Continuum robot device and holding device

Abstract

To provide a continuum robot device with an improved posture maintenance function.SOLUTION: In order to achieve the above object, the invention provides a continuum robot device including: a base; first curved part which is supported by the base and in which a first wire and a second wire are disposed; and a drive part which drives at least one of the first wire and the second wire. A part of the second wire extends in a direction intersecting with the longitudinal direction of the first wire and is restrained so that its movement is restricted in a direction orthogonal to the longitudinal direction of the second wire. The drive part drives at least one of the first wire and the second wire and the other wire is fixed to the first curved part by fixing means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a continuum robot device or a gripping device using a continuum robot. [Background technology]

[0002] In recent years, in the field of industrial robots, robot devices equipped with a gripping device called a soft gripper have been developed to grip soft objects such as food and living organisms, as well as other fragile objects. Known gripping devices include those made of flexible materials such as elastomers and driven by air pressure, and those that drive a manipulator made of a continuum by pushing and pulling a linear member such as a wire.

[0003] FIG. 14 of Patent Document 1 discloses an embodiment of a manipulator using a wire-driven bending portion.

[0004] The manipulator with a wire-driven bending section disclosed in Patent Document 1 changes the bending state of the bending section in a direction perpendicular to the longitudinal direction by pushing and pulling the wire. Furthermore, when the bending section receives an external force due to contact with an object, the bending section can deform in a direction perpendicular to the longitudinal direction of the wire in response to the external force even if the amount of pushing and pulling the wire does not change. This allows the bending section to deform so as to follow the shape of the object. Furthermore, if the object is soft, it can be grasped softly without applying a local load.

[0005] However, it is difficult to maintain the posture of the manipulator against the external force perpendicular to the longitudinal direction of the curved part, and it is difficult to increase the gripping force beyond a certain level. For example, when gripping and lifting a heavy object, the curved part may be deformed by the load more than the shape of the heavy object, making it impossible to grip the object.

[0006] To address this issue, it is possible to increase the gripping force by increasing the bending rigidity of the wire, thereby reducing the amount of deformation caused by external forces. However, this would require a larger wire driving force, which would worsen the controllability of the manipulator. It would also impair the flexibility that is a characteristic of wire-driven manipulators. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 2022-75783 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a continuum robot device that has improved posture maintenance capabilities against external forces without compromising the controllability and flexibility of wire drive. [Means for solving the problem]

[0009] The present invention includes a base and a first bending portion supported by the base and having a first wire and a second wire disposed thereon; a driving unit that drives at least one of the first wire and the second wire; A continuum robot apparatus comprising: A portion of the second wire extends in a direction intersecting a longitudinal direction of the first wire and is constrained so as to limit movement of the second wire in a direction perpendicular to the longitudinal direction of the first wire; The present invention provides a continuum robot device, characterized in that at least one of the first wire and the second wire is driven by the driving unit, and the other wire is fixed to the first curved portion by a fixing means. Effect of the Invention

[0010] According to the present invention, by driving at least one of the first wire and the second wire while fixing the other wire, it is possible to impart posture maintenance and gripping rigidity while maintaining controllability and flexibility. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view of a continuum robot device in a first embodiment. [Diagram 2] 1A and 1B are diagrams illustrating a deformation state of a continuum robot due to an external force. [Diagram 3] FIG. 2 is a schematic perspective view showing the operation of the continuum robot device in the first embodiment. [Figure 4] FIG. 1 is a schematic perspective view showing a first modified example of the continuum robot device in the first embodiment. [Diagram 5] FIG. 11 is a schematic perspective view showing a second modified example of the continuum robot device in the first embodiment. [Figure 6] FIG. 11 is a schematic perspective view showing a third modified example of the continuum robot device in the first embodiment. [Figure 7] FIG. 11 is a schematic perspective view of a continuum robot device in Example 2. [Figure 8] FIG. 11 is a schematic perspective view showing a first modified example of the continuum robot device in the second embodiment. [Figure 9] FIG. 11 is a schematic diagram showing a robot hand in a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The continuum robot device for carrying out the present invention relates to a continuum robot device including a base, a first curved portion supported by the base and having a first wire and a second wire disposed thereon, and a drive unit for driving at least one of the first wire and the second wire. More specifically, a part of the second wire extends in a direction intersecting the longitudinal direction of the first wire, and adopts a structure in which the second wire is constrained so as to restrict movement in a direction perpendicular to the longitudinal direction of the second wire. In addition, at least one of the first wire and the second wire is driven by the drive unit, and the other wire is fixed to the first curved portion by a fixing means. The first wire may be composed of a plurality of wires that can be driven independently, and the same is true for the second wire. The continuum robot device may further include a switching means that operates to release the fixation of the other wire while the drive unit is driving, and to fix the other wire while the drive unit is stopped.

[0013] Hereinafter, the embodiments of the present invention will be described in detail with reference to the attached drawings and reference numerals, and explanations of common reference numerals will be omitted. Note that the coordinate axes in the examples are common. Furthermore, the present invention is not limited to the configurations of the following examples, and also includes embodiments derived from combinations of the examples described. EXAMPLES

[0014] The configurations of various continuum robot devices in the first embodiment will be described with reference to FIGS.

[0015] FIG. 1 is a schematic perspective view of a continuum robot device 21 in the first embodiment. The base 1 is fixed to a part of the device (not shown) according to the usage form of the continuum robot 20. A plurality of intermediate members 2 and a tip member 3 are fixed to an elastic member 4 extending in the longitudinal direction of the continuum robot 20 by an elastic member fixing part 13, and are connected at a predetermined interval. The elastic member 4 does not expand or contract in the longitudinal direction, but has elasticity that allows it to bend in a direction perpendicular to the longitudinal direction, which allows the continuum robot 20 to be deformed. Focusing on the base 1 and the intermediate member 2, a first wire guide hole 7 is opened on the side away from the side fixed to the elastic member 4, and a first wire 5 extends from the base 1 to the tip member 3 through the first wire guide hole 7. The first wire 5 is fixed to a first wire fixing part 6 arranged on the tip member 3.

[0016] On the other hand, in the base 1 and the intermediate member 2, the first wire 5 is configured to be slidable by the first wire guide hole 7. A driving means 8 is connected to the base 1 side of the first wire 5 as a driving unit. The driving means 8 is fixed to a part of the device (not shown) like the base 1, and can generate a force on the first wire 5 relative to the base 1. This allows the driving means 8 to push and pull the connected first wire 5 against the base 1, and to pay out or retract it in the longitudinal direction of the continuum robot 20. The driving means 8 can be in various forms, but for example, a rotary-linear conversion mechanism combining a rotary motor with a lead screw can be used. Specifically, the desired wire payout amount can be realized at the desired timing by rotating and stopping the rotary motor and accelerating and decelerating it according to a command signal from a control unit (not shown). Since the first wire 5 transmits the pushing and pulling amount by the driving means 8 to the tip member 3, it is desirable that the material has little expansion and contraction due to tension or compression force and has rigidity that does not buckle when compressed. Furthermore, the base 1 and the intermediate member 2 are provided with a second wire guide hole 11 at a position different from the first wire guide hole 7, and the second wire 9 extends from the base 1 to the tip member 3 through the second wire guide hole 11. In this embodiment, the position of the second wire guide hole 11 in each intermediate member 2 has a portion that changes monotonically and uniformly from near the first wire guide hole 7 to near the elastic member fixing portion 13 from the base 1 toward the tip member 3.

[0017] The second wire 9 is fixed to a second wire fixing portion 10 arranged on the tip member 3. On the other hand, in the base 1 and the intermediate member 2, the second wire 9 is configured to be slidable by a second wire guide hole 11. Since the positional relationship between the tip member 3 and the base 1 changes depending on the deformation state of the continuum robot 20, the second wire 9 slides on the base 1 side and is reeled out or retracted. On the base 1 side of the second wire 9, a fixing means 12 is fixed to a part of a device (not shown) similar to the base 1. The fixing means 12 can have various forms, and for example, a brake mechanism that fixes the wire by pinching it with a friction member can be used, and a brake mechanism that is electronically controlled by a control unit (not shown) can also be adopted depending on the application. The switching means that switches the state of the wire between a fixed state and a released state can be realized by an electronically controlled brake mechanism.

[0018] The fixing means 12 is configured to clamp and fix the second wire 9, so that the amount of payout of the second wire 9 can be fixed to the base 1. In other words, by fixing the second wire 9 with the fixing means 12, the amount of payout of the second wire 9 can be fixed so as not to change relative to the base 1 even if the curved state of the continuum robot 20 changes. Like the first wire 5, the second wire 9 is desirably made of a material that is less likely to expand or contract due to tension or compression and has the rigidity to not bend or buckle when compressed.

[0019] FIG. 2 is a schematic diagram for explaining a state of deformation due to an external force other than the force due to driving of the first wire, which is applied to the continuum robot 20 in FIG.

[0020] 2(a) is a diagram showing a state before the first wire 5 is pulled in by the driving means 8. In this state, no bending moment acts on the elastic member 4, and no tension acts on the first wire 5. In addition, the fixing means 12 is not fixing the second wire.

[0021] 2(b) is a diagram showing a state in which the first wire 5 is retracted by the driving means 8. By retracting the first wire 5, the amount of payout from the base 1 to the first wire fixing portion 6 of the tip member 3 becomes shorter, and the continuum robot is deformed into a state in which it is curved downward. Due to the deformation, a bending moment is generated in the elastic member 4, which is balanced with the tension of the first wire 5. In addition, with the transition from the state shown in FIG. 2(a) to the state shown in FIG. 2(b), the amount of payout of the second wire 9 from the base 1 to the second wire fixing portion 10 of the tip member 3 also changes, but the amount of change is different from that of the first wire 5.

[0022] FIG. 2(c) is a diagram showing a state in which the continuum robot 20 transitions from the state shown in FIG. 2(b) and the tip member 3 comes into contact with an object, so that an upward external force F is applied to the continuum robot 20. At this time, the continuum robot is deformed into an S-shape in which the bending moment of the elastic member 4, the tension of the first wire 5, and the external force F are balanced, and the tip member 3 moves upward. However, the driving means 8 is not moved, and the amount of the first wire 5 that is fed from the base 1 to the first wire fixing part 6 does not change. On the other hand, in the change from FIG. 2(b) to FIG. 2(c), the amount of the second wire 9 that passes through a different path from the first wire 5 changes passively with the deformation of the continuum robot 20. This is because, when comparing the arrangement of the second wire 9 and the arrangement of the first wire 5, the second wire 9 is not parallel to the first wire, and the second wire guide hole 11 is arranged so that the interval in the deformation direction perpendicular to the longitudinal direction of the first wire changes along the longitudinal direction.

[0023] FIG. 3(a) is a schematic perspective view showing a characteristic deformation operation of the continuum robot device in the first embodiment. Before deforming the continuum robot, the fixing means 12 is first opened to allow the amount of payout of the second wire 9 relative to the base 1 to be freely changed. Next, while the fixing means 12 is kept open, the driving means 8 is driven to retract the first wire 5 to make the continuum robot bent. At this time, the second wire 9 passively slides in response to the curvature of the continuum robot, and the amount of payout changes. At this time, it is desirable that the second wire 9 can slide smoothly so that no deflection occurs in the path from the second wire fixing portion 10 to the second wire guide hole 11 of the base 1. After the continuum robot is bent, the second wire 9 is fixed by the fixing means 12 here, and the amount of payout relative to the base 1 cannot be changed. Even if an external force is applied to the tip member 3 as shown in FIG. 2(c) while maintaining this state, the amount of payout of the second wire 9 must change in order to deform to the shape of FIG. 2(c). Therefore, the continuum robot cannot be deformed when the second wire 9 is fixed. That is, by fixing the second wire 9, the posture maintenance of the continuum robot can be improved, and the rigidity in the deformation direction perpendicular to the longitudinal direction can be improved. In addition, by releasing the fixation of the second wire 9, the continuum robot can be flexibly deformed by an external force. Furthermore, by setting the second wire 9 in a state in which the change in the amount of payout of the second wire 9 between the fixed state and the released state is suppressed by the fixing means 12, it is also possible to control the posture maintenance of the continuum robot. In the case where the fixing means 12 is a brake mechanism that fixes the second wire 9 by pinching it with a friction member, it is possible to change the force of pinching the wire with the friction member so that the second wire 9 starts to slip from the friction member when the tension applied to the second wire 9 reaches a certain value or more. As a result, when an excessive external force is applied due to a collision with the outside, the second wire 9 slides, and the continuum robot 20 can be deformed, and damage to the continuum robot 20 and external contact objects can be prevented.

[0024] As shown in FIG. 3(b), the fixing means 12 can be fixed to a part of an apparatus (not shown) via an elastic member such as a spring 121. Specifically, the fixing means 12 is disposed in a part of an apparatus (not shown), and is held so as to be movable in the longitudinal direction of the second wire 9 relative to the part of the apparatus, and is fixed to the apparatus via a connected elastic member. Therefore, in a state in which the fixing means 12 fixes the second wire 9, the fixing means 12 is displaced to the left and right in the figure according to the spring rigidity of the elastic member and the force applied by the second wire 9. In the case where the configuration of FIG. 3(b) is adopted, when the second wire 9 is fixed by the fixing means 12, the rigidity of the spring 121 of the fixing means 12 via the second wire 9 is added to the rigidity in the direction perpendicular to the longitudinal direction of the continuum robot 20 composed of the elastic member 4 and the like. This can be used in cases where a higher attitude maintenance is required than when the second wire 9 is not fixed, such as when gripping an object of moderate weight, but the attitude maintenance when completely fixed is not required.

[0025] Furthermore, as shown in FIG. 3(c), the fixing means 12 can be fixed to a part of a device (not shown) via a viscous member such as a damper 122. In this case, when the second wire 9 is fixed by the fixing means 12, it deforms to follow a slowly changing force applied to the continuum robot 20 and resists a suddenly changing force. The spring 121 and the damper 122 may be used together. The spring 121 and the damper 122 may be realized by mechanical means or by electrically controlled means using an actuator. By controlling the actuator connected to the second wire 9, a completely fixed state, a state having rigidity or viscosity, or a combination of these states can be freely realized. On the other hand, since the bending rigidity of the elastic member 4 is not changed, when the second wire 9 is not fixed, the force required to push and pull the first wire 5 is the same as in the past, and controllability is maintained. In other words, by switching the fixed state of the second wire 9, it is possible to improve the posture maintenance and rigidity in the deformation direction perpendicular to the longitudinal direction when necessary without impairing the controllability and flexibility of the continuum robot.

[0026] [Another configuration of Example 1] FIG. 4 is a schematic perspective view showing a first alternative configuration of the continuum robot device in Example 1. The configuration shown in FIG. 4 differs from the embodiment in FIG. 1 in that the roles of the first wire and the second wire are interchanged. Specifically, a fixing means 12 is connected to the first wire 5, and a driving means 8 is connected to the second wire 9. In this modification, the second wire 9 is pushed and pulled by the driving means 8 to bend the continuum robot. Furthermore, by fixing the first wire 5 by the fixing means 12 in the bent state, it is possible to improve the rigidity of the continuum robot in the deformation direction perpendicular to the longitudinal direction. That is, as long as the positional relationship between the first wire 5 and the second wire 9 does not change due to the action of the first wire guide hole 7 and the second wire guide hole 11, their roles can be interchanged.

[0027] FIG. 5 is a schematic perspective view showing a second alternative configuration of the continuum robot device in Example 1. The second configuration shown in FIG. 5 is different from the embodiment in FIG. 1 in that a part of the second wire guide hole 11 is a slit-shaped wire guide hole 11a. In the embodiment in FIG. 1, the position of the second wire guide hole 11 is different in all intermediate members 2, so all intermediate members 2 need to be designed differently. On the other hand, intermediate members 2 in which the second wire guide hole 11 is a slit-shaped guide hole 111 can be designed in common, and design and manufacturing costs can be reduced. The more the proportion of intermediate members 2 having slit-shaped second wire guide holes 111 is increased and the less the proportion of intermediate members 2 having hole-shaped second wire guide holes 11, the more the cost can be reduced. On the other hand, the slit-shaped second wire guide hole 111 cannot restrict the movement of the position of the second wire 9 in the deformation direction perpendicular to the longitudinal direction. Therefore, the more the proportion of intermediate members 2 in which the second wire guide hole 11 is slit-shaped is increased, the more the second wire 9 can move in the deformation direction perpendicular to the longitudinal direction according to the deformation state of the continuum robot. As a result, the degree of change in the payout amount of the second wire 9 changes depending on the deformation state of the continuum robot. When the degree of change in the payout amount of the second wire 9 changes depending on the deformation state of the continuum robot, the degree of improvement in the rigidity and posture stability of the continuum robot when the second wire 9 is fixed by the fixing means 12 changes. Therefore, the ratio of the hole shape and slit shape of the second wire guide hole 11 can be determined by considering the effect of the rigidity and posture stability of the continuum robot and the trade-off between the design and manufacturing costs.

[0028] FIG. 6 is a schematic perspective view showing a third alternative configuration of the continuum robot device in the first embodiment. The third configuration shown in FIG. 6 is different from the embodiment shown in FIG. 1 in that the distance between the second wire guide hole 11 and the first wire guide hole 7 in each intermediate member 2 is set so as to change non-monotonously from the base 1 to the tip member 3. In the modified example shown in FIG. 6, the position of the second wire guide hole 11 is set so that the path of the second wire 9 is V-shaped. This makes it possible to standardize the design of the intermediate members 2 having the same position of the second wire guide hole 11, thereby reducing costs. In addition, it becomes possible to separate the arrangement of the driving means 8 and the fixing means 12, improving the degree of freedom in design. On the other hand, as with the second modified example, the degree of change in the amount of payout of the second wire 9 with respect to the deformation state of the continuum robot changes compared to the embodiment shown in FIG. 1, and the degree of improvement in the rigidity and the degree of improvement in the attitude maintenance of the continuum robot when the second wire 9 is fixed by the fixing means 12 changes. Therefore, the path of the second wire 9 and the arrangement of the second wire guide hole 11 can be determined by considering the effect of the rigidity and attitude maintenance of the continuum robot and the trade-off between the design and manufacturing costs. In the modification of Fig. 6, an example in which the path of the second wire 9 is V-shaped is shown, but it is also possible to increase the number of turns to make the path zigzag. Also, it is possible to combine it with a slit-shaped second wire guide hole 111 as in the second modification. EXAMPLES

[0029] 7 and 8, the configuration of various continuum robot devices in the embodiment 2 will be described. The embodiment 2 differs from the embodiment 1 in that the continuum robot 20 can bend in a plurality of directions.

[0030] FIG. 7(a) is a schematic perspective view of a continuum robot device 21 in Example 2. The base 1 is fixed to a part of a device (not shown) according to the usage form of the continuum robot 20. A plurality of intermediate members 2 and a tip member 3 are fixed to an elastic member 4 extending in the longitudinal direction by an elastic member fixing part 13, and are connected at a predetermined interval. The base 1, the intermediate member 2, and the tip member 3 are ring-shaped, and various equipment such as a camera can be passed through the internal space in an endoscope application. The elastic member 4 does not expand or contract in the longitudinal direction, but has elasticity that allows it to bend in a direction perpendicular to the longitudinal direction, which allows the continuum robot 20 to be deformed. A first wire guide hole 7 is opened on the side of the base 1 and the intermediate member 2 away from the side fixed to the elastic member 4, and two first wires 5 (5a, 5b) extend from the base 1 to the tip member 3 through the first wire guide hole 7. The first wire 5 is fixed to a first wire fixing part 6 of the tip member 3. On the other hand, in the base 1 and the intermediate member 2, the first wire 5 is configured to be slidable by the first wire guide hole 7. Driving means 8 (8a, 8b) are connected to the base 1 side of the first wire 5. The driving means 8 is fixed to a part of a device (not shown) like the base 1, and can generate a force on the first wire 5 relative to the base 1. As a result, the driving means 8 can push and pull the first wire 5 against the base 1 to reel it in and out in the longitudinal direction of the continuum robot 20. The two first wires 5 (5a, 5b) are arranged in different directions as seen from the elastic member 4 in a plane perpendicular to the longitudinal direction. Usually, the first wires 5a, 5b and the elastic member 4 are arranged to form an equilateral triangle, but other arrangements are also possible. As a result, by pushing and pulling the two first wires 5, respectively, it is possible to manipulate the deformation in two directions (arrows a, b) perpendicular to the longitudinal direction of the continuum robot 20. Furthermore, the base 1 and the intermediate member 2 are provided with a second wire guide hole 11 at a position different from the first wire guide hole 7, and the second wire 9 extends from the base 1 to the tip member 3 through the second wire guide hole 11. The position of the second wire guide hole 11 in each intermediate member 2 is provided so as to change monotonically and uniformly from near the first wire guide hole 7a to near the elastic member fixing portion 13 from the base 1 to the tip member 3.The second wire 9 is fixed to the elastic member of the tip member 3 and the second wire fixing portion 13. Meanwhile, in the base 1 and the intermediate member 2, the second wire 9 is configured to be slidable by the second wire guide hole 11. Since the positional relationship between the tip member 3 and the base 1 changes depending on the deformation state of the continuum robot 20, the second wire 9 slides on the base 1 side and is paid out or retracted. On the base 1 side of the second wire 9, a fixing means 12 is fixed to a part of a device (not shown) similar to the base 1. By fixing the second wire 9 with the fixing means 12, it is possible to fix the second wire 9 so that the amount of payout of the second wire 9 does not change relative to the base 1 even if the curved state of the continuum robot 20 changes. Various configurations that the fixing means 12 can take are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0031] FIG. 7(b) is an example of the intermediate member 2 of the continuum robot device 21 in the second embodiment, and shows the positional relationship between the elastic member fixing portion 13, the first wire guide hole 7 (7a, 7b), and the second wire guide hole 11. In all intermediate members 2, the positions of the elastic member fixing portion 13 and the first wire guide holes 7a, 7b are the same, but the position of the second wire guide hole 11 changes between the elastic member fixing portion 13 and the first wire guide hole 7a. Arrows a and b respectively represent the deformation direction operated by the first wire 5a, 5b passing through the first wire guide holes 7a, 7b. When the payout amount of the first wire 5a is operated, the length from the base 1 to the tip member 3 of the elastic member 4 passing through the elastic member fixing portion 13 and the first wire 5b passing through the first wire guide hole 7b does not change. Therefore, the perpendicular vector dropped from the first wire guide hole 7a to the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7b becomes the deformation direction that can be operated by the first wire 5a, that is, the arrow a. Similarly, the perpendicular vector dropped from the first wire guide hole 7b to the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7a is the deformation direction that can be operated by the first wire 5b, that is, the arrow b. When the positional relationship of the elastic member fixing portion 13, the first wire guide hole 7a, and the first wire guide hole 7b is an equilateral triangle, the arrows a and b are not perpendicular but are in a 60 degree relationship, but by combining them, it is possible to operate two-free deformation perpendicular to the longitudinal direction of the continuum robot 20. Since the second wire guide hole 11 is arranged between the elastic member fixing portion 13 and the first wire guide hole 7a so as to change along the ring shape of the intermediate member 2, the second wire 9 extends approximately along the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7a. Therefore, when the continuum robot 20 deforms in the direction along the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7a, the payout amount of the second wire 9 changes. This direction is perpendicular to the arrow b, and in both bending by manipulation of the first wire 5b and S-shaped deformation by an external force, deformation in the direction of the arrow b causes almost no change in the amount of payout of the second wire 9. Furthermore, as the deformation direction approaches the straight line connecting the elastic member fixing part 13 and the first wire guide hole 7a from the arrow b, the amount of payout of the second wire 9 increases.Although the second wire 9 is not parallel to the arrow a, it is not perpendicular thereto, and therefore the amount of payout of the second wire 9 changes depending on the deformation in the direction of the arrow a, both in bending due to the operation of the first wire 5a and in S-shape deformation due to an external force. Therefore, by fixing the second wire 9 with the fixing means 12, it is possible to improve the posture maintenance and rigidity of the continuum robot in the direction along the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7a. It is also possible to improve the posture maintenance and rigidity of the continuum robot against deformation in the direction of the arrow a operated by the first wire 5a. On the other hand, flexibility can be maintained against deformation in the direction of the arrow b operated by the first wire 5b.

[0032] FIG. 7(c) is a schematic perspective view showing the deformation operation of the continuum robot device 21 in the second embodiment. Before the deformation operation, the fixing means 12 is opened to allow the second wire 9 to freely change the amount of payout relative to the base 1. Next, the driving means 8 is driven to retract the two first wires 5a and 5b as much as necessary, and the continuum robot 20 is curved. At this time, the second wire 9 slides in response to the curvature of the continuum robot 20, and the amount of payout changes. At this time, it is desirable that the second wire 9 can slide smoothly so that no deflection occurs in the path from the second wire fixing portion 13 to the second wire guide hole 11 of the base 1. Here, the fixing means 12 fixes the amount of payout of the second wire 9 relative to the base 1, and the amount of payout relative to the base 1 cannot be changed. As a result, flexibility is maintained in the direction of the arrow b operated by the first wire 5b, and rigidity against deformation is improved in directions including the direction of the arrow a operated by the first wire 5a close to the direction perpendicular to the arrow b. As a result, it is possible to improve the posture maintenance of the continuum robot 20. In this embodiment, the second wire 9 is disposed between the first wire 5a and the elastic member 4, but it is also possible to dispose it between the first wire 5b and the elastic member 4, or between the first wire 5a and the first wire 5b.

[0033] [Another configuration of Example 2] FIG. 8(a) is a schematic perspective view showing a first alternative configuration of the continuum robot device 21 in the second embodiment. The first alternative configuration is different from the second embodiment shown in FIG. 7 in that it includes two second wires 9a, 9b and two fixing means 12a, 12b that are paired with the second wires 9a, 9b. The position of the second wire guide hole 11a in each intermediate member 2 is provided so as to change monotonically and uniformly from near the first wire guide hole 7a to near the elastic member fixing portion 13 from the base 1 toward the tip member 3. Similarly, the position of the second wire guide hole 11b in each intermediate member 2 is provided so as to change monotonically and uniformly from near the first wire guide hole 7b to near the elastic member fixing portion 13 from the base 1 toward the tip member 3.

[0034] FIG. 8(b) is an example of an intermediate member 2 in a first alternative configuration of the continuum robot device 21 in the second embodiment, and shows the positional relationship between the elastic member fixing portion 13, the first wire guide hole 7 (7a, 7b), and the second wire guide hole 11 (11a, 11b). This is different from the second embodiment shown in FIG. 7 in that two second wire guide holes 11 are provided. In all intermediate members 2, the positions of the elastic member fixing portion 13 and the first wire guide hole 7 are the same, but the positions of the second wire guide holes 11 are different. The second wire guide hole 11a is disposed between the elastic member fixing portion 13 and the first wire guide hole 7a so as to change along the ring shape of the intermediate member 2, so that the second wire 9a extends approximately along the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7a. Therefore, when the continuum robot 20 is deformed in the direction along the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7a, the payout amount of the second wire 9a changes. This direction is perpendicular to the arrow b, and the amount of the second wire 9 being let out is almost the same when the first wire 5b is bent by the operation and the S-shaped deformation is caused by an external force, when the second wire 9 is deformed in the direction of the arrow b. Therefore, by fixing the second wire 9a with the fixing means 12a, it is possible to improve the posture maintenance of the continuum robot and improve its rigidity in the direction along the straight line connecting the elastic member fixing part 13 and the first wire guide hole 7a. Similarly, the second wire guide hole 11b is disposed between the elastic member fixing part 13 and the first wire guide hole 7b so as to change along the ring shape of the intermediate member 2, so that the second wire 9b extends almost along the straight line connecting the elastic member fixing part 13 and the first wire guide hole 7b. Therefore, when the continuum robot 20 is deformed in the direction along the straight line connecting the elastic member fixing part 13 and the first wire guide hole 7b, the amount of the second wire 9b being let out is changed. This direction is perpendicular to the arrow a, and the amount of the second wire 9 being let out is almost the same when the first wire 5a is bent by the operation and the S-shaped deformation is caused by an external force, when the second wire 9 is deformed in the direction of the arrow a. Therefore, by fixing the second wire 9b with the fixing means 12b, it is possible to improve the posture maintenance ability and rigidity of the continuum robot in the direction along the straight line connecting the elastic member fixing portion 13 and the first wire guide hole 7b.When the positional relationship between the elastic member fixing portion 13, the first wire guide hole 7a, and the first wire guide hole 7b forms an equilateral triangle, the angle between the line connecting the elastic member fixing portion 13 and the first wire guide hole 7a and the line connecting the elastic member fixing portion 13 and the first wire guide hole 7b is 60 degrees, and by combining these, it is possible to improve the posture maintenance of the two freedoms perpendicular to the longitudinal direction of the continuum robot 20 and improve the rigidity.

[0035] FIG. 8(c) is a schematic perspective view showing a deformation operation in the first alternative configuration of the continuum robot device 21 in the second embodiment. Before the deformation operation, the fixing means 12 is opened to allow the second wire 9 to slide freely relative to the second wire guide hole 11 of the base 1. Next, the driving means 8 is driven to change the payout amount of the two first wires 5a and 5b, and the continuum robot 20 is curved in the directions of the arrows a and b, respectively. At this time, the two second wires 9a and 9b slide in response to the curvature of the continuum robot 20, and the payout amount changes. Here, the two second wires 9a and 9b are fixed to the device by the fixing means 12a and 12b, and the payout amount relative to the base 1 cannot be changed. As a result, the continuum robot 20 cannot be deformed in two directions perpendicular to the longitudinal direction, that is, the linear direction connecting the elastic member fixing portion 13 and the first wire guide hole 7a and the linear direction connecting the elastic member fixing portion 13 and the first wire guide hole 7b, and the posture maintenance of the continuum robot 20 can be improved. By fixing only one of the two second wires 9, it is possible to improve the rigidity in only one of the two directions perpendicular to the longitudinal direction, and to make the other direction flexible and deformable by an external force. In addition, for example, by using an electric control means using an actuator for the fixing means 12, the rigidity of each of the second wires 9a and 9b can be freely changed. This makes it possible to set the direction in which the posture maintenance is improved without being restricted by the two directions determined by the arrangement of the second wires 9a and 9b.

[0036] In the embodiment 2 shown in Figs. 7 and 8, the base 1, the intermediate member 2, and the tip member 3 are in a ring shape, but in the present invention, shapes other than rings are also possible. For example, a flat plate shape similar to that of the embodiment 1 is also possible, and any shape that does not prevent deformation can be used. In the ring shape shown in the embodiment 2, the direction of deformation caused by the first wire 5 and the direction of suppressing deformation caused by the second wire 9 do not match, but it is possible to make them match depending on the arrangement of the first wire 5 and the second wire 9. Also, in the embodiment 2, various forms of the fixing means 12 shown in the embodiment 1 can be combined. Furthermore, various ways of passing the second wire 9 shown in the modified example of the embodiment 1 are possible. EXAMPLES

[0037] The configuration of a robot hand using a continuum robot in the third embodiment will be described with reference to FIG.

[0038] FIG. 9 is a schematic diagram showing a robot hand in Example 3. Two continuum robots 20a and 20b described in Example 1 or Example 2 are installed facing each other on the same base 1. The common base 1 is installed on a device (such as a robot arm or a slider) not shown. The driving means 8 and the fixing means 12 associated with the two continuum robots are also installed on a device not shown, like the base 1. As a result, the driving means 8 can push and pull the connected first wire 5 against the base 1, and can pay out or retract the continuum robot 20 in the longitudinal direction. In addition, the fixing means 12 can fix the payout amount of the second wire 9 against the base 1. The two continuum robots 20 constitute two fingers of the robot hand. By driving the driving means 8 associated with the two continuum robots and retracting the first wire 5, an object not shown can be sandwiched and grasped by the two curved fingers. It is preferable that the two continuum robots 20 are installed facing each other so that the first wire 5 faces inward. As a result, by retracting the first wire 5, the two continuum robots 20 bend inward, and the object can be grasped by sandwiching it between them. At this time, tension is applied to the first wire 5. On the other hand, if the continuum robot 20 is installed so that the first wire 5 is on the outside, it is necessary to drive the first wire 5 in the direction of unwinding in order to bend it inward, and when the object is grasped, a force is applied to the first wire 5 in the compression direction, which may cause buckling. Therefore, it is desirable to avoid installing the continuum robot 20 so that the first wire 5 is on the outside. When grasping an object, the continuum robot 20 can flexibly deform by an external force, so that even a soft object can be grasped without destroying its shape by deforming according to the shape of the object. In addition, in the conventional robot hand, when the position of the object to be grasped is fixed, excessive force may be applied to the object to be grasped unless the exact position of the object to be grasped is specified. However, in the gripping device illustrated in this embodiment, the continuum robot 20 can flexibly deform in response to external forces, so by deforming to match the position of the object to be grasped, it is possible to perform a gripping operation even if the exact position is not known.By fixing the second wire 9 with the fixing means 12 while gripping the object, the posture maintenance can be improved so that the shape of the gripped state of the continuum robot 20 can be maintained. In a robot hand using a conventional continuum robot, for example, when trying to lift a soft but heavy object, even if the robot can flexibly grip the object, the weight of the continuum robot can cause the robot to deform, making it impossible to maintain the gripped state. In the robot hand of this embodiment, the rigidity of the continuum robot 20 can be increased and the posture maintenance can be improved by fixing the second wire 9 so as to maintain the shape after gripping the object flexibly according to the shape of the object, so that the gripped state can be maintained even if the weight of the object is added. In addition, when performing a gripping operation, it is possible to fix the second wire 9 only on the continuum robot 20 on the side on which the load of the object is applied to increase the rigidity and improve the posture maintenance, and to leave the second wire 9 unfixed on the continuum robot 20 on the side on which the load of the object is not applied to maintain flexibility.

[0039] In this embodiment, a robot hand configuration with two fingers using two continuum robots 20 has been described, but a configuration with three or more fingers can also be used.

[0040] As described above, the continuum robot 20 of the present invention and the robot hand using the continuum robot 20 can exhibit the effect of improving the rigidity of deformation and the stability of posture as required by a simple structure that adds the second wire 9 and the fixing means 12. As a result, for example, when the continuum robot 20 is applied to an endoscope, it can flexibly deform to match the surrounding shape during insertion, and when it is inserted to the target position, it can improve the stability of posture and perform observation in a stable posture. When applied to a robot hand, it can maintain flexibility until it grasps an object, and can deform the continuum robot 20 to match the shape and position of the object to grasp it. At the point of grasping, it becomes possible to lift or move the object while maintaining the grasped shape by improving the rigidity in a timely manner. [Explanation of symbols]

[0041] 1 base 2 Intermediate parts 3 Tip Parts 4 Elastic member (bending part) 5 First Wire 6 First wire fixing part 7 First wire guide hole 8 Driving Means 9 Second Wire 10 Second wire fixing part 11 Second wire guide hole 111 Slit-shaped second wire guide hole 12 Fixing means 121 Spring member 122 Damper 13 Elastic member fixing part 20 Continuum Robot 21 Continuum Robot Device

Claims

1. The base and a first bending portion supported by the base and having a first wire and a second wire disposed thereon; a driving unit that drives at least one of the first wire and the second wire; A continuum robot apparatus comprising: A portion of the second wire extends in a direction intersecting a longitudinal direction of the first wire and is constrained so as to limit movement of the second wire in a direction perpendicular to the longitudinal direction of the first wire; A continuum robot device, characterized in that at least one of the first wire and the second wire is driven by the driving unit, and the other wire is fixed to the first curved portion by a fixing means.

2. While the driving unit is driving, the fixing means releases the fixing of the other wire, 2. The continuum robot apparatus according to claim 1, wherein the fixing means has a switching means which operates to fix the other wire while the driving unit is stopped.

3. 3. The continuum robot device according to claim 1, further comprising a portion in which a distance between the first wire and the second wire in a direction intersecting a longitudinal direction of the first curved portion changes monotonically along the longitudinal direction.

4. 3. The continuum robot device according to claim 1, wherein the one wire comprises a plurality of wires that can be driven independently and are connected to a plurality of the driving units that respectively drive the one wire.

5. 3. The continuum robot device according to claim 1, wherein the other wire is a plurality of wires that can be driven independently, and the robot device comprises a plurality of fixing means for fixing the other wires, respectively.

6. 3. The continuum robot device according to claim 1, wherein the first curved portion comprises a plurality of intermediate members arranged at intervals and through which the first wire and the second wire pass.

7. 3. The continuum robot device according to claim 1, wherein at least one of the intermediate members is provided with a slit, and a wire connected to the fixing means passes through the slit.

8. A gripping device comprising a plurality of continuum robot devices according to claim 1 or 2 arranged on a common base, the plurality of continuum robot devices each having a curved portion that performs a gripping operation to grip an object.

9. 9. The gripping device according to claim 8, wherein, when performing the gripping operation, the other wire is fixed by the fixing means provided in one of the plurality of continuum robot devices to which a greater load of the object is applied.

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