Rigidity-adjustable flexible continuum mechanical arm, rigidity adjusting device and rigidity adjusting method

Abstract

The invention relates to a rigidity-adjustable flexible continuum mechanical arm, a rigidity adjusting device and a rigidity adjusting method.The technical problem of how to improve the load capacity of the flexible continuum mechanical arm is solved, the rigidity-adjustable flexible continuum mechanical arm comprises a supporting base, a spiral body, a first driving rod, a second driving rod, a third driving rod and three sets of hole channels, each group of hole channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, the first driving rod penetrates through each clamping device of the first group of hole channels, the second driving rod penetrates through each clamping device of the second group of hole channels, and the third driving rod penetrates through each clamping device of the third group of hole channels. The method can be applied to the technical field of solar wing in-orbit auxiliary unlocking.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible continuum mechanical arms, and in particular to a flexible continuum mechanical arm with adjustable stiffness, a stiffness adjusting device and a stiffness adjusting method. Background Art

[0002] Flexible continuum manipulators have the characteristics of high compliance and flexibility, and their applications are becoming more and more extensive. The high compliance of flexible continuum manipulators leads to their low load capacity, which restricts their application in certain scenarios.

[0003] In order to improve the load capacity of the flexible continuum manipulator and apply it to certain scenarios (such as the unlocking of solar panels in orbit), the flexible continuum manipulator must be given the ability to change stiffness. During the long-term operation of the satellite in orbit, the solar panels are mainly used to provide power. The flexible continuum manipulator drives the execution end to unlock the solar panels so that the solar panels can be deployed. During this process, the stiffness needs to be changed to improve the load capacity.

[0004] At present, the conventional variable stiffness methods mainly include four categories: blocking, phase change, antagonism and variable structure.

[0005] The principle of blocking to change stiffness is to change the overall stiffness by changing the friction between a large number of identical tiny units arranged in an orderly manner. Blocking to change stiffness is mainly divided into three methods: particle blocking, fiber blocking and layer blocking. The particle blocking method can refer to the invention patent application with publication number CN114516070A. The methods for changing friction include vacuum negative pressure method, electrostatic adsorption method, etc. Blocking to change stiffness has the advantages of real-time and continuous, but it performs poorly in repeatability and structural compactness. The vacuum negative pressure method required for blocking is not suitable for the track vacuum environment, and the electrostatic adsorption method does not meet the requirements of engineering reliability. On the other hand, since the total volume of the blocking unit is constant, the amount of expansion and contraction allowed is very small, so the flexibility of the flexible continuum robot arm cannot be improved, and it is not very suitable for a retractable flexible continuum robot arm.

[0006] Phase change stiffness adjustment is to adjust the stiffness of the robot arm by using the change of the modulus of the phase change material (solid-liquid phase change, solid-solid phase change of the material). For example, the solid-liquid phase change of low melting point alloys can achieve large-rate stiffness regulation, and the glass-rubber phase change of materials such as shape memory polymers (SMP) can achieve continuous and large-rate stiffness adjustment. However, the index E of low melting point alloys and SMP is 3 / ρ (this index can measure the contribution of unit mass of material to the bending stiffness of the structure, where E is the Young's modulus of the material and ρ is the material density) is lower than that of common metals such as steel and aluminum, and does not have a high modulus-to-density ratio, so it is not suitable for lightweight long arms.

[0007] The basic principle of antagonistic variable stiffness is to make the drive degree of freedom greater than the system's degree of freedom of movement, forming an over-constraint, thereby increasing the stiffness of the system. The antagonistic variable stiffness method for flexible robotic arms is usually implemented using pneumatics. This is because gas expansion can form the tension required for antagonism, while other flexible drives are not easy to form large tensions. Please refer to the invention patent application with application publication number CN117207165A. Antagonistic variable stiffness can achieve continuous and stable stiffness adjustment and has good passive compliance adaptability; but the pneumatic method required is not suitable for operation in an on-orbit vacuum environment.

[0008] It can be seen that in the prior art, the variable stiffness methods of the flexible continuum manipulator with variable stiffness capability all have limitations. Summary of the invention

[0009] The present application aims to solve the technical problem of how to improve the load capacity of a flexible continuum robot arm, and to provide a flexible continuum robot arm with adjustable stiffness, a stiffness adjustment device and a stiffness adjustment method.

[0010] In a first aspect of the present disclosure, there is provided a flexible continuum mechanical arm with adjustable stiffness, comprising a support base, a spiral body, a first drive rod, a second drive rod, a third drive rod and three groups of channels, wherein the rear end of the spiral body is fixedly connected to the support base, and each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, wherein the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, and the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body. The three groups of holes are evenly distributed in the radial circumferential direction; the first driving rod passes through each clamping device of the first group of holes, and the end of the first driving rod is positioned at the front end of the spiral body; the second driving rod passes through each clamping device of the second group of holes, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of holes, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base;

[0011] The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve. The clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve;

[0012] The positioning sleeve of the clamping device is fixedly connected to the periphery of the spiral body;

[0013] The cross section of the first driving rod is square, the first driving rod passes through the square hole of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the first driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively;

[0014] The cross section of the second driving rod is square, and the second driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the second driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively;

[0015] The third driving rod has a square cross section and passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four faces of the third driving rod correspond to the four inner extrusion planes at the rear of the elastic sleeve.

[0016] A second aspect of the present disclosure provides a method for adjusting the stiffness of the flexible continuum mechanical arm using the above-mentioned adjustable stiffness, comprising the following steps:

[0017] One, two or three of the three driving rods are rotated, the clamping nut is translated toward the positioning sleeve, and the elastic sleeve clamps the corresponding driving rod.

[0018] According to a third aspect of the present disclosure, a stiffness adjustment device is provided, comprising a driving rod and a clamping device, wherein the clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner side extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve;

[0019] The cross section of the driving rod is square. The driving rod passes through the positioning sleeve, the elastic sleeve and the square hole of the clamping nut of the clamping device. The four faces of the driving rod correspond to the four inner extrusion planes at the rear of the elastic sleeve.

[0020] A fourth aspect of the present disclosure provides a flexible continuum robot arm system with adjustable stiffness, comprising a flexible continuum robot arm with adjustable stiffness and a driving device;

[0021] The flexible continuum mechanical arm with adjustable stiffness comprises a support base, a spiral body, a first driving rod, a second driving rod, a third driving rod and three groups of channels, the rear end of the spiral body is fixedly connected to the support base, each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body, and the three groups of channels are evenly distributed in the radial circumferential direction; the first driving rod passes through each clamping device of the first group of channels, and the end of the first driving rod is positioned at the front end of the spiral body; the second driving rod passes through each clamping device of the second group of channels, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of channels, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base;

[0022] The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve. The clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve;

[0023] The cross section of the first driving rod is square, the first driving rod passes through the square hole of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the first driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively;

[0024] The cross section of the second driving rod is square, and the second driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the second driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively;

[0025] The third driving rod has a square cross section, and passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the third driving rod correspond to the four inner extrusion planes of the rear of the elastic sleeve respectively;

[0026] The driving device comprises three sets of rotation and translation driving mechanisms, and the three sets of rotation and translation driving mechanisms are used to respectively rotate and translate the three driving rods.

[0027] A fifth aspect of the present disclosure provides a flexible continuum robot arm system with adjustable stiffness, comprising a flexible continuum robot arm with adjustable stiffness and a driving device;

[0028] The flexible continuum mechanical arm with adjustable stiffness comprises a support base, a spiral body, a first driving rod, a second driving rod, a third driving rod and three groups of channels, the rear end of the spiral body is fixedly connected to the support base, each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body, and the three groups of channels are evenly distributed in the radial circumferential direction; the first driving rod passes through each clamping device of the first group of channels, and the end of the first driving rod is positioned at the front end of the spiral body; the second driving rod passes through each clamping device of the second group of channels, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of channels, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base;

[0029] The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve. The clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve;

[0030] The cross section of the first driving rod is square, the first driving rod passes through the square hole of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the first driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively;

[0031] The cross section of the second driving rod is square, and the second driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the second driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively;

[0032] The third driving rod has a square cross section, and passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the third driving rod correspond to the four inner extrusion planes of the rear of the elastic sleeve respectively;

[0033] The driving device includes a rear support plate, a front support plate, a mechanical arm support cylinder, a first rotation drive motor, a second rotation drive motor, a third rotation drive motor, a first screw motor, a second screw motor, a third screw motor, a first ball spline pair, a first connecting seat, a first driven synchronous pulley, a first active synchronous pulley, a first rotating shaft, a first nut seat, a first translation plate, a first bearing seat, a first synchronous belt, a second ball spline pair, a second connecting seat, a second driven synchronous pulley, a second active synchronous pulley, a second synchronous belt, a second rotating shaft, a second nut seat, a second translation plate, a second bearing seat, a third ball spline pair, a third connecting seat, a third driven synchronous pulley, a third active synchronous pulley, a third synchronous belt, a third rotating shaft, a third nut seat, a third translation plate and a third bearing seat. The mechanical arm support cylinder is fixedly connected to the front support plate, and the first rotation drive motor, the second rotation drive motor, and the third rotation The driving motor, the first screw motor, the second screw motor and the third screw motor are all fixedly connected to the front support plate, the first connecting seat is fixedly connected to the front support plate, the first ball spline pair includes a spline shaft and a spline outer cylinder, the spline outer cylinder is rotatably connected to the first connecting seat through a bearing, the spline shaft passes through the front support plate, the front end of the spline shaft is located in the mechanical arm support cylinder, the first driven synchronous pulley is fixedly connected to the spline outer cylinder, the first rotating shaft is connected to the output shaft of the first rotation drive motor, the first active synchronous pulley is fixedly connected to the first rotating shaft, the first synchronous belt is connected between the first active synchronous pulley and the first driven synchronous pulley, the first screw motor is provided with a screw, the end of the screw is rotatably connected to the rear support plate through a bearing, the first nut seat is connected to the screw, one end of the first translation plate is fixedly connected to the first nut seat, the first bearing seat is connected to the other end of the first translation plate, and the rear end of the spline shaft is connected to the first bearing seat;

[0034] The second connecting seat is fixedly connected to the front support plate, the second ball spline pair includes a spline shaft and a spline outer cylinder, the spline outer cylinder of the second ball spline pair is rotatably connected to the second connecting seat through a bearing, the spline shaft of the second ball spline pair passes through the front support plate, the front end of the spline shaft of the second ball spline pair is located in the mechanical arm support cylinder, the second driven synchronous pulley is fixedly connected to the spline outer cylinder of the second ball spline pair, the second rotating shaft is connected to the output shaft of the second rotation drive motor, the second active synchronous pulley is fixedly connected to the second rotating shaft, the second synchronous belt is connected between the second active synchronous pulley and the second driven synchronous pulley, the second screw motor is provided with a screw, the end of the screw of the second screw motor is rotatably connected to the rear support plate through a bearing, the second nut seat is connected to the screw of the second screw motor, one end of the second translation plate is fixedly connected to the second nut seat, the second bearing seat is connected to the other end of the second translation plate, and the rear end of the spline shaft of the second ball spline pair is connected to the second bearing seat;

[0035] The third connecting seat is fixedly connected to the front support plate, the third ball spline pair includes a spline shaft and a spline outer cylinder, the spline outer cylinder of the third ball spline pair is rotatably connected to the third connecting seat through a bearing, the spline shaft of the third ball spline pair passes through the front support plate, the front end of the spline shaft of the third ball spline pair is located in the mechanical arm support cylinder, the third driven synchronous pulley is fixedly connected to the spline outer cylinder of the third ball spline pair, the third rotating shaft is connected to the output shaft of the third rotation drive motor, the third active synchronous pulley is connected to the third rotating shaft, the third synchronous belt is connected between the third active synchronous pulley and the third driven synchronous pulley, the third screw motor is provided with a screw, the end of the screw of the third screw motor is rotatably connected to the rear support plate through a bearing, the third nut seat is connected to the screw, one end of the third translation plate is fixedly connected to the third nut seat, the third bearing seat is connected to the other end of the third translation plate, and the rear end of the spline shaft of the third ball spline pair is connected to the third bearing seat;

[0036] The spline shafts of the first ball spline pair, the spline shafts of the second ball spline pair, and the spline shafts of the third ball spline pair are evenly distributed in the circumferential direction;

[0037] The support base of the flexible continuum robotic arm with adjustable stiffness is fixedly connected to the robotic arm support tube, the rear end of the first driving rod is connected to the front end of the spline shaft of the first ball spline pair, the rear end of the second driving rod is connected to the front end of the spline shaft of the second ball spline pair, and the rear end of the third driving rod is connected to the front end of the spline shaft of the third ball spline pair.

[0038] In a sixth aspect of the present disclosure, a flexible continuum mechanical arm with adjustable stiffness is provided, comprising a support base, a spiral body, a first drive rod, a second drive rod, a third drive rod and three groups of channels, wherein the rear end of the spiral body is fixedly connected to the support base, and each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, wherein the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, and the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body. The three groups of holes are evenly distributed in the radial circumferential direction; the first driving rod passes through each clamping device of the first group of holes, and the end of the first driving rod is positioned at the front end of the spiral body; the second driving rod passes through each clamping device of the second group of holes, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of holes, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base;

[0039] The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve. The clamping nut is provided with a hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with a plurality of inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve;

[0040] The positioning sleeve of the clamping device is fixedly connected to the periphery of the spiral body;

[0041] The first driving rod passes through the positioning sleeve, the elastic sleeve and the hole of the clamping nut of the corresponding clamping device, the shape of the cross section of the first driving rod is consistent with the shape of the hole of the clamping nut, and the multiple faces of the first driving rod respectively correspond to the multiple inner extrusion planes of the rear part of the elastic sleeve;

[0042] The second driving rod passes through the positioning sleeve, the elastic sleeve and the hole of the clamping nut of the corresponding clamping device, the shape of the cross section of the second driving rod is consistent with the shape of the hole of the clamping nut, and the multiple faces of the second driving rod correspond to the multiple inner extrusion planes of the rear part of the elastic sleeve respectively;

[0043] The third driving rod passes through the positioning sleeve, elastic sleeve and the hole of the clamping nut of the corresponding clamping device. The shape of the cross section of the third driving rod is consistent with the shape of the hole of the clamping nut. The multiple faces of the third driving rod correspond to the multiple inner extrusion planes at the rear of the elastic sleeve.

[0044] Preferably, the hole of the clamping nut is a triangular hole, and the rear portion of the elastic sleeve is provided with three inner extrusion planes;

[0045] The cross section of the first driving rod is in the shape of a triangle, and the three faces of the first driving rod correspond to the three inner extrusion planes of the rear portion of the corresponding elastic sleeve respectively;

[0046] The cross section of the second driving rod is in the shape of a triangle, and the three faces of the second driving rod correspond to the three inner extrusion planes of the rear portion of the corresponding elastic sleeve respectively;

[0047] The cross section of the third driving rod is in the shape of a triangle, and the three faces of the third driving rod correspond to the three inner extrusion planes of the rear portion of the corresponding elastic sleeve respectively.

[0048] According to a seventh aspect of the present disclosure, a stiffness adjustment device is provided, comprising a driving rod and a clamping device, wherein the clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with a plurality of inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve;

[0049] The driving rod passes through the positioning sleeve, elastic sleeve and clamping nut hole of the clamping device. The shape of the cross section of the driving rod is consistent with the shape of the clamping nut hole. The multiple faces of the driving rod correspond to the multiple inner extrusion planes at the rear of the elastic sleeve.

[0050] Preferably, the hole of the clamping nut is a triangular hole, and the rear of the elastic sleeve is provided with three inner extrusion planes; the cross-section of the driving rod is triangular, and the three faces of the driving rod correspond to the three inner extrusion planes of the rear of the elastic sleeve respectively.

[0051] The beneficial effects of the present disclosure are that the stiffness of the flexible continuum robotic arm is adjustable, thereby improving the load capacity of the flexible continuum robotic arm; the stiffness adjustment accuracy is very high, and the stiffness adjustment is more controllable.

[0052] The variable stiffness of the structure is achieved through the movement of the mechanism, which is independent of external conditions such as air pressure. It can achieve lightweight and long arms.

[0053] The application scenarios of the flexible continuum robotic arm have been expanded and the performance of the flexible continuum robotic arm has been improved.

[0054] The present invention has a wide range of application scenarios and is not limited to the field of solving the technical field of in-orbit auxiliary unlocking of solar wings. It can also be applied to other technical fields such as the field of minimally invasive surgery.

[0055] Further features and aspects of the present disclosure will be clearly described in the following description of specific embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is an axonometric view of a flexible continuum manipulator system with adjustable stiffness;

[0057] Figure 2 yes Figure 1 A front view of the flexible continuum manipulator system with adjustable stiffness is shown;

[0058] Figure 3 is a schematic diagram of the structure of the driving device;

[0059] Figure 4 yes Figure 3 A front view of the structure shown;

[0060] Figure 5 yes Figure 4 a bottom view of the structure shown;

[0061] Figure 6 It is an axonometric view of a flexible continuum manipulator with adjustable stiffness;

[0062] Figure 7 yes Figure 6 A partial enlarged view of the P in the middle;

[0063] Figure 8 is a schematic diagram of the structure of the clamping device;

[0064] Fig. 9 yes Figure 8 Cross-section view in the AA direction;

[0065] Fig.10 yes Figure 8 An exploded view of the clamping device shown;

[0066] Fig.11 is an axonometric view of the clamping nut;

[0067] Fig.12 It is an axonometric view of the elastic sleeve;

[0068] Fig.13 It is an axonometric view of the elastic sleeve;

[0069] Fig.14 It is an axonometric view of the elastic sleeve;

[0070] Fig.15 is a side view of the clamping nut;

[0071] Fig.16 is a cross-sectional view of the clamping nut;

[0072] Fig.17 is a schematic diagram of the structure in which the first driving rod passes through the clamping device;

[0073] Fig.18 yes Fig.17 Cross-section along the middle BB direction;

[0074] Fig.19 yes Fig.18 , a structural diagram of an elastic sleeve sleeved on a first driving rod;

[0075] Fig. 20 yes Fig.19 A front view of the structure shown;

[0076] Fig.21 yes Fig. 20 a right side view of the structure shown;

[0077] Fig. 22 yes Fig. 20 Left side view of the structure shown.

[0078] Explanation of symbols in the figure:

[0079] 100. Flexible continuum mechanical arm with adjustable stiffness, 101. Screw body, 102. Clamping device, 102-1. Clamping nut, 102-1-1. Square hole, 102-1-2. Internal thread, 102-1-3. Conical extrusion inner side, 102-2. Positioning sleeve, 102-2-1. External thread, 102-2-2. Conical inner side, 102-3. Elastic sleeve, 102-3-1. Front conical outer side, 102-3-2. Separation groove, 102-3-3. Rear conical outer side surface, 102-3-4. inner extrusion plane, 103. first drive rod, 104. second drive rod, 105. third drive rod, 106. support base; 200. drive device, 201. rear support plate, 202. front support plate, 203. first rotary drive motor, 204. second rotary drive motor, 205. third rotary drive motor, 206. first screw motor, 206-1. screw, 207. second screw motor, 207-1. screw, 208 . The third screw motor, 208-1. Screw, 209. The first ball spline pair, 209-1. Spline shaft, 209-2. Spline outer cylinder, 210. The first connecting seat, 211. The first driven synchronous pulley, 212. The first active synchronous pulley, 213. The first rotating shaft, 214. The first nut seat, 215. The first translation plate, 216. The first bearing seat, 217. The first synchronous belt, 218. The mechanical arm support tube, 219. The second ball spline pair, 220. The second connecting seat, 22 1. The second driven synchronous pulley, 222. The second active synchronous pulley, 223. The second synchronous belt, 224. The second rotating shaft, 225. The second nut seat, 226. The second translation plate, 227. The second bearing seat, 228. The third ball spline pair, 229. The third connecting seat, 230. The third driven synchronous pulley, 231. The third active synchronous pulley, 232. The third synchronous belt, 233. The third rotating shaft, 234. The third nut seat, 235. The third translation plate, 236. The third bearing seat. DETAILED DESCRIPTION

[0080] The present invention will be further described in detail below with reference to the accompanying drawings by way of specific embodiments.

[0081] The specific embodiments described below are only preferred implementations of the present application, and the protection scope of the present application is not limited thereto. For those skilled in the art, some changes or variations can be made based on or according to the principles, concepts, and spirits of the present application, and the technical solutions formed by these changes or variations should be included in the protection scope of the present application.

[0082] like Figure 1 and 2 As shown, the flexible continuum robot system with adjustable stiffness includes a flexible continuum robot 100 with adjustable stiffness and a driving device 200. The driving device 200 is used to move the flexible continuum robot 100 with adjustable stiffness and can also adjust its stiffness.

[0083] like Figure 3-5As shown, the driving device 200 includes a rear support plate 201, a front support plate 202, a robot arm support cylinder 218, a first rotation drive motor 203, a second rotation drive motor 204, a third rotation drive motor 205, a first screw motor 206, a second screw motor 207, a third screw motor 208, a first ball spline pair 209, a first connecting seat 210, a first driven synchronous pulley 211, a first active synchronous pulley 212, a first rotating shaft 213, a first nut seat 214, a first translation plate 215, a first bearing seat 216, a first synchronous belt 217, a second ball spline pair 219, a second connecting seat 220, a second driven synchronous pulley 221, and a second active synchronous pulley 222 , the second synchronous belt 223, the second rotating shaft 224, the second nut seat 225, the second translation plate 226, the second bearing seat 227, the third ball spline pair 228, the third connecting seat 229, the third driven synchronous pulley 230, the third active synchronous pulley 231, the third synchronous belt 232, the third rotating shaft 233, the third nut seat 234, the third translation plate 235, the third bearing seat 236, the robot arm support tube 218 is fixedly connected to the front support plate 202, the first rotation drive motor 203, the second rotation drive motor 204, the third rotation drive motor 205, the first screw motor 206, the second screw motor 207 and the third screw motor 208 are all fixedly installed on the front support plate 202. The first connecting seat 210 is fixedly connected to the front support plate 202, the first ball spline pair 209 includes a spline shaft 209-1 and a spline outer cylinder 209-2, the spline outer cylinder 209-2 is rotatably connected to the first connecting seat 210 through a bearing, the spline shaft 209-1 passes through the front support plate 202, and the front end of the spline shaft 209-1 is located in the robot arm support cylinder 218, the first driven synchronous pulley 211 is fixedly connected to the spline outer cylinder 209-2, the first rotating shaft 213 is connected to the output shaft of the first rotary drive motor 203, the first active synchronous pulley 212 is fixedly connected to the first rotating shaft 213, and the first synchronous belt 2 17 is connected between the first active synchronous pulley 212 and the first driven synchronous pulley 211, the first screw motor 206 is provided with a screw 206-1, the end of the screw 206-1 is rotatably connected to the rear support plate 201 through a bearing, the first nut seat 214 is connected to the screw 206-1, one end of the first translation plate 215 is fixedly connected to the first nut seat 214, the first bearing seat 216 is connected to the other end of the first translation plate 215, the rear end of the spline shaft 209-1 is connected to the bearing in the first bearing seat 216, when the first screw motor 206 is working, the first translation plate 215 moves forward or backward ( Figure 4When the first rotary drive motor 203 drives the first rotating shaft 213 to rotate, the first active synchronous pulley 212, the first synchronous belt 217, and the first driven synchronous pulley 211 drive the spline outer cylinder 209-2 to rotate, and the spline outer cylinder 209-2 drives the spline shaft 209-1 to rotate, thereby realizing the rotational movement of the spline shaft 209-1.

[0084] The second connecting seat 220 is fixedly connected to the front support plate 202, the second ball spline pair 219 includes a spline shaft and a spline outer cylinder, the spline outer cylinder is rotatably connected to the second connecting seat 220 through a bearing, the spline shaft passes through the front support plate 202, the front end of the spline shaft is located in the mechanical arm support cylinder 218, the second driven synchronous pulley 221 is fixedly connected to the spline outer cylinder of the second ball spline pair 219, the second rotating shaft 224 is connected to the output shaft of the second rotary drive motor 204, and the second active synchronous pulley 222 is fixedly connected to the second rotating shaft 224. The second synchronous belt 223 is connected between the second active synchronous pulley 222 and the second driven synchronous pulley 221, the second screw motor 207 is provided with a screw 207-1, the end of the screw 207-1 is rotatably connected to the rear support plate 201 through a bearing, the second nut seat 225 is connected to the screw 207-1, one end of the second translation plate 226 is fixedly connected to the second nut seat 225, the second bearing seat 227 is connected to the other end of the second translation plate 226, and the rear end of the spline shaft of the second ball spline pair 219 is connected to the second bearing seat 227. The spline shaft of the second ball spline pair 219 can rotate and translate.

[0085] The third connecting seat 229 is fixedly connected to the front support plate 202, the third ball spline pair 228 includes a spline shaft and a spline outer cylinder, the spline outer cylinder is rotatably connected to the third connecting seat 229 through a bearing, the spline shaft passes through the front support plate 202, and the front end of the spline shaft is located in the mechanical arm support cylinder 218, the third driven synchronous pulley 230 is fixedly connected to the spline outer cylinder of the third ball spline pair 228, the third rotating shaft 233 is connected to the output shaft of the third rotary drive motor 205, and the third active synchronous pulley 231 is connected to the third rotating shaft 233. The third synchronous belt 232 is connected between the third active synchronous pulley 231 and the third driven synchronous pulley 230, the third screw motor 208 is provided with a screw 208-1, the end of the screw 208-1 is rotatably connected to the rear support plate 201 through a bearing, the third nut seat 234 is connected to the screw 208-1, one end of the third translation plate 235 is fixedly connected to the third nut seat 234, the third bearing seat 236 is connected to the other end of the third translation plate 235, and the rear end of the spline shaft of the third ball spline pair 228 is connected to the third bearing seat 236. The spline shaft of the third ball spline pair 228 can rotate and translate.

[0086] The spline shaft 209 - 1 of the first ball spline pair 209 , the spline shaft of the second ball spline pair 219 , and the spline shaft of the third ball spline pair 228 are evenly distributed along the circumferential direction.

[0087] It can be seen that the entire driving device 200 is provided with three sets of rotational translational driving mechanisms, and the three sets of rotational translational driving mechanisms are respectively used to drive the three driving rods of the flexible continuum mechanical arm 100 with adjustable stiffness.

[0088] like Figure 6As shown, the flexible continuum mechanical arm 100 with adjustable stiffness includes a support base 106, a spiral body 101, a first drive rod 103, a second drive rod 104, a third drive rod 105 and three groups of channels. The rear end of the spiral body 101 is fixedly connected to the support base 106, and each group of channels is composed of a plurality of clamping devices 102 fixedly connected to the periphery of the spiral body 101. The plurality of clamping devices 102 constituting the first group of channels are distributed along the length direction of the spiral body 101, the plurality of clamping devices 102 constituting the second group of channels are distributed along the length direction of the spiral body 101, and the plurality of clamping devices 102 constituting the third group of channels are distributed along the length direction of the spiral body 101. The three groups of channels are evenly distributed in the radial circumferential direction (that is, the angle between two adjacent groups of channels is 120°). The first drive rod 103 passes through each clamping device of the first group of channels, and the end of the first drive rod 103 is positioned at the front end of the spiral body 101. The second driving rod 104 passes through each clamping device of the second set of holes, and the end of the second driving rod 104 is positioned at the front end of the spiral body 101. The third driving rod 105 passes through each clamping device of the third set of holes, and the end of the third driving rod 105 is positioned at the front end of the spiral body 101. The rear end of the first driving rod 103 passes through the support base 106, the rear end of the second driving rod 104 passes through the support base 106, and the rear end of the third driving rod 105 passes through the support base 106.

[0089] The spiral body 101 is a spiral structure with a wide range of telescopic and bending deformation capabilities. Pulling the three drive rods under the action of external force can realize the omnidirectional bending of the spiral body 101. For example, pulling the first drive rod 103 while releasing the second drive rod 104 and the third drive rod 105 can make the spiral body 101 bend in the direction of the first drive rod 103. When the spiral body 101 is in a straight state, pulling the first drive rod 103, the second drive rod 104 and the third drive rod 105 at the same time can shrink the spiral body 101, and the length of the spiral body 101 becomes shorter. When the spiral body 101 is in a contracted state, releasing the first drive rod 103, the second drive rod 104 and the third drive rod 105 at the same time can stretch the spiral body 101, and the length of the spiral body 101 becomes longer. It can be seen that by operating the three drive rods at the same time and moving the three drive rods along the axis direction of the spiral body 101, the telescopic movement of the entire flexible continuum robot arm can be realized.

[0090] like Figure 8-10 As shown, the clamping device 102 includes a clamping nut 102-1, a positioning sleeve 102-2, and an elastic sleeve 102-3. Fig.11 , 16 As shown in Figures 17 and 17, the clamping nut 102-1 is provided with a square hole 102-1-1, an internal thread 102-1-2, and a conical extruded inner side surface 102-1-3. Figure 8 ,9 As shown in FIG. 10 , the positioning sleeve 102-2 is provided with an external thread 102-2-1 and a tapered inner side surface 102-2-2. Fig.10 , 12 As shown in FIGS. 13 and 14 , the elastic sleeve 102-3 is provided with a plurality of separation grooves 102-3-2, the front portion of the elastic sleeve 102-3 is provided with a front tapered outer side surface 102-3-1, the rear portion of the elastic sleeve 102-3 is provided with a rear tapered outer side surface 102-3-3, and the rear portion of the elastic sleeve 102-3 is provided with four inner extrusion planes 102-3-4. Figure 8 , 9 10. The positioning sleeve 102-2 is sleeved on the elastic sleeve 102-3, the conical inner side surface 102-2-2 matches the front conical outer side surface 102-3-1 of the elastic sleeve 102-3, the outer thread 102-2-1 of the positioning sleeve 102-2 is connected and matched with the inner thread 102-1-2 of the clamping nut 102-1, and the conical extrusion inner side surface 102-1-3 of the clamping nut 102-1 matches the rear conical outer side surface 102-3-3 of the elastic sleeve 102-3.

[0091] like Figure 18-22 As shown, the cross section of the first driving rod 103 is square, the first driving rod 103 passes through the clamping device 102, the first driving rod 103 passes through the positioning sleeve 102-2, the elastic sleeve 102-3 and the square hole 102-1-1 of the clamping nut 102-1 in sequence, and the four inner extrusion planes 102-3-4 at the rear of the elastic sleeve 102-3 correspond to the four surfaces of the first driving rod 103 respectively. Figure 7 The positioning sleeve 102-2 is fixedly connected to the periphery of the spiral body 101, so that the clamping device 102 is fixed to the periphery of the spiral body 101. When the first driving rod 103 rotates, the first driving rod 103 drives the clamping nut 102-1 to rotate, and the clamping nut 102-1 translates toward the positioning sleeve 102-2 while rotating, and then the conical extrusion inner side surface 102-1-3 of the clamping nut 102-1 squeezes the rear conical outer side surface 102-3-3 of the elastic sleeve 102-3, and the conical inner side surface 102-2-2 of the positioning sleeve 102-2 squeezes the front conical outer side surface 102-3-1 of the elastic sleeve 102-3, and then the four inner extrusion planes 102-3-4 of the elastic sleeve 102-3 squeeze the four surfaces of the first driving rod 103 respectively, and finally the first driving rod 103 is clamped.

[0092] When the elastic sleeve 102-3 clamps the first drive rod 103, the first drive rod 103 and the spiral body 101 become a structure, thereby greatly increasing the rigidity of the spiral body 101 and the rigidity of the entire flexible continuum robot arm. The greater the translation distance of the clamping nut 102-1 toward the positioning sleeve 102-2, the greater the clamping force applied by the elastic sleeve 102-3 to the first drive rod 103, and the correspondingly greater the rigidity of the entire robot arm.

[0093] When the elastic sleeve 102 - 3 does not clamp the first driving rod 103 , the entire flexible continuum robot arm can be bent or extended by moving the first driving rod 103 .

[0094] The working mode of the second driving rod 104 is the same as that of the first driving rod 103, which will not be described in detail. The working mode of the third driving rod 105 is the same as that of the first driving rod 103, which will not be described in detail.

[0095] refer to Figure 1 , 3 , 4, 5, the support base 106 is fixedly connected to the mechanical arm support tube 218, the rear end of the first drive rod 103 is connected to the front end of the spline shaft 209-1 of the first ball spline pair 209, the rear end of the second drive rod 104 is connected to the front end of the spline shaft of the second ball spline pair, and the rear end of the third drive rod 105 is connected to the front end of the spline shaft of the third ball spline pair. The rotational movement of the spline shaft 209-1 drives the first drive rod 103 to rotate, and the translational movement of the spline shaft 209-1 is used to pull or release the first drive rod 103; similarly, the rotational movement of the spline shaft of the second ball spline pair drives the second drive rod 104 to rotate, and the translational movement is used to pull or release the second drive rod 104; similarly, the rotational movement of the third ball spline pair drives the third drive rod 105 to rotate, and the translational movement is used to pull or release the third drive rod 105.

[0096] When the elastic sleeve 102-3 does not clamp the first driving rod 103, does not clamp the second driving rod 104, and does not clamp the third driving rod 105, the entire flexible continuum robotic arm can be bent or extended by moving the first driving rod 103, the second driving rod 104, and the third driving rod 105.

[0097] It can be seen that the stiffness of the entire robotic arm can be adjusted by rotating only one of the three drive rods, and the stiffness of the entire robotic arm can be adjusted by rotating two drive rods at the same time, and the stiffness of the entire robotic arm can be adjusted by rotating three drive rods at the same time. When the entire robotic arm is in different bending directions, independently controlling the rotation of each drive rod can achieve different stiffness when bending in different directions, presenting anisotropic stiffness. The stiffness of the entire robotic arm can be adjusted, and it can be adjusted accurately and continuously; because the clamping nut and the positioning sleeve are connected and matched through a threaded structure, the displacement of the clamping nut is highly accurate, thereby changing the clamping force applied by the elastic sleeve to the drive rod with high accuracy, so the adjustment accuracy of the stiffness is very high; because it is transmitted through a threaded structure, the controllability of the stiffness adjustment is strong, and the reliability of controlling the stiffness is high.

[0098] The above-mentioned robotic arm is used in the satellite field. During the long-term operation of the satellite in orbit, it mainly relies on solar panels to provide electricity. The robotic arm drives the execution end to unlock the solar panels so that the solar panels can be unfolded. During the process, the stiffness is changed to increase the load capacity.

[0099] It should be noted that the cross-section of the driving rod can also be a triangle, and the driving rod has three faces. Accordingly, in the clamping device 102, the square hole of the clamping nut 102-1 is changed into a triangular hole, and the elastic sleeve 102-3 is provided with three inner extrusion planes, which respectively correspond to the three faces of the driving rod.

[0100] The cross section of the driving rod may also be other shapes. The hole on the clamping nut 102 - 1 is consistent with the cross section shape of the driving rod, and the multiple inner extrusion planes of the elastic sleeve correspond to the multiple surfaces of the driving rod.

Claims

1. A flexible continuum robot arm with adjustable stiffness, characterized in that: It comprises a support base, a spiral body, a first drive rod, a second drive rod, a third drive rod and three groups of channels, the rear end of the spiral body is fixedly connected to the support base, each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body, and the three groups of channels are evenly distributed in the radial circumferential direction; the first drive rod passes through each clamping device of the first group of channels, and the end of the first drive rod is positioned at the front end of the spiral body; The second driving rod passes through each clamping device of the second group of holes, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of holes, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base; The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve; The positioning sleeve of the clamping device is fixedly connected to the periphery of the spiral body; The cross section of the first driving rod is square, the first driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the first driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively; The cross section of the second driving rod is square, and the second driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the second driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively; The third driving rod has a square cross section and passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four faces of the third driving rod correspond to the four inner extrusion planes at the rear of the elastic sleeve.

2. A method for adjusting the stiffness of a flexible continuum robot arm with adjustable stiffness according to claim 1, characterized in that: The following steps are involved: One, two or three of the three driving rods are rotated, the clamping nut is translated toward the positioning sleeve, and the elastic sleeve clamps the corresponding driving rod.

3. A stiffness adjustment device, characterized in that: It comprises a driving rod and a clamping device, wherein the clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve; The cross section of the driving rod is square, and the driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the clamping device, and the four faces of the driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively.

4. A flexible continuum robotic arm system with adjustable stiffness, characterized in that: It includes a flexible continuum robot arm with adjustable stiffness and a drive device; The flexible continuum mechanical arm with adjustable stiffness comprises a support base, a spiral body, a first driving rod, a second driving rod, a third driving rod and three groups of channels, the rear end of the spiral body is fixedly connected to the support base, each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body, and the three groups of channels are evenly distributed in the radial circumferential direction; the first driving rod passes through each clamping device of the first group of channels, and the end of the first driving rod is positioned at the front end of the spiral body; The second driving rod passes through each clamping device of the second group of holes, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of holes, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base; The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve; The cross section of the first driving rod is square, the first driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the first driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively; The cross section of the second driving rod is square, and the second driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the second driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively; The third driving rod has a square cross section, and passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the third driving rod correspond to the four inner extrusion planes of the rear of the elastic sleeve respectively; The driving device comprises three groups of rotation and translation driving mechanisms, and the three groups of rotation and translation driving mechanisms are used to respectively rotate and translate the three driving rods.

5. A flexible continuum robotic arm system with adjustable stiffness, characterized in that: It includes a flexible continuum robot arm with adjustable stiffness and a drive device; The flexible continuum mechanical arm with adjustable stiffness comprises a support base, a spiral body, a first driving rod, a second driving rod, a third driving rod and three groups of channels, the rear end of the spiral body is fixedly connected to the support base, each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body, and the three groups of channels are evenly distributed in the radial circumferential direction; the first driving rod passes through each clamping device of the first group of channels, and the end of the first driving rod is positioned at the front end of the spiral body; The second driving rod passes through each clamping device of the second group of holes, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of holes, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base; The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a square hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with four inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve; The cross section of the first driving rod is square, the first driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the first driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively; The cross section of the second driving rod is square, and the second driving rod passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the second driving rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve respectively; The third driving rod has a square cross section, and passes through the square holes of the positioning sleeve, the elastic sleeve and the clamping nut of the corresponding clamping device, and the four faces of the third driving rod correspond to the four inner extrusion planes of the rear of the elastic sleeve respectively; The driving device comprises a rear support plate, a front support plate, a mechanical arm support cylinder, a first rotation drive motor, a second rotation drive motor, a third rotation drive motor, a first screw motor, a second screw motor, a third screw motor, a first ball spline pair, a first connecting seat, a first driven synchronous pulley, a first active synchronous pulley, a first rotating shaft, a first nut seat, a first translation plate, a first bearing seat, a first synchronous belt, a second ball spline pair, a second connecting seat, a second driven synchronous pulley, a second active synchronous pulley, a second synchronous belt, a second rotating shaft, a second nut seat, a second translation plate, a second bearing seat, a third ball spline pair, a third connecting seat, a third driven synchronous pulley, a third active synchronous pulley, a third synchronous belt, a third rotating shaft, a third nut seat, a third translation plate and a third bearing seat. The mechanical arm support cylinder is fixedly connected to the front support plate, and the first rotation drive motor, the second rotation drive motor, the third rotation drive motor, the first screw motor , the second screw motor and the third screw motor are all fixedly connected to the front support plate, the first connecting seat is fixedly connected to the front support plate, the first ball spline pair includes a spline shaft and a spline outer cylinder, the spline outer cylinder is rotatably connected to the first connecting seat through a bearing, the spline shaft passes through the front support plate, the front end of the spline shaft is located in the mechanical arm support cylinder, the first driven synchronous pulley is fixedly connected to the spline outer cylinder, the first rotating shaft is connected to the output shaft of the first rotation drive motor, the first active synchronous pulley is fixedly connected to the first rotating shaft, the first synchronous belt is connected between the first active synchronous pulley and the first driven synchronous pulley, the first screw motor is provided with a screw, the end of the screw is rotatably connected to the rear support plate through a bearing, the first nut seat is connected to the screw, one end of the first translation plate is fixedly connected to the first nut seat, the first bearing seat is connected to the other end of the first translation plate, and the rear end of the spline shaft is connected to the first bearing seat; The second connecting seat is fixedly connected to the front supporting plate, the second ball spline pair includes a spline shaft and a spline outer cylinder, the spline outer cylinder of the second ball spline pair is rotatably connected to the second connecting seat through a bearing, the spline shaft of the second ball spline pair passes through the front supporting plate, the front end of the spline shaft of the second ball spline pair is located in the mechanical arm supporting cylinder, the second driven synchronous pulley is fixedly connected to the spline outer cylinder of the second ball spline pair, the second rotating shaft is connected to the output shaft of the second rotation driving motor, the second active synchronous pulley is fixedly connected to the second rotating shaft, the second synchronous belt is connected between the second active synchronous pulley and the second driven synchronous pulley, the second screw motor is provided with a screw, and the end of the screw of the second screw motor is rotatably connected to the rear supporting plate through a bearing, the second nut seat is connected to the screw of the second screw motor, one end of the second translation plate is fixedly connected to the second nut seat, the second bearing seat is connected to the other end of the second translation plate, and the rear end of the spline shaft of the second ball spline pair is connected to the second bearing seat; The third connecting seat is fixedly connected to the front support plate, the third ball spline pair includes a spline shaft and a spline outer cylinder, the spline outer cylinder of the third ball spline pair is rotatably connected to the third connecting seat through a bearing, the spline shaft of the third ball spline pair passes through the front support plate, the front end of the spline shaft of the third ball spline pair is located in the mechanical arm support cylinder, the third driven synchronous pulley is fixedly connected to the spline outer cylinder of the third ball spline pair, the third rotating shaft is connected to the output shaft of the third rotation drive motor, the third active synchronous pulley is connected to the third rotating shaft, the third synchronous belt is connected between the third active synchronous pulley and the third driven synchronous pulley, the third screw motor is provided with a screw, the end of the screw of the third screw motor is rotatably connected to the rear support plate through a bearing, the third nut seat is connected to the screw, one end of the third translation plate is fixedly connected to the third nut seat, the third bearing seat is connected to the other end of the third translation plate, and the rear end of the spline shaft of the third ball spline pair is connected to the third bearing seat; The spline shafts of the first ball spline pair, the spline shafts of the second ball spline pair, and the spline shafts of the third ball spline pair are evenly distributed in the circumferential direction; The support base of the flexible continuum robotic arm with adjustable stiffness is fixedly connected to the robotic arm support tube, the rear end of the first driving rod is connected to the front end of the spline shaft of the first ball spline pair, the rear end of the second driving rod is connected to the front end of the spline shaft of the second ball spline pair, and the rear end of the third driving rod is connected to the front end of the spline shaft of the third ball spline pair.

6. A flexible continuum robot arm with adjustable stiffness, characterized in that: It comprises a support base, a spiral body, a first drive rod, a second drive rod, a third drive rod and three groups of channels, the rear end of the spiral body is fixedly connected to the support base, each group of channels is composed of a plurality of clamping devices fixedly connected to the periphery of the spiral body, the plurality of clamping devices constituting the first group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the second group of channels are distributed along the length direction of the spiral body, the plurality of clamping devices constituting the third group of channels are distributed along the length direction of the spiral body, and the three groups of channels are evenly distributed in the radial circumferential direction; the first drive rod passes through each clamping device of the first group of channels, and the end of the first drive rod is positioned at the front end of the spiral body; The second driving rod passes through each clamping device of the second group of holes, and the end of the second driving rod is positioned at the front end of the spiral body; the third driving rod passes through each clamping device of the third group of holes, and the end of the third driving rod is positioned at the front end of the spiral body; the rear end of the first driving rod passes through the support base, the rear end of the second driving rod passes through the support base, and the rear end of the third driving rod passes through the support base; The clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with a plurality of inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve; The positioning sleeve of the clamping device is fixedly connected to the periphery of the spiral body; The first driving rod passes through the positioning sleeve, the elastic sleeve and the hole of the clamping nut of the corresponding clamping device, the shape of the cross section of the first driving rod is consistent with the shape of the hole of the clamping nut, and the multiple faces of the first driving rod respectively correspond to the multiple inner extrusion planes of the rear part of the elastic sleeve; The second driving rod passes through the positioning sleeve, the elastic sleeve and the hole of the clamping nut of the corresponding clamping device, the shape of the cross section of the second driving rod is consistent with the shape of the hole of the clamping nut, and the multiple faces of the second driving rod respectively correspond to the multiple inner extrusion planes of the rear part of the elastic sleeve; The third driving rod passes through the positioning sleeve, elastic sleeve and the hole of the clamping nut of the corresponding clamping device. The shape of the cross section of the third driving rod is consistent with the shape of the hole of the clamping nut. The multiple faces of the third driving rod correspond to the multiple inner extrusion planes at the rear of the elastic sleeve.

7. The flexible continuum mechanical arm with adjustable stiffness according to claim 6, characterized in that: The hole of the clamping nut is a triangular hole, and the rear part of the elastic sleeve is provided with three inner extrusion planes; The cross section of the first driving rod is in the shape of a triangle, and the three faces of the first driving rod correspond to the three inner extrusion planes of the rear portion of the corresponding elastic sleeve respectively; The cross section of the second driving rod is in the shape of a triangle, and the three faces of the second driving rod correspond to the three inner extrusion planes of the rear portion of the corresponding elastic sleeve respectively; The cross section of the third driving rod is in the shape of a triangle, and the three faces of the third driving rod correspond to the three inner extrusion planes of the rear part of the corresponding elastic sleeve respectively.

8. A stiffness adjustment device, characterized in that: It comprises a driving rod and a clamping device, wherein the clamping device comprises a clamping nut, a positioning sleeve and an elastic sleeve, wherein the clamping nut is provided with a hole, an internal thread and a tapered extruded inner side surface, and the positioning sleeve is provided with an external thread and a tapered inner side surface; the elastic sleeve is provided with a plurality of separation grooves, the elastic sleeve is provided with a front tapered outer side surface and a rear tapered outer side surface, and the rear of the elastic sleeve is provided with a plurality of inner extrusion planes; the positioning sleeve is sleeved on the elastic sleeve, the tapered inner side surface of the positioning sleeve matches the front tapered outer side surface of the elastic sleeve, the external thread of the positioning sleeve is connected and matched with the internal thread of the clamping nut, and the tapered extruded inner side surface of the clamping nut matches the rear tapered outer side surface of the elastic sleeve; The driving rod passes through the positioning sleeve, elastic sleeve and the hole of the clamping nut of the clamping device. The shape of the cross section of the driving rod is consistent with the shape of the hole of the clamping nut. The multiple faces of the driving rod correspond to the multiple inner extrusion planes at the rear of the elastic sleeve.

9. The stiffness adjusting device with adjustable stiffness according to claim 8, characterized in that: The hole of the clamping nut is a triangular hole, and the rear of the elastic sleeve is provided with three inner extrusion planes; the cross-section of the driving rod is triangular, and the three faces of the driving rod correspond to the three inner extrusion planes of the rear of the elastic sleeve respectively.

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