Continuum robot control system, continuum robot control method and program

Abstract

To provide a system which, when a continuum robot advances and then retreats, enables breakage of the continuum robot to be prevented.SOLUTION: When a continuum robot is caused to advance and the most-distal end curved portion (beginning curved portion) is inserted into a tube, then the continuum robot is caused to retreat and the most-distal end curved portion (beginning curved portion) is drawn from the tube, control is performed in such a manner that the most-distal end curved portion (beginning curved portion) is curved with respect to a reference axis, at a third curve angle between a curve angle b (second curve angle) and a curve angle e (first curve angle) at a position of a base portion between a position c (third position) and a position e (first position).SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a continuum robot control system and a continuum robot control method for controlling a continuum robot, and a program for causing a computer to function as the continuum robot control system. [Background technology]

[0002] Continuum robots, also known as continuum robots, are composed of multiple flexible curved sections, and their shape is controlled by deforming these curved sections. These robots have two main advantages over rigid-link robots. First, they can move along curved lines in narrow spaces or cluttered environments where rigid-link robots can get stuck. Second, their inherent flexibility allows them to manipulate fragile objects without damaging them. Therefore, they do not necessarily require the external force detection required for rigid-link robots. Taking advantage of these advantages, continuum robots are expected to be applied in the medical field, such as endoscopic sheaths and catheters, and in extreme work robots such as rescue robots.

[0003] Patent Document 1 describes a control method for causing a continuum robot used as an endoscope to enter a lumen. Specifically, Patent Document 1 describes a method for continuously propagating the shape of the endoscope by controlling the curved shape of the front curved portion in all pairs of adjacent curved portions to match the curved shape of the subsequent curved portion as the base of the endoscope advances. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2012 / 0271109 Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned Patent Document 1 describes a technology relating to control for propagating the curved shape of a front bending portion to a subsequent bending portion each time a base portion of a continuum robot used as an endoscope advances along the length of the bending portion. However, with the technology described in Patent Document 1, when the continuum robot advances and then moves backward, there is a risk that the continuum robot will come into contact with the inner wall of a lumen and be damaged if the posture is not controlled.

[0006] The present invention has been made in consideration of such problems, and aims to provide a mechanism that can prevent damage to a continuous robot when the continuous robot moves forward and then backward. [Means for solving the problem]

[0007] The continuum robot control system of the present invention is a continuum robot control system that controls a continuum robot having a base unit, a distal bending unit that bends when a distal linear member is driven, a drive unit that drives the distal linear member, and a connection unit provided between the distal bending unit and the base unit, and includes a means for operating movement to move the continuum robot forward and backward, and ... a second state in which the base unit is at a position where the distal bending portion is bent at a second bending angle with respect to the reference axis that is different from the first bending angle, and a third state in which the base unit is at a third position that is further forward than the second position, so that after the distal bending portion has been inserted into the pipe, when the base unit of the continuum robot is moved backward to extract the distal bending portion from the pipe, the position of the base unit is between the third position and the first position, and the distal bending portion is bent at a third bending angle with respect to the reference axis that is between the second bending angle and the first bending angle. and when the position of the base portion is further rearward than the fourth state, the distal bending portion is bent at the first bending angle with respect to the reference axis.and a control means for controlling the bending angle of the distal bending portion to change from the second bending angle to the first bending angle during the backward movement. angle to change Starts and finishes Until The displacement of the base portion When the distal curved portion is advanced, the bending angle of the distal curved portion is changed from the first bending angle to the second bending angle. angle to change Starts and finishes Until The displacement of the base portion than big . The present invention also includes a continuum robot control method using the above-mentioned continuum robot control system, and a program for causing a computer to function as each means of the above-mentioned continuum robot control system. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent damage to the continuum robot when the continuum robot moves backward after moving forward. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a continuum robot according to a first embodiment of the present invention. [Figure 2] 2 is a diagram showing an example of a detailed schematic configuration of one bending portion of the schematic configuration of the continuum robot shown in FIG. 1. FIG. [Figure 3] 3 is a diagram showing an example of the arrangement of the three wires shown in FIG. 2 on the xy plane. FIG. [Figure 4] 1 is a diagram showing an example of a schematic configuration of a continuum robot control system according to a first embodiment of the present invention. [Figure 5] 1 is a diagram showing an example of a schematic configuration of a continuum robot according to a first embodiment of the present invention. [Figure 6] 6 is a diagram illustrating the nth curved portion shown in FIG. 5. FIG. [Figure 7] 5 is a diagram for explaining leading follow-up control and trailing follow-up control of the continuum robot performed by the control device of FIG. 4. [Figure 8]5 illustrates the first embodiment of the present invention and is a diagram showing an example of a reference table for leading follow-up control and trailing follow-up control of a continuum robot, as a reference table stored in the control device of FIG. 4. FIG. [Figure 9] 5 illustrates the first embodiment of the present invention and is a diagram illustrating an example of a reference table for tail following control (which may also include lead following control) of a continuum robot, as a reference table stored in the control device of FIG. 4. FIG. [Figure 10] 5 illustrates the first embodiment of the present invention and is a diagram illustrating an example of a reference table for tail following control (which may also include lead following control) of a continuum robot, as a reference table stored in the control device of FIG. 4. FIG. [Figure 11] FIG. 4 is a diagram showing the results of a simulation relating to the response of leading follow-up control in the continuum robot according to the first embodiment of the present invention. [Figure 12] 8A and 8B are diagrams showing the results of a simulation relating to the response of interpolation method 1 of the tail following control shown in FIG. 8B in the continuum robot according to the first embodiment of the present invention. [Figure 13] 9A is a diagram showing the results of a simulation related to the response of interpolation method 2 of the tail following control shown in FIG. 9A in the continuum robot according to the first embodiment of the present invention. FIG. [Figure 14] 9(b) in the continuum robot according to the first embodiment of the present invention. FIG. 9(b) is a diagram showing the results of a simulation related to the response of interpolation method 2 of the tail following control shown in FIG. [Figure 15] 10(b) is a diagram showing the results of a simulation related to the response of interpolation method 2 of the tail following control shown in FIG. 10(a) in the continuum robot according to the first embodiment of the present invention. FIG. [Figure 16] 5 shows the second embodiment of the present invention and is a diagram showing an example of a reference table for tail following control (which may also include lead following control) of a continuum robot, as a reference table stored in the control device of FIG. 4. FIG. [Figure 17] FIG. 10 illustrates a third embodiment of the present invention and is a diagram showing an example of a reference table stored in the control device of FIG. 4 for tail following control (which may also include lead following control) of a continuum robot. [Figure 18] FIG. 10 is a diagram illustrating an example of a schematic configuration of a continuum robot control system according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] (First embodiment) First, a first embodiment of the present invention will be described.

[0012] FIG. 1 is a diagram illustrating an example of a schematic configuration of a continuum robot 100 according to a first embodiment of the present invention. FIG. 1 illustrates a base 140 and multiple curved sections (which may also be referred to as "curved sections") 170 as one configuration of the continuum robot 100. Specifically, in the example illustrated in FIG. 1, the multiple curved sections 170 are illustrated as n curved sections, including curved section 170-(n-2), curved section 170-(n-1), and curved section 170-n, from the side of the base 140. FIG. 1 also illustrates an xyz coordinate system in which an origin O is set at a predetermined position (e.g., the center position) on the upper surface 141 of the base 140, the z direction is the direction of travel of the continuum robot 100 (e.g., the forward direction), and the x and y directions are directions perpendicular to the z direction and mutually perpendicular to each other. Furthermore, FIG. 1 illustrates a pipe 20 corresponding to a path along which the continuum robot 100 is inserted by advancing forward and removed by reversing backward. When the continuum robot 100 is used in the medical field, this tube 20 can be, for example, the digestive tract or trachea, and when the continuum robot 100 is used in the industrial field, this tube 20 can be, for example, a pipe, but is not limited to these.

[0013] Each of the multiple bending portions 170 shown in FIG. 1 is a bending portion that is bent by driving a wire, which is a linear member provided for each bending portion. The bending portion 170-n shown in FIG. 1 is a distal bending portion (the most distal bending portion) that is further from the base portion 140 than the bending portions 170-(n-1) and 170-(n-2), and is also the leading bending portion in the direction (+z direction) in which the continuum robot 100 advances. The bending portion 170-(n-1) shown in FIG. 1 is a first subsequent bending portion that follows the bending portion 170-n, which is the leading bending portion, in the direction (+z direction) in which the continuum robot 100 advances. The bending portion 170-(n-2) shown in FIG. 1 is a second subsequent bending portion that follows the bending portion 170-n and the bending portion 170-(n-1) in the direction (+z direction) in which the continuum robot 100 advances. In addition, in FIG. 1, the curved portion 170-(n-1) and the curved portion 170-(n-2) correspond to a connecting portion provided between the curved portion 170-n, which is the distal curved portion (the most distal curved portion), and the base portion 140.

[0014] In addition, in FIG. 1, the bending angle of the distal end of the bending portion 170-n with respect to the reference axis 101 parallel to the z direction (simply referred to as the "bending angle of the bending portion 170-n") is θ n 1, the bending angle of the distal end of the bending portion 170-(n-1) with respect to the reference axis 101 parallel to the z direction (simply referred to as the "bending angle of the bending portion 170-(n-1)") is represented by θ n-1 Furthermore, in FIG. 1, the bending angle of the distal end of the bending portion 170-(n-2) with respect to the reference axis 101 parallel to the z direction (simply referred to as the "bending angle of the bending portion 170-(n-2)") is represented by θ n-2 is shown.

[0015] The base portion 140 is a component that supports the multiple bending portions 170, and is provided therein with actuators (not shown in FIG. 1) that are driving units for driving the wires of each of the bending portions 170-n to 170-(n-2).

[0016] The continuum robot 100 is capable of moving forward (+z direction) and backward (-z direction) in the z direction in addition to the bending motions performed by the above-mentioned bending sections 170. In this case, in FIG. 1, the displacement z of the base section 140 is used as an index showing the amount of movement of the continuum robot 100 in the z direction. b is illustrated.

[0017] FIG. 2 is a diagram showing an example of a detailed schematic configuration of one bending section 170 out of the schematic configuration of the continuum robot 100 shown in FIG. 1. Specifically, FIG. 2 shows a detailed schematic configuration of the proximal bending section 170-(n-2) that is closest to the base section 140 out of the multiple bending sections 170 shown in FIG. 1. In FIG. 2, the same components as those shown in FIG. 1 are denoted by the same reference symbols, and detailed descriptions thereof will be omitted. In FIG. 2, the bending angle of the bending section 170 with respect to the reference axis 101 parallel to the z direction is indicated by θ1, the turning angle of the bending section 170 is indicated by ζ1, and the radius of curvature of the bending section 170 (which corresponds to the line segment connecting the origin O and point w1 in FIG. 2) is indicated by ρ1.

[0018] In FIG. 1, the turning angle of the bending portion 170-n is ζ n and the turning angle of the curved portion 170-(n-1) is represented by ζ n-1 The turning angle of the curved portion 170-(n-2) is indicated by ζ1.

[0019] 2, in the continuum robot 100, wires 111 to 113, which are linear members, are connected to connection portions 121 to 123 at the distal end 160 of the bending portion 170, respectively. The posture (bending shape) of the continuum robot 100 is controlled by pushing and pulling the wires 111 to 113 with actuators 131 to 133 installed inside the base portion 140. Here, the actuator 131 is a drive unit for driving the wire 111, the actuator 132 is a drive unit for driving the wire 112, and the actuator 133 is a drive unit for driving the wire 113.

[0020] 2, the continuum robot 100 has wire guides 161-164, which are members for guiding the wires 111-113, which are linear members, at the bending section 170. The wire guides 161-164 may be formed by discretely arranging a plurality of members, or may be formed by continuous members such as bellows or mesh. The wire 111 is fixed to the wire guides 161-164 at fixing sections 150-153, respectively. In FIG. 2, the central axis of the continuum robot 100, which passes through the origin O, is indicated by a dashed line.

[0021] In this embodiment, the wires 111 to 113 are called the a-wire, the b-wire, and the c-wire in a counterclockwise direction in the xy plane. Specifically, in the example shown in FIG. 2, the wire 111 corresponds to the a-wire, and the driving displacement of the wire 111 by pushing and pulling the actuator 131 of the bending section 170 is called the l-wire. p1a 2, the wire 112 corresponds to the b wire, and the driving displacement of the wire 112 due to the pushing and pulling of the actuator 132 of the bending portion 170 is represented by l p1b 2, the wire 113 corresponds to the c-wire, and the driving displacement of the wire 113 due to the pushing and pulling of the actuator 133 of the bending portion 170 is represented by l p1c Here, in general, the driving displacement of the wire that drives the nth curved portion (n is a positive integer) is expressed as l pna ,l pnb ,l pnc Let's say.

[0022] 2, only the detailed schematic configuration of the bending portion 170 corresponding to the bending portion 170-(n-2) shown in FIG. 1 has been illustrated and described. In this regard, the bending portion 170-(n-1) and the bending portion 170-n shown in FIG. 1 also have a configuration similar to the detailed schematic configuration of the bending portion 170 in FIG. 2 corresponding to the bending portion 170-(n-2) shown in FIG. 1. That is, the bending portions 170-(n-1) and 170-n each include wires corresponding to the wires 111 to 113, actuators corresponding to the actuators 131 to 133, and distal ends and wire guides corresponding to the distal end 160 and the wire guides 161 to 164. For example, the bending portion 170-n, which is the most distal bending portion (leading bending portion) in FIG. 1, includes wires that are distal linear members corresponding to the wires 111 to 113 in FIG. 2, and is bent when the wires are driven by actuators that are driving units. 1 includes wires that are first subsequent linear members corresponding to the wires 111 to 113 in FIG. 2, and is bent when the wires are driven by actuators that are driving units. The bending section 170-(n-2) of FIG. 1 includes wires 111 to 113 in FIG. 2 that are second subsequent linear members, and is bent when the wires 111 to 113 are driven by actuators 131 to 133 that are driving units. That is, the continuum robot 100 shown in FIG. 1 includes actuators that are driving units that independently drive the wires that are the most distal linear members, the wires that are the first subsequent linear members, and the wires that are the second subsequent linear members.

[0023] 3 is a diagram showing an example of the arrangement of the three wires 111 to 113 (wire a to wire c) shown in FIG. 2 on the xy plane. As shown in FIG. 3, the three wires 111 to 113 (wire a to wire c) shown in FIG. 2 have lengths of r s The phase angle ξ shown in Figure 3 is n is the angle that determines the placement of the wire that drives the nth bending section.

[0024] Fig. 4 is a diagram showing an example of the schematic configuration of a continuum robot control system 10-1 according to the first embodiment of the present invention. This continuum robot control system 10-1 is a system that controls the continuum robot 100 shown in Figs. 1 and 2. As shown in Fig. 4, this continuum robot control system 10-1 is configured to include the continuum robot 100, a control device 200, and various input devices 310, 330, and 340.

[0025] In the example shown in FIG. 1, the input device 310 inputs a target bending angle θ of the bending portion 170-n, which is the most distal bending portion (first bending portion). L This is a device that inputs the above into the control device 200.

[0026] The input device 330 receives a displacement z of the base unit 140, which indicates the amount of movement of the continuum robot 100 in the z direction. b is input to the control device 200, and the base part 140 of the continuum robot 100 is displaced z b Here, the base part 140 of the continuum robot 100 is displaced by z b The input device 330 controls the continuum robot 100 to move in the z direction by the displacement z b This constitutes a "movement means" that moves the robot in the z direction by the amount of force required (movement in the +z direction is forward, and movement in the -z direction is backward).

[0027] The input device 340 is a device that inputs various types of information to the control device 200. Specifically, in the example shown in Fig. 1, the input device 340 inputs information on the length l of the multiple bending portions 170-n to 170-(n-2), instruction information on the reference table 2111 to be used, and the like to the control device 200.

[0028] As shown in FIG. 4, the control device 200 includes an angle calculation unit 210, a switching unit 220, and a kinematics calculation unit (Kinematics) 230.

[0029] The angle calculation unit 210 receives a target bending angle θ of the most distal bending portion (first bending portion) from the input device 310. L, the displacement z of the base unit 140 from the input device 330 b , information on the length l of the plurality of bending portions 170 is input from the input device 340. Then, the angle calculation unit 210 calculates a target bending angle θ of the subsequent bending portion (for example, the first subsequent bending portion described above) based on the input information. F Calculation of the target bending angle θ of the most distal bending part (first bending part) L The target bending angle θ of the subsequent bending section after the change F Furthermore, the angle calculation unit 210 calculates the target bending angle θ of the most distal bending portion (leading bending portion). L and the target bending angle θ of the subsequent bending section F The target bending angle θ of the most distal bending portion when the base unit 140 of the continuum robot 100 moves backward is stored. L ' is calculated.

[0030] As shown in Fig. 4, the angle calculation unit 210 is configured to have a multiplexer (MUX), a memory unit 211, a reference table rewriting unit 212, and an information input unit 213. The multiplexer (MUX) is a component that receives multiple pieces of input information from an external device, selects and combines them, and outputs them as one piece of information (signal). The memory unit 211 stores a target bending angle θ of the most distal bending portion (leading bending portion). L and the target bending angle θ of the subsequent bending portion F and the displacement z of the base part 140 b and various information required for processing in the angle calculation unit 210. The information input unit 213 inputs information on the lengths l of the bending portions 170 input from the input device 340, instruction information for the reference table 2111 to be used, and the like, to the reference table rewriting unit 212. The reference table rewriting unit 212 selects one reference table 2111 to be used from the multiple reference tables 2111 stored in the storage unit 211 based on the information input from the information input unit 213. Then, the reference table rewriting unit 212 calculates the target bending angle θ of the most distal bending portion (leading bending portion). L , the target bending angle θ of the subsequent bending section F and the displacement z of the base portion 140 bIn response to the change, the selected reference table 2111 is rewritten.

[0031] The switching unit 220 selects the target bending angle θ input from the input device 310 as the target bending angle of the most distal bending portion (leading bending portion). L and the target bending angle θ calculated by the angle calculation unit 210. L ' and the displacement z of the base portion 140 b Specifically, in this embodiment, the switching unit 220 switches the displacement z of the base unit 140. b When the traveling direction is the forward direction, the target bending angle θ input from the input device 310 L The switching unit 220 also switches the displacement z of the base unit 140. b When the traveling direction is a reverse direction, the target turning angle θ calculated by the angle calculation unit 210 L Switch to select '.

[0032] The kinematics calculation unit 230 receives the target bending angle (θ L or θ L '), and the target bending angle θ of the subsequent bending portion calculated by the angle calculation unit 210 F Then, based on the input information, the kinematics calculation unit 230 calculates the drive displacement when driving the wires of the most distal bending portion (first bending portion) and the subsequent bending portions with each actuator, which is the driving unit. In FIG. 4, the drive displacement of the wire of the most distal bending portion (first bending portion) and the drive displacement of the wire of the subsequent bending portions obtained by the calculation of the kinematics calculation unit 230 are combined together to form the drive displacement of the wire l p The continuum robot 100 according to this embodiment is illustrated as follows: p In response to this, bending control of the most distal bending portion (first bending portion) and subsequent bending portions is performed.

[0033] In this embodiment, all phase angles (FIG. 3) are expressed as ξ n = 0, and first, the leading follow-up control on the xz plane will be explained.

[0034] 1) Modeling In this chapter, we derive the kinematics in the xz plane of the continuum robot 100. The definitions of symbols are as follows: l n : The length of the nth curved part (of the arm housing) r n : The distance from the wire passing through the wire guide at the nth bend to the center of the wire guide e: Number of curved parts of the continuum robot 100 θ n : The bending angle (at the distal end) of the nth bending part ρ n : Radius of curvature of the nth curved part θ refn : Target bending angle (at the distal end) of the nth bending section l pn : Driving displacement of the wire at the nth bend x tn ,z tn : Coordinates of the distal end of the nth curved section z b : Displacement of the base part 140

[0035] FIG. 5 is a diagram showing an example of a schematic configuration of the continuum robot 100 according to the first embodiment of the present invention. In FIG. 5, the same components as those shown in FIGS. 1 and 2 are assigned the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the following assumptions are made to derive the kinematics of the continuum robot 100, where the number of bending portions 170 of the continuum robot 100 shown in FIG. 5 is e. Here, in the continuum robot 100 shown in FIG. 5, the e-th bending portion 170-e is the most distal bending portion located farthest from the base portion 140, and is also the leading bending portion in the direction in which the continuum robot 100 advances (+z direction). 1. The wire deforms only in the xz plane. 2. At each bend, the wire deforms to a constant curvature. 3. Torsional deformation of the wire is not taken into account. 4. The wire does not deform longitudinally.

[0036] First, consider only the first curved portion 170-1 shown in FIG. When wire a is driven and wire b and wire c are fixed, the wire drive amount l p1 The relationship between the angle θ1 and the bending angle of the first bending portion 170-1 is expressed by the following formula (1).

number

[0037] Next, the driving displacement l of the wire of the n-th bending portion 170-n shown in FIG. pn and the curvature angle θ of its distal end n Here, n is an integer equal to or greater than 2. The relative bending angle θ of the n-th bending portion 170-n is ~ n is defined as shown in the following equation (2). θ~ n =θ n -θ n-1 ···(2)

[0038] FIG. 6 is a diagram in which the n-th curved portion 170-n shown in FIG. 5 is extracted. As shown in FIG. 6, the origin O of the n-th curved portion 170-n is (x tn-1 ,z tn-1 ) and θ n-1 Direction and The relative coordinate system x consisting of the orthogonal directions n -z n Then, the relative coordinate system x n -z n The driven displacement of the wire in pn and the relative bending angle θ~ of the n-th bending portion 170-n n The relationship between these is expressed by the following equation (3).

number

[0039] In addition, the driving displacement l of the wire of the n-th bending portion 170-n pnis the sum of the displacements of the wires for driving the nth bending portion 170-n in the relative coordinate system from the first bending portion 170-1 to the (n-1)th bending portion 170-(n-1), and is expressed as the following equation (4).

number

[0040] As a result, the bending angle θ of the n-th bending portion 170-n n is the driving displacement of the wire l pn It can be seen that the value is determined only by the curve angle of the curved portion 170 in the middle.

[0041] Next, the bending angle θ (at the distal end) of the n-th bending portion 170-n n and its relationship to the coordinates of its distal end.

[0042] First, the bending angle θ1 (at the distal end) of the first bending portion 170-1 and the coordinates (x t1 ,z t1 ) are expressed by the following equations (5) and (6).

number

[0043] Next, the bending angle θ (at the distal end) of the n-th bending portion 170-n is n and the coordinates of its distal end are derived. Note that n must be 2 or greater. Relative coordinate system x n -z n The coordinates (x~) of the distal end of the nth curved portion 170-n in tn ,z~ tn ) are expressed as the following equations (7) and (8).

number

[0044] As a result, the coordinates (x tn ,z tn) is expressed as the following equation (9) using a rotation transformation matrix.

number

[0045] Next, the leading follow-up control and trailing follow-up control of the continuum robot 100 performed by the control device 200 will be described. FIG. 7 is a diagram for explaining the leading follow-up control and trailing follow-up control of the continuum robot 100 performed by the control device 200 of FIG. 4. Specifically, FIG. 7(a) is a diagram for explaining the leading follow-up control, and FIG. 7(b) is a diagram for explaining the trailing follow-up control. In addition, in the explanation of FIGS. 7(a) and 7(b), the explanation will be made assuming the continuum robot 100 shown in FIG. 5. That is, in the explanation of FIGS. 7(a) and 7(b), the e-th bending portion 170-e is the most distal bending portion (leading bending portion), and the (e-1)-th bending portion 170-(e-1) is the subsequent bending portion subsequent to the e-th bending portion 170-e. For this reason, in FIGS. 7(a) and 7(b), the same components as those shown in FIG. 5 are denoted by the same reference numerals, and detailed explanations thereof will be omitted.

[0046] 2) Leading control In this chapter, the leading follow-up control system will be explained. Here, the leading-following control is a method of controlling the subsequent bending portions, such as the (e-1)th bending portion 170-(e-1), to follow the same path as the path indicated by the dotted line taken by the e-th bending portion 170-e, which is the most distal bending portion (leading bending portion), as shown in FIG. 7(a). As a result, when the continuum robot 100 is sequentially advanced as shown in states 711 to 715 in FIG. 7(a), the continuum robot 100 can advance so as to slip through the space inside the pipe 20. In this leading-following control, it is not essential that the path is determined in advance, and for example, the bending angle θ of the e-th bending portion 170-e, which is the most distal bending portion (leading bending portion), can be controlled. emay be continuously propagated to the subsequent bending portion with a bending portion length 1. By using this method, the operator can control the continuum robot 100 to follow the leading end in real time by giving commands only for the bending angle of the most distal bending portion (leading bending portion) and the movement amount of the base unit 140 in the z direction via the input device 310 and the input device 330.

[0047] FIG. 8 illustrates the first embodiment of the present invention and is a diagram showing an example of a reference table for leading follow-up control and trailing follow-up control of the continuum robot 100, as the reference table 2111 stored in the control device 200 of FIG.

[0048] Specifically, Fig. 8(a) shows a reference table 2111 for the leading follow-up control of the continuum robot 100. Specifically, the reference table 2111 shown in Fig. 8(a) has the displacement z of the base unit 140 described above on the horizontal axis. b 8(a), the displacement z of the base portion 140 shown on the horizontal axis is plotted as a function of the bending angle θ of the most distal bending portion (first bending portion) and the subsequent bending portion. b 7(a) , the direction indicated by the right arrow is the direction in which the base unit 140 of the continuum robot 100 advances. Also, the position of the origin O (origin position) shown in FIG. 8(a) corresponds to, for example, the position of the origin O (origin position) shown in FIG. 5. Furthermore, with regard to the bending angle θ on the vertical axis of FIG. 8(a), the bending angle of the most distal bending portion (leading bending portion) 170-e shown in FIG. 7(a) is shown as "Leader", and the bending angle of the subsequent bending portion 170-(e-1) is shown as "Follower". In this case, the displacement z of the base unit 140 shown on the horizontal axis of FIG. 8(a) b In this figure, the distance between position e and position a corresponds to the length 1 of the most distal curved portion (first curved portion) 170-e, and the distance between position a and position c corresponds to the length 1 of the subsequent curved portion 170-(e-1).

[0049] In Fig. 8(a), the bending angle of the most distal bending portion (first bending portion) 170-e input from the input device 310 is indicated by a dashed line, and the bending angle of the subsequent bending portion 170-(e-1) is indicated by a thick dashed line.b At the position a in the figure, the target bending angle θ of the most distal bending portion (leading bending portion) 170-e is calculated from the input device 310. L In this case, the bending angle of the subsequent bending portion 170-(e-1) is determined by the displacement z of the base portion 140. b The angle calculation unit 210 can automatically calculate the bending angle c→d at a position c that is a distance of the length l of the subsequent bending portion 170-(e-1) from the position a in the figure. The bending angle of the subsequent bending portion 170-(e-1) is stored in the storage unit 211 of the control device 200, and the displacement z of the base unit 140 is calculated. b When the number e of bending portions 170 is 3 or more, the bending angles of all bending portions 170 can be obtained by replacing the above-mentioned subsequent bending portion with the most distal bending portion (first bending portion) and performing this process continuously.

[0050] However, in the above description of FIG. 8(a), the displacement z of the base portion 140 b When the displacement z of the base unit 140 is between the positions a and c, the bending angle of the subsequent bending section 170-(e-1) does not change, and the bending angle rises from c to d at the position c. Therefore, the continuum robot 100 exhibits a steep behavior. Therefore, in this embodiment, the displacement z of the base unit 140 is b is between position a and position c, the bending angle of the subsequent bending portion 170-(e-1) is interpolated to connect bending angle a and bending angle d. Specifically, in this embodiment, the angle calculation unit 210 of the control device 200 first generates a right-angled triangle shown by diagonal lines in FIG. 8(a), with the length l of the subsequent bending portion 170-(e-1) as the base coinciding with the line segment ac and the distance ab as the height. Next, the angle calculation unit 210 of the control device 200 calculates the displacement z of the base portion 140 from position a to position c by b At each position, the displacement z of the base portion 140 b8(a) , the angle calculation unit 210 of the control device 200 calculates the intersection point between a straight line perpendicular to the coordinate axis and the hypotenuse of the generated right-angled triangle. Then, the angle calculation unit 210 of the control device 200 adds the length from the calculated intersection point to the base of the generated right-angled triangle to the bending angle of the subsequent bending portion 170-(e-1) shown by the thick dashed line to generate the bending angle of the subsequent bending portion 170-(e-1) after interpolation. Here, the bending angle of the subsequent bending portion 170-(e-1) after interpolation is shown by the thick solid line in FIG. 8(a) .

[0051] 3) Rear-following control 3.1) Interpolation method 1 Next, in this chapter, we will explain the tail tracking control. First, in Section 1, we will explain interpolation method 1 of the tail tracking control.

[0052] In this embodiment, the tail following control shown in FIG. 7(b) is a control method for moving the continuum robot 100 backward while moving the robot 100 close to the path shown by the dotted line, and returning the base unit 140 to the origin O. As a result, when the continuum robot 100 is moved backward sequentially as shown in states 721 to 725 in FIG. 7(b), the continuum robot 100 can move backward so as to slip through the space inside the pipe 20. At this time, the target bending angle of the bending portion 170 proximal to the base unit 140 is set by adjusting the bending angle of the subsequent bending portion 170-(e-1) after interpolation shown by the thick solid line in FIG. 8(a) with the displacement z of the base unit 140. b The data may be read from the storage unit 211 according to the request.

[0053] As for the target bending angle of the most distal bending portion (leading bending portion) 170-e, first, the bending angle of the most distal bending portion (leading bending portion) 170-e input from the input device 310 in the leading tracking control is stored in the storage unit 211. At this time, similar to the bending angle of the subsequent bending portion 170-(e-1) proximal to the base unit 140, it may be interpolated using the method described in Chapter 2 and stored in the storage unit 211. Also, in this embodiment, the displacement z of the base unit 140 is b In this case, the bending angle a→b of the most distal bending portion (first bending portion) 170-e is input from the input device 310 at a position a that is distal to the position of the origin O and is longer than the length l of the most distal bending portion (first bending portion) 170-e.

[0054] FIG. 8(b) shows a reference table 2111 for the tail following control (which may also include the lead following control) of the continuum robot 100. In FIG. 8(b), elements similar to those related to the lead following control of the continuum robot 100 shown in FIG. 8(a) are given the same reference numerals, and detailed description thereof will be omitted. Specifically, in FIG. 8(b), it is assumed that the base unit 140 has advanced at least to position c by the lead following control related to the advancement of the continuum robot 100 described using FIGS. 7(a) and 8(a). Then, in FIG. 8(b), it is assumed that the tail following control is performed on the continuum robot 100 from a state in which the base unit 140 has advanced at least to position c.

[0055] In FIG. 8(b), when the rear tracking control of the most distal curved portion (first curved portion) is performed, the angle calculation unit 210 of the control device 200 first calculates the length 1 of the most distal curved portion (first curved portion) 170-e by dividing the length 1 by the line segment e a Next, the angle calculation unit 210 of the control device 200 calculates the displacement z of the base unit 140 from the position c to the position e. b At each position, the displacement z of the base portion 140 b 8(b) , the angle calculation unit 210 of the control device 200 calculates the intersection point between a straight line perpendicular to the coordinate axes and the hypotenuse of the generated right-angled triangle. Then, the angle calculation unit 210 of the control device 200 adds the length from the calculated intersection point to the base of the generated right-angled triangle to the bending angle of the distal-most bending portion (leading bending portion) 170-e indicated by the dashed line, to generate the bending angle of the distal-most bending portion (leading bending portion) 170-e after interpolation. Here, the bending angle of the distal-most bending portion (leading bending portion) 170-e after interpolation is indicated by a solid line in FIG. 8(b) .

[0056] Specifically, in the interpolation method 1 for the leading follow-up control and the trailing follow-up control of the continuum robot 100 shown in FIG. 8, the control device 200 performs the following control. In the leading follow control for the forward movement of the continuum robot 100, the control device 200 first controls the base unit 140 to be in a first state where it is at position e (first position) and the distalmost bending portion (leading bending portion) 170-e is bent at bending angle e (first bending angle) with respect to the reference axis 101. Next, the control device 200 controls the base unit to be in a second state where it is at position a (second position) advanced from position e (first position) and the distalmost bending portion (leading bending portion) 170-e is bent at bending angle b (second bending angle) different from bending angle e with respect to the reference axis 101. Next, the control device 200 controls the base unit 140 to be in a third state where it is at position c (third position) advanced from position a (second position). That is, in the leading follow control for the forward movement of the continuum robot 100, the control device 200 transitions through the first state, the second state, and the third state in that order, to bring at least the most distal curved portion (leading curved portion) 170-e into a state inserted inside the tube 20. Thereafter, the control device 200 performs rear-following control for the rearward movement of the continuum robot 100 when the continuum robot 100 is caused to move backward to extract the most distal bending portion (leading bending portion) 170-e from the pipe 20. In this rear-following control, the control device 200 performs control such that the position of the base unit 140 is between position c (third position) and position e (first position), and the most distal bending portion (leading bending portion) 170-e is in a fourth state bent at a third bending angle between bending angle d (second bending angle) and bending angle e (first bending angle) with respect to the reference axis 101. More specifically, in the example shown in FIG. 8(b), the control device 200 controls the position of the base portion 140 to be between position a (second position) and position e (first position), and to be in a fourth state in which the most distal bending portion (leading bending portion) 170-e is bent at a third bending angle between bending angle b (second bending angle) and bending angle e (first bending angle) relative to the reference axis 101.

[0057] 3.2) Interpolation Method 2 In leading-tracking control, the bending angle of the trailing bending section 170-(e-1) needs to be generated in real time, so the method using a right-angled triangle described in Chapter 2 was effective. However, for the most distal bending section (leading bending section) 170-e, it is also possible to interpolate the target bending angle at least at the time when information related to the backward movement of the base section 140 is input from the input device 330. Therefore, in Section 2, several examples will be described as interpolation method 2 for trailing-tracking control.

[0058] 9 and 10 show the first embodiment of the present invention, and are diagrams showing an example of a reference table for the tail following control (which may also include the lead following control) of the continuum robot 100, as the reference table 2111 stored in the control device 200 of FIG. 4. Specifically, FIGS. 9 and 10 show several examples of the interpolation method 2 for the tail following control, and elements similar to those shown in FIG. 8 are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0059] 9(a) shows an example in which the distal-most curved portion (leading curved portion) 170-e is set to a curved angle b at position a when the base unit 140 has advanced from position e, and then the base unit 140 advances from position a by the length l of the subsequent curved portion at position c, in which the interpolation method 2 of the trailing follow-up control is performed. In FIG. 9(a), the dashed line indicates the curved angle of the distal-most curved portion (leading curved portion) 170-e input from the input device 310, and the solid line indicates the curved angle of the distal-most curved portion (leading curved portion) 170-e after interpolation. In the example shown in FIG. 9(a), the curved angle of the distal-most curved portion (leading curved portion) 170-e is interpolated so that the base unit 140 returns to position a with the length l of the subsequent curved portion 170-(e-1). This is the bending angle of the line segment connecting the bending angle d and the bending angle a of the most distal bending portion (leading bending portion) 170-e, and this coincides with the bending angle of the subsequent bending portion 170-(e-1) after interpolation shown by the thick solid line in Figures 8(a) and 8(b). Also, the displacement z of the base portion 140 at which the bending angle of the most distal bending portion (leading bending portion) 170-e returns b is not limited to the position a, but is a displacement z of the base part 140 closer to the position of the origin O than the position c. b That's fine.

[0060] Specifically, in the interpolation method 2 of the tail tracking control shown in FIG. 9(a), the control device 200 controls the position of the base part 140 to be between position c (third position) and position a (second position), and to be in a fourth state in which the most distal curved part (leading curved part) 170-e is curved at a third curved angle between curved angle d (second curved angle) and curved angle a (first curved angle) with respect to the reference axis 101.

[0061] 9(b) shows an example in which, after the base unit 140 has advanced from position e to position a and the most distal bending portion (first bending portion) 170-e has been set to a bending angle b, interpolation method 2 of the trailing follow-up control is performed at position h midway as the base unit 140 advances from position a to the length l of the subsequent bending portion. In the example shown in FIG. 9(b), interpolation is performed so that the bending angle of the most distal bending portion (first bending portion) 170-e returns to the length l of the subsequent bending portion 170-(e-1) when the base unit 140 is at position g between positions a and e. However, the displacement z of the base unit 140 at which the bending angle of the most distal bending portion (first bending portion) 170-e returns b is not limited to the position g, but is a displacement z of the base part 140 closer to the position of the origin O than the position h. b That's fine.

[0062] Figure 10(a) is a modified example of Figure 9(a), in which the bending angle of the most distal bending portion (leading bending portion) 170-e is interpolated so as to return to a linear shape by the sum of the length l of the subsequent bending portion 170-(e-1) and the length l of the most distal bending portion (leading bending portion) 170-e.

[0063] Fig. 10(b) is a modified example of Fig. 10(a), in which the bending angle of the most distal bending portion (leading bending portion) 170-e is interpolated so as to return to a curved shape rather than a linear shape. In the example shown in Fig. 10(b), the bending angle of the most distal bending portion (leading bending portion) 170-e is interpolated to return to an elliptical arc shape, but this embodiment is not limited to this.

[0064] In the example shown in Figures 10(a) and 10(b), the control device 200 controls the position of the base part 140 to be between position c (third position) and position e (first position), and to be in a fourth state in which the most distal bending part (leading bending part) 170-e is bent at a third bending angle between bending angle d (second bending angle) and bending angle e (first bending angle) with respect to the reference axis 101.

[0065] In the interpolation method 2 of the trailing control described in this section, the displacement z of the base part 140 at which the most distal curved part (leading curved part) 170-e starts to return is b is shown as being on the proximal side of the position c to the origin O, but may also be on the distal side of the position c.

[0066] 4) Simulation This chapter describes the results of a simulation using the tail-following control described in Chapter 3. In the simulation described here, the number e of bending sections 170 of the continuum robot 100 is set to 2, and the two bending sections 170 are the distal-most bending section (leading bending section) 170-e and the subsequent bending section 170-(e-1) shown in Figures 7(a) and 7(b). Furthermore, in the simulation described here, the length of the distal-most bending section (leading bending section) 170-e is set to 0.02 m, and the length of the subsequent bending section 170-(e-1) is set to 0.02 m.

[0067] First, the response of the leading follow-up control will be described. In a simulation relating to the response of the leading follow-up control, the most distal bending portion (leading bending portion) 170-e moves forward 0.02 m in a straight state after starting operation, then bends 50 degrees with respect to the reference axis 101, and moves forward another 0.02 m.

[0068] 11A to 11K are diagrams showing the results of a simulation related to the response of leading-follow control in the continuum robot 100 according to the first embodiment of the present invention. Specifically, in Fig. 11A to Fig. 11K, the solid line indicates the curved shape of the most distal curved portion (leading curved portion) 170-e, and the dashed line indicates the curved shape of the subsequent curved portion 170-(e-1).

[0069] Next, the response of the tail tracking control will be described.

[0070] FIG. 12 shows the results of a simulation of the response of the interpolation method 1 of the tail-following control shown in FIG. 8(b) in the continuum robot 100 according to the first embodiment of the present invention. Specifically, in FIGS. 12(a) to 12(k), the solid line indicates the curved shape of the distalmost curved portion (leading curved portion) 170-e, and the dashed line indicates the curved shape of the subsequent curved portion 170-(e-1). It can be seen from FIG. 12 that after the bending angle of the subsequent curved portion 170-(e-1) returns from 50 degrees to 0 degrees, the bending angle of the distalmost curved portion (leading curved portion) 170-e also returns from 50 degrees to 0 degrees. The space occupied by the distalmost curved portion (leading curved portion) 170-e during backward movement in FIGS. 12(g) to 12(k) does not match the space occupied by the distalmost curved portion (leading curved portion) 170-e during forward movement in FIGS. 11(a) to 11(e). However, the occupied space when moving backward in Figures 12(a) to 12(f) is the same as the occupied space when moving forward in Figures 12(f) to 12(k). This shows that this is an effective method for moving backward in the continuum robot 100 while avoiding contact with distant obstacles.

[0071] FIG. 13 shows the results of a simulation of the response of the interpolation method 2 of the tail-following control shown in FIG. 9(a) in the continuum robot 100 according to the first embodiment of the present invention. Specifically, in FIGS. 13(a) to 13(k), the curved shape of the distalmost curved portion (leading curved portion) 170-e is indicated by a solid line, and the curved shape of the subsequent curved portion 170-(e-1) is indicated by a dashed line. In FIG. 13, it can be seen that the curved angle of the distalmost curved portion (leading curved portion) 170-e returns from 50 degrees to 0 degrees at the same time that the curved angle of the subsequent curved portion 170-(e-1) returns from 50 degrees to 0 degrees. The space occupied by the distalmost curved portion (leading curved portion) 170-e when moving backward in FIGS. 13(a) to 13(f) does not match the space occupied by the distalmost curved portion (leading curved portion) 170-e when moving forward in FIGS. 11(f) to 11(k). However, the occupied space when moving backward in Figures 13(f) to 13(k) is the same as the occupied space when moving forward in Figures 11(a) to 11(e). This shows that this is an effective method for moving backward in the continuum robot 100 while avoiding contact with nearby obstacles.

[0072] FIG. 14 shows the results of a simulation of the response of the interpolation method 2 of the tail-following control shown in FIG. 9(b) in the continuum robot 100 according to the first embodiment of the present invention. Specifically, in FIGS. 14(a) to 14(k), the curved shape of the distalmost curved portion (leading curved portion) 170-e is indicated by a solid line, and the curved shape of the subsequent curved portion 170-(e-1) is indicated by a dashed line. In FIG. 14(e), before the bending angle of the subsequent curved portion 170-(e-1) has completely returned from 50 degrees to 0 degrees, the bending angle of the distalmost curved portion (leading curved portion) 170-e starts to return from 50 degrees, and in FIG. 14(i), the return to 0 degrees is completed. The space occupied by the distalmost curved portion (leading curved portion) 170-e during backward movement in FIGS. 14(e) to 14(j) does not match the space occupied by the distalmost curved portion (leading curved portion) 170-e during forward movement in FIGS. 11(c) to 11(g). However, the occupied spaces when moving backward in Figures 14(a) to 14(d), 14(j), and 14(k) are the same as the occupied spaces when moving forward in Figures 11(a), 11(b), and 11(h) to 11(e). This shows that this is an effective method for moving backward in the continuum robot 100 while avoiding contact with the most distant and nearest obstacles.

[0073] FIG. 15 shows the results of a simulation of the response of the interpolation method 2 of the tail-following control shown in FIG. 10(a) in the continuum robot 100 according to the first embodiment of the present invention. Specifically, in FIGS. 15(a) to 15(k), the curved shape of the distalmost curved portion (leading curved portion) 170-e is indicated by a solid line, and the curved shape of the subsequent curved portion 170-(e-1) is indicated by a dashed line. In FIG. 15, the return of the bending angle of the distalmost curved portion (leading curved portion) 170-e is started and finished simultaneously with the start and end of backward movement. Over the entire range of backward movement, the space occupied by the distalmost curved portion (leading curved portion) 170-e does not match the space occupied during forward movement. However, the difference between the space occupied during backward movement and the space occupied during forward movement is averaged over the entire range. This demonstrates that this method is effective for the continuum robot 100 when moving backward while avoiding contact with obstacles on an average basis.

[0074] In the first embodiment described above, the control device 200 controls the continuum robot 100 to move forward to insert the most distal curved portion (leading curved portion) 170-e into the inside of the pipe 20, and then to move the continuum robot 100 backward to extract the most distal curved portion (leading curved portion) 170-e from the pipe 20, so that the position of the base portion 140 is between position c (third position) and position e (first position), and the most distal curved portion (leading curved portion) 170-e is bent at a third bending angle between bending angle d (second bending angle) and bending angle e (first bending angle) with respect to the reference axis 101. According to this configuration, when the continuum robot 100 moves forward and then backward, the posture of the continuum robot 100 is appropriately controlled, and damage to the continuum robot 100 can be prevented.

[0075] (Second embodiment) Next, a second embodiment of the present invention will be described. In the following description of the second embodiment, matters common to the first embodiment will be omitted, and only matters different from the first embodiment will be described.

[0076] The schematic configuration of the continuum robot control system according to the second embodiment is similar to the schematic configuration of the continuum robot control system 10-1 according to the first embodiment shown in Fig. 4. The schematic configuration of the continuum robot 100 according to the second embodiment is similar to the schematic configuration of the continuum robot 100 according to the first embodiment shown in Figs. 1, 2, and 5.

[0077] In the first embodiment described above, as shown in FIGS. 8 to 10, the displacement z b In the second embodiment, the distance between the position a (second position) and the position of the origin O (origin position) on the base 140 is greater than the length l of the most distal curved portion (first curved portion) 170-e. b In this figure, position a (second position) is a form assuming that the distance from the position of origin O (origin position) on the base portion 140 is shorter than the length 1 of the most distal curved portion (leading curved portion) 170-e.

[0078] Fig. 16 shows a second embodiment of the present invention, and is a diagram showing an example of a reference table 2111 stored in the control device 200 of Fig. 4 for the tail following control (which may also include the lead following control) of the continuum robot 100. In Fig. 16, elements similar to those shown in Figs. 8 to 10 are given the same reference symbols, and detailed descriptions thereof will be omitted.

[0079] In FIG. 16, the displacement z of the base portion 140 b 16 shows a case where the distance between the position of the origin O (origin position) and the position a (second position) is less than the length l of the most distal curved portion (first curved portion) 170-e. b 16 shows an example in which, at position a, an input to change the bending angle of the distal-most bending portion (leading bending portion) 170-e is made from the input device 310, and then the bending angle of the distal-most bending portion (leading bending portion) 170-e is interpolated. In Fig. 16, the broken line indicates the bending angle of the distal-most bending portion (leading bending portion) 170-e input from the input device 310, and the solid line indicates the bending angle of the distal-most bending portion (leading bending portion) 170-e after interpolation.

[0080] Displacement z of the base part 140 b In this case, the distance between the position of the origin O and the position a is less than the length l of the most distal bending portion (first bending portion) 170-e. Therefore, when the interpolation method 1 of the rear tracking control described in the first embodiment is used, the bending angle of the most distal bending portion (first bending portion) 170-e does not converge to zero at the position of the origin O. Therefore, in the second embodiment, it is preferable to use the interpolation method 2 of the first embodiment. In this case, the displacement z of the base portion 140 at which the bending angle of the most distal bending portion (first bending portion) 170-e returns to zero is b is preferably located between the position of the origin O and the position a.

[0081] Specifically, in the example shown in FIG. 16, when the control device 200 performs rear-following control of the continuum robot 100, the control device 200 controls the base unit 140 to set the bending angle of the most distal bending portion (first bending portion) 170-e to zero when the base unit 140 is at the position of the origin O (origin position).

[0082] In the second embodiment, as in the first embodiment described above, when the continuum robot 100 moves forward and then backward, the posture of the continuum robot 100 is appropriately controlled, making it possible to prevent damage to the continuum robot 100.

[0083] (Third embodiment) Next, a third embodiment of the present invention will be described. In the following description of the third embodiment, matters common to the first and second embodiments will be omitted, and only matters different from the first and second embodiments will be described.

[0084] The schematic configuration of the continuum robot control system according to the third embodiment is similar to the schematic configuration of the continuum robot control system 10-1 according to the first embodiment shown in Fig. 4. The schematic configuration of the continuum robot 100 according to the third embodiment is similar to the schematic configuration of the continuum robot 100 according to the first embodiment shown in Figs. 1, 2, and 5.

[0085] In the first and second embodiments described above, the bending angle of the most distal bending portion (leading bending portion) 170-e is adjusted based on the displacement z of the base portion 140. b However, for example, in FIG. 9(b) of the first embodiment, the base portion 140 is returned based on the displacement z b When the positions h and g are close to each other, the return movement at the bending angle of the distalmost bending portion (leading bending portion) 170-e becomes steep. This also occurs when the position a is close to the position of the origin O (origin position) in the second embodiment described above.

[0086] Therefore, in the third embodiment, the bending angle of the most distal bending portion (leading bending portion) 170-e is adjusted based on the displacement z of the base portion 140. b This shows a control method for restoring the power supply without relying on the above.

[0087] Fig. 17 shows a third embodiment of the present invention, and is a diagram showing an example of a reference table 2111 stored in the control device 200 of Fig. 4 for the tail following control (which may also include the lead following control) of the continuum robot 100. In Fig. 17, elements similar to those shown in Figs. 8 to 10 are given the same reference symbols, and detailed descriptions thereof will be omitted.

[0088] Specifically, the reference table 2111 shown in Fig. 17 is shown as a graph with time on the horizontal axis and the bending angle θ of the most distal bending portion (first bending portion) on the vertical axis. In Fig. 17, the broken line indicates the bending angle of the most distal bending portion (first bending portion) 170-e input from the input device 310, and the solid line indicates the bending angle of the most distal bending portion (first bending portion) 170-e after interpolation.

[0089] 17, at time A, an input to change the bending angle of the distalmost bending portion (leading bending portion) 170-e is made from the input device 310, and the bending angle of the distalmost bending portion (leading bending portion) 170-e changes from A to B. Thereafter, when a command to move the continuum robot 100 backward in a short time is issued in a state (third state) in which the base unit 140 has made a slight forward movement or in a state (second state) in which the base unit 140 has not made a forward movement, a speed limit is imposed on the rate of change in the bending angle of the distalmost bending portion (leading bending portion) 170-e, and the distalmost bending portion (leading bending portion) 170-e is returned from bending angle C to bending angle D. That is, in this embodiment, when a command is received to transition from the third state or the second state to the fourth state related to the backward movement in a time shorter than a predetermined time, the control device 200 limits the rate of change in the bending angle of the distalmost bending portion (leading bending portion) 170-e over time.

[0090] In the third embodiment, as in the first embodiment described above, when the continuum robot 100 moves forward and then backward, the posture of the continuum robot 100 is appropriately controlled, making it possible to prevent damage to the continuum robot 100.

[0091] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described. In the following description of the fourth embodiment, matters common to the first to third embodiments will be omitted, and only matters different from the first to third embodiments will be described.

[0092] The schematic configuration of the continuum robot 100 according to the fourth embodiment is similar to the schematic configuration of the continuum robot 100 according to the first embodiment shown in FIGS.

[0093] Fig. 18 is a diagram showing an example of the schematic configuration of a continuum robot control system 10-4 according to a fourth embodiment of the present invention. In Fig. 18, the same components as those shown in Fig. 4 are given the same reference numerals, and detailed description thereof will be omitted. The continuum robot control system 10-4 shown in Fig. 18 is a system that controls the continuum robot 100 shown in Figs. 1 and 2. As shown in Fig. 18, the continuum robot control system 10-4 is configured to include the continuum robot 100, a control device 200, and various input devices 320, 330, and 340.

[0094] The input device 320 receives the target bending angle θ of the most distal bending portion (leading bending portion) input by the input device 310 shown in FIG. L In addition, the target rotation angle ζ of the most distal curved part (leading curved part) L This is a device that inputs the above into the control device 200.

[0095] As shown in FIG. 18, the control device 200 includes an angle calculation unit 210, a switching unit 220, and a kinematics calculation unit (Kinematics) 230.

[0096] The angle calculation unit 210 receives a target bending angle θ of the most distal bending portion (first bending portion) from the input device 320. L and target turning angle ζ L , the displacement z of the base unit 140 from the input device 330 b , information on the length l of the plurality of bending portions 170 is input from the input device 340. Then, the angle calculation unit 210 calculates the target bending angle θ of the subsequent bending portion based on the input information.F and target turning angle ζ F Calculation of the target bending angle θ of the most distal bending part (first bending part) L The target bending angle θ of the subsequent bending section after the change F ' and target turning angle ζ F Furthermore, the angle calculation unit 210 calculates the target bending angle θ of the most distal bending portion (leading bending portion). L and target turning angle ζ L and the target bending angle θ of the subsequent bending section F and target turning angle ζ F The target bending angle θ of the most distal bending portion when the base unit 140 of the continuum robot 100 moves backward is stored. L ' and target turning angle ζ L ' is calculated.

[0097] The switching unit 220 selects the target bending angle θ 1 input from the input device 320 as the target bending angle and target turning angle of the most distal bending portion (leading bending portion). L and target turning angle ζ L and the target bending angle θ calculated by the angle calculation unit 210. L ' and target turning angle ζ L ' and the displacement z of the base portion 140 b Specifically, in this embodiment, the switching unit 220 switches the displacement z of the base unit 140. b When the traveling direction is a forward direction, the target bending angle θ input from the input device 320 L and target turning angle ζ L The switching unit 220 also switches the displacement z of the base unit 140. b When the traveling direction is a reverse direction, the target turning angle θ calculated by the angle calculation unit 210 L ' and target turning angle ζ L Switch to select '.

[0098] The kinematics calculation unit 230 receives the target bending angle (θ L or θ L ') and target turning angle (ζ L or ζ L'), and the target bending angle θ of the subsequent bending portion calculated by the angle calculation unit 210 F ' and target turning angle ζ F Then, based on the input information, the kinematics calculation unit 230 calculates the drive displacement when driving the wires of the most distal bending portion (first bending portion) and the subsequent bending portions with each actuator, which is the driving unit. In FIG. 18, the drive displacement of the wire of the most distal bending portion (first bending portion) and the drive displacement of the wire of the subsequent bending portions obtained by the calculation of the kinematics calculation unit 230 are combined together to form the drive displacement of the wire l. p The continuum robot 100 according to this embodiment is illustrated as follows: p In response to this, bending control of the most distal bending portion (first bending portion) and subsequent bending portions is performed.

[0099] In the above-described first to third embodiments, the control method for the tail tracking control of the continuum robot 100 in the xz plane has been mainly described. In this embodiment, the tail tracking control is performed in a three-dimensional space.

[0100] Kinematics is derived to determine the drive displacement of the actuator for controlling the bending angle and rotation angle of the bending portion 170 of the continuum robot 100. The definitions of symbols are shown below. l d : Length of the central axis of the curved part θ n : The bending angle (at the distal end) of the nth bending part ζ n : The turning angle (at the distal end) of the nth curved portion ρ n : Radius of curvature of the nth curved part ζ refn : Target turning angle (at the distal end) of the nth curved section

[0101] In this embodiment, the kinematics of the continuum robot 100 is derived based on the following assumptions. 1. At each bend, the wire deforms to a constant curvature. 2. Torsional deformation of the wire is not taken into account. 3. The wire does not deform longitudinally. 4. Friction between the wire guide and the wire is not taken into account.

[0102] First, the driving displacement l of the a-wire, b-wire, and c-wire of the first bending portion 170-1 p1a , l p1b and l p1c The relationship between the bending angle θ1 and the turning angle ζ1 of the first bending portion 170-1 is expressed by the following formula (10).

number

[0103] Next, in the continuum robot 100 having a plurality of bending portions, the driving displacement l of the a-wire, the b-wire, and the c-wire of the n-th bending portion 170-n is calculated. pna , l pnb and l pnc and the bending angle θ of the n-th bending portion 170-n. n and turning angle ζ n Furthermore, let the number of bending portions of the continuum robot 100 be e, and the phase angle ξ of the wire that drives the n-th bending portion n is expressed as the following equation (11).

number

[0104] As a result, the wire-driven displacement l of the n-th bending portion 170-n pna , l pnb and l pnc is expressed as the following equation (12).

number

[0105] A target bending angle θ for the most distal bending portion (leading bending portion) 170-e is input from the input device 320. L and target turning angle ζ LWhen this command is input, the control device 200 can control the angle of the most distal bending portion (leading bending portion) 170-e by calculating the driving displacement of the wire using equation (12). The tail-following control in this embodiment can be performed by interpolating the target bending angle and reading it from the storage unit 211, similar to the first to third embodiments in the xz plane described above, and by replacing the bending angle in the first to third embodiments with the turning angle and calculating the target turning angle using a similar algorithm. In this embodiment, the tail-following control of the continuum robot 100 in three-dimensional space can be performed by calculating the driving displacement of the wire for each of the multiple bending portions 170 using equation (12).

[0106] In the fourth embodiment, as in the first embodiment described above, when the continuum robot 100 moves forward and then backward, the posture of the continuum robot 100 is appropriately controlled, making it possible to prevent damage to the continuum robot 100.

[0107] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions. This program and a computer-readable storage medium storing the program are included in the present invention.

[0108] It should be noted that the above-described embodiments of the present invention are merely illustrative examples of the implementation of the present invention, and the technical scope of the present invention should not be construed as being limited by these. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0109] 10: Continuum robot control system, 20: pipe, 100: continuum robot, 140: base unit, 170: bending unit, 200: control device, 210: angle calculation unit, 211: memory unit, 2111: lookup table, 212: lookup table rewriting unit, 213: information input unit, 220: switching unit, 230: kinematics calculation unit (Kinematics), 310 to 340: input device

Claims

1. A base portion; a distal bending portion that is bent by driving the distal linear member; a driving unit that drives the distal linear member; a connecting portion provided between the distal curved portion and the base portion; A continuum robot control system for controlling a continuum robot having a means for operating the movement of the continuum robot to move forward and backward; a control means for controlling the robot to transition from a first state in which the base unit of the continuum robot is at a first position and the distal bending portion is bent at a first bending angle with respect to a reference axis, a second state in which the base unit is at a second position further advanced than the first position and the distal bending portion is bent at a second bending angle with respect to the reference axis that is different from the first bending angle, to a third state in which the base unit is at a third position further advanced than the second position, so that after the distal bending portion has been inserted into the pipe, when the base unit of the continuum robot is moved backward to extract the distal bending portion from the pipe, the position of the base unit is between the third position and the first position and the distal bending portion is bent at the third bending angle with respect to the reference axis that is between the second bending angle and the first bending angle, and the distal bending portion is bent at the first bending angle with respect to the reference axis when the position of the base unit is moved further backward than the fourth state; and a displacement amount of the base unit from the start to the completion of the change in the bending angle of the distal bending portion from the second bending angle to the first bending angle when the robot moves backward is greater than a displacement amount of the base unit from the start to the completion of the change in the bending angle of the distal bending portion from the first bending angle to the second bending angle when the robot moves forward.

2. 2. The continuum robot control system according to claim 1, wherein the control means controls the position of the base unit to take the fourth state between the second position and the first position.

3. 2. The continuum robot control system according to claim 1, wherein the control means controls the position of the base unit to take the fourth state between the third position and the second position.

4. The continuum robot control system according to any one of claims 1 to 3, characterized in that when the distance between the origin position and the second position on the base portion is less than the length of the distal bending portion, the control means sets the third bending angle to zero at the origin position when controlling the robot to assume the fourth state.

5. 5. The continuum robot control system according to claim 1, wherein the control means limits the rate of change of the third bending angle over time when the control means receives an instruction to transition from the third state or the second state to the fourth state in a time shorter than a predetermined time.

6. 6. The continuum robot control system according to claim 1, wherein the control means controls a rotation angle of the distal bending portion in addition to the bending angles at the first bending angle, the second bending angle, and the third bending angle of the distal bending portion.

7. the connecting portion includes a curved portion subsequent to the distal curved portion, the curved portion being curved by driving a subsequent linear member, 7. The continuum robot control system according to claim 1, wherein the driving unit drives the trailing linear member independently of the distal linear member.

8. A base portion; a distal bending portion that is bent by driving the distal linear member; a driving unit that drives the distal linear member; a connecting portion provided between the distal curved portion and the base portion; A continuum robot control method for controlling a continuum robot having performing a movement operation to move the continuum robot forward and backward; a control step of controlling the robot to transition from a first state in which the base unit of the continuum robot is at a first position and the distal bending portion is bent at a first bending angle with respect to a reference axis, a second state in which the base unit is at a second position further forward than the first position and the distal bending portion is bent at a second bending angle with respect to the reference axis that is different from the first bending angle, to a third state in which the base unit is at a third position further forward than the second position, so that after the distal bending portion has been inserted into the pipe, when the base unit of the continuum robot is moved backward to extract the distal bending portion from the pipe, the position of the base unit is between the third position and the first position and the distal bending portion is bent at the first bending angle with respect to the reference axis; and a displacement amount of the base unit from the start to the completion of the change in the bending angle of the distal bending portion from the second bending angle to the first bending angle when the robot moves backward is greater than a displacement amount of the base unit from the start to the completion of the change in the bending angle of the distal bending portion from the first bending angle to the second bending angle when the robot moves forward.

9. A program for causing a computer to function as each means of the continuum robot control system according to any one of claims 1 to 7.

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