Continuum robot and control method and storage medium therefor

Abstract

A continuum robot, a control method thereof, and a storage medium are provided. In a wire-driven continuum robot, a bending angle of a following bending segment is controlled to reach a first target bending angle in accordance with a first bending angle configuration regarding the bending angle of the following bending segment set in correspondence with forward movement of the continuum robot and in accordance with an input first target bending angle of a distal bending segment. Before an amount of movement of the forward movement reaches a first movement amount, the following control is performed. More specifically, a second bending angle configuration different from the first bending angle configuration is set, and the bending angle of the following bending segment reaches a second target bending angle in accordance with the second bending angle configuration by further forward movement of the continuum robot.

Description

Technical Field

[0001] The present invention relates to a continuous robot including a bendable portion and a control method thereof, as well as a storage medium storing programs for enabling a computer to be used as various units of the continuous robot, the bendable portion being provided with a plurality of bending segments configured to bend segments by means of wires. Background Technology

[0002] Continuum robots, also known as continuum robots, include a bendable section equipped with multiple bending sections with flexible structures. The shape of the continuum robot is controlled by the deformation of these bending sections. Compared to rigid-link robots, which include rigid links, continuum robots have two main advantages. First, they can move along curves in confined spaces where rigid-link robots would get stuck, or in environments with scattered objects. Second, because of their inherent flexibility, continuum robots can be manipulated without damaging fragile targets. Continuum robots do not always need to detect external forces, which is required for rigid-link robots. Utilizing this characteristic, continuum robots hold promise for applications in the medical field (such as sheaths or catheters for endoscopes) and robotics in hazardous environments (such as rescue robots).

[0003] Patent Document 1 describes a control method for a continuum robot used as an endoscope that enters a space. Specifically, in Patent Document 1, in all groups of adjacent bending segments, the bending shape is continuously propagated by controlling the bending shape of the preceding bending segment to be propagated to the subsequent bending segment based on the forward movement of the base unit of the continuum robot.

[0004] Reference List

[0005] Patent documents

[0006] PTL 1: U.S. Patent Application Publication No. 2012 / 0271109 Summary of the Invention

[0007] Technical issues

[0008] Patent Document 1 describes a control method in which the bending shape of a preceding bending segment is propagated to subsequent bending segments whenever the base unit of the continuum robot moves forward by the length of a bending segment. However, Patent Document 1 does not assume that the propagation of the bending shape to subsequent bending segments occurs when the displacement of the base unit is less than the length of the bending segment and the bending shape of the preceding bending segment changes. Therefore, the technology described in Patent Document 1 has the following problem: because the difference between the operator's intention and the shape of the continuum robot increases, and the continuum robot has difficulty entering the target path, the operability of the continuum robot cannot be improved.

[0009] The present invention was designed in view of such problems, and its purpose is to provide a structure that can improve the operability of a continuum robot.

[0010] Technical solutions to the problem

[0011] According to one aspect of the invention, a continuum robot includes: a base unit; a distal bending segment configured to bend via a conductor for driving the distal segment; a following bending segment disposed between the distal bending segment and the base unit, and configured to bend via a conductor for driving the following segment; a drive unit configured to independently drive the conductor for the distal segment and the conductor for the following segment; a movement unit configured to move the base unit, the distal bending segment, and the following bending segment forward as a whole; and a control unit, wherein the control unit is configured to, according to a first bending angle of the following bending segment, set according to a first target bending angle of the distal bending segment corresponding to the forward movement of the continuum robot and according to an input first bending angle of the distal bending segment. A profile is configured to control the bending angle of the following bending segment to achieve a first target bending angle. The profile further specifies that, after the distal bending segment bends at the first target bending angle, the following bending segment bends and moves forward according to the first bending angle profile. If, before the forward displacement reaches a first displacement corresponding to the length of the following bending segment, the target bending angle of the distal bending segment changes from the first target bending angle to a second target bending angle, a second bending angle profile, different from the first bending angle profile, is set. Furthermore, through further forward movement of the continuum robot, the bending angle of the following bending segment reaches the second target bending angle according to the second bending angle profile.

[0012] In addition, the present invention includes a control method for a continuum robot to be executed by the control system of the continuum robot described above, and a program for using a computer as the control system of the continuum robot described above.

[0013] Advantages of the present invention

[0014] According to exemplary embodiments of the present invention, the operability of a continuum robot can be improved. Attached Figure Description

[0015] [ Figure 1A ] Figure 1A This is a diagram illustrating an example of a schematic construction of a continuum robot according to a first exemplary embodiment of the present invention.

[0016] [ Figure 1B ] Figure 1B It is shown Figure 1A The figure shows an example of a detailed schematic construction of a curved segment of a continuum robot.

[0017] [ Figure 2 ] Figure 2 It is shown Figure 1B The figure shows an example of the arrangement of the three conductors (a to c) in the xy plane.

[0018] [ Figure 3 ] Figure 3 This is a diagram illustrating an example of a schematic construction of a control system for a continuum robot according to a first exemplary embodiment of the present invention.

[0019] [ Figure 4 ] Figure 4 This illustrates a first exemplary embodiment of the invention and shows... Figure 1A The figure shows an example of a kinematic model of a continuum robot.

[0020] [ Figure 5 ] Figure 5 This illustrates a first exemplary embodiment of the invention and shows... Figure 1A The figure shows an example of a kinematic model of a continuum robot.

[0021] [ Figure 6 ] Figure 6 This is a diagram illustrating an example of front-end following control of a continuum robot according to a first exemplary embodiment of the present invention.

[0022] [ Figure 7A ] Figure 7A This is a diagram illustrating a first exemplary embodiment of the invention and showing an example of a calculation process for the target bending angle of subsequent bending segments obtained after considering the change caused by the change in the target bending angle of the furthest bending segment. This calculation process will be performed by... Figure 3 The subsequent bending angle calculation unit is executed.

[0023] [ Figure 7B ] Figure 7BThis is a diagram illustrating a first exemplary embodiment of the invention and showing an example of a calculation process for the target bending angle of subsequent bending segments obtained after considering the change caused by the change in the target bending angle of the furthest bending segment. This calculation process will be performed by... Figure 3 The subsequent bending angle calculation unit is executed.

[0024] [ Figure 8 ] Figure 8 This is a flowchart illustrating an example of the processing procedure of a control method for a continuum robot, which is executed by the control system 10 of the continuum robot according to a first exemplary embodiment of the present invention.

[0025] [ Figure 9 ] Figure 9 This is a diagram illustrating a first exemplary embodiment of the present invention and showing an example of simulation results of the target bending angle of subsequent bending segments obtained when a first change operation command and a second change operation command for the target bending angle of the furthest bending segment are issued in the same direction.

[0026] [ Figure 10A ] Figure 10A This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 9 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0027] [ Figure 10B ] Figure 10B This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 9 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0028] [ Figure 10C ] Figure 10C This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 9 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0029] [ Figure 10D ] Figure 10D This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 9 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0030] [ Figure 11 ] Figure 11 This is a diagram illustrating a first exemplary embodiment of the present invention and showing an example of simulation results of the target bending angle of subsequent bending segments obtained when a first change operation command and a second change operation command for the target bending angle of the furthest bending segment are issued in opposite directions.

[0031] [ Figure 12A ] Figure 12A This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 11 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0032] [ Figure 12B ] Figure 12B This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 11 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0033] [ Figure 12C ] Figure 12C This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 11 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0034] [ Figure 12D ] Figure 12D This illustrates a first exemplary embodiment of the invention and shows a reflection Figure 11 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0035] [ Figure 13 ] Figure 13 This is a diagram illustrating a second exemplary embodiment of the invention and showing an example of a calculation process for the target bending angle of subsequent bending segments obtained after considering the change caused by the change in the target bending angle of the furthest bending segment. This calculation process will be performed by... Figure 3 The subsequent bending angle calculation unit is executed.

[0036] [ Figure 14 ] Figure 14 This is a diagram illustrating a second exemplary embodiment of the present invention and showing an example of the simulation results of the target bending angle of subsequent bending segments obtained when a first change operation command and a second change operation command for the target bending angle of the furthest bending segment are issued in the same direction.

[0037] [ Figure 15A ] Figure 15A This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 14 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0038] [ Figure 15B ] Figure 15B This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 14The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0039] [ Figure 15C ] Figure 15C This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 14 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0040] [ Figure 15D ] Figure 15D This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 14 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0041] [ Figure 16 ] Figure 16 This is a diagram illustrating a second exemplary embodiment of the present invention and showing an example of simulation results of the target bending angle of subsequent bending segments obtained when a first change operation command and a second change operation command for the target bending angle of the furthest bending segment are issued in opposite directions.

[0042] [ Figure 17A ] Figure 17A This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 16 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0043] [ Figure 17B ] Figure 17B This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 16 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0044] [ Figure 17C ] Figure 17C This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 16 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0045] [ Figure 17D ] Figure 17D This illustrates a second exemplary embodiment of the invention and shows a reflection Figure 16 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0046] [ Figure 18 ] Figure 18This is a diagram illustrating a third exemplary embodiment of the invention and showing an example of a calculation process for the target bending angle of subsequent bending segments obtained after considering the change caused by the change in the target bending angle of the furthest bending segment. This calculation process will be performed by... Figure 3 The subsequent bending angle calculation unit is executed.

[0047] [ Figure 19 ] Figure 19 This is a diagram illustrating a third exemplary embodiment of the present invention and showing an example of the simulation results of the target bending angle of subsequent bending segments obtained when a first change operation command and a second change operation command for the target bending angle of the furthest bending segment are issued in the same direction.

[0048] [ Figure 20A ] Figure 20A This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 19 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0049] [ Figure 20B ] Figure 20B This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 19 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0050] [ Figure 20C ] Figure 20C This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 19 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0051] [ Figure 20D ] Figure 20D This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 19 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0052] [ Figure 21 ] Figure 21 This is a diagram illustrating a third exemplary embodiment of the present invention and showing an example of a simulation result of the target bending angle of a subsequent bending segment obtained when a first change operation command and a second change operation command for the target bending angle of the furthest bending segment are issued in opposite directions.

[0053] [ Figure 22A ] Figure 22A This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 21 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0054] [ Figure 22B ] Figure 22B This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 21 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0055] [ Figure 22C ] Figure 22C This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 21 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results.

[0056] [ Figure 22D ] Figure 22D This illustrates a third exemplary embodiment of the invention and shows a reflection of... Figure 21 The figure shows an example of the operational state of the bendable portion of a continuum robot, illustrating simulation results. Detailed Implementation

[0057] Hereinafter, a mode for implementing the invention (exemplary embodiment) will be described with reference to the accompanying drawings. A specific continuum robot includes: a base unit; a distal bending segment configured to bend via a conductor for driving the distal segment; and a following bending segment disposed between the distal bending segment and the base unit, configured to bend via a conductor for driving the following segment. The continuum robot further includes: a drive unit configured to independently drive the conductors for the distal segment and the following segment; a movement unit configured to move the base unit, the distal bending segment, and the following bending segment forward as a whole; and a control unit.

[0058] The control unit is configured to control the bending angle of the following bending segment to achieve the first target bending angle, based on a profile of the bending angle of the following bending segment set according to the first target bending angle of the input distal bending segment and corresponding to the forward movement of the continuum robot.

[0059] Furthermore, if the distal bending segment bends at a first target bending angle and then the following bending segment bends and moves forward according to the configuration of the first bending angle, and the target bending angle of the distal bending segment changes from the first target bending angle to the second target bending angle before the forward movement reaches a first movement corresponding to the length of the following bending segment, the control unit performs the following control.

[0060] More specifically, a second bending angle configuration is set that is different from the first bending angle configuration, and the second target bending angle is achieved by further forward movement of the continuum robot, following the bending angle of the bending segment according to the second bending angle configuration.

[0061] First, a first exemplary embodiment of the present invention will be described.

[0062] Figure 1A This is a diagram illustrating an example of a schematic construction of a continuum robot 100 according to a first exemplary embodiment of the present invention. Figure 1A The base unit 140 and the flexible portion 170 are shown as a configuration of the continuum robot 100.

[0063] The flexible portion 170 is a component equipped with multiple bending segments 171 to 173 configured to be bent by a conductor (linear member). Specifically, Figure 1A The n bending segments corresponding to the (n-2)th bending segment 171, the (n-1)th bending segment 172, and the nth bending segment 173 are shown. Furthermore, in Figure 1A In the middle, the bending angle of the bending segment 173 is denoted by θ. n The bending angle of the bending segment 172 is represented by θ. n-1 The bending angle of the bending segment 171 is represented by θ. n-2 The base unit 140 is a component that supports the flexible portion 170. An actuator is disposed inside the base unit 140. Figure 1A (Not shown in the image), this actuator is a driving unit for independently driving the conductors used for bending segments 171 to 173. Furthermore, Figure 1A An xyz coordinate system is shown, wherein the origin O is set at a predetermined position (e.g., the center position) on the top surface 141 of the base unit 140, the travel direction of the continuum robot 100 (e.g., the forward movement direction) is set as the z-direction, and mutually orthogonal directions orthogonal to the z-direction are set as the x-direction and y-direction. In this way, in addition to bending operations performed by the plurality of bending segments 171 to 173 included in the bendable portion 170 of the continuum robot 100, the bending segments 171 to 173 and the base unit 140 can also move as a whole (forward movement) in the z-direction via a position control slider (movement unit). At this time, Figure 1A The displacement z of the base element 140 is shown. b It serves as an indicator of the amount of movement (forward movement, displacement) of the continuum robot 100 in the z-direction.

[0064] In the following text, the farthest bending segment in a continuum robot will sometimes be described as an example of a distal bending segment. Subsequent bending segments following the farthest bending segment will sometimes be described as examples of following bending segments.

[0065] exist Figure 1A In the bendable portion 170, the bending segment 173 is the farthest bending segment located at the furthest position from the base unit 140 among the multiple bending segments 171 to 173 included in the bendable portion 170. The bending segment 172 (and similarly for bending segment 171) is a following bending segment located between the base unit 140 and the farthest bending segment 173, and follows the farthest bending segment 173 as the continuum robot 100 moves forward. When the continuum robot 100 moves forward ( Figure 1A In the positive z-direction), the bending segment 173, which is the farthest bending segment, becomes the leading bending segment.

[0066] Figure 1B It is shown Figure 1A The diagram shows an example of a detailed schematic construction of a curved segment 171 of the schematic structure of the continuum robot 100. In other words, Figure 1B A detailed schematic construction of the curved segment 171, which is located at the proximal curved segment closest to the base unit 140, is shown. Figure 1B In, with Figure 1A Components shown in the figures are assigned the same reference numerals, and their detailed descriptions will be omitted. Figure 1B In this context, θ1 represents the bending angle of the bending segment 171, ζ1 represents the lateral displacement angle of the bending segment 171, and ρ1 represents the radius of curvature of the bending segment 171 (corresponding to...). Figure 1B (The line segment connecting point O and point w1).

[0067] The orientation (bending shape) of the continuum robot 100 is controlled by connecting the wires (linear members) 111 to 113 to the connection portions 121 to 123 at the distal end 160 of the curved segment 171 and by pushing or pulling the wires 111 to 113 by actuators 131 to 133 mounted inside the base unit 140. Here, actuator 131 is a drive unit for driving the wire 111, actuator 132 is a drive unit for driving the wire 112, and actuator 133 is a drive unit for driving the wire 113.

[0068] The continuum robot 100 also includes wire guides 161 to 164 in the bending segment 171, which are components for guiding wires 111 to 113. Besides the method of discretely arranging multiple components, accordion-shaped or mesh-like continuum components can also be used as wire guides 161 to 164. Wire guides 161 to 164 are fixed to wire 111 at fixed portions 150 to 153. Figure 1B In the diagram, a dashed line is used to indicate the central axis of the continuum robot 100.

[0069] In this exemplary embodiment, wires 111 to 113 will be referred to as wire a, wire b, and wire c in a counterclockwise direction in the xy plane. Specifically, in Figure 1B In the example shown, conductor 111 corresponds to conductor a, and the driving displacement of conductor 111 caused by the actuator 131 for bending segment 171 pushing or pulling conductor 111 is represented by l. p1a It indicates. In Figure 1B In the example shown, conductor 112 corresponds to conductor b, and the driving displacement of conductor 112 caused by the actuator 132 for bending segment 171 pushing or pulling conductor 112 is represented by l. p1b It indicates. Furthermore, in Figure 1B In the example shown, conductor 113 corresponds to conductor c, and the driving displacement of conductor 113 caused by the actuator 133 for bending segment 171 pushing or pulling conductor 113 is represented by l. p1c express.

[0070] exist Figure 1B In the example shown, only a detailed schematic construction of the curved segment 171 is described. At this point, with... Figure 1B The detailed schematic construction of the curved segment 171 shown in the figure is similar. Figure 1A The bending segments 172 and 173 shown each include a conductor corresponding to conductors (linear members) 111 to 113, an actuator corresponding to actuators 131 to 133, a distal end corresponding to distal end 160, and a conductor corresponding to conductor guides 161 to 164. As a generalization, the driving displacement of the conductor driving the nth bending segment is represented by l. pna l pnb and l pnc express.

[0071] Figure 2 It is shown Figure 1B The diagram shows an example of the arrangement of the three conductors 111 to 113 (conductors a to c) in the xy plane. Figure 2 As shown, Figure 1B The three wires 111 to 113 (wires a to c) shown are arranged on a side with a length of r. sThe vertices of the equilateral triangle are represented, and Figure 2 The phase angle ξ shown in the figure n It is used to determine the angle of the arrangement of the conductor driving the nth curved segment.

[0072] Figure 3 This is a diagram illustrating an example of the schematic construction of a control system 10 for a continuum robot according to a first exemplary embodiment of the present invention. Figure 3 As shown, the control system 10 of the continuum robot includes a continuum robot 100, a continuum robot control device 200 (control unit), and various input devices 310 and 330 to 340.

[0073] Input device 310 inputs the target bending angle θ of the furthest bending segment to the continuum robot control device 200. L The equipment. Specifically, in Figure 1A In the example shown, input device 310 inputs the target bending angle θ of the bending segment 173 as the farthest bending segment to the subsequent bending angle calculation unit 210 and kinematic model calculation unit 220 of the continuum robot control device 200. n The target bending angle θ of the furthest bending segment L Except for the target bending angle θ of the furthest bending segment. L In addition, the input device 310 can also input the target lateral displacement angle ζ of the furthest bending segment to the continuum robot control device 200. L .

[0074] Input device 330 inputs the displacement z of base unit 140 in the travel direction (e.g., forward movement direction) of continuous robot 100 to continuous robot control device 200. b And control is applied to move the base unit 140 of the continuum robot 100 by a displacement z in the z direction. b The device allows the base unit and multiple curved segments to move forward as a whole through this control.

[0075] Input device 340 is a device that inputs various types of information to the continuous robot control device 200. Specifically, input device 340 inputs information such as the length l of the bending segment 172 (which may include the length of the bending segment 171) as a subsequent bending segment and instruction information about the reference table 2111 to be used to the information input unit 213 of the continuous robot control device 200.

[0076] like Figure 3 As shown, the continuum robot control device 200 includes a subsequent bending angle calculation unit 210 and a kinematic model calculation unit 220.

[0077] The subsequent bending angle calculation unit 210 is a calculation unit that calculates based on the target bending angle θ of the farthest bending segment input from the input device 310. L The target bending angle θ of the subsequent bending segment F The displacement z of the base unit 140 input from the input device 330 b The target bending angle θ is calculated based on the length l of the subsequent bending segment input from input device 340 and the length l of the subsequent bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the change. F '.like Figure 3 As shown, the subsequent bending angle calculation unit 210 includes a multiplexer (Mux), a storage unit 211, a reference table rewriting unit 212, and an information input unit 213. The storage unit 211 stores the target bending angle θ indicating the farthest bending segment. L and the target bending angle θ of the subsequent bending segment F Displacement z of base element 140 b The information input unit 213 is an information input unit that inputs information about the length l of the subsequent bending segment and the various types of information required for processing in the subsequent bending angle calculation unit 210, which is input from the input device 340 via the multiplexer Mux, to the reference table rewriting unit 212. The reference table rewriting unit 212 is a rewriting unit that, based on the information input from the information input unit 213, selects the reference table 2111 to be used from the multiple reference tables 2111 stored in the storage unit 211, and calculates the target bending angle θ of the farthest bending segment. L The changes will be rewritten from the selected reference table 2111. The following will refer to... Figure 7A and Figure 7B This section describes a detailed processing example of the subsequent bending angle calculation unit 210 described here.

[0078] The kinematic model calculation unit 220 is a calculation unit that is based on the changed target bending angle θ of the subsequent bending segment calculated by the subsequent bending angle calculation unit 210. F The calculation unit 220 calculates the driving displacement caused when the conductor (linear member) of the subsequent bending segment is driven by each actuator of the driving unit. Furthermore, the kinematic model calculation unit 220 calculates the target bending angle θ of the furthest bending segment input by the input device 310. L Calculate the driving displacement caused when the conductor (linear member) of the farthest curved segment is driven by each actuator as a driving unit. Figure 3Together, the driving displacements of the conductor at the furthest bending segment and the driving displacements of the conductor at subsequent bending segments, obtained by the kinematic model calculation unit 220, are shown as the driving displacement l of the conductor. p Then, the continuum robot 100 according to this exemplary embodiment, based on the driving displacement l of each guide wire... p Perform bending control on the furthest bending segment and subsequent bending segments.

[0079] In this exemplary embodiment, Figure 2 All phase angles shown are set to ξ n =0, and the front-end follower control on the xz plane will be described first below.

[0080] 1) Modeling

[0081] In this chapter, the kinematic model of the continuum robot 100 on the xz plane is derived.

[0082] The symbols used in this chapter are defined as follows.

[0083] l n : Length of the arm sleeve in the nth curved segment

[0084] r n The distance between line a and line b in the xz plane

[0085] e: The number of bending segments of the bendable portion 170 of the continuum robot 100.

[0086] θ n The bending angle of the nth bending segment (at the distal end).

[0087] ρ n The radius of curvature of the nth curved segment

[0088] θ refn : Target bending angle of the nth bending segment (at the distal end)

[0089] l pn The driving displacement of the conductor in the nth curved segment

[0090] x tn , z tn : Coordinates of the nth curved segment (at the distal end)

[0091] z b Displacement of base element 140

[0092] Figure 4 and Figure 5 This illustrates a first exemplary embodiment of the invention and each shows... Figure 1A A diagram showing an example of the kinematic model of a continuum robot 100.

[0093] In this example, the following assumptions are used to derive... Figure 4 The kinematic model of a continuum robot 100 with n bending segments is shown in the figure.

[0094] 1. The conductor only deforms in the xz plane.

[0095] 2. In each bending segment, the conductor deforms with a fixed curvature.

[0096] 3. Torsional deformation of the conductor is not considered.

[0097] 4. The conductor does not deform longitudinally.

[0098] First, only the first bending segment (corresponding to) will be considered. Figure 1A and Figure 1B (171) of the curved segment.

[0099] When conductor a is driven and conductors b and c are fixed, the driving displacement l of the conductors is represented by the following formula (1). p1 The relationship between the bending angle θ1 of the first bending segment (at the distal end).

[0100] [Mathematical Expression 1]

[0101]

[0102] Next, the driving displacement l of the conductor in the nth bending segment is derived. pn Its bending angle θ at its distal end n The relationship between them. Here, n is set to a number equal to or greater than 2. The relative bending angle θ of the nth bending segment (at the distal end). ～ n The definition is as follows.

[0103] θ ～ n =θ n -θ n-1 (2)

[0104] Then, as Figure 5 As shown, when the coordinates of the origin O are set to (x... tn -1, z tn-1 ), and set θ n-1 The relative coordinate system x of the direction and its orthogonal direction n -z n At that time, the conductor is in the relative coordinate system x n -z n The driving displacement l in ～ pn The relative bending angle θ with respect to the nth bending segment (at the distal end) ～n The relationship between them is expressed by the following formula (3). In the following formula (3), “l ～ pn The "~" is described above "l", and "θ" ～ n The ~ symbol is described above θ.

[0105] [Mathematical Expression 2]

[0106]

[0107] The driving displacement l of the conductor in the nth bending segment pn It becomes the sum of the displacements of the conductor used to drive the nth bending segment from the first bending segment to the (n-1)th bending segment in the relative coordinate system, and is expressed by the following formula (4).

[0108] [Mathematical Expression 3]

[0109]

[0110] This shows that the bending angle θ at the distal end of the nth bending segment is... n Driven displacement l based solely on the conductor pn It is determined by the angle of the mid-bend segment, rather than by the angle of the segment.

[0111] Next, the relationship between the bending angle of the nth bending segment at the distal end and the coordinates of the distal end is derived. First, when considering the first bending segment, the following formulas (5) and (6) represent the relationship between the bending angle θ1 of the first bending segment at the distal end and the coordinates of the distal end (x). t1 , z t1 The relationship between ).

[0112] [Mathematical Expression 4]

[0113]

[0114]

[0115] Next, the relative bending angle θ of the nth bending segment at the distal end is represented by the following formulas (7) to (9). ～ n Relative coordinates x and x to the far end n -z n coordinates (x) ～ tn , z ～ tn The relationship between ) . Here, n is set to a number equal to or greater than 2. In the following formulas (7) and (8), “θ ～ nThe '~' symbol is described above 'θ', and 'x' is above 'θ'. ～ tn " and "z ～ tn The ~ symbol is described above “x” and “z”.

[0116] [Mathematical Expression 5]

[0117]

[0118]

[0119]

[0120] Using this construction, a rotation transformation matrix is ​​used to represent the coordinates (x, y) of the far end in the absolute coordinate system. tn , z tn ).

[0121] 2) Control System Design

[0122] In this chapter, a front-end following control system is designed.

[0123] Figure 6 This is a diagram illustrating an example of front-end following control of a continuum robot 100 according to a first exemplary embodiment of the present invention. Figure 6 In, with Figure 1A Components similar to those shown in the figures are assigned the same reference numerals. Furthermore, in Figure 6 middle, Figure 1A The z-direction shown is set from the bottom of the paper towards the top of the paper. Figure 6 In the diagram, the dotted lines indicate the target route 610, along which the continuum robot 100, including the base unit 140 and the flexible portion 170, moves forward.

[0124] Here, the front-end follow control controls the subsequent bending segment to pass through the... Figure 6 The method shown is the same route (target route 610) traversed by the furthest bending segment of the bendable portion 170. Examples of front-end following control include controlling the bending angle of the following bending segment to achieve the first target bending angle, based on a configuration of a first bending angle about the bending angle of the following bending segment, set according to a first target bending angle input to the input distal bending segment, corresponding to the forward movement of the continuum robot.

[0125] exist Figure 6 In this context, time point 601 indicates the initial state where the flexible portion 170 extending along the z-direction from the top surface of the base unit 140 is not bent. Afterwards, Figure 6The diagram illustrates how the base unit 140 moves in the z-direction and the flexible portion 170 bends as time progresses to time points 602, 603, 604, and 605.

[0126] Through this front-end following control, the continuum robot 100 can move forward in a gliding manner through space. In front-end following control, it is not always necessary to predefine the target path 610. For example, the bending angle of the furthest bending segment can be propagated continuously along the length of the bending segment to the bending angle of subsequent bending segments. Using this method, for example by issuing commands via a joystick for only the bending angle of the furthest bending segment and the displacement (movement amount (forward movement amount)) of the base unit 140, the operator can perform front-end following control of the continuum robot 100 in real time.

[0127] Figure 7A and Figure 7B This illustrates a first exemplary embodiment of the invention and each shows the target bending angle θ based on the furthest bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the change. F A diagram illustrating an example of computational processing, which will be performed by... Figure 3 The subsequent bending angle calculation unit 210 is executed. (Refer to...) Figure 7A and Figure 7B The following example will be described, in which, Figure 1A The curved segment 173 in the text is used as the farthest curved segment, while Figure 1A The curved segment 172 in the middle is used as a subsequent curved segment.

[0128] The coordinates on the diagram indicate the pairing of the position of the base element and the bending angle of the bending segment. For ease of explanation, the bending angle corresponding to coordinate a will sometimes be referred to as "angle a" below, and the position (displacement) of the base element corresponding to coordinate a will sometimes be referred to as position a (displacement a) below.

[0129] exist Figure 7A In the middle, the horizontal axis indicates the displacement z of the base unit 140. b The vertical axis indicates the bending angle θ of the furthest bending segment and subsequent bending segments. Figure 7A In the diagram, the dashed "front end" indicates the configuration of the bending angle of the furthest bending segment, which is related to the target bending angle θ of the furthest bending segment input by the operator via input device 310. L Correspondingly. In Figure 7A In the diagram, the thick dashed line "follower" indicates the configuration of the bending angle of the following bending segment, which is consistent with the target bending angle θ of the subsequent bending segment set before the reference table rewriting unit 212 rewrites the data. F Correspondingly.

[0130] Specifically, if the displacement z of the base element 140 b For displacement a, the target bending angle θ of the farthest bending segment L If the furthest bending angle a is changed to the furthest bending angle b, then the target bending angle θ of the subsequent bending segment, indicated by the thick dashed "follower" element, will be... F When the displacement z of the base element 140 b The bending angle is automatically generated by changing from the subsequent bending angle c to the subsequent bending angle d when the displacement is c. Here, the displacement c is determined such that the length between displacement a and displacement c becomes the length l of the subsequent bending segment.

[0131] However, in Figure 7A The target bending angle θ for subsequent bending segments is indicated by the thick dashed "follower" element. F In the configuration of the bending angle, when the displacement z of the base unit 140 b When the bending angle θ exists between displacements a and c, the target bending angle θ of the subsequent bending segment is... F No change. Then, in Figure 7A The target bending angle θ for subsequent bending segments is indicated by the thick dashed "follower" element. F In the configuration of the bending angle, the bending angle changes from a subsequent bending angle c to a subsequent bending angle d at displacement c. Therefore, the continuum robot 100 exhibits abrupt change behavior, and the operability of the continuum robot 100 is impaired. In view of the above, in the first exemplary embodiment of the present invention, as in... Figure 7A The solid line "interpolation follower" indicates the changed target bending angle θ for subsequent bending segments. F The bending angle is configured such that, by interpolating the bending angle, a straight line connects the target bending angle c and the target bending angle d at the position between displacement a and displacement c.

[0132] Specifically, the reference table rewriting unit 212 of the subsequent bending angle calculation unit 210 will be in the following manner Figure 7A The target bending angle θ for subsequent bending segments is indicated by the thick dashed line "follower" in the reference table shown. F The configuration of the bending angle is rewritten as the target bending angle θ, indicated by the solid line "interpolation follower," for subsequent bending segments. F The configuration of the bending angle.

[0133] First, if in Figure 7A The target bending angle θ of the farthest bending segment is shown in the reference table. LWhen the first farthest bending angle 'a' changes to the second farthest bending angle 'b', the reference table rewriting unit 212 generates a right-angled triangle. The length of the base of this right-angled triangle corresponds to the length from the first displacement 'a' to the second displacement 'c', and the height of this right-angled triangle corresponds to the difference between the second farthest bending angle 'b' and the first farthest bending angle 'a'. The first displacement 'a' is the displacement of the base unit 140 where the bending angle becomes the second farthest bending angle 'b', and the second displacement 'c' is the displacement of the subsequent bending segment forward by the length 'l' from the first displacement 'a' (the sum of the first displacement 'a' and the length 'l'). Specifically, the reference table rewriting unit 212 generates... Figure 7A A right-angled triangle is shaded by a diagonal shading line. In other words, the right-angled triangle is generated by the reference table rewriting unit 212, the length of the base of the right-angled triangle corresponds to the length from the first displacement a to the second displacement c, and the height of the right-angled triangle corresponds to the difference between the target bending angle d and the target bending angle c at the second displacement c.

[0134] Subsequently, referring to the table rewriting unit 212, the target bending angle value from the point on the hypotenuse of the generated right triangle to the base of the right triangle is obtained (specifically, when the hypotenuse of the right triangle and the displacement z of the base unit 140 are obtained at each displacement from the first displacement a to the second displacement c). b When the coordinate axes (horizontal axis) intersect with the perpendicular lines, the length from that intersection point to the base of the right triangle is the value of the distance between the points of intersection and the coordinate axes (horizontal axis). Figure 7A The target bending angle θ of the subsequent bending segment is indicated by the thick dashed "follower". F The value (in) Figure 7A In the example shown, the values ​​are 0 and 0 respectively, and the target bending angle of the subsequent bending segment obtained after this addition is set as the changed target bending angle θ of the subsequent bending segment indicated by the solid line "interpolation follower". F ', to rewrite Figure 7A The reference table is shown. Then, the reference table rewriting unit 212 stores the rewritten reference table in the storage unit 211.

[0135] Figure 7A This shows the response to the target bending angle θ for the furthest bending segment. L A change operation command alters the target bending angle θ of subsequent bending segments. F The processing method. In this exemplary embodiment, in response to the target bending angle θ for the furthest bending segment. L Further modification commands (multiple modification commands issued) can also use a similar algorithm to determine the target bending angle θ of subsequent bending segments. F Changes to the processing.

[0136] Figure 7B It shows that in response to Figure 7A The target bending angle θ of the furthest bending segment shown in the figure L An example of issuing a second change operation command after issuing the first change operation command.

[0137] exist Figure 7B In, with Figure 7A Similarly, the horizontal axis indicates the displacement z of the base unit 140. b The vertical axis indicates the bending angle θ of the furthest bending segment and subsequent bending segments. Figure 7B In the middle, the dashed "front end" indicates the target bending angle θ for the furthest bending segment input by the operator via input device 310. L The configuration of the bending angle. Furthermore, in Figure 7B In, obtained after the first change and in Figure 7A The target bending angle θ of the subsequent bending segment is indicated by the solid line "interpolation follower". F The target bending angle θ for subsequent bending segments is indicated by the thick dashed line "First Interpolation". F Configuration of the bending angle. Figure 7B The example shown indicates the following situation: when the displacement z of the base element 140 b When the length l of the subsequent bending segment is less than the displacement (which falls within the range from displacement a to displacement c), the target bending angle θ of the farthest bending segment is... L Change from the furthest bending angle b to the furthest bending angle b'.

[0138] exist Figure 7B In the reference table shown, if the target bending angle θ of the farthest bending segment... L When the first farthest bending angle b changes to the second farthest bending angle b', the reference table rewriting unit 212 generates a right-angled triangle. The length of the base of this right-angled triangle corresponds to the length from the first displacement a' to the second displacement c', and the height of this right-angled triangle corresponds to the difference between the second farthest bending angle b' and the first farthest bending angle b. The first displacement a' is the displacement of the base unit 140 where the bending angle becomes the second farthest bending angle b', and the second displacement c' corresponds to the sum of the lengths l of the subsequent bending segments. Specifically, the reference table rewriting unit 212 generates... Figure 7B A right-angled triangle is shaded by a diagonal shading line. In other words, the right-angled triangle is generated by the reference table rewriting unit 212, the length of the base of the right-angled triangle corresponds to the length from the first displacement a' to the second displacement c', and the height of the right-angled triangle corresponds to the difference between the target bending angle d' and the target bending angle c' at the second displacement c'.

[0139] Subsequently, referring to the table rewriting unit 212, the target bending angle value from the point on the hypotenuse of the generated right triangle to the base of the right triangle is obtained (specifically, when the hypotenuse of the right triangle and the displacement z of the base unit 140 are obtained at each displacement from the first displacement a' to the second displacement c'). b When the coordinate axes (horizontal axis) intersect with the perpendicular lines, the length from that intersection point to the base of the right triangle is the value of the distance between the points of intersection and the coordinate axes (horizontal axis). Figure 7B The target bending angle θ of the subsequent bending segment is indicated by the thick dashed line "First Interpolation". F The values ​​are added together, and the target bending angle of the subsequent bending segment obtained after this addition is set as the changed target bending angle θ of the subsequent bending segment indicated by the solid line "interpolation follower". F ', to rewrite Figure 7B The reference table is shown. Then, the reference table rewriting unit 212 stores the rewritten reference table in the storage unit 211.

[0140] like Figure 7B As shown, if a target bending angle θ is emitted for the furthest bending segment within a range from displacement a to displacement c that is smaller than the length l of the subsequent bending segment,... L The second change operation command then makes the slope of line ef the sum of the slopes of line ad and line a'd'. This is because when the displacement z of the base element 140 is less than the length l of the subsequent bending segment... b When consecutively issued change operation commands are considered as corrections to the operation, the changed target bending angle θ of subsequent bending segments in this exemplary embodiment... F The calculation method of ' has the following characteristics.

[0141] *Issue the target bending angle θ for the furthest bending segment in the same direction. L In the case of the first change operation command and the second change operation command, the bending shape of the subsequent bending segment is controlled so that at the displacement from point a' to point d, the angular velocity of the bending angle is increased, and the second change operation command is enhanced.

[0142] *Issue the target bending angle θ for the furthest bending segment in the opposite direction. L In the case of the first change operation command and the second change operation command, the bending shape of the subsequent bending segment is controlled so that at the displacement from point a' to point d, the angular velocity of the bending angle is reduced and the first change operation command is mitigated.

[0143] In the manner described above, the following bending segment (subsequent bending segment) is controlled to reach point d' based on a second bending angle configuration that differs from the configuration of the first bending angle.

[0144] In this way, a second bending angle configuration, different from the first bending angle configuration, is set. Then, based on the second bending angle configuration (which replaces the first bending angle configuration), the bending angle of the following bending segment (subsequent bending segment) is controlled to achieve the second target bending angle. The user can determine whether the bending angle has reached the target bending angle using desired criteria.

[0145] Reference Figure 7A and Figure 7B The above describes such an example situation, in which, Figure 1A The curved segment 173 is used as the farthest curved segment. Figure 1A The bending segment 172 in the continuum robot 100 is applied as a subsequent bending segment. Then, in cases where the number of bending segments in the bendable portion 170 of the continuum robot 100 is three or more (e.g., in...), Figure 1A (In the case where the number of bending segments of the bendable portion 170 shown is three, for example, it can be achieved by...) Figure 1A The bending segment 172 immediately preceding the bending segment 171 is used as the farthest bending segment mentioned above, in order to... Figure 1A The curved segment 171 in the above-mentioned curved segment is used as the subsequent curved segment.

[0146] Figure 8 This is a flowchart illustrating an example of the processing procedure of a control method for a continuum robot, which is executed by the control system 10 of the continuum robot according to a first exemplary embodiment of the present invention.

[0147] First, in step S801, the continuum robot control device 200 receives operational input from input device 310 for the farthest bending segment, which is the bending segment located furthest from the base unit 140. In step S801, the continuum robot control device 200 receives, for example, a target bending angle θ for the farthest bending segment from input device 310. L The input is then used. Subsequently, in step S802, the continuum robot control device 200 uses the kinematic model calculation unit 220 to calculate the target bending angle θ of the furthest bending segment based on the input. L The system calculates the driving displacement of the conductor (linear component) of the furthest bending segment and controls the continuum robot 100 based on the calculation results. Through this control, the bending shape of the bendable portion 170 of the continuum robot 100 is changed.

[0148] Subsequently, in step S803, the continuum robot control device 200 determines, for example, based on input information from input devices 310 and 330 to 340, whether the operation input to the continuum robot 100 has ended.

[0149] If, as a result of the determination in step S803, it is determined that the operation input to the continuum robot 100 has not yet ended ("No" in step S803), the process proceeds to step S804. If the process proceeds to step S804, the continuum robot control device 200 determines, for example, based on the input information from the input device 330, whether the base unit 140 of the continuum robot 100 has moved forward. If, as a result of the determination in step S804, it is determined that the base unit 140 of the continuum robot 100 has not moved forward ("No" in step S804), the process returns to step S801, and the processing in step S801 and subsequent steps is performed again.

[0150] On the other hand, if it is determined, as a result of step S804, that the base unit 140 of the continuum robot 100 has moved forward ("Yes" in step S804), the process proceeds to step S805. If the process proceeds to step S805, the reference table rewriting unit 212 of the subsequent bending angle calculation unit 210 then... Figure 7A or Figure 7B The reference table shown generates right-angled triangle data obscured by diagonal shading. In reference table rewriting unit 212... Figure 7A When right-angled triangle data is generated in the reference table shown, the reference table rewriting unit 212 generates right-angled triangles. The length (width) of the base of the right-angled triangle corresponds to the length l of the subsequent bending segment from the first displacement a to the second displacement c. The height of the right-angled triangle corresponds to the second farthest bending angle θ. L2 The target bending angle b and the corresponding first farthest bending angle θ L1 The difference between the target bending angle 'a' and the target bending angle 'c' corresponds to (more specifically, this height corresponds to the difference between the target bending angle 'd' and the target bending angle 'c' at the second displacement 'c'). In reference table rewriting unit 212... Figure 7B When right-angled triangle data is generated in the reference table shown, the reference table rewriting unit 212 generates right-angled triangles whose base length (width) corresponds to the length l of the subsequent bending segment from the first displacement a' to the second displacement c', and whose height corresponds to the second farthest bending angle θ. L2 The target bending angle b' and the corresponding first farthest bending angle θ L1 The difference between the target bending angle b corresponds to the difference between the target bending angle d' and the target bending angle c' at the second displacement c' (more specifically, this height corresponds to the difference between the target bending angle d' and the target bending angle c' at the second displacement c').

[0151] Subsequently, in step S806, the reference table rewriting unit 212 of the subsequent bending angle calculation unit 210 modifies the right-angled triangle data generated in step S805 with the target bending angle θ of the subsequent bending segment stored in the current reference table in the storage unit 211. F The values ​​are added together to interpolate the bending angle. Figure 7A or Figure 7B In the reference table shown, the solid line indicates the modified target bending angle θ of the subsequent bending segment obtained through interpolation. F '.

[0152] Subsequently, in step S807, the reference table rewriting unit 212 of the subsequent bending angle calculation unit 210 calculates the target bending angle θ of the farthest bending segment. L Perform write from Figure 7A Data starting from displacement c (to the right of displacement c) or from Figure 7B The processing begins with the data starting from displacement c' (to the right of displacement c'). If the processing in step S807 is complete, the processing returns to step S801.

[0153] If it is determined, as a result of step S803, that the input operation to the continuum robot 100 has ended (in step S803, it is "Yes"), Figure 8 The process shown in the flowchart has ended.

[0154] 3) Simulation

[0155] In this chapter, a simulation is performed using the front-end following control system described in section 2) of the previous chapter on control system design. In the simulation, for the following continuum robot 100: the number of bending segments is set to 2, the length of the first bending segment is set to 0.02 meters, and the length of the second bending segment is set to 0.02 meters. Here, for example, the second bending segment is used as the farthest bending segment mentioned above, while the first bending segment is used as the subsequent bending segment mentioned above.

[0156] Figure 9 This illustrates a first exemplary embodiment of the invention and shows a target bending angle θ for the furthest bending segment emitted in the same direction. L An example diagram showing the simulation results of the target bending angle of the subsequent bending segment obtained under the first and second change of operation commands. Figure 9 In the middle, the horizontal axis indicates the displacement z of the base unit 140. b The vertical axis indicates the bending angle θ of the furthest bending segment and subsequent bending segments. Furthermore, in Figure 9 In the middle, the dashed "front end" indicates the target bending angle θ of the farthest bending segment. LThe configuration of the bending angle, while the solid line "follower" indicates the target bending angle θ based on the farthest bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the change. F The configuration of the bending angle.

[0157] exist Figure 9 In the process, the following first bending change operation command is issued: After the operation of the continuous robot 100 begins, the continuous robot 100 is moved forward 0.02 meters in the z-direction while in a direct forward state, and at this position, the farthest bending segment is bent at 45 degrees. Then, the following second bending change operation command is issued: The continuous robot 100 is moved forward 0.01 meters in the z-direction, and at this position, the farthest bending segment is further bent 15 degrees in the same direction (ultimately 60 degrees).

[0158] Figures 10A to 10D This illustrates a first exemplary embodiment of the invention and each shows a reflection of... Figure 9 The diagram shows an example of the operational state of the bendable portion 170 of the continuum robot 100, illustrating simulation results. Specifically, Figures 10A to 10D The operational states of the bendable portion 170 of the continuum robot 100 are shown in chronological order, with the horizontal axis indicating displacement in the x-direction and the vertical axis indicating displacement in the z-direction. Figures 10A to 10D In the diagram, the solid line indicates the bending state of the bendable portion 170 of the continuum robot 100, while the dashed line indicates the target route 610.

[0159] exist Figure 10A In the process, the continuum robot 100 moves forward 0.02 meters along the z-direction in a direct forward motion, and the farthest bending segment of the bendable portion 170 bends at 45 degrees at this position. Subsequently, in Figure 10B In order to correct the deviation from the target path 610, the forward movement of the continuum robot 100 is stopped, and... Figure 10C In the process, the furthest bending segment of the bendable portion 170 is subsequently bent up to 60 degrees. From the first bending operation, the displacement z of the base element 140... b The second bending operation is performed without exceeding the length of the bending segment (the length of the subsequent bending segment l = 0.02 meters). Therefore, as follows... Figure 9 As shown, the target bending angle θ for the subsequent bending segment is indicated by the solid line "follower". F In the configuration of the bending angle, when the displacement z of the base unit 140 b When the angular velocity is between 0.03 m and 0.04 m, it is relatively large, and in the subsequent short displacement z of the base element 140. b In this process, the correction for the bending operation is reflected in subsequent bending segments. Using this construction, in... Figure 10DIn the meantime, the flexible portion 170 can approximate the target route 610.

[0160] Figure 11 This illustrates a first exemplary embodiment of the invention and shows the target bending angle θ for the furthest bending segment emitted in the opposite direction. L An example diagram showing the simulation results of the target bending angle of the subsequent bending segment obtained under the first and second change of operation commands. Figure 11 In the text, the references will be omitted. Figure 9 The description of the matter is similar to the description of the matter.

[0161] exist Figure 11 In the process, the following first bending change operation command is issued: After the operation of the continuous robot 100 begins, the continuous robot 100 is moved forward 0.02 meters in the z-direction while in a direct forward state, and at that position, the farthest bending segment is bent at 45 degrees. Then, the following second bending change operation command is issued: The continuous robot 100 is moved forward 0.01 meters in the z-direction, and at that position, the farthest bending segment is bent in the opposite direction by 20 degrees (ultimately 25 degrees).

[0162] Figures 12A to 12D This illustrates a first exemplary embodiment of the invention and each shows a reflection of it. Figure 11 The diagram shows an example of the operational state of the bendable portion 170 of the continuum robot 100, illustrating simulation results. Specifically, Figures 12A to 12D The operational states of the bendable portion 170 of the continuum robot 100 are shown in chronological order, with the horizontal axis indicating displacement in the x-direction and the vertical axis indicating displacement in the z-direction. Figures 12A to 12D In the diagram, the solid line indicates the bending state of the bendable portion 170 of the continuum robot 100, while the dashed line indicates the target route 610.

[0163] exist Figure 12A In the process, the continuum robot 100 moves forward 0.02 meters along the z-direction in a direct forward motion, and the farthest bending segment of the bendable portion 170 bends at 45 degrees at this position. Subsequently, in Figure 12B In order to correct the deviation from the target path 610, the forward movement of the continuum robot 100 is stopped, and... Figure 12C In this process, the bending of the furthest bending segment of the bendable portion 170 is shallower, reaching 25 degrees. Therefore, as... Figure 11 As shown, the target bending angle θ for the subsequent bending segment is indicated by the solid line "follower". F In the configuration of the bending angle, when the displacement z of the base unit 140 b When the angular velocity is between 0.03 m and 0.04 m, the target bending angle θ of the subsequent bending segment is relatively small. FThe stop reaches 45 degrees, and thereafter a short displacement z in the base unit 140. b In this process, the correction for the bending operation is reflected in subsequent bending segments. Using this construction, in... Figure 12D In the meantime, the flexible portion 170 can approximate the target route 610.

[0164] In the control system 10 of the continuum robot according to the first exemplary embodiment described above, such as Figure 7A and Figure 7B As shown, the target bending angle θ is based on the farthest bending segment. L The displacement z of base element 140 b And the length l of the subsequent bending segment, to calculate the target bending angle θ based on the farthest bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the change. F '.

[0165] Using this structure, even with a displacement z of the base element 140 b When the length of the bending segment is less than that of the subsequent bending segment in this exemplary embodiment, the target bending angle θ of the furthest bending segment is changed. L In this case, the operability of the continuum robot 100 can also be improved. Therefore, malfunctions that could damage the target object operating the continuum robot 100 along the target route 610 or destroy the continuum robot 100 can be suppressed or avoided.

[0166] (Second exemplary embodiment)

[0167] Next, a second exemplary embodiment of the present invention will be described. In the following description of the second exemplary embodiment, descriptions of matters similar to those in the first exemplary embodiment described above will be omitted, and matters different from those in the first exemplary embodiment described above will be described.

[0168] The schematic construction of the continuum robot according to the second exemplary embodiment is similar to... Figure 1A and Figure 1B The schematic configuration of the continuum robot 100 according to the first exemplary embodiment is shown in the figure. Furthermore, the schematic configuration of the control system of the continuum robot according to the second exemplary embodiment is similar to... Figure 3 The schematic configuration of the control system 10 of the continuum robot according to the first exemplary embodiment is shown in the figure.

[0169] In the first exemplary embodiment described above, a configuration was described in which the target bending angle of the subsequent bending segment was set such that the bendable portion 170 approached the target route 610. In the second exemplary embodiment, a configuration will be described in which the target bending angle of the subsequent bending segment is faithfully set to the target bending angle of the farthest bending segment.

[0170] Figure 13 This illustrates a second exemplary embodiment of the invention and shows the target bending angle θ based on the furthest bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the change. F A diagram illustrating an example of computational processing, which will be performed by... Figure 3 The subsequent bending angle calculation unit 210 is executed. (Refer to...) Figure 13 The following will describe an example of such a situation, in which, Figure 1A The curved segment 173 in the middle was used as the farthest curved segment. Figure 1A The curved segment 172 in the middle was used as the subsequent curved segment. Furthermore, Figure 13 An example situation is shown where, for Figure 7A The target bending angle θ of the furthest bending segment shown in the figure L After issuing the first change operation command, issue the second change operation command.

[0171] exist Figure 13 In, with Figure 7B Similarly, the horizontal axis indicates the displacement z of the base unit 140. b The vertical axis indicates the target bending angle θ for the furthest bending segment and subsequent bending segments. Figure 13 In the middle, the dashed "front end" indicates the target bending angle θ of the furthest bending segment input by the operator via input device 310. L The configuration of the bending angle. In Figure 13 In, obtained after the first change and in Figure 7A The target bending angle θ for subsequent bending segments is indicated by the solid line "interpolation follower". F The configuration of the bending angle is indicated by the thick dashed line "First Interpolation" indicating the target bending angle θ for subsequent bending segments. F Configuration of the bending angle. Figure 13 The example shown indicates the following situation: when the displacement z of the base element 140 b When the length l of the subsequent bending segment is less than the displacement (which falls within the range from displacement a to displacement c), the target bending angle θ of the farthest bending segment is... L Change from the furthest bending angle b to the furthest bending angle b'.

[0172] If in Figure 13 The target bending angle θ of the farthest bending segment shown in the reference table L If the first farthest bending angle b changes to the second farthest bending angle b', then the reference table rewrite unit 212 is used for the displacement z of the base unit 140 from displacement a' (i.e., the bending angle becomes the second farthest bending angle b'). b The range from the first displacement d to the second displacement c' is excluded from the range of the base unit 140 where the bending angle is the first farthest bending angle b, excluding the range from the first displacement d to the first displacement d (i.e., the displacement corresponding to the sum of the lengths l of the subsequent bending segments). The value of the target bending angle on the straight line connecting the value of the first farthest bending angle b at the first displacement d and the value of the second farthest bending angle b' at the second displacement c' is used to determine the range of the target bending angle from the first displacement d to the second displacement c'. Figure 13 The thick dashed line shown in the image, "First Interpolation," indicates the target bending angle θ for subsequent bending segments. F The bending angle configuration is interpolated. Then, the target bending angle of the subsequent bending segment obtained after interpolation is set to the modified target bending angle θ for the subsequent bending segment, indicated by the solid line "interpolation follower". F The configuration of the bending angle is used to rewrite Figure 13 The reference table shown is then used. The reference table rewriting unit 212 stores the rewritten reference table in the storage unit 211.

[0173] In this manner, in the control system of this exemplary embodiment, all bending operations performed by the operator on the furthest bending segment are interpolated and propagated to subsequent bending segments.

[0174] Reference Figure 13 The above describes such an example situation, in which, Figure 1A The curved segment 173 in the middle was used as the farthest curved segment and Figure 1A The bending segment 172 in the continuum robot 100 is applied as a subsequent bending segment. Then, in cases where the number of bending segments in the bendable portion 170 of the continuum robot 100 is three or more (e.g., in...), Figure 1A (In the case where the number of bending segments of the bendable portion 170 shown is three, for example, it can be achieved by...) Figure 1A The bending segment 172 immediately preceding the bending segment 171 is used as the farthest bending segment mentioned above, in order to... Figure 1A The curved segment 171 in the above-mentioned curved segment is used as the subsequent curved segment.

[0175] Figure 14 This illustrates a second exemplary embodiment of the invention and shows a target bending angle θ for the furthest bending segment emitted in the same direction. LA figure illustrating an example of simulation results for the target bending angle of subsequent bending segments obtained under the first and second change operation commands in the configuration of the bending angle. Figure 14 In the middle, the horizontal axis indicates the displacement z of the base unit 140. b The vertical axis indicates the bending angle θ of the furthest bending segment and subsequent bending segments. Figure 14 In the middle, the dashed "front end" indicates the target bending angle θ of the farthest bending segment. L The solid line "follower" indicates the target bending angle θ based on the furthest bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the change. F The configuration of the bending angle.

[0176] Figures 15A to 15D This illustrates a second exemplary embodiment of the invention, and each shows a reflection of... Figure 14 The diagram shows an example of the operational state of the bendable portion 170 of the continuum robot 100, illustrating simulation results. Specifically, Figures 15A to 15D The operational states of the bendable portion 170 of the continuum robot 100 are shown in chronological order, with the horizontal axis indicating displacement in the x-direction and the vertical axis indicating displacement in the z-direction. Figures 15A to 15D In the diagram, the solid line indicates the bending state of the bendable portion 170 of the continuum robot 100, while the dashed line indicates the target route 610.

[0177] Figures 15A to 15C The responses in are respectively equal to those in the first exemplary embodiment described above. Figures 10A to 10C The response in. Figure 15D In the control method of the second exemplary embodiment, since the bending operation performed by the operator is interpolated and propagated as is to subsequent bending segments, rapid changes in the angular velocity of subsequent bending segments as described in the first exemplary embodiment do not occur. Therefore, the approximation of the target route 610 by the bendable portion 170 becomes gentler.

[0178] Figure 16 This illustrates a second exemplary embodiment of the invention and shows the target bending angle θ for the furthest bending segment emitted in the opposite direction. L An example diagram showing the simulation results of the target bending angle of the subsequent bending segment obtained under the first and second change of operation commands. Figure 16 In the text, the references will be omitted. Figure 14 The description of the matter is similar to the description of the matter.

[0179] Figures 17A to 17D This illustrates a second exemplary embodiment of the invention and each shows a reflection of... Figure 16The diagram shows an example of the operational state of the bendable portion 170 of the continuum robot 100, illustrating simulation results. Specifically, Figures 17A to 17D The operational states of the bendable portion 170 of the continuum robot 100 are shown in chronological order, with the horizontal axis indicating displacement in the x-direction and the vertical axis indicating displacement in the z-direction. Figures 17A to 17D In the diagram, the solid line indicates the bending state of the bendable portion 170 of the continuum robot 100, while the dashed line indicates the target route 610.

[0180] Figures 17A to 17C The responses in are respectively equal to those in the first exemplary embodiment described above. Figures 12A to 12C The response in. Figure 17D In the control method of the second exemplary embodiment, the amount of manipulation on subsequent bending segments is not reduced before propagation, as described in the first exemplary embodiment. Therefore, the approximation of the target route 610 by the bendable portion 170 becomes abrupt, and the bendable portion 170 may be excessive, but the amount of manipulation on the furthest bending segment is faithfully propagated.

[0181] Furthermore, in the second exemplary embodiment, similar to the first exemplary embodiment described above, even when the displacement z of the base unit 140... b When the length of the subsequent bending segment is less than the target bending angle θ of the farthest bending segment, change the target bending angle θ of the farthest bending segment. L In this case, the operability of the continuum robot 100 can also be improved. This can avoid damage to the target object that operates the continuum robot 100 along the target route 610 or malfunctions that could destroy the continuum robot 100.

[0182] (Third exemplary embodiment)

[0183] Next, a third exemplary embodiment of the present invention will be described. In the following description of the third exemplary embodiment, descriptions of matters similar to those in the first and second exemplary embodiments described above will be omitted, and matters different from those in the first and second exemplary embodiments described above will be described.

[0184] The schematic construction of the continuum robot according to the third exemplary embodiment is similar to... Figure 1A and Figure 1B The schematic configuration of the continuum robot 100 according to the first exemplary embodiment is shown in the figure. Furthermore, the schematic configuration of the control system of the continuum robot according to the third exemplary embodiment is similar to... Figure 3 The schematic configuration of the control system 10 of the continuum robot according to the first exemplary embodiment is shown in the figure.

[0185] In the second exemplary embodiment described above, a configuration is described in which the target bending angle of subsequent bending segments is faithfully set to the target bending angle of the furthest bending segment. In the third exemplary embodiment, a configuration will be described in which the bending operation is propagated to subsequent bending segments, while the displacement z of the base unit 140... b Cancel the bending operation on the furthest bending segment if the bending length l does not exceed the length of the bending segment.

[0186] Figure 18 This illustrates a third exemplary embodiment of the invention and shows the target bending angle θ based on the furthest bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the change. F A diagram illustrating an example of computational processing, which will be performed by... Figure 3 The subsequent bending angle calculation unit 210 is executed. (Refer to...) Figure 18 The following example will be described, in which, Figure 1A The curved segment 173 in the middle was used as the farthest curved segment. Figure 1A The curved segment 172 in the middle was used as the subsequent curved segment. Furthermore, Figure 18 The following example situation is shown, where, for Figure 7A The target bending angle θ of the furthest bending segment shown in the figure L After issuing the first change operation command, issue the second change operation command.

[0187] exist Figure 18 In, with Figure 7B Similarly, the horizontal axis indicates the displacement z of the base unit 140. b The vertical axis indicates the bending angle θ of the furthest bending segment and subsequent bending segments. Figure 18 In the middle, the dashed "front end" indicates the target bending angle θ of the furthest bending segment input by the operator via input device 310. L The configuration of the bending angle. Additionally, in Figure 18 In, obtained after the first change and in Figure 7A The solid line "interpolation follower" indicates the target bending angle θ for the subsequent bending segment. F The configuration of the bending angle is indicated by the thick dashed line "First Interpolation" indicating the target bending angle θ for subsequent bending segments. F Configuration of the bending angle. Figure 18 The example shown indicates the following situation: when the displacement z of the base element 140 b When the length l of the subsequent bending segment is less than the displacement (which falls within the range from displacement a to displacement c), the target bending angle θ of the farthest bending segment is... L Change from the furthest bending angle b to the furthest bending angle b'.

[0188] If in Figure 18 The target bending angle θ of the farthest bending segment shown in the reference table L If the first farthest bending angle b changes to the second farthest bending angle b', then the reference table rewriting unit 212 refers to the displacement z of the base unit 140 from the first displacement a' (i.e., the bending angle becomes the second farthest bending angle b'). b The displacement range from the first displacement a' to the second displacement c' (i.e., the displacement corresponding to the sum of the lengths l of the subsequent bending segments) is used to determine the target bending angle θ of the subsequent bending segment at the first displacement a'. F The value of the target bending angle on the straight line connecting the value of the second farthest bending angle b' at the second displacement c' is the value of the bending angle of the target angle. Figure 18 The thick dashed line shown in the image, "First Interpolation," indicates the target bending angle θ for subsequent bending segments. F Interpolation is performed. Then, the target bending angle of the subsequent bending segment obtained after interpolation is set to the modified target bending angle θ for the subsequent bending segment, indicated by the solid line "Interpolation Follower". F The configuration of the bending angle is used to rewrite Figure 18 The reference table shown is shown.

[0189] like Figure 18 As shown, in the third exemplary embodiment, the target bending angle θ for the furthest bending segment is cancelled. L The first change operation command propagates to point d of the subsequent bending segment. Using this configuration, when the displacement z of the base element 140... b When bending operations are performed continuously without exceeding the length l of the bending segment, the displacement between the bending angle of the subsequent bending segment set during the last bending operation and the target bending angle formed by the last bending operation is linearly interpolated, and the bending angle obtained by the interpolation is propagated to the subsequent bending segments.

[0190] Reference Figure 18 The above describes such an example situation, in which, Figure 1A The curved segment 173 in the middle was used as the farthest curved segment and Figure 1A The bending segment 172 in the continuum robot 100 is applied as a subsequent bending segment. Then, in cases where the number of bending segments in the bendable portion 170 of the continuum robot 100 is three or more (e.g., in...), Figure 1A (In the case where the number of bending segments of the bendable portion 170 shown is three, for example, it can be achieved by...) Figure 1A The bending segment 172 immediately preceding the bending segment 171 is used as the farthest bending segment mentioned above, in order to... Figure 1A The curved segment 171 in the above-mentioned curved segment is used as the subsequent curved segment.

[0191] Figure 19 This illustrates a third exemplary embodiment of the invention and shows a target bending angle θ for the furthest bending segment emitted in the same direction. L An example diagram showing the simulation results of the target bending angle of the subsequent bending segment obtained under the first and second change of operation commands. Figure 19 In the middle, the horizontal axis indicates the displacement z of the base unit 140. b The vertical axis indicates the bending angle θ of the furthest bending segment and subsequent bending segments. Figure 19 In the middle, the dashed "front end" indicates the target bending angle θ for the furthest bending segment. L The configuration of the bending angle, while the solid line "follower" indicates the target bending angle θ based on the farthest bending segment. L The target bending angle θ of the subsequent bending segment is obtained after the change caused by the configuration of the bending angle. F The configuration of the bending angle.

[0192] Figures 20A to 20D This illustrates a third exemplary embodiment of the invention and each shows a reflection of... Figure 19 The diagram shows an example of the operational state of the bendable portion 170 of the continuum robot 100, illustrating simulation results. Specifically, Figures 20A to 20D The operational states of the bendable portion 170 of the continuum robot 100 are shown in chronological order, with the horizontal axis indicating displacement in the x-direction and the vertical axis indicating displacement in the z-direction. Figures 20A to 20D In the diagram, the solid line indicates the bending state of the bendable portion 170 of the continuum robot 100, while the dashed line indicates the target route 610.

[0193] Figures 20A to 20C The responses in are respectively equal to those in the first exemplary embodiment described above. Figures 10A to 10C The response in. Figure 20D In the control method of the third exemplary embodiment, since the target bending angle is calculated by linearly interpolating the displacement between the bending angle of the subsequent bending segment set at the final bending operation and the angle of the final bending operation on the distal bending segment, no change in the angular velocity of the subsequent bending segment as described in the first exemplary embodiment occurs. Therefore, the approximation of the target route 610 by the bendable portion 170 becomes gentler.

[0194] Figure 21 This illustrates a third exemplary embodiment of the invention and shows the target bending angle θ for the furthest bending segment emitted in the opposite direction. L An example diagram showing the simulation results of the target bending angle of the subsequent bending segment obtained under the first and second change of operation commands. Figure 21In the text, the references will be omitted. Figure 19 The description of the matter is similar to the description of the matter.

[0195] Figures 22A to 22D This illustrates a third exemplary embodiment of the invention and each shows a reflection of... Figure 21 The diagram shows an example of the operational state of the bendable portion 170 of the continuum robot 100, illustrating simulation results. Specifically, Figures 22A to 22D The operational states of the bendable portion 170 of the continuum robot 100 are shown in chronological order, with the horizontal axis indicating displacement in the x-direction and the vertical axis indicating displacement in the z-direction. Figures 22A to 22D In the diagram, the solid line indicates the bending state of the bendable portion 170 of the continuum robot 100, while the dashed line indicates the target route 610.

[0196] Figures 22A to 22C The responses in are respectively equal to those in the first exemplary embodiment described above. Figures 12A to 12C The response in. Figure 22D In the control method of the third exemplary embodiment, the displacement z of the base unit 140 is... b Corrective bending operations not exceeding the length l of the bending segment are not propagated. Therefore, the following characteristics of the bendable portion 170 to the target route 610 become smoother, but the bendable portion 170 does not extend beyond the target route 610 due to the bending of subsequent bending segments as described in the second exemplary embodiment.

[0197] Similarly, in the third exemplary embodiment, as in the first exemplary embodiment described above, even when the displacement z of the base unit 140... b When the length of the subsequent bending segment is less than the target bending angle θ of the farthest bending segment, change the target bending angle θ of the farthest bending segment. L In this case, the operability of the continuum robot 100 can also be improved. This can avoid damage to the target object that operates the continuum robot 100 along the target route 610 or malfunctions that could destroy the continuum robot 100.

[0198] (Fourth exemplary embodiment)

[0199] Next, a fourth exemplary embodiment of the present invention will be described. In the following description of the fourth exemplary embodiment, descriptions of matters similar to those in the first to third exemplary embodiments described above will be omitted, and matters different from those in the first to third exemplary embodiments will be described.

[0200] In the first to third exemplary embodiments described above, a method for front-end following control of the continuum robot 100 in the xz plane has been described. In the fourth exemplary embodiment, in Figure 1A and Figure 1BThe front-end follows and controls the device in the xyz three-dimensional space shown in the figure.

[0201] In order to obtain the driving displacement caused by the actuator used to control the bending angle and lateral angle of the continuum robot 100, a kinematic model is derived.

[0202] The following are definitions of the symbols that will be used in this exemplary embodiment.

[0203] l d Length of the central axis of the curved segment

[0204] θ n Bending angle of the distal bending segment

[0205] ζ n : Lateral displacement angle of the distal bending segment

[0206] ρ n Radius of curvature of the curved segment

[0207] ζ refn : The lateral displacement angle of the nth curved segment at the distal end of the target

[0208] In this example, the kinematic model of the continuum robot 100 is derived based on the following assumptions.

[0209] 1. In each bending segment, the conductor deforms with a fixed curvature.

[0210] 2. Torsional deformation of the conductor is not considered.

[0211] 3. The conductor does not deform longitudinally.

[0212] 4. Friction between the conductor and the conductor is not considered.

[0213] First, the first bending segment (corresponding to) is represented by the following formula (10). Figure 1A and Figure 1B The driving displacement l of conductors a, b, and c in the bending segment 171) p1a l p1b and l p1c The relationship between the bending angle θ1 and the lateral displacement angle ζ1 at its distal end.

[0214] [Mathematical Expression 6]

[0215]

[0216] Next, the driving displacements l of the a-guide, b-guide, and c-guide of the continuum robot 100, which includes multiple curved segments, are obtained. pna l pnb and l pnc The bending angle θ at its distal endn and lateral angle ζ n The relationship between them. When the number of curved segments is represented by “e”, the phase angle of the conductor driving the nth curved segment is represented by the following formula (11).

[0217] [Mathematical Expression 7]

[0218]

[0219] Therefore, the conductor driving displacement l of the nth bending segment can be represented by the following formula (12). pna l pnb and l pnc .

[0220] [Mathematical Expression 8]

[0221]

[0222] When the operator inputs the target bending angle θ for the farthest e-th bending segment via input device 310 refe And the target lateral movement angle ζ refe At that time, the angle at the farthest end can be controlled by obtaining the conductor drive displacement using formula (12). Then, the front-end follow control only needs to propagate the target bending angle similarly to the planar drive in the first exemplary embodiment to the third exemplary embodiment, and calculate the target angle using a similar algorithm by treating the bending angle in the first exemplary embodiment to the third exemplary embodiment as a lateral angle. Then, the front-end follow control can be performed in three-dimensional space by obtaining the conductor drive displacement using formula (12) for each subsequent bending segment.

[0223] (Other exemplary embodiments)

[0224] As another exemplary embodiment, the storage unit 211 may store a reference table 2111 to be used in the front-end follow control method according to the first exemplary embodiment to the third exemplary embodiment described above, and the reference table rewriting unit 212 may perform processing after selecting the reference table 2111 to be used in the corresponding exemplary embodiment based on the input information from the information input unit 213.

[0225] Exemplary embodiments of the present invention can also be implemented by supplying a program that implements one or more functions of the above exemplary embodiments to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reading and executing the program. Alternatively, exemplary embodiments of the present invention can also be implemented by a circuit (e.g., an application-specific integrated circuit (ASIC)) that implements the above one or more functions.

[0226] The program and the computer-readable storage medium storing the program are included in this invention.

[0227] The exemplary embodiments described above are merely specific examples illustrating the implementation of the invention and should not be construed as limiting the scope of the invention. In other words, exemplary embodiments of the invention can be implemented in various forms without departing from the technical concept or key features of the invention.

[0228] This invention is not limited to the above embodiments, and various changes and modifications can be made within the spirit and scope of this invention. Therefore, the claims are appended to disclose the scope of this invention.

[0229] This application claims priority to Japanese Patent Application No. 2020-107933, filed on June 23, 2020, and Japanese Patent Application No. 2021-099452, filed on June 15, 2021, the entire contents of which are incorporated herein by reference.

Claims

1. A continuum robot, comprising: Base unit; The distal bending segment is configured to bend by driving a linear member for the distal bending segment; A follower bending segment is disposed between the distal bending segment and the base unit and is configured to bend by driving a linear member for the follower bending segment; A drive unit configured to independently drive a linear member for the distal bending segment and a linear member for the following bending segment; A moving unit is configured to move the base unit, the distal bending segment, and the following bending segment forward as a whole; as well as Control unit The control unit is configured to control the bending angle of the following bending segment, based on a configuration of a first bending angle corresponding to the forward movement of the continuum robot and set according to the first target bending angle of the input distal bending segment, to achieve the first target bending angle. Specifically, this occurs before the forward displacement of the continuum robot reaches a first displacement corresponding to the length of the following bending segment while controlling the following bending segment according to the configuration of the first bending angle, and after the distal bending segment bends at the first target bending angle, the target bending angle of the distal bending segment changes from the first target bending angle to a second target bending angle. The control unit is configured to set a second bending angle configuration that is different from the configuration for the first bending angle used for the following bending segment, and The control unit is configured to control the bending angle of the following bending segment such that, through further forward movement of the continuum robot, the bending angle of the following bending segment reaches the second target bending angle according to the configuration of the second bending angle.

2. The continuum robot according to claim 1, wherein, The control unit includes: A storage unit is configured to store a reference table indicating the relationship between the target bending angle of the distal bending segment and the target bending angle of the following bending segment and the displacement of the base unit; and The rewrite unit is configured to rewrite the reference table stored in the storage unit based on the change in the target bending angle of the distal bending segment.

3. The continuum robot according to claim 2, in, In the reference table stored in the storage unit, when the target bending angle of the distal bending segment changes from the first target bending angle to the second target bending angle... The rewriting unit generates a right-angled triangle, the length of the base of which corresponds to the length from the first displacement to the second displacement, and the height of which corresponds to the difference between the second distal bending angle and the first distal bending angle. The first displacement is the displacement of the base unit caused by the change, and the second displacement is the displacement of the following bending segment forward from the first displacement. The rewriting unit rewrites the reference table by adding the value of the change in bending angle from the bending angle corresponding to the point on the hypotenuse of the right triangle to the bending angle corresponding to the base, to the value of the bending angle of the following bending segment stored in the reference table in the storage unit, and setting the target bending angle of the following bending segment obtained after the addition as the target bending angle of the following bending segment obtained after the change.

4. The continuum robot according to claim 2, in, In the reference table stored in the storage unit, when the target bending angle of the distal bending segment changes from the first target bending angle to the second target bending angle, the rewriting unit rewrites the reference table by excluding the range of displacements from the base unit where the bending angle becomes the first distal bending angle to the first displacement corresponding to the sum of the lengths of the following bending segments within the range of displacements from the base unit where the bending angle becomes the second farthest bending angle to the second displacement, which is the displacement corresponding to the sum of the lengths of the following bending segments. The rewriting unit then interpolates the displacement between the first and second displacements at the target bending angle of the following bending segment in the reference table using the value of the target bending angle on the straight line connecting the value of the first distal bending angle at the first displacement and the value of the second distal bending angle at the second displacement. Finally, the rewriting unit sets the target bending angle of the following bending segment obtained after the interpolation as the target bending angle of the following bending segment obtained after the change.

5. The continuum robot according to claim 2, in, In the reference table stored in the storage unit, when the target bending angle of the distal bending segment changes from a first distal bending angle to a second distal bending angle, the rewriting unit rewrites the reference table by interpolating the displacement between the first displacement and the second displacement at the target bending angle of the following bending segment in the reference table using the value of the target bending angle on a straight line connecting the value of the target bending angle of the following bending segment at the first displacement and the value of the second distal bending angle at the second displacement, for a displacement range from a first displacement of the base unit where the bending angle becomes the second distal bending angle to a second displacement corresponding to the sum of the lengths of the following bending segments. The rewriting unit then sets the target bending angle of the following bending segment obtained after the interpolation as the target bending angle of the following bending segment obtained after the change.

6. The continuum robot according to claim 2, in, The storage unit stores multiple different reference tables, and The rewriting unit selects one reference table from the plurality of reference tables and rewrites the selected reference table.

7. A control method for a continuum robot, the continuum robot comprising: Base unit; The distal bending segment is configured to bend by driving a linear member for the distal bending segment; And a following bending segment, disposed between the distal bending segment and the base unit, and configured to bend by driving a linear member for the following bending segment, wherein the base unit, the distal bending segment, and the following bending segment move forward as a whole, the control method comprising the following steps: The bending angle of the following bending segment is controlled according to a configuration of a first bending angle, set based on a first target bending angle of the distal bending segment and corresponding to the forward movement of the continuous robot, in order to achieve the first target bending angle. Before the forward displacement of the continuum robot reaches a first displacement corresponding to the length of the following bending segment while controlling the following bending segment according to the configuration of the first bending angle, and after the distal bending segment bends at the first target bending angle, the target bending angle of the distal bending segment changes from the first target bending angle to the second target bending angle. A second bending angle configuration is set that is different from the configuration of the first bending angle used for the following bending segment, and Controlling the bending angle of the following bending segment allows the bending angle of the following bending segment to reach the second target bending angle as the continuous robot moves further forward.

8. A storage medium storing a program that enables a computer to function as units of a continuum robot according to claim 1.

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