Less-drive planar continuum robot based on stable self-locking rotary joint

Abstract

The invention discloses a few-drive planar continuum robot based on stable self-locking rotary joints, which comprises a driving device, a mounting seat and a continuum robot module, and is characterized in that the driving device comprises a frame, a linear module, a traction rope, a force transducer, a hand-screwing adjusting screw and the like; the continuum robot module comprises a stable self-locking rotary joint, an elastic rod and a tail end flange. The stable self-locking rotary joint is triggered by a memory alloy coil and a spring, so that after the end face ratchet sliding block and the rotary connecting piece form mechanical constraint, each joint can keep a self-locking or rotating state with zero power consumption. Therefore, under the condition that only one set of driving unit is arranged, the robot has multiple operation modes of whole-section movement, joint-section movement and joint movement, and the robot has flexible movement performance and various working spaces. Meanwhile, the rigidity of the robot is changed along with the locking state of the joints, and when all the joints are self-locked, the robot can maintain the shape without being driven by a motor.

Description

Technical Field

[0001] The invention relates to the field of continuum robots, in particular to a planar continuum robot with few drivers based on stable self-locking rotary joints. Background Art

[0002] Continuum robots have the characteristics of flexible bending, flexible controllability, and strong adaptability, and are expected to be applied to a variety of unstructured special scene tasks, such as minimally invasive surgery, environmental detection, rescue, etc. Therefore, continuum robots have become one of the current research hotspots.

[0003] The common structural types of continuum robots at present are: (1) Continuous flexible overall drive structure, including a drive device, a flexible backbone and a traction rope group. The drive device usually realizes the overall bending control of the flexible backbone through the traction rope group. The drive is simple but the working range is limited. (2) Continuous flexible multi-segment drive structure, usually including a drive device, a multi-segment continuum backbone and a traction rope group. The drive device realizes independent bending movement between segments, which improves the flexibility and working range to a limited extent. (3) Discrete rigid full-drive continuum robot, including a drive device, multiple connecting joints, multiple universal joints and multiple traction rope groups. The drive device usually realizes independent control of the angle of each universal joint through each traction rope group. The flexibility and working range are good, but its rope arrangement and drive are relatively complicated, which also makes it difficult to lighten the whole.

[0004] Therefore, how to maintain the flexibility and workspace of the continuum robot while maintaining simple drive remains a major problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the present invention aims to provide a planar continuum robot with few drives based on stable self-locking rotary joints, which can have different motion modes according to a variety of joint locking strategies under a set of drive units, and has both flexibility and workspace range. The stiffness of the robot will change when the joints are locked.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A planar continuum robot with few drives based on stable self-locking rotary joints, characterized in that it comprises a drive device, a mounting seat, and a continuum robot module;

[0008] The mounting seat is fixedly connected to the driving device through bolts, and the proximal end of the continuum robot module is fixedly connected to the mounting seat through bolts.

[0009] Further, the driving device includes a frame, a base plate, a first linear module, a first U-shaped plate, a first pulley, a second pulley, a first traction rope, a first lifting lug screw, a first force sensor, a first stud, a first hand screw, a second linear module, a second U-shaped plate, a third pulley, a fourth pulley, a second traction rope, a second lifting lug screw, a second force sensor, a second stud, a second hand screw, and a first fixing plate;

[0010] The base plate is fixedly connected to the frame by bolts, the first linear module and the second linear module are symmetrically fixedly connected to the base plate by bolts, the first U-shaped plate and the second U-shaped plate are fixedly connected to the first linear module and the second linear module by bolts, the first pulley and the second pulley are symmetrically fixedly connected to the first U-shaped plate by bolts, the third pulley and the fourth pulley are symmetrically fixedly connected to the second U-shaped plate by bolts, the first traction rope passes around the first pulley and the second pulley, and one end is fixedly connected to the first lifting ear screw by knotting or locking, and the other end is fixedly connected to the end flange, the second traction rope passes around the third pulley and the fourth pulley, and one end is fixedly connected to the second lifting ear screw by knotting or locking, and the other end is fixedly connected to the end flange, the first lifting ear screw and the second lifting ear screw are fixedly connected to the first force sensor and the second force sensor by bolts, the first stud and the second stud are fixedly connected to the first force sensor and the second force sensor by threads, and the first stud and the second stud are threadedly connected to the first hand screw and the second hand screw.

[0011] Further, the mounting seat includes a second fixing plate, a first side plate, a first supporting plate, a second supporting plate, a second side plate, and a mounting plate;

[0012] The second fixing plate is fixedly connected to the first fixing plate by bolts, the first supporting plate is fixedly connected to the second fixing plate and the first side plate by bolts, the second supporting plate is fixedly connected to the second fixing plate and the second side plate by bolts, and the first side plate and the second side plate are symmetrically fixedly connected to the second fixing plate and the mounting plate by bolts.

[0013] Further, the continuum robot module comprises a stable self-locking rotary joint, a first elastic rod, a second elastic rod, and an end flange;

[0014] A plurality of stable self-locking rotating joints are connected in series by bolts in a manner that the rotating axes are parallel, the first elastic rod and the second elastic rod both pass through each stable self-locking rotating joint and are fixedly connected thereto by gluing, and the end flange is fixedly connected to the stable self-locking rotating joint at the end by bolts;

[0015] The stable self-locking rotary joint comprises a mounting shell, a first slider, a first shape memory alloy coil, a first end face ratchet slider, a first conductive copper sheet, a rotary connector, a second end face ratchet slider, a second conductive copper sheet, a second slider, a linear guide rail, a third wiring piece, a third shape memory alloy coil, a second spring, a fourth wiring piece, a second elastic pressing piece, a second pull rod, a fourth shape memory alloy coil, a first pull rod, a first spring, a second shape memory alloy coil, a first elastic pressing piece, a stepped shaft, a first wiring piece, a second wiring piece, a first flange bearing, a second flange bearing, a first miniature bearing, and a second miniature bearing;

[0016] The linear guide is fixedly connected to the mounting shell by bolts, the first slider and the second slider are respectively connected to the linear guide in a linear displacement manner, the first end face ratchet slider and the second end face ratchet slider are respectively fixedly connected to the first slider and the second slider by bolts, one end of the first shape memory alloy coil and one end of the second shape memory alloy coil are respectively connected to the first wiring piece and the second wiring piece by bolts and fixed to the mounting shell, and the other ends are connected to the first conductive copper sheet by bolts and fixed to the surface of the first end face ratchet slider, one end of the third shape memory alloy coil and one end of the fourth shape memory alloy coil are respectively connected to the third wiring piece and the fourth wiring piece by bolts and fixed to the mounting shell, and the other ends are connected to the second conductive copper sheet by bolts and fixed to the surface of the second end face ratchet slider, and the stepped shaft is fixed to the mounting shell by bolts. The first spring and the second spring are connected to the stepped shaft by a nesting manner, the two sides of the first spring are respectively connected to the first end face ratchet slider and the mounting shell, the two sides of the second spring are respectively connected to the second end face ratchet slider and the mounting shell, the first flange bearing and the second flange bearing are integrated with the rotating connector by a nesting manner, and are fixedly connected to the stepped shaft by bolts, the first miniature bearing and the second miniature bearing are respectively fixedly connected to the mounting shell by a nesting manner, one end of the first pull rod is connected to the first miniature bearing by a nesting manner, and the other end is connected to the first end face ratchet slider by a contact manner, one end of the second pull rod is connected to the second miniature bearing by a nesting manner, and the other end is connected to the second end face ratchet slider by a contact manner, the first elastic pressing plate and the second elastic pressing plate are respectively fixedly connected to the mounting shell by bolts.

[0017] Furthermore, in the driving device:

[0018] The frame can be assembled from profiles or welded from plates to maintain a stable structure;

[0019] The first U-shaped plate and the second U-shaped plate can be made by welding, sheet metal, etc., and threaded through holes are provided on the corresponding mounting surfaces;

[0020] The surface of the first fixing plate is provided with a plurality of light holes or threaded holes to facilitate the fixed connection of the second fixing plate and the penetration of the first traction rope and the second traction rope;

[0021] The first traction rope and the second traction rope are ropes with a retractable ratio of less than 0.5%, and the materials that can be selected include but are not limited to nylon rope, jade line or steel wire rope.

[0022] Furthermore, in the mounting seat:

[0023] The second fixing plate, the first side plate, the first supporting plate, the second supporting plate, the second side plate and the mounting plate are all processed with countersunk holes for easy fixed connection.

[0024] Furthermore, in the continuum robot module:

[0025] A plurality of stable self-locking rotational joints are connected in series by screws in a manner that the rotation axes are parallel;

[0026] The first elastic rod and the second elastic rod are both made of circular cross-section rods with superelasticity, which maintain their initial straight shape when not subjected to external force. The elastic rods may be made of materials including but not limited to nickel-titanium alloy rods and fiber rods.

[0027] The end flange is provided with a plurality of threaded holes and light holes, and the light holes are convenient for the first traction rope, the second traction rope, the first elastic rod and the second elastic rod to pass through and be fixed in a knotted or locked manner.

[0028] Furthermore, the stable self-locking rotary joint in the continuum robot module:

[0029] The mounting housing can be made by machining or 3D printing, and a plurality of holes are arranged on its surface;

[0030] One side of the first end face ratchet slider and the second end face ratchet slider is processed with a through hole, and the other side is processed with a stepped guide groove, each step height is 0.5mm, and the bottom boss is processed with end face ratchet teeth in opposite directions;

[0031] The upper and lower annular bosses of the rotating connector are machined with end face ratchets in opposite directions, a through hole is drilled in the center of the rotation, and a groove is machined in the center of the rotating side surface to facilitate the movement of the first traction rope and the second traction rope. The tail is machined with a platform with a hole to facilitate fixed connection with other mounting housings;

[0032] The first elastic pressing piece and the second elastic pressing piece have superelasticity and are made of, but not limited to, spring steel or spring sheet. The first elastic pressing piece and the second elastic pressing piece respectively elastically press the first pull rod and the second pull rod, so that the end of the first pull rod and the end of the second pull rod respectively form stable contact with the first end face ratchet slider guide groove and the second end face ratchet slider guide groove;

[0033] The first conductive copper sheet and the second conductive copper sheet are configured to be convex and can be made by stamping, cutting, etc., so as to stably fit with the surfaces of the first end face ratchet slider and the second end face ratchet slider;

[0034] The first shape memory alloy coil, the second shape memory alloy coil, the third shape memory alloy coil, and the fourth shape memory alloy coil are all made of the same material and have the same specifications, and shrink when heated.

[0035] Compared with the prior art, the low-drive planar continuum robot based on stable self-locking rotary joints described in the present invention has the following beneficial effects:

[0036] The stable self-locking rotation joint proposed by the present invention has four stable states: forward rotation, reverse rotation, bidirectional rotation, and self-locking. After each stable state is formed, no energy consumption is required to maintain it.

[0037] The present invention realizes independent control of a single joint, synchronous control of a single joint segment and overall synchronous control under a set of drive units, has multiple motion modes, maintains flexibility and a large working range while reducing the number of drives;

[0038] In the present invention, when some stable self-locking rotary joints are in a self-locking state, the stiffness of the robot changes. When all stable self-locking rotary joints are in a self-locking state, the stiffness of the robot is the largest, and the shape can be maintained without the need for motor driving force.

[0039] The invention has the advantages of simple structure, convenient manufacture, stable performance, strong adaptability and wide application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 is an axonometric view of the present invention;

[0042] Figure 2 is a top view of the driving device of the present invention;

[0043] Figure 3 is an axonometric view of the mounting base of the present invention;

[0044] Figure 4 is a front view of a continuum robot module of the present invention;

[0045] Figure 5 is an axonometric view of the stable self-locking rotary joint of the present invention;

[0046] Figure 6is a front view of the stable self-locking rotary joint of the present invention;

[0047] Figure 7 The first end face ratchet slider is shown in front view, left-hand view and right-hand view;

[0048] Figure 8 It is a passive unidirectional movement process of the first pull rod in the guide groove of the ratchet slider on the first end surface;

[0049] Fig. 9 It is the passive unidirectional movement process of the second pull rod in the guide groove of the ratchet slider on the second end face;

[0050] Fig.10 It is a schematic diagram of the working state of the stable self-locking rotary joint of the present invention;

[0051] Fig.11 It is a schematic diagram of the robot's state in the operation mode of the entire movement;

[0052] Fig.12 It is a schematic diagram of the state of the robot in the operation mode of joint segment motion;

[0053] Fig.13 It is a schematic diagram of the robot's state in the joint motion operation mode.

[0054] Description of reference numerals:

[0055] In the figure, 1-driving device, 2-mounting seat, 3-continuum robot module;

[0056] 101-frame, 102-bottom plate, 103-first linear module, 104-first U-shaped plate, 105-first pulley, 106-second pulley, 107-first traction rope, 108-first ear screw, 109-first force sensor, 110-first stud, 111-first hand screw, 112-second linear module, 113-second U-shaped plate, 114-third pulley, 115-fourth pulley, 116-second traction rope, 117-second ear screw, 118-second force sensor, 119-second stud, 120-second hand screw, 121-first fixing plate;

[0057] 201-second fixing plate, 202-first side plate, 203-first supporting plate, 204-second supporting plate, 205-second side plate, 206-mounting plate;

[0058] 31-stable self-locking rotating joint, 32-first elastic rod, 33-second elastic rod, 34-end flange;

[0059] 3101-mounting housing, 3102-first slider, 3103-first shape memory alloy coil, 3104-first end face ratchet slider, 3105-first conductive copper sheet, 3106-rotating connector, 3107-second end face ratchet slider, 3108-second conductive copper sheet, 3109-second slider, 3110-linear guide, 3111-third wiring piece, 3112-third shape memory alloy coil, 3113-second spring, 3114-fourth wiring piece , 3115-second elastic pressing plate, 3116-second pull rod, 3117-fourth shape memory alloy coil, 3118-first pull rod, 3119-first spring, 3120-second shape memory alloy coil, 3121-first elastic pressing plate, 3122-step shaft, 3123-first wiring piece, 3124-second wiring piece, 3125-first guard side bearing, 3126-second guard side bearing, 3127-first miniature bearing, 3128-second miniature bearing. DETAILED DESCRIPTION

[0060] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0061] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0062] A planar continuum robot with few drivers based on stable self-locking rotary joints comprises: a driving device 1, a mounting seat 2, and a continuum robot module 3;

[0063] The driving device 1 includes a frame 101, a base plate 102, a first linear module 103, a first U-shaped plate 104, a first pulley 105, a second pulley 106, a first traction rope 107, a first lifting ear screw 108, a first force sensor 109, a first stud 110, a first hand screw 111, a second linear module 112, a second U-shaped plate 113, a third pulley 114, a fourth pulley 115, a second traction rope 116, a second lifting ear screw 117, a second force sensor 118, a second stud 119, and a second hand screw 120. , a first fixed plate 121, wherein the bottom plate 102 is fixedly connected to the frame 101 by bolts, the first linear module 103 and the second linear module 112 are fixedly connected to the bottom plate 102 by bolts in a symmetrical manner, the first U-shaped plate 104 and the second U-shaped plate 113 are fixedly connected to the first linear module 103 and the second linear module 112 by bolts, the first pulley 105 and the second pulley 106 are fixedly connected to the first U-shaped plate 104 by bolts in a symmetrical manner, the third pulley 114 and the fourth pulley 115 are fixedly connected to the second U-shaped plate 104 by bolts in a symmetrical manner, 13 is fixedly connected, the first traction rope 107 passes through the first pulley 105 and the second pulley 106, and one end is fixedly connected to the first lifting ear screw 108 by knotting or locking, and the other end passes through the multiple stable self-locking rotation joints 31 of the continuum robot module 3 and is fixedly connected to the end flange 34, the second traction rope 116 passes through the third pulley 114 and the fourth pulley 115, and one end is fixedly connected to the second lifting ear screw 117 by knotting or locking, and the other end passes through the multiple stable self-locking rotation joints 31 of the continuum robot module 3 and is fixedly connected to the end flange 34. The flange 34 is fixedly connected, the first lifting ear screw 108 and the second lifting ear screw 117 are fixedly connected to the first force sensor 109 and the second force sensor 118 respectively through bolts, the first stud 110 and the second stud 119 are fixedly connected to the first force sensor 109 and the second force sensor 118 respectively through threads, the first stud 110 and the second stud 119 are threadedly connected to the first hand screw 111 and the second hand screw 120 respectively, and the first hand screw 111 and the second hand screw 120 are both fitted and connected to the first fixing plate 121;

[0064] In the driving device 1, the traction rope is driven by the linear module to realize the driving displacement, and the pulley is fixedly connected to the linear module through a U-shaped plate to form a movable pulley structure, which makes the driving displacement of the linear module be magnified by two times, and effectively reduces the size of the driving device; the real-time monitoring of the traction rope tension before and during driving is realized through the force sensor; the coordination of the stud and the hand screw, combined with the force sensor, realizes the flexible adjustment of the traction rope tension before driving.

[0065] The mounting base 2 comprises a second fixing plate 201, a first side plate 202, a first supporting plate 203, a second supporting plate 204, a second side plate 205, and a mounting plate 206, wherein the second fixing plate 201 is fixedly connected to the first fixing plate 121 by bolts, the first supporting plate 203 is fixedly connected to the second fixing plate 201 and the first side plate 202 by bolts, the second supporting plate 204 is fixedly connected to the second fixing plate 201 and the second side plate 205 by bolts, and the first side plate 202 and the second side plate 205 are fixedly connected to the second fixing plate 201 and the mounting plate 206 in a symmetrical manner by bolts;

[0066] In the mounting seat 2, the stability of the mounting seat is enhanced by the support plate, and the spacing of the traction ropes is changed through the mounting plate and the second fixing plate to adapt to the spacing arrangement of the traction ropes of the driving device.

[0067] The continuum robot module 3 comprises a plurality of stable self-locking rotary joints 31, a first elastic rod 32, a second elastic rod 33, and an end flange 34, wherein the plurality of stable self-locking rotary joints 31 are connected in series by bolts in a manner that the rotation axes are parallel, the first elastic rod 32 and the second elastic rod 33 both pass through each stable self-locking rotary joint 31 and are fixedly connected thereto by gluing, and the end flange 34 is fixedly connected to the stable self-locking rotary joint 31 at the end by bolts;

[0068] In the continuum robot module 3, the continuum robot is made flexible by passing an elastic rod through each stable self-locking rotary joint and fixing it; each stable self-locking rotary joint can be self-locked and released independently, which makes the continuum robot driveable as a whole or partially; when all the stable self-locking rotary joints are in self-locking, the continuum robot can maintain its shape without the need for motor drive.

[0069] The stable self-locking rotary joint 31 in the continuum robot module 3 includes a mounting housing 3101, a first slider 3102, a first shape memory alloy coil 3103, a first end face ratchet slider 3104, a first conductive copper sheet 3105, a rotary connector 3106, a second end face ratchet slider 3107, a second conductive copper sheet 3108, a second slider 3109, a linear guide 3110, a third wiring piece 3111, a third shape memory alloy coil 3112, a second spring 3113, a fourth wiring piece 3114, a second elastic pressing piece 3115, a second pull rod 3116, a fourth shape memory alloy coil 3117, a first pull rod 3118, a first spring 3119, and a second shape memory alloy coil 312 0, a first elastic pressing piece 3121, a stepped shaft 3122, a first wiring piece 3123, a second wiring piece 3124, a first flange bearing 3125, a second flange bearing 3126, a first miniature bearing 3127, and a second miniature bearing 3128, wherein the linear guide 3110 is fixedly connected to the mounting housing 3101 by bolts, the first slider 3102 and the second slider 3109 are respectively connected to the linear guide 3110 in a linear displacement manner, the first end face ratchet slider 3104 and the second end face ratchet slider 3107 are respectively fixedly connected to the first slider 3102 and the second slider 3109 by bolts, one end of the first shape memory alloy coil 3103 and one end of the second shape memory alloy coil 3112 are respectively connected by screws The bolt is connected to the first wiring piece 3123 and the second wiring piece 3124 and fixed on the mounting housing 3101, and the other end is connected to the first conductive copper sheet 3105 by a bolt and fixed to the surface of the first end face ratchet slider 3104, one end of the third shape memory alloy coil 3112 and one end of the fourth shape memory alloy coil 3117 are respectively connected to the third wiring piece 3111 and the fourth wiring piece 3114 by a bolt and fixed to the mounting housing 3101, and the other end is connected to the second conductive copper sheet 3108 by a bolt and fixed to the surface of the second end face ratchet slider 3107, the stepped shaft 3122 is fixedly connected to the mounting housing 3101 by a bolt, and the first spring 3119 and the second spring 3113 are connected to the stepped shaft 3112 by a nesting manner. The first and second side bearings 3125 and 3126 are connected to the stepped shaft 3122, the two sides of the first spring 3119 are respectively connected to the first end face ratchet slider 3104 and the mounting shell 3101, the two sides of the second spring 3113 are respectively connected to the second end face ratchet slider 3107 and the mounting shell 3101, the first side bearing 3125 and the second side bearing 3126 are formed into one body with the rotating connector 3106 by nesting, and are fixedly connected to the stepped shaft 3122 by bolts, the first miniature bearing 3127 and the second miniature bearing 3128 are respectively fixedly connected to the mounting shell 3101 by nesting, one end of the first pull rod 3118 is connected to the first miniature bearing 3127 by nesting, and the other end is connected to the first end face ratchet slider 3104 by contacting,One end of the second pull rod 3116 is connected to the second micro bearing 3128 by nesting, and the other end is connected to the second end face ratchet slider 3107 by contacting, and the first elastic pressing piece 3121 and the second elastic pressing piece 3115 are fixedly connected to the mounting housing 3101 by bolts respectively;

[0070] In the stable self-locking rotary joint 31, the reciprocating movement of the end ratchet slider is achieved by the cooperation of the shape memory alloy coil and the spring; the end of the pull rod is stably contacted with the bottom of the guide groove of the end ratchet slider under the pre-pressure of the elastic pressure plate, so that the end of the pull rod can only move unidirectionally in the guide groove.

[0071] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

[0072] At the same time, for the overall structure described in this solution, the following implementation method is provided:

[0073] like Figure 8 , Fig. 9 The figures show the passive movement process of the first pull rod of the stable self-locking rotary joint in the guide groove of the first end face ratchet slider and the passive movement process of the second pull rod in the guide groove of the second end face ratchet slider of the present solution, and the execution principle is the same. Figure 8 Taking the passive movement process of the first pull rod in the guide groove of the first end face ratchet slider as an example, it is completed by the cooperation of the first shape memory alloy spring, the second shape memory alloy spring and the first compression spring. Combined with the step characteristics of the guide groove on the side of the first end face ratchet slider, the first pull rod can only passively move in one direction in the guide groove. The movement process of the pull rod is explained in several stages:

[0074] ① Point a to point b, point c to point d: In this process, the heating contraction force of the first shape memory alloy spring and the second shape memory alloy spring being electrically short-circuited is used as the execution force, and the first compression spring is compressed during the contraction process;

[0075] ② Point b to point c, point d to point a: This process does not require energy consumption. The first shape memory alloy spring and the second shape memory alloy spring are powered off, and the release force of the compressed first compression spring is used as the execution force. During the process, the first shape memory alloy spring and the second shape memory alloy spring are extended;

[0076] ③ When and only when the first pull rod is at point a or point c, it can be maintained at this position without consuming energy, so as to stably change the engagement and disengagement states of the first end face ratchet slider and the rotating connector in the stable self-locking rotary joint.

[0077] like Fig.10 As shown, the four states of the stable self-locking rotary joint of the present invention include forward rotation, reverse rotation, bidirectional rotation and self-locking, which can be switched independently and flexibly. The formation process of the four states is completed by the passive movement of the first pull rod and the second pull rod in the guide grooves of the first end face ratchet slider and the second end face ratchet slider respectively.

[0078] In the following description, the stable self-locking rotation joint is simplified as "joint", and it is simplified into two states: self-locking and rotation. Under a set of tendon drive units, the robot has different operating modes according to different joint locking and release strategies. Its representative operating modes include whole-segment motion, joint segment motion and joint motion. In this study, we define the joint near the mounting end as joint 1, the end joint as joint n, and the number of joint segments divided into the continuum robot module is S. The specific operating modes are as follows:

[0079] ① Whole-segment motion (S=1): This mode means that the robot uses the entire body segment as an independent motion unit and moves through synchronous drive control. During the motion process, when any number of joints in any position are in a self-locking state, the remaining rotating joints follow the constant curvature model, that is, each free joint rotates at the same angle. Fig.11 As shown, there are several situations including the front part of the joints being self-locking, the middle part of the joints being self-locking, the rear part of the joints being self-locking, and all the joints being rotating. In this motion mode, the continuum robot module has a total of 2 n -1 type of motion track.

[0080] ② Joint segment motion (2≤S≤n-1): In this motion mode, the continuum robot module is divided into S segments starting from the mounting base. During the motion process, each joint segment is an independent motion unit, and the joint segments need to move through step-by-step drive control. That is, when any joint segment moves, the remaining joint segments are in a locked state. It is worth noting that the motion of each joint segment still follows the constant curvature model, that is, the rotation angle of each joint in the joint segment is the same. Fig.12 As shown in the figure, the robot is divided into 2 joint segments and 3 joint segments, respectively, and the movement states from the joint segment of the mounting base to the distal joint segment are shown. In this movement mode, the continuum robot module has a total of 2 n -2 joint segment division methods, when divided into S joint segments, there are Kind of motion trajectory.

[0081] ③ Joint motion (S = n): This motion mode means that the robot uses each joint as an independent motion unit, and its flexibility is maximized under this structure. The drive control method is similar to the joint segment motion, except that the independent motion unit is changed into a single joint. Fig.13 As shown, the sequential movement states from the joint of the mounting base to the distal joint and another sequential movement state are shown.

[0082] It is worth adding that when all the joints in the continuum robot module are in a self-locking state, the shape of the continuum robot module is rigid as a whole and does not require any driving force to maintain.

[0083] Those of ordinary skill in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0084] In the several embodiments provided in the present application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of the units described above is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present invention.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A planar continuum robot with few drives based on stable self-locking rotary joints, characterized in that: It comprises a driving device (1), a mounting seat (2), and a continuum robot module (3); The mounting seat (2) is fixedly connected to the driving device (1) via bolts; The proximal end of the continuum robot module (3) is fixedly connected to the mounting seat (2) via bolts.

2. The low-drive planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: The driving device (1) comprises a frame (101), a base plate (102), a first linear module (103), a first U-shaped plate (104), a first pulley (105), a second pulley (106), a first traction rope (107), a first lifting ear screw (108), a first force sensor (109), a first stud (110), a first tension adjustment screw (111), a second linear module (112), a second U-shaped plate (113), a third pulley (114), a fourth pulley (115), a second traction rope (116), a second lifting ear screw (117), a second force sensor (118), a second stud (119), a second tension adjustment screw (120), and a first fixing plate (121); The bottom plate (102) is fixedly connected to the frame (101) by bolts, the first linear module (103) and the second linear module (112) are fixedly connected to the bottom plate (102) by bolts in a symmetrical manner, the first U-shaped plate (104) and the second U-shaped plate (113) are fixedly connected to the first linear module (103) and the second linear module (112) by bolts, the first pulley (105) and the second pulley (106) are fixedly connected to the first U-shaped plate (104) and the second U-shaped plate (113) by bolts in a symmetrical manner, 04), the third pulley (114) and the fourth pulley (115) are symmetrically fixedly connected to the second U-shaped plate (113) by bolts, the first traction rope (107) passes around the first pulley (105) and the second pulley (106), and one end is fixedly connected to the first hanging ear screw (108) by knotting or locking, and the other end passes through multiple stable self-locking rotation joints (31) of the continuum robot module (3) and is fixedly connected to the end flange (34), the second The traction rope (116) passes around the third pulley (114) and the fourth pulley (115), and one end is fixedly connected to the second lifting eye screw (117) by knotting or locking, and the other end passes through multiple stable self-locking rotation joints (31) of the continuum robot module (3) and is fixedly connected to the end flange (34); the first lifting eye screw (108) and the second lifting eye screw (117) are respectively fixedly connected to the first force sensor (109) and the second force sensor (118) by bolts; the first stud (110) and the second stud (119) are respectively fixedly connected to the first force sensor (109) and the second force sensor (118) by threads; the first stud (110) and the second stud (119) are respectively threadedly connected to the first tension adjustment screw (111) and the second tension adjustment screw (120); the first tension adjustment screw (111) and the second tension adjustment screw (120) are both fitted and connected to the first fixing plate (121).

3. The low-drive planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: The mounting seat (2) comprises a second fixing plate (201), a first side plate (202), a first supporting plate (203), a second supporting plate (204), a second side plate (205), and a mounting plate (206); The second fixing plate (201) is fixedly connected to the first fixing plate (121) by bolts, the first support plate (203) is fixedly connected to the second fixing plate (201) and the first side plate (202) by bolts, the second support plate (204) is fixedly connected to the second fixing plate (201) and the second side plate (205) by bolts, and the first side plate (202) and the second side plate (205) are symmetrically fixedly connected to the second fixing plate (201) and the mounting plate (206) by bolts.

4. The low-drive planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: The continuum robot module (3) comprises a plurality of stable self-locking rotation joints (31), a first elastic rod (32), a second elastic rod (33), and an end flange (34); A plurality of stable self-locking rotating joints (31) are connected in series by bolts in a manner where the rotating axes are parallel, a first elastic rod and a second elastic rod both pass through each stable self-locking rotating joint and are fixedly connected thereto by gluing, and an end flange (34) is fixedly connected to the stable self-locking rotating joint (31) at the end by bolts.

5. The low-drive planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: The stable self-locking rotary joint (31) in the continuum robot module (3) comprises a mounting housing (3101), a first slider (3102), a first shape memory alloy coil (3103), a first end face ratchet slider (3104), a first conductive copper sheet (3105), a rotary connector (3106), a second end face ratchet slider (3107), a second conductive copper sheet (3108), a second slider (3109), a linear guide rail (3110), a third wiring sheet (3111), a third shape memory alloy coil (3112), a second spring (31 13), a fourth connecting piece (3114), a second elastic pressing piece (3115), a second pull rod (3116), a fourth shape memory alloy coil (3117), a first pull rod (3118), a first spring (3119), a second shape memory alloy coil (3120), a first elastic pressing piece (3121), a stepped shaft (3122), a first connecting piece (3123), a second connecting piece (3124), a first flange bearing (3125), a second flange bearing (3126), a first micro bearing (3127), and a second micro bearing (3128); The linear guide rail (3110) is fixedly connected to the mounting housing (3101) by bolts, the first slider (3102) and the second slider (3109) are respectively connected to the linear guide rail (3110) in a linear displacement manner, the first end face ratchet slider (3104) and the second end face ratchet slider (3107) are respectively fixedly connected to the first slider (3102) and the second slider (3109) by bolts, one end of the first shape memory alloy coil (3103) and one end of the second shape memory alloy coil (3112) are respectively connected to the first wiring piece (3123) and the second wiring piece (3124) by bolts and fixed thereto. The first end of the third shape memory alloy coil (3112) and the second end of the fourth shape memory alloy coil (3117) are connected to the third connecting piece (3111) and the fourth connecting piece (3114) by bolts and fixed to the mounting housing (3101), and the other end of the third shape memory alloy coil (3112) and the fourth shape memory alloy coil (3117) are connected to the third connecting piece (3111) and the fourth connecting piece (3114) by bolts and fixed to the mounting housing (3101), respectively, and the other end of the third shape memory alloy coil (3112) and the fourth shape memory alloy coil (3117) are connected to the third connecting piece (3111) and the fourth connecting piece (3114) by bolts and fixed to the mounting housing (3101), respectively, and the other end of the third shape memory alloy coil (3112) and the fourth shape memory alloy coil (3117) are connected to the second conductive copper sheet (3108) by bolts and fixed to the second end ratchet slider (3107), and the stepped shaft (3122) is fixed to the mounting housing (3101) by bolts. The first spring (3119) and the second spring (3113) are connected to the stepped shaft (3122) in a nested manner. The two sides of the first spring (3119) are respectively connected to the first end face ratchet slider (3104) and the mounting housing (3101). The two sides of the second spring (3113) are respectively connected to the second end face ratchet slider (3107) and the mounting housing (3101). The first side bearing (3125) and the second side bearing (3126) are formed into one piece with the rotating connector (3106) in a nested manner and are fixedly connected to the stepped shaft (3122) by bolts. The first miniature bearing (312 7) The second micro-bearing (3128) is fixedly connected to the mounting housing (3101) by a nesting manner, one end of the first pull rod (3118) is connected to the first micro-bearing (3127) by a nesting manner, and the other end is connected to the first end face ratchet slider (3104) by a contact manner, one end of the second pull rod (3116) is connected to the second micro-bearing (3128) by a nesting manner, and the other end is connected to the second end face ratchet slider (3107) by a contact manner, and the first elastic pressing piece (3121) and the second elastic pressing piece (3115) are fixedly connected to the mounting housing (3101) by bolts.

6. The low-actuation planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: In the driving device (1): The frame (101) can be assembled by profiles or welded by plates to maintain a stable structure; The first U-shaped plate (104) and the second U-shaped plate (113) can be made by welding, sheet metal, etc., and threaded through holes are provided on the corresponding mounting surfaces; The surface of the first fixing plate (121) is provided with a plurality of light holes or threaded holes to facilitate the fixed connection of the second fixing plate (201) and the penetration of the first traction rope (107) and the second traction rope (116); The first traction rope (107) and the second traction rope (116) are ropes with a retractable ratio of less than 0.5%, and the materials that can be selected include but are not limited to nylon rope, jade wire or steel wire rope.

7. The low-drive planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: In the mounting seat (2): The second fixing plate (201), the first side plate (202), the first supporting plate (203), the second supporting plate (204), the second side plate (205), and the mounting plate (206) are all processed with countersunk holes to facilitate fixed connection.

8. The low-actuation planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: In the continuum robot module (3): A plurality of stable self-locking rotary joints (31) are connected in series via screws in a manner where the rotary axes are parallel; The first elastic rod (32) and the second elastic rod (33) are both made of circular cross-section rods with superelasticity, which maintain their initial straight shape when not subjected to external force. The elastic rods may be made of materials including but not limited to nickel-titanium alloy rods and fiber rods. The end flange (34) is provided with a plurality of threaded holes and light holes, and the light holes facilitate the first traction rope (107), the second traction rope (116), the first elastic rod (32), and the second elastic rod (33) to pass through and be fixed in a knotted or locked manner.

9. The low-actuation planar continuum robot based on stable self-locking rotary joints according to claim 1, characterized in that: The stable self-locking rotary joint (31) in the continuum robot module (3): The mounting housing (3101) can be manufactured by machining or 3D printing, and a plurality of holes are arranged on its surface; One side of the first end face ratchet slider (3104) and the second end face ratchet slider (3107) is processed with a through hole, and the other side is processed with a stepped guide groove, each step height is 0.5 mm, and the bottom boss is processed with end face ratchet teeth in opposite directions; The upper and lower annular boss surfaces of the rotating connector (3106) are processed with end face ratchets in opposite directions, a through hole is drilled in the rotating center, and a groove is processed in the center of the rotating side surface to facilitate the movement of the first traction rope (107) and the second traction rope (116), and a platform with a hole is processed at the tail to facilitate fixed connection with other mounting housings (3101); The first elastic pressing plate (3121) and the second elastic pressing plate (3115) have superelasticity and are made of, but not limited to, spring steel or spring sheet. At the same time, the first elastic pressing plate (3121) and the second elastic pressing plate (3115) respectively maintain elastic pressure on the first pull rod (3118) and the second pull rod (3116), so that the ends of the first pull rod (3118) and the second pull rod (3116) respectively form stable contact with the guide groove of the first end face ratchet slider (3104) and the guide groove of the second end face ratchet slider (3107); The first conductive copper sheet (3105) and the second conductive copper sheet (3108) are configured to be convex and can be made by stamping, cutting, etc., so as to be stably fitted with the surfaces of the first end face ratchet slider (3104) and the second end face ratchet slider (3107); The first shape memory alloy coil (3103), the second shape memory alloy coil (3120), the third shape memory alloy coil (3112), and the fourth shape memory alloy coil (3117) are all made of the same material and have the same specifications, and shrink when heated.

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