A few-actuated planar continuum robot based on stable self-locking revolute joints

Abstract

The application discloses a few-drive plane continuum robot based on stable self-locking rotary joints, which comprises a driving device, a mounting seat and a continuum robot module, wherein the driving device comprises a frame, a linear module, a traction rope, a force sensor, a hand screw adjusting screw and the like; the continuum robot module comprises stable self-locking rotary joints, elastic rods and end flanges. The stable self-locking rotary joints are triggered by a memory alloy coil and a spring, so that after a face ratchet slider and a rotary connecting piece form mechanical constraint, each joint can be kept in a self-locking or rotating state with zero power consumption. Therefore, the robot has multiple operation modes, such as whole section movement, joint section movement and joint movement, under the condition that only one set of driving units is arranged, so that the robot has flexible movement performance and various work spaces. Meanwhile, the rigidity of the robot also changes with the joint locking state, and when all the joints are self-locked, the robot can maintain the shape without the need of motor driving.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of continuum robots, in particular to a few-drive planar continuum robot based on stable self-locking rotary joints. BACKGROUND

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

[0003] The common structure types of the current continuum robots are: (1) a continuous flexible whole drive structure, including a driving device, a flexible backbone and a traction rope group, which usually realizes the whole bending control of the flexible backbone by the driving device through the traction rope group, and the driving is simple but the working range is limited. (2) A continuous flexible multi-section drive structure, usually including a driving device, a multi-section continuum backbone and a traction rope group, which realizes the independent bending motion between the section bodies by the driving device, and limitedly improves the flexibility and working range. (3) A discrete rigid fully driven continuum robot, including a driving device, a plurality of connecting joints, a plurality of universal joints and a plurality of traction rope groups, which usually realizes the angle independent control of each universal joint by the driving device through each traction rope group, and has good flexibility and working range, but the rope arrangement and driving are relatively complex, which also makes the whole lightweight.

[0004] Therefore, how to maintain the flexibility and working space of the continuum robot under simple driving is still a big problem to be solved. SUMMARY

[0005] Therefore, the present application aims to provide a few-drive planar continuum robot based on stable self-locking rotary joints, which can have different motion modes according to various joint locking strategies under a group of driving units, and has flexibility and working space range, and the stiffness of the robot changes when the joint is locked.

[0006] To achieve the above purpose, the technical scheme of the present application is as follows:

[0007] A few-drive planar continuum robot based on stable self-locking rotary joints, characterized by comprising a driving device, a mounting seat and a continuum robot module.

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

[0009] Further, the driving device comprises a frame, a bottom 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 fixed plate.

[0010] The bottom plate is fixedly connected with the frame through bolts, the first linear module and the second linear module are symmetrically fixedly connected with the bottom plate through bolts respectively, the first U-shaped plate and the second U-shaped plate are fixedly connected with the first linear module and the second linear module through bolts respectively, the first pulley and the second pulley are symmetrically fixedly connected with the first U-shaped plate through bolts, the third pulley and the fourth pulley are symmetrically fixedly connected with the second U-shaped plate through bolts, the first traction rope passes through the first pulley and the second pulley, and is fixedly connected with the first lifting lug screw at one end and with the end flange at the other end through knotting or a lock buckle, the second traction rope passes through the third pulley and the fourth pulley, and is fixedly connected with the second lifting lug screw at one end and with the end flange at the other end through knotting or a lock buckle, the first lifting lug screw and the second lifting lug screw are fixedly connected with the first force sensor and the second force sensor through bolts respectively, the first stud and the second stud are fixedly connected with the first force sensor and the second force sensor through threads respectively, and the first stud and the second stud are in threaded connection with the first hand screw and the second hand screw respectively.

[0011] Further, the mounting seat comprises a second fixed plate, a first side plate, a first support plate, a second support plate, a second side plate, and a mounting plate.

[0012] The second fixed plate is fixedly connected with the first fixed plate through bolts, the first support plate is fixedly connected with the second fixed plate and the first side plate through bolts, the second support plate is fixedly connected with the second fixed plate and the second side plate through bolts, and the first side plate and the second side plate are symmetrically fixedly connected with the second fixed plate and the mounting plate through bolts.

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

[0014] The plurality of stable self-locking rotary joints are connected in series through bolts in a parallel manner of rotary shafts, the first elastic rod and the second elastic rod pass through each stable self-locking rotary joint and are fixedly connected therewith through gluing, and the end flange is fixedly connected with the end stable self-locking rotary joint through a bolt.

[0015] The stable self-locking rotary joint comprises a mounting shell, a first sliding block, a first shape memory alloy coil, a first end face ratchet sliding block, a first conductive copper sheet, a rotary connecting piece, a second end face ratchet sliding block, a second conductive copper sheet, a second sliding block, a linear guide rail, a third connecting sheet, a third shape memory alloy coil, a second spring, a fourth connecting sheet, a second elastic pressing sheet, 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 sheet, a stepped shaft, a first connecting sheet, a second connecting sheet, a first flange bearing, a second flange bearing, a first micro bearing and a second micro bearing.

[0016] The linear guide rail is fixedly connected with the mounting shell through bolts, the first sliding block and the second sliding block are connected with the linear guide rail in a linear displacement manner, the first end face ratchet sliding block and the second end face ratchet sliding block are fixedly connected with the first sliding block and the second sliding block through bolts, one end of the first shape memory alloy coil and one end of the second shape memory alloy coil are connected with the first connecting sheet and the second connecting sheet through bolts and are fixed on the mounting shell, the other ends are connected with the first conductive copper sheet through bolts and are fixed on the surface of the first end face ratchet sliding block, one end of the third shape memory alloy coil and one end of the fourth shape memory alloy coil are connected with the third connecting sheet and the fourth connecting sheet through bolts and are fixed on the mounting shell, the other ends are connected with the second conductive copper sheet through bolts and are fixed on the surface of the second end face ratchet sliding block, the stepped shaft is fixedly connected with the mounting shell through bolts, the first spring and the second spring are connected with the stepped shaft in a nesting manner, the two sides of the first spring are connected with the first end face ratchet sliding block and the mounting shell, the two sides of the second spring are connected with the second end face ratchet sliding block and the mounting shell, the first flange bearing and the second flange bearing are integrally formed with the rotary connecting piece in a nesting manner and are fixedly connected with the stepped shaft through bolts, the first micro bearing and the second micro bearing are fixedly connected with the mounting shell in a nesting manner, one end of the first pull rod is connected with the first micro bearing in a nesting manner, the other end is connected with the first end face ratchet sliding block in a contact manner, one end of the second pull rod is connected with the second micro bearing in a nesting manner, the other end is connected with the second end face ratchet sliding block in a contact manner, and the first elastic pressing sheet and the second elastic pressing sheet are fixedly connected with the mounting shell through bolts.

[0017] Further, in the driving device:

[0018] The frame can be assembled by profiles or welded by plates, and the stable structure is maintained.

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

[0020] The first fixed plate is provided with a plurality of light holes or threaded holes, so as to facilitate the fixed connection of the second fixed plate, 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 stretchable ratio less than 0.5%, which can be selected from, but not limited to, nylon rope, jade line or steel wire rope.

[0022] Further, the mounting seat is provided with:

[0023] The second fixed plate, the first side plate, the first support plate, the second support plate, the second side plate and the mounting plate are all processed with countersunk holes, so as to facilitate the fixed connection.

[0024] Further, the continuum robot module is provided with:

[0025] The plurality of stable self-locking rotary joints are connected in series by screws in a parallel manner of rotary shafts.

[0026] The first elastic rod and the second elastic rod are both selected to be circular-section rods with super-elasticity, which remain the initial straight shape when not subjected to external force, and the elastic rods can be selected from, 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 used for the penetration of the first traction rope, the second traction rope, the first elastic rod and the second elastic rod and the fixation by knotting or locking.

[0028] Further, the stable self-locking rotary joint in the continuum robot module is provided with:

[0029] The mounting shell can be manufactured by machining or 3D printing, and the surface thereof is provided with a plurality of holes.

[0030] One side of the first end face ratchet block and the second end face ratchet block is processed with a through hole, and the other side is processed with a stepped guide groove, each step has a height of 0.5 mm, and the bottom bosses are respectively processed with end face ratchet teeth in opposite directions.

[0031] The upper and lower annular bosses of the rotary connecting piece are processed with end face ratchet teeth in opposite directions, the rotary center is drilled with a through hole, the rotary side center is processed with a groove, so as to facilitate the movement of the first traction rope and the second traction rope, and the tail is processed with a platform with a hole, so as to facilitate the fixed connection with other mounting shells.

[0032] The first elastic pressing piece and the second elastic pressing piece have super-elasticity and are selected from, but not limited to, spring steel or spring sheet, and at the same time, 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 first pull rod end and the second pull rod end respectively form stable contact with the first end face ratchet block guide groove and the second end face ratchet block guide groove.

[0033] The first and second conductive copper sheets are convex and can be manufactured by stamping, cutting and other methods, so as to facilitate stable contact with the surfaces of the first end face ratchet slider and the second end face ratchet slider.

[0034] The first, second, third, and fourth shape memory alloy coils all use the same material and have the same specifications, and shrink when heated.

[0035] Compared with existing technologies, the planar continuum robot with few drives based on a stable self-locking rotary joint described in this invention has the following advantages:

[0036] The stable self-locking rotary joint proposed in this invention has four stable states: forward rotation, reverse rotation, bidirectional rotation, and self-locking. Once each stable state is formed, it can be maintained without consuming energy.

[0037] This invention achieves independent control of individual joints, synchronous control of individual joint segments, and overall synchronous control under a set of drive units, and has multiple motion modes, maintaining flexibility and a large working range with fewer drives.

[0038] The invention states that 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 at its maximum, and at this time, the shape can be maintained without motor driving force.

[0039] This invention has a simple structure, is easy to manufacture, has stable performance, and is highly adaptable, making it suitable for a wide range of applications. Attached Figure Description

[0040] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

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

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

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

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

[0045] Figure 5 This 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 application;

[0047] Figure 7 is a front view, a left view and a right view of the first end face ratchet slider;

[0048] Figure 8 is a passive one-way movement process of the first pull rod in the guide groove of the first end face ratchet slider;

[0049] Figure 9 is a passive one-way movement process of the second pull rod in the guide groove of the second end face ratchet slider;

[0050] Figure 10 is a working state schematic diagram of the stable self-locking rotary joint of the present application;

[0051] Figure 11 is a state schematic of the robot in the running mode of the whole segment movement;

[0052] Figure 12 is a state schematic of the robot in the running mode of the joint segment movement;

[0053] Figure 13 is a state schematic of the robot in the running mode of the joint movement.

[0054] Explanation of reference signs:

[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 lug 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 lug screw, 118 - second force sensor, 119 - second stud, 120 - second hand screw, 121 - first fixed plate;

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

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

[0059] 3101 - mounting shell, 3102 - first slider, 3103 - first shape memory alloy coil, 3104 - first end face ratchet slider, 3105 - first conductive copper sheet, 3106 - rotary connecting piece, 3107 - second end face ratchet slider, 3108 - second conductive copper sheet, 3109 - second slider, 3110 - linear guide rail, 3111 - third connecting sheet, 3112 - third shape memory alloy coil, 3113 - second spring, 3114 - fourth connecting sheet, 3115 - second elastic pressing sheet, 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 sheet, 3122 - stepped shaft, 3123 - first connecting sheet, 3124 - second connecting sheet, 3125 - first flange bearing, 3126 - second flange bearing, 3127 - first micro bearing, 3128 - second micro bearing. DETAILED DESCRIPTION

[0060] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

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

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

[0063] The driving device 1 includes a frame 101, a bottom 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 lug 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 lug screw 117, a second force sensor 118, a second stud 119, a second hand screw 120, and a first fixed plate 121, wherein the bottom plate 102 is fixedly connected with the frame 101 by bolts, the first linear module 103 and the second linear module 112 are symmetrically fixedly connected with the bottom plate 102 by bolts respectively, the first U-shaped plate 104 and the second U-shaped plate 113 are fixedly connected with the first linear module 103 and the second linear module 112 by bolts respectively, the first pulley 105 and the second pulley 106 are symmetrically fixedly connected with the first U-shaped plate 104 by bolts, the third pulley 114 and the fourth pulley 115 are symmetrically fixedly connected with the second U-shaped plate 113 by bolts, the first traction rope 107 passes through the first pulley 105 and the second pulley 106 and is fixedly connected with the first lug screw 108 at one end and with the end flange 34 of the continuum robot module 3 at the other end by knotting or locking, the second traction rope 116 passes through the third pulley 114 and the fourth pulley 115 and is fixedly connected with the second lug screw 117 at one end and with the end flange 34 of the continuum robot module 3 at the other end by knotting or locking, the first lug screw 108 and the second lug screw 117 are fixedly connected with the first force sensor 109 and the second force sensor 118 by bolts respectively, the first stud 110 and the second stud 119 are fixedly connected with the first force sensor 109 and the second force sensor 118 by threads respectively, the first stud 110 and the second stud 119 are threadedly connected with 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 attached to the first fixed plate 121.

[0064] In the driving device 1, the traction rope is driven to displace by the linear module, the pulley is fixedly connected with the linear module through the U-shaped plate to form a movable pulley structure, so that the driving displacement of the linear module is magnified by two times, and the size of the driving device is effectively reduced; the tension of the traction rope before and during driving is monitored in real time through the force sensor; the tension of the traction rope before driving is flexibly adjusted through the cooperation of the stud and the hand screw combined with the force sensor.

[0065] The mounting base 2 comprises a second fixed plate 201, a first side plate 202, a first support plate 203, a second support plate 204, a second side plate 205, and a mounting plate 206, wherein the second fixed plate 201 is fixedly connected with the first fixed plate 121 through bolts, the first support plate 203 is fixedly connected with the second fixed plate 201 and the first side plate 202 through bolts, the second support plate 204 is fixedly connected with the second fixed plate 201 and the second side plate 205 through bolts, and the first side plate 202 and the second side plate 205 are fixedly connected with the second fixed plate 201 and the mounting plate 206 through bolts in a symmetrical manner.

[0066] In the mounting base 2, the stability of the mounting base is enhanced through the support plates, and the spacing of the traction ropes is changed through the mounting plate and the second fixed plate, thereby adapting 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 a terminal flange 34, wherein the plurality of stable self-locking rotary joints 31 are connected in series through bolts in a parallel manner of rotary shafts, the first elastic rod 32 and the second elastic rod 33 each pass through each stable self-locking rotary joint 31 and are fixedly connected therewith through gluing, and the terminal flange 34 is fixedly connected with the terminal stable self-locking rotary joint 31 through a bolt.

[0068] In the continuum robot module 3, the continuum robot has flexibility through the elastic rods passing through each stable self-locking rotary joint and being fixed; each stable self-locking rotary joint can be independently self-locked and released, which enables the continuum robot to be driven as a whole or partially; when all the stable self-locking rotary joints are self-locked, the continuum robot can maintain the shape without the need of motor driving.

[0069] The stable self-locking rotary joint 31 in the continuum robot module 3 comprises a mounting shell 3101, a first sliding block 3102, a first shape memory alloy coil 3103, a first end face ratchet sliding block 3104, a first conductive copper sheet 3105, a rotary connecting piece 3106, a second end face ratchet sliding block 3107, a second conductive copper sheet 3108, a second sliding block 3109, a linear guide rail 3110, a third connecting sheet 3111, a third shape memory alloy coil 3112, a second spring 3113, a fourth connecting sheet 3114, a second elastic pressing sheet 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 sheet 3121, a stepped shaft 3122, a first connecting sheet 3123, a second connecting sheet 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 with the mounting shell 3101 by bolts. The first sliding block 3102 and the second sliding block 3109 are respectively connected with the linear guide rail 3110 in a linear displacement manner. The first end face ratchet sliding block 3104 and the second end face ratchet sliding block 3107 are fixedly connected with the first sliding block 3102 and the second sliding block 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 connected with the first connecting sheet 3123 and the second connecting sheet 3124 by bolts and fixed on the mounting shell 3101. The other ends are connected with the first conductive copper sheet 3105 by bolts and fixed on the surface of the first end face ratchet sliding block 3104. One end of the third shape memory alloy coil 3112 and one end of the fourth shape memory alloy coil 3117 are connected with the third connecting sheet 3111 and the fourth connecting sheet 3114 by bolts and fixed on the mounting shell 3101. The other ends are connected with the second conductive copper sheet 3108 by bolts and fixed on the surface of the second end face ratchet sliding block 3107. The stepped shaft 3122 is fixedly connected with the mounting shell 3101 by bolts. The first spring 3119 and the second spring 3113 are connected with the stepped shaft 3122 in a nesting manner. The two sides of the first spring 3119 are connected with the first end face ratchet sliding block 3104 and the mounting shell 3101 respectively. The two sides of the second spring 3113 are connected with the second end face ratchet sliding block 3107 and the mounting shell 3101 respectively. The first flange bearing 3125 and the second flange bearing 3126 are integrally formed with the rotary connecting piece 3106 in a nesting manner and fixedly connected with the stepped shaft 3122 by bolts. The first micro bearing 3127 and the second micro bearing 3128 are fixedly connected with the mounting shell 3101 in a nesting manner. One end of the first pull rod 3118 is connected with the first micro bearing 3127 in a nesting manner and the other end is connected with the first end face ratchet sliding block 3104 in a contact manner.One end of the second pull rod 3116 is connected with the second micro bearing 3128 in a nested manner, and the other end is connected with the second end face ratchet block 3107 in a contact manner. The first elastic pressing piece 3121 and the second elastic pressing piece 3115 are fixedly connected with the mounting shell 3101 through bolts.

[0070] In the stable self-locking rotary joint 31, the end face ratchet block reciprocating movement is realized by the cooperation of the shape memory alloy coil and the spring. The pull rod end is stably contacted on the bottom of the guide groove of the end face ratchet block through the pre-pressing of the elastic pressing piece, so that the pull rod end can only move in one direction in the guide groove.

[0071] Although the present application has been described in detail by general description and specific embodiments above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, all belong to the scope of protection claimed by the present application.

[0072] Meanwhile, for the overall structure of the present scheme, the following implementation method is provided:

[0073] As shown in Figure 8 , Figure 9 , they are 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 block and the passive movement process of the second pull rod in the guide groove of the second end face ratchet block, respectively, and the execution principles are the same. Taking the passive movement process of the first pull rod in the guide groove of the first end face ratchet block as an example, it is executed 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 block, the first pull rod can only passively move in one direction in the guide groove. The movement process of the pull rod is explained as follows: Figure 8

[0074] ①From point a to point b, from point c to point d: In this process, the heating shrinkage force of the first shape memory alloy spring and the second shape memory alloy spring energized short-circuit is used as the execution force, and the first compression spring is compressed in the shrinkage process;

[0075] ②From point b to point c, from point d to point a: In this process, no energy is consumed, the first shape memory alloy spring and the second shape memory alloy spring are de-energized, and the release force of the compressed first compression spring is used as the execution force. In the process, the first shape memory alloy spring and the second shape memory alloy spring are elongated;

[0076] ③When and only when the first pull rod is at point a or point c, it can be kept at this position without consuming energy, so that the stable change of the engagement and disengagement state of the first end face ratchet block and the rotary connecting piece in the stable self-locking rotary joint is realized. ​

[0077] As Figure 10 shown, four states of the stable self-locking rotary joint of the present scheme, including forward rotation, reverse rotation, bidirectional rotation and self-locking, can be independently and flexibly switched. 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 groove of the first end face ratchet slider and the second end face ratchet slider respectively.

[0078] In the following description, the stable self-locking rotary joint is simplified as "joint", and it is simplified as two states: self-locking and rotation. Under a group of tendon-driven units, according to different joint locking and releasing strategies, the robot has different running modes, and the representative running modes include whole motion, joint segment motion and joint motion. In this study, we define the joint at the proximal mounting base end as joint 1, the end joint as joint n, and the number of joint segments divided by the continuum robot module as S, and the specific of each running mode is:

[0079] ① Whole motion (S = 1): This mode represents that the robot takes the whole body segment as an independent motion unit and moves through synchronous driving control. In the motion process, when any number and any position of joints are in the self-locking state, the remaining joints in rotation follow the constant curvature model, i.e. each free joint has the same rotation angle. As Figure 11 shown, it includes several cases such as the front end part joint in self-locking, the middle part joint in self-locking, the rear end part joint in self-locking and all joints in rotation. In this motion mode, the continuum robot module has a total of 2 n -1 motion trajectories.

[0080] ② Joint segment motion (2 ≤ S ≤ n-1): In this motion mode, the continuum robot module is divided into S segments from the mounting base. In the motion process, each joint segment is an independent motion unit, and the joint segments need to be moved through step-by-step driving control, i.e. when any joint segment moves, the remaining joint segments are in the locked state. It is worth noting that the motion of each joint segment still follows the constant curvature model, i.e. each joint in the joint segment has the same rotation angle. As Figure 12 shown, it respectively shows the motion state of the joint segment from the mounting base to the distal end joint segment when the robot is divided into 2 joint segments and 3 joint segments. In this motion mode, the continuum robot module has a total of 2 n -2 joint segment division methods, and when divided into S joint segments, there are motion trajectories.

[0081] (3) Joint motion (S = n): This mode of motion indicates that the robot takes each joint as an independent motion unit, and its flexibility is amplified to the limit under this structure. The driving control mode is similar to the joint segment motion, except that the independent motion unit is changed to a single joint. As shown in FIG. 8, a sequential motion state from the joint of the mounting seat to the distal joint and another sequential motion state are shown. Figure 13

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

[0083] Those skilled in the art can realize that the units and method steps of the examples described in combination with the embodiments disclosed herein can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of the examples have been described in the above description in general terms. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0084] In several embodiments provided in the present application, it should be understood that the disclosed method and system can be implemented in other ways. For example, the division of the above-mentioned units is only a logical functional division, and actual implementation can have another division manner, for example, 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 can be or can not be physically separated, and the components displayed as units can be or can not be physical units, i.e. they can be located in one place or distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment of the present application.

[0085] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and 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 application, and they should be covered in the scope of the claims and description of the present application.

[0086] ​The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A few-actuated planar continuum robot based on stable self-locking revolute joints, characterized by: The utility model relates to a kind of continuum robot module, including driving device (1), mounting seat (2), continuum robot module (3); Mounting seat (2) is fixedly connected with driving device (1) by bolt; The proximal end of continuum robot module (3) is fixedly connected with mounting seat (2) by bolt; The continuum robot module (3) includes a plurality of stable self-locking rotary joints (31); The stable self-locking rotary joint (31) includes mounting shell (3101), first slider (3102), first shape memory alloy coil (3103), first end face ratchet slider (3104), first conductive copper sheet (3105), rotary connecting piece (3106), second end face ratchet slider (3107), second conductive copper sheet (3108), second slider (3109), linear guide (3110), third terminal lug (3111), third shape memory alloy coil (3112), second spring (3113), fourth terminal lug (3114), second elastic pressing piece (3115), second pull rod (3116), fourth shape memory alloy coil (3117), first pull rod (3118), first spring (3119), second shape memory alloy coil (3120), first elastic pressing piece (3121), stepped shaft (3122), first terminal lug (3123), second terminal lug (3124), first flange bearing (3125), second flange bearing (3126), first micro bearing (3127), second micro bearing (3128); The linear guide rail (3110) is fixedly connected with the mounting shell (3101) through bolts, the first slider (3102) and the second slider (3109) are connected with the linear guide rail (3110) in a linear displacement mode respectively, the first end face ratchet slider (3104) and the second end face ratchet slider (3107) are fixedly connected with the first slider (3102) and the second slider (3109) through bolts respectively, one end of the first shape memory alloy coil (3103) and one end of the second shape memory alloy coil (3120) are connected with the first connecting piece (3123) and the second connecting piece (3124) through bolts and are fixed on the mounting shell (3101), the other ends are connected with the first conductive copper sheet (3105) through bolts and are fixed on 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 connected with the third connecting piece (3111) and the fourth connecting piece (3114) through bolts and are fixed on the mounting shell (3101), the other ends are connected with the second conductive copper sheet (3108) through bolts and are fixed on the surface of the second end face ratchet slider (3107), the stepped shaft (3122) is fixedly connected with the mounting shell (3101) through bolts, the first spring (3119) and the second spring (3113) are connected with the stepped shaft (3122) in a nesting mode, the first spring (3119) is connected with the first end face ratchet slider (3104) and the mounting shell (3101) on the two sides respectively, the second spring (3113) is connected with the second end face ratchet slider (3107) and the mounting shell (3101) on the two sides respectively, the first flanged bearing (3125) and the second flanged bearing (3126) are integrally formed with the rotary connecting piece (3106) in a nesting mode and are fixedly connected with the stepped shaft (3122) through bolts, the first micro bearing (3127) and the second micro bearing (3128) are fixedly connected with the mounting shell (3101) in a nesting mode respectively, one end of the first pull rod (3118) is connected with the first micro bearing (3127) in a nesting mode, the other end is connected with the first end face ratchet slider (3104) in a contact mode, one end of the second pull rod (3116) is connected with the second micro bearing (3128) in a nesting mode, the other end is connected with the second end face ratchet slider (3107) in a contact mode, the first elastic pressing piece (3121) and the second elastic pressing piece (3115) are fixedly connected with the mounting shell (3101) through bolts respectively.

2. A few-actuated planar continuum robot based on stable self-locking revolute joints as claimed in claim 1, wherein: The driving device (1) comprises a frame (101), a bottom 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 lug screw (108), a first force sensor (109), a first stud (110), a first tension adjusting 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 lug screw (117), a second force sensor (118), a second stud (119), a second tension adjusting screw (120), a first fixed plate (121); The bottom plate (102) is fixedly connected with the frame (101) through bolts, the first linear module (103) and the second linear module (112) are symmetrically fixedly connected with the bottom plate (102) through bolts respectively, the first U-shaped plate (104) and the second U-shaped plate (113) are fixedly connected with the first linear module (103) and the second linear module (112) through bolts respectively, the first pulley (105) and the second pulley (106) are symmetrically fixedly connected with the first U-shaped plate (104) through bolts, the third pulley (114) and the fourth pulley (115) are symmetrically fixedly connected with the second U-shaped plate (113) through bolts, the first traction rope (107) passes through the first pulley (105) and the second pulley (106), and is fixedly connected with the first lug screw (108) at one end and fixedly connected with the end flange (34) through a plurality of stable self-locking rotary joints (31) at the other end through knotting or locking buckle, the second traction rope (116) passes through the third pulley (114) and the fourth pulley (115), and is fixedly connected with the second lug screw (117) at one end and fixedly connected with the end flange (34) through a plurality of stable self-locking rotary joints (31) at the other end through knotting or locking buckle, the first lug screw (108) and the second lug screw (117) are fixedly connected with the first force sensor (109) and the second force sensor (118) through bolts respectively, the first stud (110) and the second stud (119) are fixedly connected with the first force sensor (109) and the second force sensor (118) through threads respectively, the first stud (110) and the second stud (119) are in threaded connection with the first tension adjusting screw (111) and the second tension adjusting screw (120) respectively, and the first tension adjusting screw (111) and the second tension adjusting screw (120) are attached to the first fixed plate (121).

3. A few-actuated planar continuum robot based on stable self-locking revolute joints as claimed in claim 1, wherein: The mounting seat (2) comprises a second fixed 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 fixed plate (201) is fixedly connected with the first fixed plate (121) through bolts, the first support plate (203) is fixedly connected with the second fixed plate (201) and the first side plate (202) through bolts, the second support plate (204) is fixedly connected with the second fixed plate (201) and the second side plate (205) through bolts, and the first side plate (202) and the second side plate (205) are fixedly connected with the second fixed plate (201) and the mounting plate (206) in a symmetrical manner through bolts.

4. A few-actuated planar continuum robot based on stable self-locking revolute joints as claimed in claim 1, wherein: The continuum robot module (3) comprises a first elastic rod (32), a second elastic rod (33) and a terminal flange (34). A plurality of stable self-locking rotary joints (31) are connected in series through bolts in parallel with the rotary shafts, and the first elastic rod and the second elastic rod each pass through each stable self-locking rotary joint and are fixedly connected thereto through adhesion, and the terminal flange (34) is fixedly connected with the terminal stable self-locking rotary joint (31) through bolts.

5. A few-actuated planar continuum robot based on stable self-locking revolute joints as claimed in claim 1, wherein, In the driving device (1): The frame (101) is assembled by profiles or welded by plates, and has a stable structure; The first U-shaped plate (104) and the second U-shaped plate (113) are made by welding or sheet metal processing, and are provided with threaded through holes corresponding to the mounting surfaces; A plurality of light holes or threaded holes are arranged on the surface of the first fixed plate (121) to facilitate the fixed connection of the second fixed 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 an extension ratio less than 0.5%.

6. A few-actuated planar continuum robot based on stable self-locking revolute joints as claimed in claim 1, wherein, In the mounting seat (2): The second fixed plate (201), the first side plate (202), the first support plate (203), the second support plate (204), the second side plate (205) and the mounting plate (206) are all machined with countersunk holes to facilitate fixed connection.

7. A few-actuated planar continuum robot based on stable self-locking revolute joints as claimed in claim 1, wherein, In the continuum robot module (3): A plurality of stable self-locking rotary joints (31) are connected in series through screws in parallel with the rotary shafts; The first elastic rod (32) and the second elastic rod (33) are both selected to be circular-section rods with super-elasticity, and remain in an initial straight shape when not subjected to external force; A plurality of threaded holes and light holes are arranged on the terminal flange (34), and the light holes facilitate the penetration of the first traction rope (107), the second traction rope (116), the first elastic rod (32) and the second elastic rod (33) and the fixing by knotting or locking.

8. A few-actuated planar continuum robot based on stable self-locking revolute joints as claimed in claim 1, wherein, The stable self-locking rotary joint (31) in the continuum robot module (3): The mounting shell (3101) is made by machining or 3D printing, and is provided with a plurality of holes on the surface; One side of the first end face ratchet block (3104) and the second end face ratchet block (3107) is machined with a through hole, and the other side is machined with a stepped guide groove, each step has a height of 0.5mm, and the bottom bosses are machined with end face ratchet teeth in opposite directions; The upper and lower annular boss surfaces of the rotary connecting piece (3106) are machined with end face ratchets in opposite directions, the rotary center is drilled with a through hole, the rotary side center is machined with a groove, facilitating the movement of the first traction rope (107) and the second traction rope (116), and the tail is machined with a platform with a hole, facilitating fixed connection with other mounting shells (3101); The first elastic pressing piece (3121) and the second elastic pressing piece (3115) have superelasticity, and the first elastic pressing piece (3121) and the second elastic pressing piece (3115) respectively elastically press the first pull rod (3118) and the second pull rod (3116), so that the first pull rod (3118) and the second pull rod (3116) respectively stably contact with the first end face ratchet slider (3104) guide groove and the second end face ratchet slider (3107) guide groove; The first conductive copper sheet (3105) and the second conductive copper sheet (3108) are set to be convex, and are made by stamping or cutting, facilitating stable adhesion 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 the same specification, and shrink when heated.

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