it is movable along the movable frame 30, and may be changed as appropriate depending on the embodiment. Any device may be attached to the mobile unit 40. Note that attaching the target device may be configured by deploying the target device relative to the mobile unit 40 in a form in which the mobile unit 40 is at least a part of the target device, the target device is suspended, a linear structure of the target device passes through, or a linear structure of the target device is held. The form in which the target device is deployed is not particularly limited, and may be selected as appropriate depending on the embodiment.

[0184] <4.11> In the above embodiment, an example is given of a situation in which the frame system ST is used as the load-relieving device 60. However, the scope of application of the frame system ST is not limited to such an example. The mobile unit 40 may be equipped with any device together with or instead of the load-relieving device 60.

[0185] (1) Exoskeleton Robot Fig. 11A schematically illustrates an example of another situation in which the frame system ST of the present disclosure is used. The example of Fig. 11A assumes a situation in which an exoskeleton robot 61 is used together with the load-relieving device 60. The exoskeleton robot 61 includes four artificial muscles 617, a first assist unit 618, and a second assist unit 619. The type of each artificial muscle 617 may be selected arbitrarily. In one example, the above-described artificial muscle 500 may be used for each artificial muscle 617.

[0186] The first assist unit 618 is configured to receive the driving force of two of the four artificial muscles 617 and assist the extension and flexion of the knee joint of the user W. The second assist unit 619 is configured to receive the driving force of the remaining two of the four artificial muscles 617 and assist the extension and flexion of the ankle joint of the user W. The four artificial muscles 617 may be carried on the user W's back as appropriate.

[0187] The exoskeleton robot 61 may include one or more linear structures related to the four artificial muscles 617. In one example, each artificial muscle 617 may be a pneumatic artificial muscle. Accordingly, the exoskeleton robot 61 may include a compressor and four air valves. The compressor may be connected to each air valve via an air tube. Each air tube may also be connected to each artificial muscle 617 via an air tube. The compressor and the air tubes of each air valve are an example of a linear structure. Each air tube may be routed as appropriate.

[0188] 11B and 11C are a perspective view and a partial cross-sectional view, respectively, schematically illustrating an example of the routing of the linear structure (air tube) of the exoskeleton robot 61 in the mobile unit 40 of the present disclosure. The compressor may be disposed in any location. The compressor may be connected to each of the air valves 6121 to 6124 via an air tube 611. The air tube 611 may be routed from the compressor to the upper part of the movable frame 30. The portion of the air tube 611 that is routed around the upper part of the movable frame 30 and passes through the cavities (410, 420) of the pair of base portions (41, 42) may be arranged similarly to the wires (603, 604) of the load-relieving device 60. In one example, the portion of the air tube 611 may be inserted into a cable bearing CB1 together with the wire 603 and placed in the bracket 38 ( FIG. 11C ). In another example, the air tube 611 may be placed in the cable bearing CB2 along with the wire 604 and disposed in the groove 385.

[0189] The four air valves 6121 to 6124 may be arranged as appropriate. In the example of FIGS. 11A and 11B , the four air valves 6121 to 6124 may be divided into pairs, and each pair may be fixed to each moving portion (434, 435) of the rotation unit 43 in a connected state. When connected, each air valve 6121 to 6124 may be configured to be able to receive air pressure through a single tube. Accordingly, the air tube 611 may be supplied into the cavities (410, 420) of the pair of base portions (41, 42) and then branch into two tubes (6111, 6112).

[0190] The tube 6111 may be connected to a pair of air valves (6121, 6122), and the tube 6112 may be connected to a pair of air valves (6123, 6124). In this case, each tube (6111, 6112) may be routed to form a curl, similar to each wire (603, 604) of the load-relieving device 60, and then connected to each pair. The connection portion of each pair of air valves is an example of a holding portion. By routing the tubes in this manner, it is possible to more easily handle rotations of the user W about the vertical direction, even in situations where the exoskeleton robot 61 is used.

[0191] The air tubes 6131 to 6134 hanging down from the air valves 6121 to 6124 may be bundled together, covered by a sleeve 616, and connected to the artificial muscles 617. When two or more linear structures are connected with an object sandwiched between them, as in the relationship between the tubes (6111, 6112) and the air tubes 6131 to 6134, the two or more linear structures may be regarded as a single linear structure or as separate linear structures.

[0192] Known air valves may be used for each of the air valves 6121-6124. Each of the air valves 6121-6124 may be controlled wirelessly or by wire. When each of the air valves 6121-6124 is controlled by wire, the communication cable may be routed in the same manner as the air tube 611, etc. Furthermore, each of the air valves 6121-6124 may be equipped with a battery or connected to a power cable. When electricity is supplied to each of the air valves 6121-6124 via a power cable, the power cable may also be routed in the same manner as the air tube 611, etc. Furthermore, a controller may be provided in the mobile unit 40 together with each of the air valves 6121-6124. In this case, the power cable of the controller may also be routed in the same manner as the air tube 611, etc. In this application example, the effects of the above-described embodiment can be expected even in situations where the exoskeleton robot 61 is used. The arrangement of the air valves 6121-6124 may be changed as appropriate depending on the embodiment.

[0193] FIG. 12 schematically illustrates an example of another scenario in which the frame system ST of the present disclosure is used. In the exoskeleton robot 62 of FIG. 12 , air valves 622 are disposed near the upper ends of four artificial muscles 627. The four artificial muscles 627 correspond to the four artificial muscles 617. The air tube 621 from the compressor corresponds to the air tube 611. In this case, the air tube 621 may pass through the cavities (410, 420) of the pair of base portions (41, 42) and then be supplied directly toward the back of the user W without branching. The other configurations of the exoskeleton robot 62 may be similar to those of the exoskeleton robot 61. This simplifies the handling of linear structures. Note that in a modified version of this exoskeleton robot (61, 62), the load-relieving device 60 may be omitted. The type of each artificial muscle 627 may be selected arbitrarily. In one example, the artificial muscle 500 may be used for each artificial muscle 627.

[0194] (2) Robot Arm FIG. 13 schematically illustrates an example of another scenario in which the frame system ST of the present disclosure is used. In one example, a robot arm 63 may be attached to the moving unit 40. This allows the robot arm 63 to move horizontally while suspended. This allows the robot arm 63 to easily move, for example, ignoring obstacles or steps on the floor. Furthermore, the first speed-up unit 14 can increase the mobility of the robot arm 63 in the first direction. The second speed-up unit 24 can smoothly move the robot arm 63 in the first direction. Furthermore, the third speed-up unit 34 can increase the mobility of the robot arm 63 in the second direction.

[0195] In one example, the robot arm 63 may be attached to the moving unit 40 via a balancer 631. The balancer 631 may be appropriately configured to assist the vertical movement of the robot arm 63 and maintain the robot arm 63 at any height. A known balancer may be used for the balancer 631. When moving the robot arm 63 horizontally, the robot arm 63 is first raised vertically upward and then begins moving horizontally, thereby reducing interference with obstacles on the floor. On the other hand, when in use, the robot arm 63 may be lowered vertically downward. In this modification, the balancer 631 facilitates the vertical movement of the robot arm 63. This improves the convenience of the robot arm 63. Note that in another example, the balancer 631 may be omitted.

[0196] In this modification, variable stiffness actuators are used for the actuators (15, 25, 35), so that even if the stiffness of the robot arm 63 itself is high, impedance control of the tip of the robot arm 63 is possible. The stiffness of the tip of the robot arm 63 corresponds to the combined stiffness of the robot arm 63 itself and the stiffness of each actuator (15, 25, 35). Therefore, even if it is difficult to lower the stiffness of the robot arm 63 itself, a soft state can be created at the tip of the robot arm 63 by lowering the stiffness of each actuator (15, 25, 35).

[0197] (Operation Example) Figure 14 is a flowchart showing an example of the processing procedure of the control device 70 when the frame system ST is used with the robot arm 63. The processing procedure of the control device 70 described below is an example of a control method (information processing method). However, the processing procedure described below is merely an example, and each step may be changed as much as possible. Furthermore, steps may be omitted, replaced, or added to the following processing procedure as appropriate depending on the embodiment.

[0198] In step S201, the control unit 71 operates as the information acquisition unit 711 and accepts a designation of a position to which the robot arm 63 is to be moved. The designation of the position may be performed by any method, such as input via the input device 74, voice input, or image input (gestures, etc.). For example, when using sensor input such as voice input or image input, the control device 70 may acquire information about the designated position by acquiring observation data from a sensor SE such as a microphone or an image sensor and analyzing the acquired observation data by any method. The position may be specifically designated, or may be abstractly designated, for example, by a demonstrative term or a call. When the position is abstractly designated, the control unit 71 may determine the designated position according to a predetermined rule (e.g., setting the designated position within a certain range from the user). After acquiring the information about the designated position, the control unit 71 proceeds to the next step S202.

[0199] In step S202, the control unit 71 operates as the drive unit 712 and controls the operation of each actuator (15, 25, 35) so as to gradually move the balanced position of each actuator (15, 25, 35) to a designated position. This allows the control device 70 to use the frame system ST to move the robot arm 63 to the designated position. When the balanced position of each actuator (15, 25, 35) reaches the designated position, the movement of the robot arm 63 is completed.

[0200] Typically, the control unit 71 may move the robot arm 63 along a linear path. However, the movement path is not limited to this example and may be determined appropriately depending on the embodiment. The control unit 71 may perform path planning using any method. For example, the control unit 71 may acquire the position of an obstacle and determine the movement path of the robot arm 63 so as to avoid the position of the obstacle. Note that the position of the obstacle may be acquired using any method. In one example, the sensor SE may include an image sensor, and the control unit 71 may identify the position of the obstacle from an image obtained from the image sensor. In another example, the position of the obstacle may be set in advance.

[0201] Furthermore, if the balancer 631 is computer-controllable, the control device 70 may be directly or indirectly connected to the balancer 631. In this case, the control unit 71 may drive the balancer 631 to raise the position of the robot arm 63 vertically upward before starting movement. Then, after the movement is completed, the control unit 71 may drive the balancer 631 to lower the position of the robot arm 63 vertically downward. When the movement of the robot arm 63 is completed, the control unit 71 proceeds to the next step S203.

[0202] In step S203, the control unit 71 determines whether or not to terminate the control of each actuator (15, 25, 35). The determination criteria may be set arbitrarily. In one example, the determination criteria in step S203 may be the same as those in step S103 described above. In another example, the control unit 71 may determine to terminate the control of each actuator (15, 25, 35) each time the movement of the robot arm 63 is completed. If it is determined not to terminate the control, the control unit 71 returns to step S201 and executes the process again from step S201. On the other hand, if it is determined to terminate the control, the control unit 71 terminates the processing procedure of the control device 70 according to this operation example. According to this operation example, the robot arm 63 can be moved to any location using the frame system ST.

[0203] In this modification, the brake may be provided. This brake can freely stop the movement of the robot arm 63. As a result, the positioning accuracy of the tip of the robot arm 63 can be improved.

[0204] <4.12> In addition, the attributes of each component of the frame system ST, such as the shape, material, and structure, may be changed as appropriate. Regarding the specific hardware configuration of the frame system ST, components may be omitted, replaced, or added as appropriate depending on the embodiment. The shape of each frame (10, 20, 30, 51, 52) is not limited to the examples shown in the figures and may be changed as appropriate depending on the embodiment. As long as the movable frame 30 is movable, at least one of the first fixed frame 10, the second fixed frame 20, and the movable frame 30 may be partially curved. Known methods may be used as appropriate for connecting, fixing, supporting, and coupling each component.

[0205] <4.13> In one example, a system may be configured using a plurality of frame systems ST each having the configuration of any of the above-described embodiments and modifications.

[0206] FIG. 15 schematically illustrates an example of a system ST100 according to the present disclosure. In the example illustrated in FIG. 15 , the system ST100 includes a first frame system ST1 and a second frame system ST2. The first frame system ST1 is disposed in a first space SC1. The second frame system ST2 is disposed in a second space SC2 adjacent to the first space SC1. Each frame system (ST1, ST2) may be configured similarly to any of the frame systems ST in the above-described embodiments and modifications. The first frame system ST1 and the second frame system ST2 may be disposed at or near a boundary SC3 between the first space SC1 and the second space SC2, at a distance such that a load-relieving device 60 can be attached to the moving units 40 of both the first frame system ST1 and the second frame system ST2. A door may be provided at the boundary SC3 between the first space SC1 and the second space SC2. A wall SC30 may be provided above the boundary SC3 (entrance / exit) to separate the first space SC1 and the second space SC2.

[0207] 16A and 16B schematically show an example of a scene in which a user W of the load-relieving device 60 moves from the first space SC1 to the second space SC2 in the system ST100 of the present disclosure. In one example, components (drive sources, linear structures, etc.) other than the attachments (606, 607) of the load-relieving device 60 may be provided in each frame system (ST1, ST2). In the example shown in FIGS. 15, 16A, and 16B, the artificial muscles (601, 602) and wires (603, 604) of the load-relieving device 60 may be provided in each frame system (ST1, ST2). 16A , in the region of each space (SC1, SC2) near the boundary SC3 or the boundary SC3, the first frame system ST1 and the second frame system ST2 may be arranged within a range where the linear structures (wires 603, 604) of the load-relieving device 60 extending from the mobile unit 40 of each frame system (ST1, ST2) can reach the mounting fixtures (606, 607). As a result, the first frame system ST1 and the second frame system ST2 may be arranged at a distance where the load-relieving device 60 can be attached to the mobile unit 40 of both the first frame system ST1 and the second frame system ST2, at least in either the region near the boundary SC3 or the boundary SC.

[0208] According to one example of the present disclosure, when moving from the first space SC1 to the second space SC2 and from the second space SC2 to the first space SC1, the attachment point of the attachment tool (606, 607) of the weight-relieving device 60 can be changed at or near the boundary SC3 without the user W becoming detached from the weight-relieving device 60. This allows the weight-relieving device 60 to be used continuously in the first space SC1 and the second space SC2.

[0209] In addition, when a wall SC30 is provided above the boundary SC3, sliding members (SC31, SC32) may be disposed near the lower end of the wall SC30 of each space (SC1, SC2) to prevent the linear structures (wires 603, 604) of the load-relief device 60 from contacting the lower end of the wall SC30. The type of each sliding member (SC31, SC32) is not particularly limited as long as it is a member with a slidable surface, and may be appropriately selected depending on the embodiment. The sliding members (SC31, SC32) may be, for example, a rotating member (bearing, etc.), a member with a sliding surface, etc. This prevents the linear structures (wires 603, 604) of the load-relief device 60 from getting caught on the corners of the lower end of the wall SC30 when changing the attachment location of the attachment devices (606, 607) of the load-relief device 60 at or near the boundary SC3. As a result, wear of the linear structures (wires 603 and 604) of the load-relieving device 60 can be suppressed.

[0210] Furthermore, the first space SC1 and the second space SC2 are not particularly limited and may be selected appropriately depending on the embodiment. In one example, one of the first space SC1 and the second space SC2 may be a bathroom, and the other may be a room adjacent to the bathroom (such as a dressing room). According to one example of the present disclosure, the weight-relieving device 60 can be used in the bathroom. This is expected to reduce the burden on the caregiver in the bathroom. Furthermore, the user W can be placed in the bathtub while being weight-relieved by the weight-relieving device 60, without using a dedicated bed.

[0211] Regarding the specific hardware configuration of the system ST100, components can be omitted, replaced, or added as appropriate depending on the embodiment. The number of frame systems used does not need to be limited to two and can be three or more. The number of spaces also does not need to be limited to two and can be three or more. One or more frame systems may be arranged in one space. When three or more frame systems are used, as in the example shown in FIG. 15 above, two adjacent frame systems may be arranged at a distance such that the load relief device 60 can be attached to the mobile units 40 of both adjacent frame systems at or near the boundary. This allows the load relief device 60 to be used continuously in each space.

[0212] 17 schematically shows an example of the overall configuration of an artificial muscle 500A according to another embodiment. Like the artificial muscle 500 described above, the artificial muscle 500A includes a chamber 501, a pair of end portions (502, 503), a pipe cylinder 504, a wire 505, a stopper 506, and an elastic member 507. The internal space 5015 of the chamber 501 is connected to an air valve via a supply port 509. The artificial muscle 500A further includes an outer cylinder 520 that defines an internal space 525 that houses these components. In the outer cylinder 520, the connections between the wire 505 and the supply port 509 and the external space may be sealed as appropriate.

[0213] When the artificial muscle 500A is used in a humid location such as a bathroom, if the chamber 501 and the outer cylinder 520 are sealed, condensation may easily occur in the internal space 525 of the outer cylinder 520. Therefore, one or more through holes may be provided in at least one of the ends (502, 503) of the chamber 501, connecting the internal space 5015 of the chamber 501 to the internal space 525 of the outer cylinder 520. Furthermore, one or more through holes may be provided in at least one of the ends (521, 522) of the outer cylinder 520, connecting the internal space 525 of the outer cylinder 520 to the external space. The number of through holes may be determined arbitrarily. In the example shown in FIG. 17 , two through holes 541 are provided in the end 502 of the chamber 501. Two through holes 542 are also provided in the end 503 of the chamber 501. A through hole 543 is provided in the end 521 of the outer cylinder 520. A through-hole 544 is also provided at the end 522 of the outer cylinder 520. According to an example of the present disclosure, dry air is supplied from the air valve to the internal space 5015 of the chamber 501. This dry air is supplied from the internal space 5015 of the chamber 501 to the internal space 525 of the outer cylinder 520 via the respective through-holes (541, 542). By supplying dry air from the chamber 501 to the internal space 525 of the outer cylinder 520, the air present in the internal space 525 is pushed out to the external space via the respective through-holes (543, 544). This allows the air in the internal space 525 to be dried, thereby suppressing condensation in the internal space 525. Note that at least one of the respective through-holes (541, 542) may be omitted. At least one of the respective through-holes (543, 544) may be omitted. To prevent air from entering the internal space 525 from the external space, each through-hole (543, 544) provided at each end (521, 522) of the outer cylinder 520 may be provided with a check valve.

[0214] Sensors for measuring the actuation of the artificial muscle 500A may be appropriately arranged in the internal space 525 of the outer cylinder 520. In one example, when sensors are arranged only on one end side of the artificial muscle 500A, it is preferable that a through-hole be provided in the chamber 501 at the end on the side where the sensors are arranged. Alternatively, it is preferable that the diameter of the through-hole at the end on the side where the sensors are arranged be larger than the through-hole provided at the end opposite the side where the sensors are arranged. Furthermore, it is preferable that a through-hole be provided in the end on the opposite side from the side where the sensors are arranged. Alternatively, it is preferable that the diameter of the through-hole at the end opposite the side where the sensors are arranged be larger than the through-hole at the end on the side where the sensors are arranged. When multiple through-holes are provided, having a through-hole on one side that is larger in diameter than the through-hole on the other side means that the amount of air that can be discharged from all of the through-holes on one side is greater than the amount of air that can be discharged from all of the through-holes on the other side.

[0215] 17 , a load cell 531, an encoder 532, and a scale 533 are arranged on the end 521 side of the internal space 525 of the outer cylinder 520. The load cell 531 is attached to the end 502 of the chamber 501 so as to contact the stopper 506, and is configured to measure the driving force of the artificial muscle 500A. The scale 533 is attached to the inner wall of the outer cylinder 520. The encoder 532 is attached to the side of the end 502 of the chamber 501, and is configured to measure the contraction rate of the artificial muscle 500A by reading the scale 533. The load cell 531 and the encoder 532 are examples of sensors. The end 521 side of the outer cylinder 520 is an example of the side on which sensors are arranged, and the end 522 side is an example of the side opposite to the side on which sensors are arranged. In this case, the through-hole 542 in the end 503 of the chamber 501 may be omitted. Alternatively, the diameter of the through-hole 541 at the end 502 of the chamber 501 may be larger than the through-hole 542 at the end 503. Furthermore, the through-hole 543 at the end 521 of the outer cylinder 520 may be omitted. Alternatively, the diameter of the through-hole 544 at the end 522 of the outer cylinder 520 may be larger than the through-hole 543 at the end 521. According to one example of the present disclosure, dry air supplied from the air valve can be easily discharged from the internal space 5015 of the chamber 501 to the side of the internal space 525 where the sensors are arranged through a through-hole (through-hole 541 in FIG. 17 ) provided at the end of the chamber 501 where the sensors are arranged. Furthermore, in the internal space 525, the air discharged to the side where the sensors are arranged can be made to flow to the opposite side, and the air in the internal space 525 can be easily discharged through a through-hole (through-hole 544 in FIG. 17 ) provided at the opposite end. This makes it possible to easily suppress condensation in the area where the sensors are arranged. In one example, the artificial muscle 500A may be used as at least one of the artificial muscles (151, 152, 251, 252, 351, 352, 601, 602, 617, 627).

[0216] In one example, the portion of the wire 505 extending from the outer tube 520 into the external space may be covered with a casing 552. In the example shown in FIG. 17 , the wire 505 extends from an end 521 of the outer tube 520 into the external space. The end of the casing 552 may be appropriately fixed to the end 521 with a fastener 551. Chemical fibers may be used for the wire 505. The wire 505 may be appropriately joined to a stopper 506. A PTFE (polytetrafluoroethylene) tube may be used for the casing 552. This can prevent the wire 505 from rusting. The casing 552 may have a two-layer structure in which PTFE is disposed on the inside and nylon or polyurethane is disposed on the outside. For example, the casing 552 may be formed by covering a PTFE tube with a nylon tube. For example, the casing 552 may be formed by coating the outer surface of a PTFE tube with polyurethane. This allows the flexibility of the casing 552 to be increased.

[0217] <4.15> Figure 18 schematically shows an example of force control according to the present disclosure. In the above embodiment, when the load-relieving device 60 is used, the position of the user W may be observed by the sensor SE. An entry prevention area EA may be set in the observation space of this sensor SE. The observation space of the sensor SE may be defined as appropriate using a known method, etc. The entry prevention area EA may be set as appropriate using the control device 70. In this case, the control device 70 (control unit 71) may control the operation of each actuator (15, 25, 35) so that the equilibrium positions (equilibrium point BP, point TO) of the artificial muscles (151, 152) (251, 252) (351, 352) do not enter the entry prevention area EA.

[0218] In one example, if the position of the user W obtained in step S101 is away from the entry prevention area EA, in step S102, the control unit 71 may drive each actuator (15, 25, 35) so that the equilibrium position (equilibrium point BP, point T0) of each artificial muscle (151, 152) (251, 252) (351, 352) follows the position of the user W, as in the above embodiment. On the other hand, if the position of the user W acquired in step S101 is at the boundary of the entry prevention area EA or is about to enter the entry prevention area EA, the control unit 71 may drive the actuators (15, 25, 35) so that the equilibrium positions (equilibrium points BP, points T0) of the artificial muscles (151, 152), (251, 252), and (351, 352) are stopped at the boundary of the entry prevention area EA or move in a direction away from the entry prevention area EA. This makes it difficult for the user W to enter the entry prevention area EA. As illustrated in FIG. 18 , when the user W enters the entry prevention area EA, a force can be applied to the user W in a direction away from the entry prevention area EA. Therefore, according to one example of the present disclosure, the user W can be prevented from entering the set entry prevention area EA.

[0219] The method for determining the equilibrium position with respect to the entry-restricted area EA is not limited to the above example and may be modified as appropriate depending on the embodiment. In another example, when the position of the user W obtained in step S101 is within the entry-restricted area EA, the control unit 71 may drive the actuators (15, 25, 35) so that the equilibrium position (equilibrium point BP, point T0) of the artificial muscles (151, 152), (251, 252), and (351, 352) is set between the boundary of the entry-restricted area EA and the position of the user W. This allows the user W to be moved outside the entry-restricted area EA with a gentle force.

[0220] §5 Experimental Example The following experiment was carried out to verify the applicability of curling in the above embodiment, however, the present invention is not limited to the following experimental example.

[0221] (First Experimental Example) First, a frame system with a configuration similar to that of the above embodiment was prototyped. Next, a load-relief device with a configuration similar to that of the above embodiment was prepared. Pneumatic artificial muscles were used as the artificial muscles. As in the above embodiment, artificial muscles and cables (Bowden cables) were arranged. The cables extending from each artificial muscle were curled in the rotation unit and then held by their respective holders. The ends of each cable from their respective holders were hung vertically downward and connected to their respective attachments. In the first experimental example, a scenario was assumed in which the user was stationary, and a weight was fixed to the subject wearing the load-relief device to prevent it from moving up, down, left, or right. Using the method described in Non-Patent Document 3, the same target value was applied to the left and right artificial muscles of the load-relief device. The load-relief device was then driven while dynamically changing the target value of the load-relief force, and the actual load-relief force from the artificial muscles was measured using a load cell.

[0222] (Second Experimental Example) In the second experimental example, a step (a wooden frame 19 cm high and 28 cm deep) was prepared, and a user was asked to ascend and descend the step. While the user was ascending and descending the step, the unloading device was controlled to apply a constant unloading force (100 N), and the actual unloading force from the artificial muscle was measured with a load cell. The frame system and unloading device used were the same as those in the first experimental example.

[0223] (Results) Figures 19A and 19B show the left and right target values ​​and the load cell measurement results in the first experimental example. Figures 20A and 20B show the left and right target values, the contraction amount of the artificial muscle, and the load cell measurement results in the second experimental example. As shown in Figures 19A and 19B, it was found that force control that appropriately tracks the dynamically changing target value is possible even when a curled portion is provided in the cable. Also, as shown in Figures 20A and 20B, the contraction amount of the artificial muscle increases when the user climbs the step (around 9 s) and decreases when the user descends the step (around 14 s). This enabled force control that provides a constant load-relief force even while the user ascends or descends the step. In other words, it was found that appropriate force control for the user's movement is possible even when a curled portion is provided in the cable. These results demonstrate that when using a load-relief device, the device can be used without any problems even when the configuration of the above embodiment in which a curled portion is provided in the linear structure is adopted.

[0224] REFERENCE SIGNS LIST 10...first fixed frame, 11...first output pulley, 12...first auxiliary pulley, 13...first belt, 14...first speed increasing unit, 15...first actuator, 20...second fixed frame, 30...movable frame, 40...moving unit

Claims

1. A frame system comprising: a first fixed frame extending in a first direction, the first fixed frame comprising: a first output pulley arranged at one end of the first fixed frame; a first auxiliary pulley arranged at the other end of the first fixed frame; an endless first belt stretched between the first output pulley and the first auxiliary pulley; and a first speed increasing unit configured to receive a driving force input from a first actuator and increase a speed of movement of the first belt by outputting the input driving force to the first output pulley; a second fixed frame extending in the first direction and arranged in parallel to the first fixed frame; a movable frame supported by the first fixed frame and the second fixed frame and extending in a second direction intersecting the first direction, the movable frame having one end connected to the first belt and configured to move along the first fixed frame and the second fixed frame in response to movement of the first belt; and a moving unit supported by the movable frame and configured to move along the movable frame.

2. The frame system described in claim 1, wherein the second fixed frame comprises: a second output pulley arranged at one end of the second fixed frame; a second auxiliary pulley arranged at the other end of the second fixed frame; an endless second belt stretched between the second output pulley and the second auxiliary pulley; and a second speed-up unit configured to receive input of a driving force from a second actuator and output the driving force input from the second actuator to the second output pulley, thereby speeding up the movement of the second belt; and the other end of the movable frame is connected to the second belt.

3. The frame system described in claim 1, wherein the movable frame comprises: a third output pulley arranged at one of the one end and the other end of the movable frame; a third auxiliary pulley arranged at the other of the one end and the other end of the movable frame; an endless third belt stretched between the third output pulley and the third auxiliary pulley; and a third speed-up unit configured to receive input of a driving force from a third actuator and output the driving force input from the third actuator to the third output pulley, thereby speeding up the movement of the third belt, and the moving unit is connected to the third belt.

4. The moving unit comprises: a base portion having a cavity that opens in the vertical direction, the base portion being configured to supply a plurality of linear structures including a first linear structure and a second linear structure from vertically above through the cavity to vertically below; and a rotation unit configured to rotate around the cavity in the vertical direction, the rotation unit comprising: a first moving portion that is arranged outside the cavity and configured to rotate and move around the vertical direction in response to rotation of the rotation unit, and a second moving portion that is arranged outside the cavity at a distance from the first moving portion in the vertical direction and configured to rotate and move around the vertical direction in response to rotation of the rotation unit while maintaining a positional relationship with the first moving portion, the first moving portion including a first holding portion configured to hold a first end of a curl formed when the first linear structure hangs down vertically downward from the cavity and is then taken around vertically upward, the first linear structure including a first holding portion that hangs down further vertically downward from the first end, and The frame system of claim 1, wherein the second moving portion is a second holding portion configured to hold a second end of a curl formed by the second linear structure hanging vertically downward from the cavity and then being wrapped around vertically upward, and the second linear structure includes a second holding portion that hangs further vertically downward from the second end.

5. The frame system described in claim 4, wherein the rotating unit further comprises: a central portion supported on the base portion so as to be rotatable about the vertical direction, and having a hollow portion that is open in the vertical up-down direction and communicates with the cavity of the base portion; a first arm portion extending vertically downward or at an incline from the central portion, the first arm portion connecting the central portion and the first moving portion; and a second arm portion extending vertically downward or at an incline from the central portion, the second arm portion connecting the central portion and the second moving portion.

6. The frame system described in claim 1, wherein the moving unit comprises: a base portion having a cavity that opens in the vertical direction, the base portion configured to pass a linear structure from vertically above through the cavity and supply it vertically downward; and a rotation unit configured to rotate around the cavity in the vertical direction, the rotation unit comprising a moving portion that is disposed outside the cavity and configured to rotate around the vertical direction in response to rotation of the rotation unit, the moving portion including a holding portion configured to hold an end of a curl formed when the linear structure hangs vertically downward from the cavity and then is taken vertically upward, the linear structure hanging further vertically downward from the end portion.

7. The frame system of claim 1, wherein the first actuator is a variable stiffness actuator.

8. The frame system according to claim 7, wherein the variable stiffness actuator is constituted by a pair of artificial muscles.

9. The frame system described in claim 8, wherein each of the artificial muscles includes: a wire for inputting the driving force to the first acceleration unit; a stopper configured to transmit the driving force to the wire when each of the artificial muscles contracts in a direction pulling the wire; and an elastic member configured to maintain tension in the wire when each of the artificial muscles relaxes and the stopper is released.

10. The frame system according to claim 8, wherein each of the artificial muscles is a fluid pressure artificial muscle.

11. The frame system of claim 3, wherein the third actuator is a variable stiffness actuator.

12. The frame system according to claim 1, wherein the moving unit is fitted with a load-relieving device.

13. The moving unit comprises: a base portion having a cavity that opens in the vertical direction, the base portion being configured to supply a plurality of linear structures including the first linear structure and the second linear structure of the load-relieving device from vertically above through the cavity to vertically below; and a rotation unit configured to rotate around the cavity in the vertical direction; the rotation unit comprises: a first moving portion that is arranged outside the cavity and configured to rotate and move around the vertical direction in response to rotation of the rotation unit; and a second moving portion that is arranged outside the cavity at a distance from the first moving portion in the vertical direction and configured to rotate and move around the vertical direction in response to rotation of the rotation unit while maintaining a positional relationship with the first moving portion; The frame system described in claim 12, wherein the first moving part is a first holding part configured to hold a first end of a curl formed when the first linear structure hangs vertically downward from the cavity and then is wrapped around vertically upward, the first linear structure including a first holding part that hangs further vertically downward from the first end toward one of the left and right sides of a user of the load-relieving device, and the second moving part is a second holding part configured to hold a second end of a curl formed when the second linear structure hangs vertically downward from the cavity and then is wrapped around vertically upward, the second linear structure including a second holding part that hangs further vertically downward from the second end toward the other of the left and right sides of the user.

14. The frame system of claim 1, wherein the movement unit is attached to a robotic arm.

15. The frame system described in claim 14, wherein the movable frame comprises: a third output pulley arranged at one of the one end and the other end of the movable frame; a third auxiliary pulley arranged at the other of the one end and the other end of the movable frame; an endless third belt stretched between the third output pulley and the third auxiliary pulley; and a third speed-up unit configured to receive input of a driving force from a third actuator and output the driving force input from the third actuator to the third output pulley, thereby speeding up movement of the third belt, and the moving unit is connected to the third belt.

16. The frame system according to claim 14, wherein the robot arm is attached to the movement unit via a balancer.

17. A system comprising: a first frame system disposed in a first space; and a second frame system disposed in a second space adjacent to the first space, wherein each of the first frame system and the second frame system comprises: a first fixed frame extending in a first direction, the first fixed frame comprising: a first output pulley disposed at one end of the first fixed frame; a first auxiliary pulley disposed at the other end of the first fixed frame; an endless first belt stretched between the first output pulley and the first auxiliary pulley; and a first speed increasing unit configured to receive an input of a driving force from a first actuator and to increase a speed of movement of the first belt by outputting the input driving force to the first output pulley; a second fixed frame extending in the first direction and disposed in parallel to the first fixed frame; a movable frame supported by the first fixed frame and the second fixed frame and extending in a second direction intersecting the first direction, the movable frame having one end connected to the first belt and configured to move along the first fixed frame and the second fixed frame in response to movement of the first belt; a moving unit supported by the movable frame and configured to move along the movable frame, wherein the first frame system and the second frame system are positioned at a distance such that a load-relief device can be attached to the moving units of both the first frame system and the second frame system at or near a boundary between the first space and the second space.

18. The system of claim 17, wherein one of the first space and the second space is a bathroom.

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