A rigid-flexible coupling continuous type mechanical arm based on four-pole tension integral structure

Abstract

The application discloses a continuous mechanical arm based on a four-bar tension whole structure, which has a multi-section continuous mechanical arm structure, and the mechanical arm body comprises at least one driving system, at least one supporting platform, at least one continuum mechanism and at least one flexible connecting mechanism; the at least one driving system comprises at least one driving motor, at least one controller, at least one winding reel and at least one winding shaft; the at least one continuum mechanism has at least one telescopic rod, a top layer unit, a middle layer unit and at least one bottom layer unit; the at least one flexible connecting mechanism is configured to make adjacent at least one continuum mechanism away from each other, and the adjacent at least one continuum mechanism is connected through the at least one flexible connecting mechanism and forms at least one bending deformation section and at least one telescopic deformation section; wherein the middle layer unit of the at least one continuum mechanism is connected with at least one top layer unit or at least one bottom layer unit of the at least one continuum structure through at least one flexible connecting mechanism, and realizes telescopic and bending rotation; the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure can realize multi-angle freedom motion in space and realize flexible operation capability of the mechanical arm structure.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a rigid-flexible coupled continuous robotic arm based on a four-bar tensioned integral structure. Background Technology

[0002] Currently, robotics technology research has matured significantly and is widely applied in many fields such as aerospace and industrial production, undoubtedly bringing great convenience to humankind. However, the traditional rigid robots widely used today have only limited degrees of freedom, poor deformation capabilities, and difficulty in achieving flexible maneuvering in space.

[0003] The design and application of continuous robotic arms presents a challenge in simultaneously achieving both structural compliance and load-bearing capacity (or structural stiffness). This necessitates improving stiffness while ensuring compliance during the robotic arm's structural design process. Therefore, leveraging the advantages of the variable stiffness and rich morphological variations of tensioned integral structures to design a high-performance continuous robotic arm is of great significance to the development of continuous robots. Summary of the Invention

[0004] The problem this invention aims to solve is to design a continuous robotic arm that combines structural stiffness, load-bearing capacity, and structural flexibility by leveraging the advantages of the variable stiffness and rich morphological changes of the tensioned integral structure, and to achieve multi-degree-of-freedom spatial movement with flexible operation capabilities.

[0005] To solve the above problems, the present invention adopts the following technical solution:

[0006] A continuous robotic arm based on a four-bar tensioning integral structure has a multi-segment continuous robotic arm structure. The robotic arm body includes: at least one drive system, at least one support platform, at least one continuous body mechanism, and at least one flexible connection mechanism.

[0007] At least one drive system is used to drive two-degree-of-freedom bending within the space of the at least one bending deformation segment and to drive elongation and contraction within the space of the at least one telescopic deformation segment;

[0008] The at least one support platform comprises a top-level motor fixing plate, a middle-level fixing rod, and a bottom-level fixing rod, wherein all drive systems are fixed to the top-level motor fixing plate, which is supported by the middle-level fixing rod and the bottom-level fixing rod, for fixing and moving the entire drive system and the continuous robotic arm;

[0009] The at least one continuum mechanism has at least one telescopic rod, a top layer unit, a middle layer unit and at least one bottom layer unit; the at least one top layer unit is fixed on the at least one driving mechanism and the at least one bottom layer unit; the continuum mechanism supports the rigidity of the continuum manipulator, the middle layer unit is connected with the top layer unit or the bottom layer unit through the telescopic rod, and stable rigidity support is provided for the structure when the continuum manipulator is folded, bent and twisted, so that the structure has greater stability and carrying capacity.

[0010] The at least one flexible connecting mechanism comprises at least one driving rope and at least one elastic element; the adjacent at least one continuum structure is separated from each other, and the adjacent at least one continuum structure is connected through the at least one flexible connecting mechanism and forms at least one bending deformation section and at least one telescopic deformation section.

[0011] In the rigid-flexible coupling continuum manipulator based on the four-bar tensegrity, the top layer unit and the bottom layer unit in the continuum structure are connected through the flexible connecting mechanism, the flexible connecting mechanism is respectively hinged with the top layer unit and the bottom layer unit, the flexible connecting member is arranged, the continuum structure has good flexibility in the shape change process, and greater freedom is maintained, the continuum structure can restore to the original state when the load is removed, and good stability is achieved.

[0012] In the rigid-flexible coupling continuum manipulator based on the four-bar tensegrity, the top layer unit and the top layer unit, and the bottom layer and the bottom layer unit in the continuum structure are fixedly connected with each other, and the top layer unit and the bottom layer unit in the continuum structure are annular structures, the top layer unit and the bottom layer unit are connected by the flexible connecting mechanism, and the top layer unit is fixedly connected, so that the space utilization rate of the continuum manipulator structure is higher, when the manipulator is elongated or contracted, the top layer unit and the next top layer unit in the continuum structure are stably connected, the middle bottom layer unit is rotated to realize the elongation or contraction of the continuum structure in the axial direction, and the flexibility and the stability of the manipulator are improved.

[0013] In the rigid-flexible coupling continuum manipulator based on the four-bar tensegrity, the driving system comprises at least one driving motor, at least one controller, at least one rope winding disc and at least one rope winding shaft.

[0014] The at least one driving motor is fixed on the top motor fixing plate, is connected with the at least one controller, has a controller to control the forward rotation and reverse rotation of the motor and position control and speed control, is connected with the at least one rope winding shaft, and drives the rotation of the rope winding shaft to realize the winding and unwinding of the driving rope.

[0015] The at least one rope winding mechanism has at least one rope winding disc and at least one rope winding disc, which can ensure the winding and unwinding of the driving rope, so as to realize the rapid response of the movement of the manipulator.

[0016] The top layer unit and the bottom layer unit in the continuum structure are connected with the flexible connecting mechanism, and a through hole for placing the driving rope is arranged at the connecting position; at least one driving rope is wound on the rope winding shaft; the through hole for the driving rope is arranged at the connecting position of the top layer unit and the flexible connecting mechanism; the traction shaft pulls the driving rope to be tightened and released when rotating; the rope winding shaft is driven by the driving motor; one end of the driving rope is wound on the rope winding shaft to realize the tightening and release of the other end; the middle section of the driving rope passes through the through hole arranged on the top layer unit in the continuum structure; and the other end of the driving rope is fixedly connected with the through hole on the end top layer unit.

[0017] In the rigid-flexible coupling continuum mechanical arm based on the four-pole tensegrity, the support platform further comprises a top layer motor fixing plate, the driving motor and the rope winding shaft are fixed above the top layer motor fixing plate, and the driving rope passes through the through hole on the top layer motor fixing plate and is connected to the continuum structure.

[0018] The through hole through which the driving rope can pass is arranged on the top layer motor fixing plate.

[0019] In the rigid-flexible coupling continuum mechanical arm based on the four-pole tensegrity, the rigid connection between the top layer unit and the bottom layer unit in the continuum structure is based on the structural balance principle of the four-pole tensegrity unit, and a telescopic rod connection mode is adopted, wherein the top layer unit and the telescopic rod are connected in a spherical pair, the bottom layer unit and the telescopic rod are connected in a spherical pair, and the connection modes are connected in a spiral mode in turn and are staggered, so that the top layer unit and the bottom layer unit can realize axial contraction or release when the continuum structure is axially loaded, the continuum structure can realize axial folding or unfolding, and the continuum mechanical arm has better flexibility.

[0020] The telescopic rod in the continuum structure is connected with the top layer unit and the bottom layer unit in a two-end spherical pair connection mode, the telescopic rod structure is composed of at least one first connecting rod, at least one elastic compression spring and at least one second connecting rod. The first connecting rod is composed of a telescopic hole and a first connecting base, the second connecting rod is composed of a telescopic shaft and a second connecting base, the compression spring is fixedly connected with the first connecting base and the second connecting base in the connecting rod, and the telescopic shaft in the second connecting rod is connected with the telescopic hole in the first connecting rod in an interference fit.

[0021] The beneficial effects of the present application are that the space four-degree-of-freedom folding, bending and torsion movement can be carried out, the flexible movement of the continuous mechanical arm is realized, the continuous mechanical arm driving control system meets the requirements of structure movement control, and various movement control tasks in the space of the mechanical arm can be completed, meanwhile, the whole mechanical arm system has good mechanical properties and can meet the rigidity conditions corresponding to the task requirements. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced.

[0023] Figure 1 It is a front view of the overall structure of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0024] Figure 2 It is a schematic diagram of the overall structure of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0025] Figure 3 It is a schematic diagram of the unit joint of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0026] Figure 4 It is a top view of the unit joint of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0027] Figure 5 It is a front view of the unit joint of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0028] Figure 6 It is a front view of the multi-joint combination of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0029] Figure 7 It is a schematic diagram of the telescopic rod of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0030] Figure 8 It is a sectional view of the telescopic rod of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0031] Figure 9 It is a schematic diagram of the multi-joint combination of the rigid-flexible coupling continuous mechanical arm based on the four-bar tension whole structure of the present application.

[0032] Label:

[0033] 10. Driving system; 11. Controller, 12. Take-up reel, 13. Driving motor, 14. Take-up shaft; 111. First driving system, 112. First driving system, 113. First driving system, 114. First driving system;

[0034] 20. Support platform; 21. Top layer motor fixing plate, 22. Middle layer fixing rod, 23. Bottom layer fixing rod; 211. First fixing plate through hole, 212. Second fixing plate through hole, 213. Third fixing plate through hole, 214. Fourth fixing plate through hole;

[0035] 30. Continuum mechanism; 31. Telescopic rod, 32. Middle layer unit, 33. Bottom layer unit, 34. Top layer unit; 311. First spherical pair, 312. First connecting rod, 313. Second connecting rod, 314. Second spherical pair, 315. Elastic compression spring, 316. First fixed pair, 317. Second fixed pair; 331. First driving rope through hole, 332. Second driving rope through hole, 333. Third driving rope through hole, 334. Fourth driving rope through hole, 335. First elastic element hinge, 336. Second elastic element hinge, 337. First rod spherical pair, 338. First rod spherical pair;

[0036] 40. Flexible connection mechanism; 41. Driving rope, 42. Elastic element;

[0037] 50. First layer four-bar tension unit, 51. Second layer four-bar tension unit, 52. Third layer four-bar tension unit, 53. Fourth layer four-bar tension unit. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments will be described clearly and completely in combination with the accompanying drawings in the embodiments.

[0039] As Figure 1 , 2As shown, the present application based on four-pole tension integral structure of rigid-flexible coupling continuous mechanical arm contains three parts, respectively, the driving system 10, support platform 20, continuum mechanism 30 and flexible connection mechanism 40; the driving system 10 is used to drive the continuous mechanical arm folding and unfolding, bending and twisting; the support platform 20 is used to fix the top driving system 10, fix the first four-pole tension unit 50, and play the role of mechanical arm base fixation; the continuum mechanism 30 is used to connect the bottom unit 33 with the intermediate layer unit 32 and the top layer unit 34 through the telescopic rod 31; the flexible connection mechanism 40 contains driving telescopic 41 and elastic element 42, wherein the driving rope 41 is mainly caused by length change to cause structure form change, and the existence of the elastic element 42 will make the continuous mechanical arm keep the structure stable and the ability to restore the original state; the whole mechanical arm structure can complete multi-angle free motion in space, has good flexibility, the whole structure has good mechanical properties, can bear certain load at the end, and completes the end reaching task.

[0040] As shown in Figure 1 , 2 , the driving system 10 includes controller 11, rope winding disc 12, driving motor 13, rope winding shaft 14. The driving system 10 is modulated by the controller 11 and the driving signal of the driving motor 13 is input, the driving motor 13 is fixedly connected with the rope winding shaft 14, the driving motor 13 drives the rope winding shaft 14 to rotate forward or reverse, the driving rope 41 is fixed in the rope winding disc 12, the middle section is wound on the rope winding shaft 14, and the other end is fixed on the driving rope through hole of the bottom unit 33 of the last unit of the continuum mechanism 30. The forward or reverse rotation of the rope winding shaft 14 will drive the driving rope 41 to release or shrink, complete the folding and unfolding, bending or twisting of the continuum mechanism.

[0041] The driving system 10 is used for host computer input driving information and structure feedback information, drives the continuous mechanical arm to complete folding and unfolding, bending and twisting in space, end reaching in space and space obstacle avoidance task. According to the simulation and experiment of the tension integral continuous mechanical arm unit structure, the unit structure can realize itself foldable by 50%, the end can bear the tangential weight of 115% of itself, the end axial bearing capacity is more than 200% of itself, the unit bending angle is greater than 40°; the overall (ten units) bending angle is greater than 300°, has winding and grabbing capacity, and the end 180 degree conveying reaching capacity.

[0042] The support platform 20 is mainly composed of a top motor fixing plate 21, a middle layer fixing rod 22 and a bottom fixing rod 23, wherein all the driving systems 10 are fixed on the top motor fixing plate 21, the top motor fixing plate 21 is supported by the middle layer fixing rod 22 and the bottom fixing rod 23, and is used for fixing and moving the whole driving system and the continuous mechanical arm; wherein the driving motor in the top motor driving system 10 drives the winding shaft 14 to complete forward rotation and reverse rotation, so as to cause the length change of the driving rope 41, the top motor fixing plate 21 is provided with a through hole 211 matched with the driving rope 41, and is used for connecting the winding shaft 14 above and the continuum mechanism 30 below, so that flexible control of the driving system can be realized.

[0043] The continuum mechanism 30 has a telescopic rod 31, a middle layer single unit 32, a bottom unit 33 and a top unit 34; wherein the telescopic rod 31 is composed of a first spherical pair 311, a first connecting rod 312, a second connecting rod 313, a second spherical pair 314 and a compression spring 315; the telescopic rod 31 is used for connecting the middle layer single unit 32 and the top unit 34 or the bottom unit 33, the first spherical pair 311 is connected with the first spherical pair of the rod of the middle layer unit or the top unit, can complete large-angle fixed rotation change according to the change of the internal force of the structure, and guarantees the spatial flexible change of the continuum structure; the second spherical pair 312 is connected with the second spherical pair 338 of the rod of the middle layer unit 32; the first connecting rod 313 and the second connecting rod 312 are nested and connected, can realize axial movement, and the length is limited, the length of the circular shaft on the connecting rod is greater than that of the circular hole; the compression spring 315 is fixedly connected with the end of the circular shaft and the inner bottom surface of the circular hole, so that the telescopic rod has a good telescopic ratio and a corresponding good stiffness change; the existence of the compression spring 315 in the telescopic rod 31 can realize the contraction or release of the rod when the continuum mechanism is pulled or pressed, and the change range is 20% of the length of the telescopic rod.

[0044] In the continuum structure 30, when the driving rope 41 between the top unit 33 or the bottom unit 34 is contracted, due to the existence of the middle layer unit 31 and the connection mode of the two telescopic rods, the top unit 33 and the bottom unit 34 can realize axial folding, at this time the elastic element 42 will be compressed and has a certain supporting capacity, and the structural stiffness will increase; when the driving rope 41 is released, due to the release of the internal force of the elastic element 42, the whole continuum mechanism 30 will gradually unfold, the structural stiffness decreases to the initial equilibrium state, has a good variable interval of structural stiffness, can appropriately contract or release the driving rope according to the size of the end load, maintains the adaptation of the structural stiffness to the end load, and completes the task requirement of variable stiffness.

[0045] The flexible connecting mechanism 40 comprises two parts, a driving rope 41 and an elastic element 42; wherein the driving rope 41 can be provided with four or eight according to whether segmented driving, and the elastic element 42 is used for connecting the intermediate layer unit 31 and the bottom layer unit 34 or the top layer unit 33 in the continuum mechanism 30, one end of the elastic element 42 is connected with the elastic element first hinge 335 in the intermediate layer unit 31 in a hinge connection mode, and can rotate in any direction in the plane from the hinge point; the other end of the elastic element 42 is connected with the elastic element second hinge 336 of the bottom layer or the top layer unit 33 in a hinge connection mode, so as to realize the two force balance connection mode of the elastic element; according to the description of the continuum mechanism 30, the elastic element is mainly used for balancing the internal force stress of the continuum structure, and maintaining the structural stability when the continuum mechanical arm is folded or unfolded; each layer of the continuum structure is composed of eight elastic elements, and the existence of the plurality of elastic elements makes each elastic element maintain good mechanical properties when the structure is folded and unfolded.

[0046] The driving rope 41 in the flexible connecting structure 40 is firstly fixed in the rope winding disc 12 for winding storage of the driving rope retracted; secondly, the driving of the driving rope is wound by the rope winding shaft 14, and one end of the driving rope is driven to rotate forward and reverse by the driving motor; four or eight driving ropes pass through the corresponding through holes on the top motor fixing plate to connect the through holes of each bottom unit or top unit, and are fixedly connected with the through holes on the bottom unit of the optimal four-bar tensioning unit; therefore, when the driving motor drives a section of rope to change, each section of the continuum unit will complete the corresponding folding and unfolding and bending change; in multi-section control, the driving ropes of the upper half section are increased to eight, and the driving ropes of the lower half section are still four; when the S-bend needs to be completed, the eight driving ropes of the structure respectively drive the upper half section of the continuum mechanical arm to complete the upper half arc of the S-bend, and the lower half section of the mechanical arm to complete the lower half arc of the S-bend, so as to complete the bending deformation.

[0047] In the application, the continuum mechanical arm body has five or more tensioning units, only five tensioning units are shown in the following picture, has four degrees of freedom of space folding and unfolding, bending and twisting, and has the characteristics of structural rigidity, carrying capacity and compliance, the radial dimension can be less than 60mm, and the axial dimension can be greater than 80cm.

[0048] In the description of the specification, the description of the terms "the embodiment", "some embodiments" or "specific examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate way in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples, without contradiction.

[0049] Although the above has shown the embodiments of the present application, the protection scope of the present application is not limited thereto, and any changes and replacements not thought through creative labor should be included in the protection scope of the present application, unless explicitly stated.

Claims

1. A rigid-flexible coupled serial manipulator based on four-bar tensegrity structure, characterized in that, The rigid-flexible coupling continuous type mechanical arm comprises: At least one drive system, having at least one drive motor, at least one controller, at least one winding reel and at least one winding shaft, the at least one drive system being fixedly arranged on the at least one top motor fixing plate; At least one support platform, having at least one top motor fixing plate, at least one middle layer fixing rod and at least one bottom fixing rod, providing a base and support for the entire drive system and the continuous type mechanical arm; At least one continuum mechanism, composed of at least one telescopic rod, at least one middle layer unit, at least one top layer unit and a bottom layer unit, the continuum mechanism being evolved from a four-bar tensile whole structure, capable of providing sufficient structural stiffness, the overall structural stiffness being within a certain range of change when the structural morphology changes, a stiffness model of the structure being established, the corresponding stiffness of the structural morphology being obtained according to the task requirements, thereby realizing the function of variable stiffness; At least one flexible connection mechanism, comprising at least one drive rope and at least one elastic element, used for driving the continuous type mechanical arm to complete folding and unfolding, bending and twisting movements, and providing internal stress for restoring the structure to the original state; The middle layer unit is connected with the top layer unit and the bottom layer unit in turn by four-bar telescopic rods in spiral circumferential arrangement, and the telescopic rods are connected with the middle layer unit, the top layer unit and the bottom layer unit in a spherical pair connection mode; The telescopic rod comprises at least one first connecting rod, at least one second connecting rod and at least one compression spring, the first connecting rod and the second connecting rod are connected by a circular shaft and a circular hole, and the compression spring is fixedly connected with the bottom end of the circular shaft in the first connecting rod and the bottom end of the circular hole of the second connecting rod, so that the first connecting rod and the second connecting rod can change their length by 20% through the compression spring; The drive rope passes through the winding reel, the winding shaft and the through hole of the top motor fixing plate, and then passes through the top layer unit and the bottom layer unit in the continuum mechanism, and finally passes through the through hole of the bottom layer unit in the last layer of the continuum mechanism, so as to ensure the continuous deformation of the continuous type mechanical arm; One end of the elastic element is connected with the elastic element first hinge in the middle layer unit in a hinge connection mode, which can rotate in any direction in the plane from the hinge point, and the other end of the elastic element is connected with the elastic element second hinge of the bottom layer or the top layer unit in a hinge connection mode, thereby realizing the two-force balanced connection mode of the elastic element; each continuum mechanism is connected by eight elastic elements, and the existence of the elastic elements provides a certain stiffness for the continuous type mechanical arm, and also provides a certain flexibility and stiffness recovery capability.

2. The rigid-flexible coupled serial manipulator based on four-bar tensegrity structure according to claim 1, wherein, The drive motor drives the winding shaft to rotate forward or reverse, one end of the drive rope is fixed in the winding reel, the middle section is wound on the winding shaft, and the other end is fixed on the drive rope through hole of the bottom layer unit of the last layer unit of the continuum mechanism; The forward or reverse rotation of the winding shaft drives the drive rope to release or contract, and completes the folding and unfolding, bending or twisting of the continuum mechanism.

3. The rigid-flexible coupled serial manipulator based on four-bar tensegrity structure according to claim 1, wherein, The driving system and the continuum mechanism are both assembled on the at least one top motor fixing plate; wherein the at least one top motor fixing plate is provided with at least one through hole matched with the driving rope.

4. The rigid-flexible coupled serial manipulator based on four-bar tensegrity structure according to claim 1, wherein, The continuum mechanism is a unit of a continuum mechanical arm structure, the continuum mechanical arm is composed of five or more than five above-mentioned continuum mechanisms, and is fixed on the top motor fixing plate and sequentially connected to the mechanical arm end.

5. The rigid-flexible coupled serial manipulator based on four-bar tensegrity structure according to claim 1, wherein, The number of the driving ropes is at least four, which are respectively controlled by four driving systems, so that the continuum mechanical arm can be controlled to bend in any direction in space.

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