Stiffness-adjustable flexible continuum manipulator, stiffness adjustment device, and stiffness adjustment method

Abstract

The present application relates to a kind of stiffness-adjustable flexible continuum manipulator, stiffness adjusting device and stiffness adjusting method, it solves how to improve the technical problem of load capacity of flexible continuum manipulator, it includes support base, screw body, first driving rod, second driving rod, third driving rod and three groups of channels, each group of channels is made of several clamping devices fixedly connected on the periphery of screw body, first driving rod passes through each clamping device of first group of channels, second driving rod passes through each clamping device of second group of channels, and third driving rod passes through each clamping device of third group of channels.The present application can be applied in solar wing on-orbit auxiliary unlocking technical field.

Description

Technical Field

[0001] This invention relates to the field of flexible continuous robotic arm technology, and more specifically, to a flexible continuous robotic arm with adjustable stiffness, a stiffness adjustment device, and a stiffness adjustment method. Background Technology

[0002] Flexible continuum robotic arms are characterized by high compliance and flexibility, and their applications are becoming increasingly widespread. However, the high compliance of flexible continuum robotic arms results in a lower load capacity, which limits their application in certain scenarios.

[0003] To enhance the load-bearing capacity of flexible continuum manipulators and enable their application in specific scenarios (such as on-orbit assisted unlocking of solar arrays), it is essential to endow them with variable stiffness capabilities. During long-term on-orbit operation, satellites primarily rely on solar arrays for power. The flexible continuum manipulator drives the end effector to perform unlocking operations on the solar arrays, thereby deploying them. This process requires adjusting stiffness to increase load-bearing capacity.

[0004] Currently, conventional variable stiffness methods mainly fall into four categories: blocking, phase change, antagonism, and variable structure.

[0005] The principle of variable stiffness blocking is to change the overall stiffness by altering the friction between a large number of ordered, identical micro-units. Variable stiffness blocking mainly includes three methods: particle blocking, fiber blocking, and layer blocking. For particle blocking, please refer to the invention patent application with publication number CN114516070A. Methods for changing friction include vacuum negative pressure and electrostatic adsorption. Variable stiffness blocking has the advantages of real-time and continuous operation, but it performs poorly in terms of repeatability and structural compactness. The vacuum negative pressure method required for blocking is unsuitable for the vacuum environment of a track, and the electrostatic adsorption method does not meet the requirements for engineering reliability. Furthermore, because the total volume of the blocking unit is constant, its allowable expansion and contraction is very small, thus it cannot improve the flexibility of the flexible continuous body manipulator and is not very suitable for telescopic flexible continuous body manipulators.

[0006] Phase change stiffness adjustment utilizes the change in modulus of a phase change material (solid-liquid or solid-solid phase transition) to adjust the stiffness of a robotic arm. For example, the solid-liquid phase transition of low-melting-point alloys can achieve large-scale stiffness control, while the glass-rubber phase transition of materials such as shape memory polymers (SMPs) can achieve continuous, large-scale stiffness adjustment. However, the E-parameter of low-melting-point alloys and SMPs... 3 / ρ (this index measures the contribution of a unit mass of material to the bending stiffness of a structure, where E is the Young's modulus of the material and ρ is the density of the material) is lower than that of commonly used metals such as steel and aluminum, and does not have a high modulus-density ratio, so it is not suitable for lightweight long arms.

[0007] The basic principle of antagonistic variable stiffness is to increase the number of actuating degrees of freedom compared to the system's motion degrees of freedom, creating overconstraint and thus increasing the system's stiffness. Antagonistic variable stiffness for flexible robotic arms is typically achieved pneumatically because gas expansion can generate the tension required for antagonism, while other flexible actuations are less likely to generate significant tension. See the invention patent application CN117207165A for reference. Antagonistic variable stiffness allows for continuous and stable stiffness adjustment and exhibits good passive compliance; however, the required pneumatic method is not suitable for operation in an on-orbit vacuum environment.

[0008] It is evident that the existing technologies for variable stiffness in flexible continuum robotic arms with variable stiffness capability all have limitations. Summary of the Invention

[0009] This application aims to solve the technical problem of how to improve the load capacity of a flexible continuous robotic arm, and provides a flexible continuous robotic arm with adjustable stiffness, a stiffness adjustment device, and a stiffness adjustment method.

[0010] A first aspect of this disclosure provides a stiffness-adjustable flexible continuous robotic arm, comprising a support base, a helical body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the helical body is fixedly connected to the support base. Each set of channels consists of a plurality of clamping devices fixedly connected to the periphery of the helical body. The clamping devices constituting the first set of channels are distributed along the length direction of the helical body, the clamping devices constituting the second set of channels are distributed along the length direction of the helical body, and the clamping devices constituting the third set of channels are distributed along the length direction of the helical body. The three sets of channels are evenly distributed in the radial and circumferential directions. The first drive rod passes through each clamping device of the first set of channels, and the end of the first drive rod is positioned at the front end of the spiral body. The second drive rod passes through each clamping device of the second set of channels, and the end of the second drive rod is positioned at the front end of the spiral body. The third drive rod passes through each clamping device of the third set of channels, and the end of the third drive rod is positioned at the front end of the spiral body. The rear end of the first drive rod passes through the support base, the rear end of the second drive rod passes through the support base, and the rear end of the third drive rod passes through the support base.

[0011] The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered extrusion inner surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner extrusion planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered extrusion inner surface of the clamping nut matches the rear tapered outer 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 drive rod is square. The first drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the first drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve.

[0014] The cross-section of the second drive rod is square. The second drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the second drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve.

[0015] The cross-section of the third drive rod is square. The third drive rod passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the third drive rod correspond to the four inner extrusion planes of the rear of the elastic sleeve.

[0016] A second aspect of this disclosure provides a stiffness adjustment method for a flexible continuum manipulator with adjustable stiffness described above, comprising the following steps:

[0017] Rotate one, two, or all three drive rods, and the clamping nut will move towards the positioning sleeve, causing the elastic sleeve to clamp the corresponding drive rod.

[0018] A third aspect of this disclosure provides a stiffness adjustment device, including a drive rod and a clamping device. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve.

[0019] The drive rod has a square cross-section and passes through the square holes of the positioning sleeve, elastic sleeve, and clamping nut of the clamping device. The four sides of the drive rod correspond to the four inner extrusion planes on the rear of the elastic sleeve.

[0020] A fourth aspect of this disclosure provides a stiffness-adjustable flexible continuum manipulator system, including a stiffness-adjustable flexible continuum manipulator and a drive device.

[0021] The stiffness-adjustable flexible continuous robotic arm includes a support base, a helical body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the helical body is fixedly connected to the support base. Each set of channels consists of several clamping devices fixedly connected to the periphery of the helical body. The clamping devices constituting the first set of channels are distributed along the length of the helical body, the second set of channels are distributed along the length of the helical body, and the third set of channels are distributed along the length of the helical body. The three sets of channels are evenly distributed in the radial circumferential direction. The first drive rod passes through each clamping device in the first set of channels, and its end is positioned at the front end of the helical body. The second drive rod passes through each clamping device in the second set of channels, and its end is positioned at the front end of the helical body. The third drive rod passes through each clamping device in the third set of channels, and its end is positioned at the front end of the helical body. The rear ends of the first, second, and third drive rods pass through the support base.

[0022] The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered extrusion inner surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner extrusion planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered extrusion inner surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve.

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

[0024] The cross-section of the second drive rod is square. The second drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the second drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve.

[0025] The cross-section of the third drive rod is square. The third drive rod passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the third drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve.

[0026] The drive unit includes three sets of rotation and translation drive mechanisms, which are used to rotate and translate the three drive rods respectively.

[0027] A fifth aspect of this disclosure provides a stiffness-adjustable flexible continuum manipulator system, including a stiffness-adjustable flexible continuum manipulator and a drive device.

[0028] The stiffness-adjustable flexible continuous robotic arm includes a support base, a helical body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the helical body is fixedly connected to the support base. Each set of channels consists of several clamping devices fixedly connected to the periphery of the helical body. The clamping devices constituting the first set of channels are distributed along the length of the helical body, the second set of channels are distributed along the length of the helical body, and the third set of channels are distributed along the length of the helical body. The three sets of channels are evenly distributed in the radial circumferential direction. The first drive rod passes through each clamping device in the first set of channels, and its end is positioned at the front end of the helical body. The second drive rod passes through each clamping device in the second set of channels, and its end is positioned at the front end of the helical body. The third drive rod passes through each clamping device in the third set of channels, and its end is positioned at the front end of the helical body. The rear ends of the first, second, and third drive rods pass through the support base.

[0029] The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered extrusion inner surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner extrusion planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered extrusion inner surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve.

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

[0031] The cross-section of the second drive rod is square. The second drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the second drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve.

[0032] The cross-section of the third drive rod is square. The third drive rod passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the third drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve.

[0033] The drive unit includes a rear support plate, a front support plate, a robotic arm support cylinder, a first rotary drive motor, a second rotary drive motor, a third rotary drive motor, a first lead screw motor, a second lead screw motor, a third lead screw motor, a first ball spline pair, a first connecting seat, a first driven synchronous pulley, a first driving 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 driving 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 driving synchronous pulley, a third synchronous belt, a third rotating shaft, a third nut seat, a third translation plate, and a third bearing seat. The robotic arm support cylinder is fixedly connected to the front support plate. The first rotary drive motor, the second rotary drive motor, the third rotary drive motor, and the third rotary drive motor... The drive motor, the first lead screw motor, the second lead screw motor, and the third lead 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, and the front end of the spline shaft is located in the robotic 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 rotary drive motor. The first driving synchronous pulley is fixedly connected to the first rotating shaft. The first synchronous belt is connected between the first driving synchronous pulley and the first driven synchronous pulley. The first lead screw motor is provided with a lead screw. The end of the lead screw is rotatably connected to the rear support plate through a bearing. The first nut seat is connected to the lead 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. 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 support cylinder of the robotic arm. 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 rotary drive motor. The second driving synchronous pulley is fixedly connected to the second rotating shaft. The second synchronous belt is connected between the second driving synchronous pulley and the second driven synchronous pulley. The second lead screw motor is provided with a lead screw. The end of the lead screw of the second lead screw motor is rotatably connected to the rear support plate through a bearing. The second nut seat is connected to the lead screw of the second lead 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. 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 support cylinder of the robotic arm. 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 rotary drive motor. The third driving synchronous pulley is connected to the third rotating shaft. The third synchronous belt is connected between the third driving synchronous pulley and the third driven synchronous pulley. The third lead screw motor is provided with a lead screw. The end of the lead screw of the third lead screw motor is rotatably connected to the rear support plate through a bearing. The third nut seat is connected to the lead 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. 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 second ball spline pair, and the third ball spline pair are evenly distributed along the circumferential direction.

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

[0038] A sixth aspect of this disclosure provides a stiffness-adjustable flexible continuous robotic arm, including a support base, a helical body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the helical body is fixedly connected to the support base. Each set of channels consists of a plurality of clamping devices fixedly connected to the periphery of the helical body. The plurality of clamping devices constituting the first set of channels are distributed along the length direction of the helical body, the plurality of clamping devices constituting the second set of channels are distributed along the length direction of the helical body, and the plurality of clamping devices constituting the third set of channels are distributed along the length direction of the helical body. The three sets of channels are evenly distributed in the radial and circumferential directions. The first drive rod passes through each clamping device of the first set of channels, and the end of the first drive rod is positioned at the front end of the spiral body. The second drive rod passes through each clamping device of the second set of channels, and the end of the second drive rod is positioned at the front end of the spiral body. The third drive rod passes through each clamping device of the third set of channels, and the end of the third drive rod is positioned at the front end of the spiral body. The rear end of the first drive rod passes through the support base, the rear end of the second drive rod passes through the support base, and the rear end of the third drive rod passes through the support base.

[0039] The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a hole, an internal thread, and a tapered extrusion inner surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has multiple inner extrusion planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered extrusion inner surface of the clamping nut matches the rear tapered outer 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 drive rod passes through the positioning sleeve, elastic sleeve and clamping nut holes of the corresponding clamping device. The shape of the cross-section of the first drive rod is consistent with the shape of the hole of the clamping nut. Multiple surfaces of the first drive rod correspond to multiple inner extrusion planes at the rear of the elastic sleeve.

[0042] The second drive rod passes through the positioning sleeve, elastic sleeve, and clamping nut holes of the corresponding clamping device. The shape of the cross-section of the second drive rod is consistent with the shape of the hole of the clamping nut. Multiple surfaces of the second drive rod correspond to multiple inner extrusion planes at the rear of the elastic sleeve.

[0043] The third drive rod passes through the positioning sleeve, elastic sleeve, and clamping nut holes of the corresponding clamping device. The cross-sectional shape of the third drive rod is consistent with the shape of the clamping nut hole. Multiple surfaces of the third drive rod correspond to multiple inner extrusion planes at the rear of the elastic sleeve.

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

[0045] The cross-sectional shape of the first drive rod is triangular, and the three faces of the first drive rod correspond to the three inner extrusion planes of the rear part of the corresponding elastic sleeve.

[0046] The cross-sectional shape of the second drive rod is triangular, and the three faces of the second drive rod correspond to the three inner extrusion planes of the rear part of the corresponding elastic sleeve.

[0047] The cross-sectional shape of the third drive rod is triangular, and the three faces of the third drive rod correspond to the three inner extrusion planes of the rear part of the corresponding elastic sleeve.

[0048] A seventh aspect of this disclosure provides a stiffness adjustment device, including a drive rod and a clamping device. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has multiple inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve.

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

[0050] Preferably, the hole for clamping the nut is a triangular hole, and the rear part of the elastic sleeve is provided with three inner extrusion planes; the cross-sectional shape of the drive rod is triangular, and the three faces of the drive rod correspond to the three inner extrusion planes of the rear part of the elastic sleeve.

[0051] The beneficial effects of this disclosure are that the stiffness of the flexible continuous manipulator is adjustable, which improves the load capacity of the flexible continuous manipulator; the stiffness adjustment accuracy is very high, and the controllability of stiffness adjustment is stronger.

[0052] The structure achieves variable stiffness through mechanical movement, independent of external conditions such as air pressure. This enables lightweight robotic arms as well as long-arm robotic arms.

[0053] This expands the application scenarios of flexible continuous robotic arms and improves their performance.

[0054] This invention has a wide range of applications, not limited to solving the problem of on-orbit assisted unlocking of solar arrays, but also applicable to other technical fields such as minimally invasive surgery.

[0055] Further features and aspects of this disclosure will be clearly described in the following detailed description with reference to the accompanying drawings. Attached Figure Description

[0056] Figure 1 It is an isometric view of a flexible continuum robotic arm system with adjustable stiffness;

[0057] Figure 2 yes Figure 1 The front view of the flexible continuum robotic arm system with adjustable stiffness is shown.

[0058] Figure 3 This is a schematic diagram of the drive unit;

[0059] Figure 4 yes Figure 3 The 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 isometric view of a flexible continuum robotic arm with adjustable stiffness;

[0062] Figure 7 yes Figure 6 A magnified view of a section at point P in the middle;

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

[0064] Figure 9 yes Figure 8 Cross-sectional view along the AA direction;

[0065] Figure 10 yes Figure 8 Exploded view of the clamping device shown;

[0066] Figure 11 It is an isometric view of the clamping nut;

[0067] Figure 12 It is an isometric view of the elastic sleeve;

[0068] Figure 13 It is an isometric view of the elastic sleeve;

[0069] Figure 14 It is an isometric view of the elastic sleeve;

[0070] Figure 15 This is a side view of the clamping nut;

[0071] Figure 16 This is a cross-sectional view of the clamping nut;

[0072] Figure 17 This is a schematic diagram of the structure of the first drive rod passing through the clamping device;

[0073] Figure 18 yes Figure 17 Cross-sectional view along the BB direction;

[0074] Figure 19 yes Figure 18 The diagram shows the structure of the elastic sleeve fitted onto the first drive rod.

[0075] Figure 20 yes Figure 19 The front view of the structure shown;

[0076] Figure 21 yes Figure 20 Right view of the structure shown;

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

[0078] Explanation of symbols in the diagram:

[0079] 100. Adjustable stiffness flexible continuous robotic arm; 101. Helical body; 102. Clamping device; 102-1. Clamping nut; 102-1-1. Square hole; 102-1-2. Internal thread; 102-1-3. Conical extrusion inner surface; 102-2. Positioning sleeve; 102-2-1. External thread; 102-2-2. Conical inner surface; 102-3. Elastic sleeve; 102-3-1. Front conical outer surface; 102-3-2. Separating groove; 102-3-3. Rear... 102-3-4. Conical outer surface, 103. Inner extrusion plane, 104. First drive rod, 105. Second drive rod, 106. Third drive rod, 107. 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 lead screw motor, 206-1. Lead screw, 207. Second lead screw motor, 207-1. Lead screw, 208. 208-1. Third lead screw motor; 209. Lead screw; 209-1. First ball spline pair; 209-2. Spline outer cylinder; 210. First connecting seat; 211. First driven synchronous pulley; 212. First driving synchronous pulley; 213. First rotating shaft; 214. First nut seat; 215. First translation plate; 216. First bearing seat; 217. First synchronous belt; 218. Robotic arm support cylinder; 219. Second ball spline pair; 220. Second connecting seat; 22 1. Second driven synchronous pulley; 222. Second driving synchronous pulley; 223. Second synchronous belt; 224. Second shaft; 225. Second nut seat; 226. Second translation plate; 227. Second bearing seat; 228. Third ball spline pair; 229. Third connecting seat; 230. Third driven synchronous pulley; 231. Third driving synchronous pulley; 232. Third synchronous belt; 233. Third shaft; 234. Third nut seat; 235. Third translation plate; 236. Third bearing seat. Detailed Implementation

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

[0081] The specific embodiments described below are merely preferred embodiments of this application, and the scope of protection of this application is not limited thereto. Those skilled in the art can make modifications or variations based on the principles, concepts, and spirit of this application, and the resulting technical solutions should all be covered within the scope of protection of this application.

[0082] like Figure 1 and 2 As shown, the stiffness-adjustable flexible continuous manipulator system includes a stiffness-adjustable flexible continuous manipulator 100 and a drive unit 200. The drive unit 200 is used to move the stiffness-adjustable flexible continuous manipulator 100 and can also adjust its stiffness.

[0083] like Figure 3-5As shown, the drive device 200 includes a rear support plate 201, a front support plate 202, a robotic arm support cylinder 218, a first rotary drive motor 203, a second rotary drive motor 204, a third rotary drive motor 205, a first lead screw motor 206, a second lead screw motor 207, a third lead screw motor 208, a first ball spline pair 209, a first connecting seat 210, a first driven synchronous pulley 211, a first driving 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 driving synchronous pulley 222. The following components are included: second synchronous belt 223, second rotating shaft 224, second nut seat 225, second translation plate 226, second bearing seat 227, third ball spline pair 228, third connecting seat 229, third driven synchronous belt pulley 230, third driving synchronous belt pulley 231, third synchronous belt 232, third rotating shaft 233, third nut seat 234, third translation plate 235, third bearing seat 236, and the robotic arm support cylinder 218 is fixedly connected to the front support plate 202. The first rotary drive motor 203, second rotary drive motor 204, third rotary drive motor 205, first lead screw motor 206, second lead screw motor 207, and third lead 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 robotic 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 driving synchronous pulley 212 is fixedly connected to the first rotating shaft 213. The first synchronous belt 212... 17 is connected between the first driving synchronous pulley 212 and the first driven synchronous pulley 211. The first lead screw motor 206 is equipped with a lead screw 206-1. The end of the lead screw 206-1 is rotatably connected to the rear support plate 201 through a bearing. The first nut seat 214 is connected to the lead 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 lead screw motor 206 works, the first translation plate 215 moves forward or backward. Figure 4When the first rotary drive motor 203 operates, it drives the first rotating shaft 213 to rotate. This rotation is achieved by the first driving synchronous pulley 212, the first synchronous belt 217, and the first driven synchronous pulley 211, which in turn drive the spline outer cylinder 209-2 to rotate. The spline outer cylinder 209-2 then drives the spline shaft 209-1 to rotate, thus 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 via a bearing. The spline shaft passes through the front support plate 202, and its front end is located in the robotic 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. The second driving synchronous pulley 222 is fixedly connected to the second rotating shaft 224. The second synchronous belt 223 is connected between the second driving synchronous pulley 222 and the second driven synchronous pulley 221. The second lead screw motor 207 is equipped with a lead screw 207-1. The end of the lead screw 207-1 is rotatably connected to the rear support plate 201 via a bearing. The second nut seat 225 is connected to the lead screw 207-1. One end of the second translation plate 226 is fixedly connected to the second nut seat 225. The other end of the second bearing seat 227 is connected to the second translation plate 226. 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 via a bearing. The spline shaft passes through the front support plate 202, and its front end is located in the robotic 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. The third driving synchronous pulley 231 is connected to the third rotating shaft 233. The third synchronous belt 232 is connected between the third driving synchronous pulley 231 and the third driven synchronous pulley 230. The third lead screw motor 208 is equipped with a lead screw 208-1. The end of the lead screw 208-1 is rotatably connected to the rear support plate 201 through a bearing. The third nut seat 234 is connected to the lead 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. 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 shafts 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] As can be seen, the entire drive device 200 is equipped with three sets of rotation and translation drive mechanisms, which are used to drive the three drive rods of the flexible continuous robotic arm 100 with adjustable stiffness.

[0088] like Figure 6As shown, the stiffness-adjustable flexible continuous robotic arm 100 includes a support base 106, a helical body 101, a first drive rod 103, a second drive rod 104, a third drive rod 105, and three sets of channels. The rear end of the helical body 101 is fixedly connected to the support base 106. Each set of channels consists of several clamping devices 102 fixedly connected to the periphery of the helical body 101. The clamping devices 102 constituting the first set of channels are distributed along the length direction of the helical body 101, the clamping devices 102 constituting the second set of channels are distributed along the length direction of the helical body 101, and the clamping devices 102 constituting the third set of channels are distributed along the length direction of the helical body 101. The three sets of channels are evenly distributed in the radial circumferential direction (that is, the included angle between two adjacent sets of channels is 120°). The first drive rod 103 passes through each clamping device in the first set of channels, and the end of the first drive rod 103 is positioned at the front end of the helical body 101. The second drive rod 104 passes through each clamping device of the second set of channels, and its end is positioned at the front end of the spiral body 101. The third drive rod 105 passes through each clamping device of the third set of channels, and its end is positioned at the front end of the spiral body 101. The rear end of the first drive rod 103 passes through the support base 106, the rear end of the second drive rod 104 passes through the support base 106, and the rear end of the third drive rod 105 passes through the support base 106.

[0089] The helical body 101 has a helical structure with a wide range of extension, contraction, and bending deformation capabilities. Under external force, pulling the three drive rods enables omnidirectional bending of the helical body 101. For example, pulling the first drive rod 103 while simultaneously releasing the second drive rod 104 and the third drive rod 105 will cause the helical body 101 to bend towards the first drive rod 103. When the helical body 101 is in a straight state, simultaneously pulling the first drive rod 103, the second drive rod 104, and the third drive rod 105 will cause the helical body 101 to contract, shortening its length. When the helical body 101 is in a contracted state, simultaneously releasing the first drive rod 103, the second drive rod 104, and the third drive rod 105 will cause the helical body 101 to extend, lengthening its length. Therefore, by simultaneously operating the three drive rods, moving them along the axis of the helical body 101, the entire flexible continuous robotic arm can achieve its extension and contraction movements.

[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. For example... Figure 11 , 16 As shown in Figure 17, the clamping nut 102-1 has a square hole 102-1-1, an internal thread 102-1-2, and a tapered extruded inner surface 102-1-3. For example... Figure 8 ,9 As shown in Figure 10, the positioning sleeve 102-2 has an external thread 102-2-1 and a tapered inner surface 102-2-2. Figure 10 , 12 As shown in Figures 13 and 14, the elastic sleeve 102-3 has multiple dividing grooves 102-3-2, the front part of the elastic sleeve 102-3 has a front conical outer surface 102-3-1, the rear part of the elastic sleeve 102-3 has a rear conical outer surface 102-3-3, and the rear part of the elastic sleeve 102-3 has four inner extrusion surfaces 102-3-4. (Reference) Figure 8 , 9 10. Positioning sleeve 102-2 is fitted onto elastic sleeve 102-3. The conical inner surface 102-2-2 matches the front conical outer surface 102-3-1 of elastic sleeve 102-3. The external thread 102-2-1 of positioning sleeve 102-2 is connected and engaged with the internal thread 102-1-2 of clamping nut 102-1. The conical extrusion inner surface 102-1-3 of clamping nut 102-1 matches the rear conical outer surface 102-3-3 of elastic sleeve 102-3.

[0091] like Figure 18-22 As shown, the first drive rod 103 has a square cross-section. The first drive rod 103 passes through the clamping device 102. It sequentially passes through the square holes 102-1-1 of the positioning sleeve 102-2, the elastic sleeve 102-3, and the clamping nut 102-1. The four inner pressing planes 102-3-4 at the rear of the elastic sleeve 102-3 correspond to the four surfaces of the first drive rod 103. (Reference) Figure 7 The positioning sleeve 102-2 is fixedly connected to the periphery of the spiral body 101, thereby fixing the clamping device 102 to the periphery of the spiral body 101. When the first drive rod 103 rotates, it drives the clamping nut 102-1 to rotate. As the clamping nut 102-1 rotates, it translates towards the positioning sleeve 102-2. Consequently, the conical inner pressing surface 102-1-3 of the clamping nut 102-1 presses the rear conical outer surface 102-3-3 of the elastic sleeve 102-3, and the conical inner surface 102-2-2 of the positioning sleeve 102-2 presses the front conical outer surface 102-3-1 of the elastic sleeve 102-3. Furthermore, the four inner pressing surfaces 102-3-4 of the elastic sleeve 102-3 press the four surfaces of the first drive rod 103 respectively, ultimately clamping the first drive rod 103.

[0092] When the elastic sleeve 102-3 clamps the first drive rod 103, the first drive rod 103 and the helical body 101 become a single structure, thereby significantly increasing the stiffness of the helical body 101 and the overall stiffness of the flexible continuous robotic arm. The greater the translational distance of the clamping nut 102-1 towards the positioning sleeve 102-2, the greater the clamping force applied by the elastic sleeve 102-3 to the first drive rod 103, and consequently, the greater the stiffness of the entire robotic arm.

[0093] Even when the elastic sleeve 102-3 does not clamp the first drive rod 103, moving the first drive rod 103 can bend or extend the entire flexible continuous robotic arm.

[0094] The second drive lever 104 operates in the same way as the first drive lever 103, and will not be described again. The third drive lever 105 operates in the same way as the first drive lever 103, and will not be described again.

[0095] refer to Figure 1 , 3 4, 5. The support base 106 is fixedly connected to the robotic arm support cylinder 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. 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 motion of the spline shaft 209-1 drives the first drive rod 103 to rotate. The translational motion of the spline shaft 209-1 pulls or releases the first drive rod 103. Similarly, the rotational motion of the spline shaft of the second ball spline pair drives the second drive rod 104 to rotate. The translational motion pulls or releases the second drive rod 104. Similarly, the rotational motion of the third ball spline pair drives the third drive rod 105 to rotate. The translational motion pulls or releases the third drive rod 105.

[0096] Without the elastic sleeve 102-3 clamping the first drive rod 103, the second drive rod 104, or the third drive rod 105, moving the first drive rod 103, the second drive rod 104, and the third drive rod 105 can bend or extend the entire flexible continuous robotic arm.

[0097] It is evident that rotating just one of the three drive rods can adjust the stiffness of the entire robotic arm; rotating two drive rods simultaneously also adjusts the stiffness, and rotating all three also adjusts the stiffness. By independently controlling the rotation of each drive rod in different bending directions, different stiffnesses can be achieved, exhibiting anisotropic stiffness. The stiffness of the entire robotic arm is adjustable and can be precisely and continuously adjusted. Because the clamping nut and the positioning sleeve are connected by a threaded structure, the displacement accuracy of the clamping nut is high, thus the accuracy of changing the clamping force applied by the elastic sleeve to the drive rod is also high. Therefore, the adjustment precision of the stiffness is very high. Due to the threaded transmission structure, the controllability of the stiffness adjustment is strong, and the reliability of stiffness control is high.

[0098] The aforementioned robotic arm is used in the satellite field. During the long-term operation of a satellite in orbit, it mainly relies on the solar panels to provide power. The robotic arm drives the end effector to unlock the solar panels, thereby deploying them. During the process, the stiffness is changed to improve the load capacity.

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

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

Claims

1. A flexible continuous robotic arm with adjustable stiffness, characterized in that, The system includes a support base, a spiral body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the spiral body is fixedly connected to the support base. Each set of channels consists of several clamping devices fixedly connected to the periphery of the spiral body. The clamping devices constituting the first set of channels are distributed along the length of the spiral body, the clamping devices constituting the second set of channels are distributed along the length of the spiral body, and the clamping devices constituting the third set of channels are distributed along the length of the spiral body. The three sets of channels are evenly distributed in the radial circumferential direction. The first drive rod passes through each clamping device in the first set of channels, and the end of the first drive rod is positioned at the front end of the spiral body. The second drive rod passes through each clamping device of the second set of channels, and the end of the second drive rod is positioned at the front end of the spiral body; the third drive rod passes through each clamping device of the third set of channels, and the end of the third drive rod is positioned at the front end of the spiral body; the rear end of the first drive rod passes through the support base, the rear end of the second drive rod passes through the support base, and the rear end of the third drive rod passes through the support base. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple dividing grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve. The positioning sleeve of the clamping device is fixedly connected to the periphery of the spiral body; The first drive rod has a square cross-section. The first drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the first drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The cross-section of the second drive rod is square. The second drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the second drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The cross-section of the third drive rod is square. The third drive rod passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the third drive rod correspond to the four inner extrusion planes of the rear of the elastic sleeve.

2. A stiffness adjustment method applied to the stiffness-adjustable flexible continuous manipulator as described in claim 1, characterized in that, Includes the following steps: Rotate one, two, or all three drive rods, and the clamping nut will move towards the positioning sleeve, causing the elastic sleeve to clamp the corresponding drive rod.

3. A stiffness adjustment device, applied to the stiffness-adjustable flexible continuous robotic arm as described in claim 1, characterized in that, The device includes a drive rod and a clamping device. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve. The drive rod has a square cross-section and passes through the square holes of the positioning sleeve, elastic sleeve, and clamping nut of the clamping device. The four sides of the drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve.

4. A flexible continuous robotic arm system with adjustable stiffness, characterized in that, This includes a flexible continuous robotic arm with adjustable stiffness and a drive unit; The stiffness-adjustable flexible continuous robotic arm includes a support base, a helical body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the helical body is fixedly connected to the support base. Each set of channels consists of several clamping devices fixedly connected to the periphery of the helical body. The clamping devices constituting the first set of channels are distributed along the length direction of the helical body, the clamping devices constituting the second set of channels are distributed along the length direction of the helical body, and the clamping devices constituting the third set of channels are distributed along the length direction of the helical body. The three sets of channels are evenly distributed in the radial circumferential direction. The first drive rod passes through each clamping device in the first set of channels, and the end of the first drive rod is positioned at the front end of the helical body. The second drive rod passes through each clamping device of the second set of channels, and the end of the second drive rod is positioned at the front end of the spiral body; the third drive rod passes through each clamping device of the third set of channels, and the end of the third drive rod is positioned at the front end of the spiral body; the rear end of the first drive rod passes through the support base, the rear end of the second drive rod passes through the support base, and the rear end of the third drive rod passes through the support base. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple dividing grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve. The first drive rod has a square cross-section. The first drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the first drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The cross-section of the second drive rod is square. The second drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the second drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The cross-section of the third drive rod is square. The third drive rod passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the third drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The driving device includes three sets of rotation and translation driving mechanisms, which are used to rotate and translate the three driving rods respectively.

5. A flexible continuous robotic arm system with adjustable stiffness, characterized in that, This includes a flexible continuous robotic arm with adjustable stiffness and a drive unit; The stiffness-adjustable flexible continuous robotic arm includes a support base, a helical body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the helical body is fixedly connected to the support base. Each set of channels consists of several clamping devices fixedly connected to the periphery of the helical body. The clamping devices constituting the first set of channels are distributed along the length direction of the helical body, the clamping devices constituting the second set of channels are distributed along the length direction of the helical body, and the clamping devices constituting the third set of channels are distributed along the length direction of the helical body. The three sets of channels are evenly distributed in the radial circumferential direction. The first drive rod passes through each clamping device in the first set of channels, and the end of the first drive rod is positioned at the front end of the helical body. The second drive rod passes through each clamping device of the second set of channels, and the end of the second drive rod is positioned at the front end of the spiral body; the third drive rod passes through each clamping device of the third set of channels, and the end of the third drive rod is positioned at the front end of the spiral body; the rear end of the first drive rod passes through the support base, the rear end of the second drive rod passes through the support base, and the rear end of the third drive rod passes through the support base. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a square hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple dividing grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has four inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve. The first drive rod has a square cross-section. The first drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the first drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The cross-section of the second drive rod is square. The second drive rod passes through the square hole of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the second drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The cross-section of the third drive rod is square. The third drive rod passes through the square holes of the positioning sleeve, elastic sleeve and clamping nut of the corresponding clamping device. The four sides of the third drive rod correspond to the four inner extrusion planes of the rear part of the elastic sleeve. The driving device includes a rear support plate, a front support plate, a robotic arm support cylinder, a first rotary drive motor, a second rotary drive motor, a third rotary drive motor, a first lead screw motor, a second lead screw motor, a third lead screw motor, a first ball spline pair, a first connecting seat, a first driven synchronous pulley, a first driving 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 driving 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 driving synchronous pulley, a third synchronous belt, a third rotating shaft, a third nut seat, a third translation plate, and a third bearing seat. The robotic arm support cylinder is fixedly connected to the front support plate. The first rotary drive motor, the second rotary drive motor, the third rotary drive motor, and the first lead screw motor... The second and third lead screw motors are both 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, and the front end of the spline shaft is located in the robotic 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 rotary drive motor. The first driving synchronous pulley is fixedly connected to the first rotating shaft. The first synchronous belt is connected between the first driving synchronous pulley and the first driven synchronous pulley. The first lead screw motor is provided with a lead screw. The end of the lead screw is rotatably connected to the rear support plate through a bearing. The first nut seat is connected to the lead 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. The rear end of the spline shaft is connected to the first bearing seat. 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 robotic 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 rotary drive motor. The second driving synchronous pulley is fixedly connected to the second rotating shaft. The second synchronous belt is connected between the second driving synchronous pulley and the second driven synchronous pulley. The second lead screw motor is provided with a lead screw. The end of the lead screw of the second lead screw motor is rotatably connected to the rear support plate through a bearing. The second nut seat is connected to the lead screw of the second lead 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. 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 robotic 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 rotary drive motor. The third driving synchronous pulley is connected to the third rotating shaft. The third synchronous belt is connected between the third driving synchronous pulley and the third driven synchronous pulley. The third lead screw motor is provided with a lead screw. The end of the lead screw of the third lead screw motor is rotatably connected to the rear support plate through a bearing. The third nut seat is connected to the lead 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. 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 second ball spline pair, and the third ball spline pair are evenly distributed along the circumferential direction. The support base of the stiffness-adjustable flexible continuous robotic arm is fixedly connected to the robotic arm support cylinder. The rear end of the first drive rod is connected to the front end of the spline shaft of the first ball spline pair, the rear end of the second drive rod 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 is connected to the front end of the spline shaft of the third ball spline pair.

6. A flexible continuous robotic arm with adjustable stiffness, characterized in that, The system includes a support base, a spiral body, a first drive rod, a second drive rod, a third drive rod, and three sets of channels. The rear end of the spiral body is fixedly connected to the support base. Each set of channels consists of several clamping devices fixedly connected to the periphery of the spiral body. The clamping devices constituting the first set of channels are distributed along the length of the spiral body, the clamping devices constituting the second set of channels are distributed along the length of the spiral body, and the clamping devices constituting the third set of channels are distributed along the length of the spiral body. The three sets of channels are evenly distributed in the radial circumferential direction. The first drive rod passes through each clamping device in the first set of channels, and the end of the first drive rod is positioned at the front end of the spiral body. The second drive rod passes through each clamping device of the second set of channels, and the end of the second drive rod is positioned at the front end of the spiral body; the third drive rod passes through each clamping device of the third set of channels, and the end of the third drive rod is positioned at the front end of the spiral body; the rear end of the first drive rod passes through the support base, the rear end of the second drive rod passes through the support base, and the rear end of the third drive rod passes through the support base. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has multiple inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve. The positioning sleeve of the clamping device is fixedly connected to the periphery of the spiral body; The first drive rod passes through the positioning sleeve, elastic sleeve, and clamping nut holes of the corresponding clamping device. The shape of the cross-section of the first drive rod is consistent with the shape of the hole of the clamping nut. Multiple surfaces of the first drive rod correspond to multiple inner extrusion planes at the rear of the elastic sleeve. The second drive rod passes through the positioning sleeve, elastic sleeve, and clamping nut holes of the corresponding clamping device. The shape of the cross-section of the second drive rod is consistent with the shape of the hole of the clamping nut. Multiple surfaces of the second drive rod correspond to multiple inner extrusion planes at the rear of the elastic sleeve. The third drive rod passes through the positioning sleeve, elastic sleeve, and clamping nut holes of the corresponding clamping device. The shape of the cross-section of the third drive rod is consistent with the shape of the hole of the clamping nut. Multiple surfaces of the third drive rod correspond to multiple inner extrusion planes at the rear of the elastic sleeve.

7. The stiffness-adjustable flexible continuous robotic arm according to claim 6, characterized in that, The clamping nut has a triangular hole, and the elastic sleeve has three inner extrusion planes at the rear. The cross-sectional shape of the first drive rod is triangular, and the three faces of the first drive rod correspond to the three inner extrusion planes of the rear part of the corresponding elastic sleeve. The cross-sectional shape of the second drive rod is triangular, and the three faces of the second drive rod correspond to the three inner extrusion planes of the rear part of the corresponding elastic sleeve. The cross-sectional shape of the third drive rod is triangular, and the three faces of the third drive rod correspond to the three inner extrusion planes of the rear part of the corresponding elastic sleeve.

8. A stiffness adjustment device, applied to the stiffness-adjustable flexible continuous robotic arm as described in claim 6, characterized in that, The device includes a drive rod and a clamping device. The clamping device includes a clamping nut, a positioning sleeve, and an elastic sleeve. The clamping nut has a hole, an internal thread, and a tapered inner pressing surface. The positioning sleeve has an external thread and a tapered inner surface. The elastic sleeve has multiple partition grooves, a front tapered outer surface, and a rear tapered outer surface. The rear of the elastic sleeve has multiple inner pressing planes. The positioning sleeve is fitted onto the elastic sleeve. The tapered inner surface of the positioning sleeve matches the front tapered outer surface of the elastic sleeve. The external thread of the positioning sleeve is connected to the internal thread of the clamping nut. The tapered inner pressing surface of the clamping nut matches the rear tapered outer surface of the elastic sleeve. The drive rod passes through the positioning sleeve, elastic sleeve, and clamping nut holes of the clamping device. The cross-sectional shape of the drive rod is consistent with the shape of the clamping nut hole, and multiple surfaces of the drive rod correspond to multiple inner extrusion planes at the rear of the elastic sleeve.

9. The stiffness adjustment device according to claim 8, characterized in that, The clamping nut has a triangular hole, and the elastic sleeve has three inner pressing planes at its rear. The drive rod has a triangular cross-section, and the three faces of the drive rod correspond to the three inner pressing planes at the rear of the elastic sleeve.

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