Polymorphic variable-rigidity continuum robot and control method

Abstract

The invention discloses a multi-form variable-rigidity continuum robot and a control method. The multi-form variable-rigidity continuum robot comprises a continuum module, a variable driving module and an air pump. The continuum module comprises a base, a first flexible assembly and a tendon driving assembly, the head end of the first flexible assembly is arranged on the base, the tendon driving assembly is arranged on the base, and the tendon driving assembly is connected with the tail end of the first flexible assembly through a driving rope; the variable driving module comprises a plurality of head movement units, a tail movement unit, an actuator box and a plurality of second flexible assemblies, the second flexible assemblies are connected to the head movement units and the tail movement unit respectively, the actuator box is connected with the second flexible assemblies, and the air pump is detachably connected with the second flexible assemblies through air pipes. When the continuum robot faces a multi-task environment, the rigidity can be adjusted according to requirements, switching of different tasks can be rapidly adapted through tendon driving and gas driving, and the task execution efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of robotics, and in particular to a multi-morph variable stiffness continuum robot and a control method thereof. Background Art

[0002] With the continuous development of robotics technology, continuum robots, with their flexible components and high adaptability, have gradually become an important direction in the field of robotics research. Unlike traditional rigid manipulators, continuum robots can change shape through continuous movement, just like organisms, and have strong flexibility and compliance. This makes continuum robots more flexible and efficient than traditional manipulators when dealing with complex, irregular, and unknown environments. They have been widely used in fields such as medicine, industry, and exploration. For example, in the medical field, continuum robots can be used for minimally invasive surgery and can enter and operate in confined spaces. In deep-sea exploration or space exploration, continuum robots can flexibly adapt to various complex environments and complete tasks.

[0003] However, despite the high flexibility and adaptability of continuum robots, their performance in practical applications still faces some technical difficulties, especially the two problems of non-adjustable stiffness and poor multi-task adaptability. Traditional continuum robots usually adopt a fixed stiffness design, which means that when they perform tasks, the stiffness cannot be adjusted according to environmental changes, resulting in the robot being unable to effectively respond to some special work scenarios or task requirements. In addition, the control method of traditional continuum robots is single, usually relying on a fixed drive system and control strategy. This single control method shows weak adaptability in the execution of multiple or complex tasks. Especially in some scenarios that require high-precision operations or handling different mechanical loads, the robot lacks effective stiffness adjustment capabilities, making it difficult to complete complex tasks.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] The main purpose of this application is to provide a multi-morphous variable stiffness continuum robot and control method, aiming to solve the problem in the prior art that the continuum robot cannot adjust the stiffness and has a single control method, thus being unable to quickly adapt to switching between multiple tasks in a multi-task environment, resulting in low task execution efficiency.

[0006] According to a first aspect of an embodiment of the present application, there is provided a multi-morphological variable-stiffness continuum robot, which includes a continuum module, a variable drive module and an air pump; the continuum module includes a base, a first flexible component and a tendon drive component, the head end of the first flexible component is arranged on the base, the tendon drive component is arranged on the base, and the tendon drive component is connected to the end of the first flexible component through a drive rope, and a accommodating cavity is formed in the first flexible component; the variable drive module includes a plurality of head motion units, a tail motion unit, an actuator box and a plurality of second flexible components, the plurality of second flexible components are respectively connected to the head motion unit and the tail motion unit, the actuator box is connected to the plurality of second flexible components, and the air pump is detachably connected to the plurality of second flexible components through an air tube;

[0007] When the polymorphic variable stiffness continuum robot performs fixed base movement, the tendon drive component is used to drive the first flexible component to perform bending and / or telescopic movement through the drive rope, and the air pump is used to control multiple second flexible components through the air tube, so that the variable drive module moves in the accommodating cavity to complete the variable stiffness adjustment of the polymorphic variable stiffness continuum robot; when the polymorphic variable stiffness continuum robot performs cable movement, the air pump is used to control multiple second flexible components through the air tube, so that the variable drive module moves outside the accommodating cavity; when the polymorphic variable stiffness continuum robot performs cable-free movement, the actuator box is used to control multiple second flexible components, so that the variable drive module moves outside the accommodating cavity.

[0008] Optionally, in one embodiment of the present application, the first flexible component includes a plurality of flexible ring structures and a plurality of unit fixing plates, the flexible ring structures and the unit fixing plates are arranged at intervals, and the unit fixing plate at the head end is connected to the base, the drive rope passes through the plurality of unit fixing plates, and the end of the drive rope is connected to the unit fixing plate at the end.

[0009] Optionally, in one embodiment of the present application, the tendon drive assembly includes multiple motors and multiple winding devices, the multiple motors are connected to the multiple winding devices in a one-to-one correspondence, the multiple motors and the multiple winding devices are respectively connected to the base, the multiple winding devices are respectively wound with corresponding drive ropes, and the ends of the multiple drive ropes are evenly distributed on the unit fixing plate at the end.

[0010] Optionally, in one embodiment of the present application, each of the flexible ring structures includes an annular sponge and two spacer discs, the two spacer discs are respectively arranged on both sides of the annular sponge, the unit fixing plate is connected to the spacer disc, and the unit fixing plate and the spacer disc are correspondingly provided with a plurality of through holes, and the plurality of drive ropes correspond one-to-one to the plurality of through holes on each unit fixing plate and each spacer disc.

[0011] Optionally, in one embodiment of the present application, there are three motors, there are three winding devices, and the three winding devices are arranged on the base in the form of an equilateral triangle.

[0012] Optionally, in one embodiment of the present application, the head motion unit includes a top plate and a first friction structure, the top plate is connected to multiple second flexible components, and the first friction structure is arranged on the top plate; the tail motion unit includes a tail plate and a second friction structure, the tail plate is connected to multiple second flexible components, and the second friction structure is arranged on the tail plate; the first friction structure and the second friction structure are arranged opposite to each other, and the friction coefficient of the first friction structure is greater than the friction coefficient of the second friction structure.

[0013] Optionally, in one embodiment of the present application, each of the second flexible components includes a head flexible tube, a tail flexible tube and a three-way joint, and the two ends of the three-way joint are respectively connected to the head flexible tube and the tail flexible tube; the actuator box includes a drive box, multiple negative pressure pumps, multiple air pipe joints and multiple solenoid valves, and the multiple negative pressure pumps, multiple air pipe joints and multiple solenoid valves are arranged in the drive box, and the multiple negative pressure pumps, multiple air pipe joints and multiple solenoid valves correspond to each other one by one, the negative pressure pump is connected to one air port corresponding to the air pipe joint, the second air port of the air pipe joint is connected to one port corresponding to the solenoid valve, the third air port of the air pipe joint is connected to the third end corresponding to the three-way joint, and the two ports of the solenoid valve are connected to the atmosphere.

[0014] Optionally, in one embodiment of the present application, the head flexible tube and the tail flexible tube both include multiple sponge tubes, multiple constraint plates and a thin film structure, each two sponge tubes are connected by the constraint plates, and the thin film structure is wrapped around the outside of the multiple sponge tubes and the multiple constraint plates.

[0015] Optionally, in one embodiment of the present application, three second flexible components are provided, and three negative pressure pumps, three trachea connectors and three solenoid valves are provided respectively, the trachea connector is a three-way trachea connector, and the solenoid valve is a two-way solenoid valve.

[0016] A second aspect of the embodiments of the present application further provides a control method for the multi-morphological variable stiffness continuum robot according to any one of the above solutions, wherein the control method comprises:

[0017] When the multi-morph variable stiffness continuum robot performs fixed base movement, the tendon drive component drives the first flexible component to perform bending and / or telescopic movement through the drive rope, and the air pump controls the plurality of second flexible components through the air pipe, so that the variable drive module moves in the accommodating cavity, thereby completing the variable stiffness adjustment of the multi-morph variable stiffness continuum robot;

[0018] When the multi-morph variable stiffness continuum robot performs cable motion, the air pump controls the plurality of second flexible components through the air pipe, so that the variable drive module moves outside the accommodating cavity;

[0019] When the multi-morph variable stiffness continuum robot performs cable-free motion, the actuator box controls the plurality of second flexible components to enable the variable drive module to move outside the accommodating cavity.

[0020] Beneficial effects: The present application provides a multi-morphous variable stiffness continuum robot and a control method. The present application adjusts the length distance of the variable drive module in the continuum module through air drive, thereby adjusting the stiffness of the robot according to the movement requirements. Moreover, since the variable drive module can be in the accommodating cavity of the continuum module or partially or completely out of the accommodating cavity, the adjustment range of the robot stiffness is improved and the stiffness adjustment accuracy is guaranteed. Therefore, when facing a multi-task environment, the robot can quickly switch between fixed base movement, cable movement and cable-free movement, so that the stiffness can be adjusted according to the needs, and the switching of different tasks can be quickly adapted through tendon drive and air drive, thereby improving the task execution efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A perspective view of a preferred embodiment of the multi-morph variable stiffness continuum robot of the present application;

[0023] Figure 2 This is a structural diagram of a continuum module in a preferred embodiment of the multi-morph variable stiffness continuum robot of the present application;

[0024] Figure 3This is a structural diagram of a variable-stiffness drive module in a preferred embodiment of the multi-morph variable-rigidity continuum robot of the present application;

[0025] Figure 4 Schematic diagram of the fixed base motion in a preferred embodiment of the multi-morph variable stiffness continuum robot of the present application;

[0026] Figure 5 This is a schematic diagram of a preferred embodiment of the multi-morph variable stiffness continuum robot of the present application performing cable-free motion;

[0027] Figure 6 This is a schematic diagram of a preferred embodiment of the multi-morph variable stiffness continuum robot of the present application performing cable motion;

[0028] Figure 7 Schematic diagram of implementing inter-combat to achieve variable stiffness in a preferred embodiment of the multi-morph variable stiffness continuum robot of the present application;

[0029] Figure 8 This is a schematic diagram of the connection between the three-way air pipe interface, the negative pressure pump and the solenoid valve in a preferred embodiment of the multi-morph variable stiffness continuum robot of the present application;

[0030] Figure 9 This is a diagram showing the principle of the tendon-air hybrid drive control system and the control block diagram of the motion mode in a preferred embodiment of the multi-morph variable stiffness continuum robot of this application;

[0031] Figure 10 This is a flow chart of a preferred embodiment of the control method of the multi-morph variable stiffness continuum robot of the present application.

[0032] Description of reference numerals:

[0033] 10. Continuum module; 20. Variable drive module;

[0034] 101. First flexible component; 11. Base; 12. Drive rope; 13. Unit fixing plate; 14. Annular sponge; 15. Spacer disc; 16. Motor; 17. Winding device; 201. Head motion unit; 202. Tail motion unit; 203. Actuator box; 204. Second flexible component; 21. Top disc; 22. Tail disc; 221. Spacer disc; 23. Drive box; 231. Negative pressure pump; 232. Air pipe connector; 233. Solenoid valve; 234. Connecting disc; 241. Sponge tube; 242. Constraint sheet; 243. Thin film structure.

[0035] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and effects of this application clearer and more specific, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. The described embodiments are only possible technical implementations of this application and are not all possible implementations. Based on the embodiments in this application, those skilled in the art can fully combine the embodiments of this application to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of this application.

[0037] Among the related technologies, first, the stiffness adjustment range is limited: although the existing shape memory alloy technology and pneumatic drive system can adjust the stiffness of the robot to a certain extent, the amplitude and accuracy of the adjustment are usually limited. In some tasks, the robot may need very precise stiffness control to cope with changes in different objects or environments, and it cannot provide a sufficiently precise or wide adjustment range. Second, the control system is complex and lacks flexibility: its control system is usually complex and the control method is single. Especially those robots that rely on a single drive method (such as pneumatic systems or shape memory alloys) show insufficient adaptability in multi-task environments. When the robot needs to switch between multiple tasks, the traditional control method is often unable to quickly adapt to these changes, resulting in low task execution efficiency. Third, the modular design lacks flexibility. The modular structure of the related technology usually does not effectively solve the problem of unifying stiffness adjustment and task switching, resulting in insufficient adaptability of the robot when performing different tasks.

[0038] The present application adjusts the length and distance of the variable drive module in the continuum module through air drive, thereby adjusting the stiffness of the robot according to the movement requirements. Since the variable drive module can be in the accommodating cavity of the continuum module or partially or completely out of the accommodating cavity, the adjustment range of the robot stiffness is improved and the stiffness adjustment accuracy is guaranteed. Therefore, when facing a multi-task environment, the robot can quickly switch between fixed base movement (that is, the base is fixed, the first flexible component is driven to bend or extend by the rope, and the air pump is contracted or extended by the air drive variable drive module), cable movement (the air pump is driven by the air drive variable drive module to move forward, turn and roll outside the accommodating cavity, and the air pipe is connected to the air pump at this time, that is, there is a cable) and cable-free movement (the corresponding negative pressure pump air drives the variable drive module to move forward, turn and roll outside the accommodating cavity, and the air pipe is disconnected from the air pump at this time, that is, there is no cable), so that the stiffness can be adjusted according to the needs, and the switching of different tasks can be quickly adapted through tendon drive (that is, flexible rope control) and air drive (that is, gas positive and negative pressure control), thereby improving the efficiency of task execution.

[0039] In response to the problems of unadjustable stiffness and poor multi-task adaptability of continuum robots, the multi-morphological variable stiffness continuum robot of the present application adopts a tendon-air hybrid drive system, which can realize the control of multiple forms and multiple motion modes. The present application can not only flexibly adjust the stiffness of the robot according to task requirements, but also enable the robot to achieve more efficient and precise motion and task execution capabilities in a variety of environments. The multi-morphological variable stiffness continuum robot of the present application has the following advantages: the integration of multiple motion modes: the robot can flexibly switch between different motion modes (cable motion, free motion, fixed base motion, etc.) according to the requirements of the task, which greatly improves its adaptability and multi-task execution capability; the realization of variable stiffness function: through the tendon-air hybrid drive system, the robot can adjust the stiffness in real time and flexibly respond to different operational requirements, thereby significantly improving the performance of the robot in different industries and scenarios, especially in tasks that require delicate operations or carry large loads, the adjustment of stiffness can help the robot maintain stability in various environments; through the collaborative control method of tendon-air hybrid drive, combined with the advantages of high control precision of tendon rope drive and fast response speed of fluid drive, the continuum robot can meet the requirements of control precision and response speed for different tasks.

[0040] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0041] like Figure 1 、 Figure 2 and Figure 3 As shown, an embodiment of the present application provides a multi-morphological variable stiffness continuum robot, which includes a continuum module 10, a variable drive module 20 and an air pump; the continuum module 10 includes a base 11, a first flexible component 101 and a tendon drive component, the head end of the first flexible component 101 is arranged on the base 11, the tendon drive component is arranged on the base 11, and the tendon drive component is connected to the end of the first flexible component 101 through a drive rope 12, and a accommodating cavity is formed in the first flexible component 101; the variable drive module 20 includes a plurality of head motion units 201, a tail motion unit 202, an actuator box 203 and a plurality of second flexible components 204, the plurality of second flexible components 204 are respectively connected to the head motion unit 201 and the tail motion unit 202, the actuator box 203 is connected to the plurality of second flexible components 204, and the air pump is detachably connected to the plurality of second flexible components 204 through an air tube;

[0042] When the polymorphic variable stiffness continuum robot performs fixed base movement, the tendon drive component is used to drive the first flexible component 101 to perform bending and / or telescopic movement through the drive rope 12, and the air pump is used to control multiple second flexible components 204 through the air tube, so that the variable drive module 20 moves in the accommodating cavity to complete the variable stiffness adjustment of the polymorphic variable stiffness continuum robot; when the polymorphic variable stiffness continuum robot performs cable movement, the air pump is used to control multiple second flexible components 204 through the air tube, so that the variable drive module 20 moves outside the accommodating cavity; when the polymorphic variable stiffness continuum robot performs cable-free movement, the actuator box 203 is used to control multiple second flexible components 204, so that the variable drive module 20 moves outside the accommodating cavity.

[0043] It should be noted that the air pump is not shown in the figure. The air pump drives the multiple second flexible components 204 of the variable drive module 20 through the air pipe (i.e., through positive pressure inflation or negative pressure exhaust), so that the air pump controls the variable drive module 20 through air drive to perform fixed base movement or cable movement.

[0044] See also Figure 2 The continuum module 10 is the main body of the robot, responsible for its basic movements and morphological transformations. The continuum module 10 controls the displacement of the drive rope 12 through a tendon drive control system, thereby enabling the robot's main body to bend and extend. The tendon drive system utilizes high-strength, low-friction tendons to precisely adjust the rope's displacement via a motor 16, thereby controlling the robot's posture changes and bending degree under specific tasks. This not only provides high-precision control but also enables flexible bending, enabling the robot to adapt to tasks in confined spaces or complex terrain. Figure 3 The variable drive module 20 mainly realizes the robot's forward, turning and rolling movements through the pneumatic drive control system. The module enables the robot to perform tasks such as movement and turning in different environments through the contraction and extension of pneumatic muscles (i.e. flexible components). The flexibility of pneumatic drive enables the robot to maintain efficient power output and stability when it needs to change direction, angle or perform complex movements. The design of the variable drive module 20 enables the robot to not only have the ability to adjust its stiffness, but also have diversity in movement methods, further improving its adaptability.

[0045] See for example Figure 4 When performing fixed-base motion, i.e., in fixed-base 11 mode, the robot achieves local bending and extension through tendon control, which is suitable for performing tasks requiring high precision, such as operation or manipulation within a fixed work area. The base 11 provides stable support, and the tendon is driven by the motor 16, enabling the robot to achieve fine posture adjustment. Figure 5 When performing cable-free movement, i.e., in the cable-free movement mode, the robot achieves free movement through pneumatically driven contraction and extension. The cable-free mode allows the robot to move in a wider range without being restricted by the base 11. The cable-free drive system enables the robot to have good mobility in multiple directions, making it suitable for tasks such as exploration and transportation. Figure 6 When performing cable movement, that is, in the cable mode, the modules work together, and the robot can perform traction movement along the cable direction with the support of the base 11. This movement mode is suitable for long-distance movement or navigation operations within a certain range, while ensuring movement stability and direction control.

[0046] In this application, variable stiffness control is one of the key features of the present invention. Figure 7 As shown, by adjusting the structure of the variable drive module 20, the robot can achieve a change in stiffness. This control principle relies on the design structure of the variable drive module 20, which is set in the central cavity of the continuum module 10. The distance between the upper and lower parts of the module (denoted as H) determines the stiffness of the robot. By adjusting the length of H, the system can change the stiffness of the module. Figure 7 In (a) and (b), increasing the length of H increases the module's stiffness, thereby enhancing the robot's ability to support heavy loads. Reducing the length of H reduces the module's stiffness, giving the robot greater flexibility, making it suitable for tasks requiring delicate manipulation or flexible adaptation. The robot can automatically adjust the length of H based on task requirements, changing stiffness in real time. Figure 7 In (c) and (d), the bending directions of the variable drive module 20 and the continuum module 10 are different. This is to create an antagonism between the two, not only to adjust the stiffness but also to ensure the stability of the robot. In the cable motion mode, the robot can adjust the stiffness according to the contact force of the object and the operation requirements; in the free motion mode, the robot can become more flexible, thereby improving the flexibility and adaptability of the task. Through this variable stiffness design, the robot of the present application can flexibly adapt to multi-tasking environments and enhance its versatility.

[0047] In one embodiment of the present application, the first flexible component 101 includes multiple flexible ring structures and multiple unit fixing plates 13, the flexible ring structures and the unit fixing plates 13 are arranged at intervals, and the unit fixing plate 13 at the head end is connected to the base 11, the driving rope 12 passes through the multiple unit fixing plates 13, and the end of the driving rope 12 is connected to the unit fixing plate 13 at the end.

[0048] Specifically, such as Figure 2 and Figure 4, there are three first flexible components 101, but not limited to this, and can also be set to 4 or 6; there are six flexible ring structures, and the unit fixing plates 13 are set to 7. A unit fixing plate 13 is set between each two adjacent flexible ring structures, and a unit fixing plate 13 is set on the outside of the head end flexible ring structure and the outside of the tail end flexible ring structure, that is, multiple flexible ring structures are located between the head and tail unit fixing plates 13, but not limited to this, and the number can be set according to needs. By setting the unit fixing plates 13 and the flexible ring structures, a flexible unit is formed, so that each drive rope 12 (i.e., flexible rope) passes through each unit fixing plate 13 and is connected to the tail end (i.e., Figure 2 The flexible units are pulled on the unit fixing plate 13 at the right end by the drive rope 12 to make the first flexible component 101 bend (completed by pulling part of the drive rope 12 and releasing the other part) and telescopic movement (contraction is achieved by pulling all the drive ropes 12).

[0049] In one embodiment of the present application, the tendon drive assembly includes multiple motors 16 and multiple winding devices 17, and the multiple motors 16 are connected to the multiple winding devices 17 in a one-to-one correspondence. The multiple motors 16 and the multiple winding devices 17 are respectively connected to the base 11, and the corresponding driving ropes 12 are respectively wound around the multiple winding devices 17, and the ends of the multiple driving ropes 12 are evenly distributed on the unit fixing plate 13 at the end.

[0050] In one embodiment of the present application, three motors 16 are provided, three winding devices 17 are provided, and the three winding devices 17 are arranged on the base 11 in the shape of an equilateral triangle.

[0051] Specifically, such as Figure 2 and Figure 4 As shown, three motors 16 are arranged in the shape of an equilateral triangle on the base 11, and each motor 16 is connected to a corresponding winding device 17. A driving rope 12 is wound around each winding device 17. Therefore, under the control of the motor 16, the winding device 17 will wind the corresponding driving rope 12, thereby driving the first flexible component 101 to complete the contraction or bending action, and the winding device 17 will release the corresponding driving rope 12 to drive the first flexible component 101 to complete the extension or bending action.

[0052] In one embodiment of the present application, each of the flexible ring structures includes an annular sponge 14 and two spacer discs 15, and the two spacer discs 15 are respectively arranged on both sides of the annular sponge 14, and the unit fixing plate 13 is connected to the spacer disc 15. The unit fixing plate 13 and the spacer disc 15 are correspondingly provided with a plurality of through holes, and the plurality of drive ropes 12 correspond one-to-one to the plurality of through holes on each unit fixing plate 13 and each spacer disc 15.

[0053] Specifically, such as Figure 2 As shown, the annular sponge 14 and the spacer discs 15 connected on both sides are annular, the spacer discs 15 are arranged to fit the annular sponge 14, and the outer edge of the spacer discs 15 exceeds the annular sponge 14, and through holes are provided on the outer edge of the spacer discs 15. Correspondingly, the unit fixing plate 13 connected to the spacer discs 15 is also provided with the same number of through holes. The driving rope 12 wound on the winding device 17 passes through the through holes of the unit fixing plate 13, the spacer discs 15, and the unit fixing plate 13 in turn, and is thereby connected to the tail end unit fixing plate 13, so as to enable the first flexible component 101 to complete bending and telescopic movements.

[0054] In one embodiment of the present application, the head motion unit 201 includes a top plate 21 and a first friction structure, the top plate 21 is connected to multiple second flexible components 204, and the first friction structure is arranged on the top plate 21; the tail motion unit 202 includes a tail plate 22 and a second friction structure, the tail plate 22 is connected to multiple second flexible components 204, and the second friction structure is arranged on the tail plate 22; the first friction structure and the second friction structure are arranged opposite to each other, and the friction coefficient of the first friction structure is greater than the friction coefficient of the second friction structure.

[0055] Specifically, such as Figure 3 and Figure 5 As shown, the tail motion unit 202 includes a tail plate 22, a spacer plate 221 and a second friction structure, and the head motion unit 201 includes a top plate 21, a spacer plate 221 (the same as the tail) and a first friction structure. The motion unit is connected to the second flexible component 204, so that the variable drive module 20 is driven by air to multiple second flexible groups, so that the first friction structure and the second friction structure are moved in the ground or the continuum module 10. Since the friction coefficient of the first friction structure is greater than the friction coefficient of the second friction structure, the first friction structure and the second friction structure are in contact with the ground or the inner wall of the annular sponge 14 respectively, and the forward, turning and rolling movements are completed by the peristalsis of the second flexible component 204.

[0056] Furthermore, the first friction structure comprises a connecting plate and a triangular-section abutment block connected to the connecting plate. The abutment block protrudes from the top plate 21, enabling contact with the ground or the inner wall of the annular sponge 14. The second friction structure is an L-shaped plate, the lower surface of which protrudes from the tail plate 22, enabling contact with the ground or the inner wall of the annular sponge 14. When the variable drive module 20 moves, the air-driven operation of the multiple second flexible components 204 causes the first and second friction structures to respectively contact the ground or the inner wall of the annular sponge 14, and the creeping motion of the second flexible components 204 completes the forward movement, turning, and rolling movements.

[0057] In one embodiment of the present application, each of the second flexible components 204 includes a head flexible tube, a tail flexible tube and a three-way joint, and the two ends of the three-way joint are respectively connected to the head flexible tube and the tail flexible tube; the actuator box 203 includes a drive box 23, multiple negative pressure pumps 231, multiple air pipe joints 232 and multiple solenoid valves 233, and the multiple negative pressure pumps 231, multiple air pipe joints 232 and multiple solenoid valves 233 are arranged in the drive box 23, and the multiple negative pressure pumps 231, multiple air pipe joints 232 and multiple solenoid valves 233 correspond to each other one by one, the negative pressure pump 231 is connected to one air port corresponding to the air pipe joint 232, the second air port of the air pipe joint 232 is connected to one port corresponding to the solenoid valve 233, the third air port of the air pipe joint 232 is connected to the third end corresponding to the three-way joint, and the two ports of the solenoid valve 233 are connected to the atmosphere.

[0058] In one embodiment of the present application, three second flexible components 204 are provided, and three negative pressure pumps 231, three air pipe connectors 232 and three solenoid valves 233 are provided respectively. The air pipe connector 232 is a three-way air pipe connector 232, and the solenoid valve 233 is a two-way solenoid valve 233.

[0059] Specifically, such as Figure 3 and Figure 8 As shown, each second flexible component 204 is divided into two sections, namely a head flexible tube and a tail flexible tube, and the two sections of the flexible tube are connected through the interfaces at both ends of the tee joint, so that the head flexible tube, the tee joint and the tail flexible tube form Figure 7 The robot air cavity in the robot, the third end of the three-way connector is connected to the second air port of the three-way air pipe interface, Figure 7 The three air ports of the three-way air pipe interface (which is not the same interface as the three-way joint) are respectively connected to the three-way joint, the negative pressure pump 231 (i.e., a micro diaphragm pump, which provides negative pressure to pump air from the head flexible tube and the tail flexible tube) and the solenoid valve 233. The solenoid valve 233 is a two-way two-dimensional solenoid valve 233. The two ports of the solenoid valve 233 are connected to the atmosphere (cable system, i.e., cable movement) and the three-way air pipe interface.

[0060] It should be noted that, see Figure 8 and Figure 5 In the cable-free driving mode, when the micro-diaphragm pump and the micro-two-way solenoid valve 233 are working, the micro-diaphragm pump outputs negative pressure (i.e., draws air from the second flexible component 204), the micro-two-way solenoid valve 233 is closed, and the gas in the robot cavity flows to the micro-diaphragm pump; when the micro-diaphragm pump and the micro-two-way solenoid valve 233 stop working, the micro-two-way solenoid valve 233 is opened, and the gas in the atmosphere flows to the robot air cavity (i.e., due to the negative pressure, the atmosphere inflates the second flexible component 204). Figure 8 and Figure 6In the cable drive mode, the micro diaphragm pump and the micro two-way solenoid valve 233 stop working (i.e., the solenoid valve 233 is closed), and the robot's air cavity is only connected to the cable drive control system. The gas flow direction in the robot's air cavity is regulated by the cable drive control system, that is, the robot's air cavity (i.e., the head flexible tube, the three-way connector, and the tail flexible tube) is inflated or exhausted only by the air pump through the air pipe.

[0061] like Figure 3 and Figure 5 As shown, the drive box 23 is provided with a connecting disk 234, and three notches are evenly distributed on the connecting disk 234. The corresponding second flexible component 204 is fixedly connected through the notches. The circular hole set in the center of the connecting disk 234 is used to fix the air pipe connected to the air pump.

[0062] In one embodiment of the present application, the head flexible tube and the tail flexible tube both include a plurality of sponge tubes 241, a plurality of constraint plates 242 and a thin film structure 243. Every two sponge tubes 241 are connected by the constraint plates 242, and the thin film structure 243 is wrapped around the outside of the plurality of sponge tubes 241 and the plurality of constraint plates 242.

[0063] Specifically, such as Figure 3 As shown, the head flexible tube and the tail flexible tube are similar to the flexible ring structure, and a film structure 243 (i.e., PE film) is provided on the outside of the sponge tube 241 and the constraint sheet 242 of the flexible tube to prevent air leakage. By controlling the gas in the three second flexible components 204, the forward movement, turning and rolling of the variable drive module 20 are realized.

[0064] In the present application, an adsorption block is provided on the end of the continuum module 10 , namely, the tail unit fixing plate 13 ; and a camera is provided on the end of the variable drive module 20 , namely, the top plate 21 .

[0065] like Figure 9As shown, the tendon-pneumatic hybrid drive control system precisely regulates the coordinated operation of tendon drive and pneumatic drive, giving the robot higher motion precision and multifunctional adaptability. The system includes the following main modules: a main control board, which receives control signals from the user, decodes them, and sends them to each drive module for operation. The main control board adjusts the working status of the tendon drive and pneumatic drive in real time according to the needs of different tasks to adapt to the robot's different motion modes and stiffness requirements; a motor 16 speed control module, consisting of a motor 16 speed regulator and a brushless DC motor 16, which is responsible for precisely controlling the robot's motion speed and direction. The motor 16 speed control module's main function is to drive the tendon drive system to achieve precise bending and extension motion through the speed and torque output of motor 16, ensuring the robot's precise and stable movement; and a pneumatic drive control system. The pneumatic drive system includes a cable drive control system and a cableless drive control system. The cable drive control system is suitable for tasks requiring precise position control, while the cableless drive control system is suitable for use when greater flexibility and adaptability are required. The two systems switch alternately according to task requirements to jointly regulate the robot's motion mode. By combining these two drive systems, the tendon-air hybrid drive control system can adjust the robot's stiffness and motion state in real time according to the needs of different tasks. The robot can achieve varying degrees of flexibility or rigidity depending on the task, ensuring the completion of various tasks in complex environments.

[0066] like Figure 9 As shown, the feedback signal processing module of the tendon-air hybrid drive control system is responsible for receiving feedback information from various control modules to ensure the stability and accuracy of the robot's movement. The feedback mechanism includes feedback signals from the motor 16 speed control module and the pneumatic control system: the motor 16 feedback signal, the motor 16 speed regulator monitors the speed and torque changes of the motor 16 through sensors, and uploads this information to the main control board. The main control board adjusts the working state of the motor 16 according to the feedback signal to ensure the accuracy of the robot's movement; the air pressure feedback signal, the pneumatic control system monitors the air pressure state through components such as the proportional valve and the solenoid valve 233, and feeds back the air pressure information to the main control board. The main control board adjusts the control parameters of the pneumatic drive in real time based on these feedback signals to achieve precise movement and stiffness adjustment of the robot. Real-time processing of feedback signals enables the robot to automatically adjust its motion parameters according to changes in the environment, ensuring that the robot can work stably in complex task environments.

[0067] The implementation of this application mainly relies on technical features such as tendon-air hybrid drive system and modular design. In order to fully illustrate how to implement the present invention, several feasible implementation methods will be listed in detail below.

[0068] The drive method of this application is a tendon-air hybrid drive system. By combining tendon drive with pneumatic drive, this system provides flexible stiffness adjustment capabilities and precise motion control. Its implementation can be as follows:

[0069] Implementation 1: Parallel Control of Tendon and Pneumatic Drives: In this implementation, the robot uses an electric servo motor 16 to drive the tendon system, while a pneumatic device (such as an airbag or pneumatic actuator) controls the robot's stiffness. The electric servo motor 16 precisely controls the robot's position and trajectory, while the pneumatic device adjusts the robot's stiffness based on task requirements. By using these two drive methods in parallel, the requirements for precise motion control and rapid stiffness adjustment can be met simultaneously, ensuring the robot's flexibility and adaptability for complex tasks.

[0070] Implementation method two, coordinated control of tendon drive and pneumatic drive: Tendon drive is combined with pneumatic drive and adopts a closed-loop control system. During the execution of complex tasks, the system can flexibly switch between three motion modes, including fixed-base motion, cable motion and cable-free motion. Through the coordinated control of tendon drive and pneumatic drive, the robot can select the most appropriate motion mode according to specific task requirements and achieve more complex and diverse functions. For example, when high-precision operation is required, the robot can adopt a fixed-base motion mode to ensure stability; when performing remote operation or navigation, it switches to a cable or cable-free motion mode to improve flexibility and adaptability.

[0071] It should be noted that the replacement of drive methods, such as hydraulic drive instead of pneumatic drive, can provide higher force and more precise force control than pneumatic drive. Therefore, for tasks that require greater driving force and more precise control, hydraulic drive may become an alternative to pneumatic drive. In addition to traditional pneumatic or hydraulic systems, the replacement of stiffness adjustment modules with smart materials (such as shape memory alloys, piezoelectric materials, etc.) to achieve dynamic changes in stiffness may also become an alternative. Shape memory alloys can adjust their shape according to changes in temperature, providing a variable stiffness effect similar to pneumatic control, and can operate under higher temperature conditions, suitable for application under specific environmental conditions. Elastic materials can replace pneumatic systems. In some application scenarios where stiffness changes are not required, highly elastic materials (such as sponges, rubber materials, etc.) can be considered to replace pneumatic drive modules. These elastic materials can adaptively deform under load, providing a certain degree of flexibility and stiffness adjustment. They are especially suitable for application scenarios with relatively simple environments and tasks with low stiffness adjustment requirements.

[0072] The following describes the specific application process of the multi-modal variable stiffness continuum robot of this application by combining the multi-task scenarios of fixed base motion, cable motion, and cable-free motion:

[0073] When inserting a plug into a socket, the fixed base moves, and the air pump's air drive controls the length of the drive module 20 within the accommodating cavity of the first flexible component 101, thereby adjusting the robot's stiffness to ensure that the suction block on the continuum module 10 can absorb the plug and insert it into the socket (if the stiffness is insufficient, the plug cannot be inserted into the socket). Tendon drive (winding and releasing the drive rope 12) causes the first flexible component 101 to bend and extend, so that the suction block aligns with the suction plug and inserts it into the socket.

[0074] In the task of switching to moving to the target object for filming, both cabled and cable-free motion are performed. First, the variable drive module 20 is controlled by the air pump to separate from the accommodating cavity of the first flexible component 101. Then, the variable drive module 20 is disconnected from the air tube. The variable drive module 20 is controlled by the air pump 231 to move and turn to move to the target object for filming. This application can realize variable stiffness adjustment of the robot, switching between multiple motion modes, and efficient task execution.

[0075] In the present application, an adaptive control system can also be combined with augmented reality technology. Combining augmented reality (AR) technology with the interactive control system of the present application can provide users with a more intuitive and intelligent operating experience. Through AR glasses or other AR devices, the operator can not only view the robot's motion state and task progress in real time, but also directly see the robot's operating trajectory and perceived object information in the virtual environment, thereby helping the operator to make more precise control and decisions. For example, when the robot is navigating in a complex environment, the operator can see the robot's real-time position, environmental map and task objectives through the AR interface, and accurately adjust the robot's movements through gesture control or voice control. The combination of AR technology and robot control can greatly improve the efficiency and operability of human-computer interaction, and is particularly suitable for tasks that require precise operation and real-time feedback. In addition, the multi-level modular design proposed in this application has great scalability. In the future, the reconfigurability of the module can be further improved so that the robot can automatically adjust its structure during task execution. For example, robots can use their self-diagnosis and self-repair capabilities to automatically reorganize their structure based on module damage or changes in task requirements. This adaptive reconstruction capability allows robots to maximize the use of existing resources, improve efficiency, and reduce failure rates when performing tasks. In addition, with the development of materials science, lighter and higher-strength intelligent materials can be introduced in the future, making the various modules of the robot not only more flexible but also having greater load-bearing capacity and durability. The combination of modular and reconfigurable design will enable robots to have greater adaptability in complex and changing working environments.

[0076] The control method of the multi-morph variable stiffness continuum robot described in the preferred embodiment of the present application is as follows: Figure 10 As shown, the control method of the polymorphic variable stiffness continuum robot includes the following steps:

[0077] In step S101, when the multi-morph variable stiffness continuum robot performs fixed base movement, the tendon drive component drives the first flexible component to perform bending and / or telescopic movement via the drive rope, and the air pump controls the plurality of second flexible components via the air pipe, so that the variable drive module moves in the accommodating cavity, thereby completing variable stiffness adjustment of the multi-morph variable stiffness continuum robot;

[0078] In step S102, when the multi-morph variable stiffness continuum robot performs cable motion, the air pump controls the plurality of second flexible components through the air pipe, so that the variable drive module moves outside the accommodation cavity;

[0079] In step S103 , when the multi-morph variable stiffness continuum robot performs cable-free motion, the actuator box controls the plurality of second flexible components so that the variable drive module moves outside the accommodating cavity.

[0080] The present application provides a multi-form variable stiffness continuum robot control method through tendon-air hybrid drive control, that is, it realizes the combination of two drive methods. By combining the precise control of the tendon drive system and the adjustable stiffness characteristics of the pneumatic drive system. This innovative technical solution enables the continuum robot to achieve more precise motion control when performing tasks, while adjusting the overall stiffness of the robot according to task requirements. The tendon drive can accurately control the position and motion trajectory of the robot end, while the pneumatic drive allows the robot to quickly change its own stiffness when facing different tasks, so that it can adapt to changes in complex environments. Therefore, the present application solution not only improves the control accuracy of the robot, but also enhances the adaptability of the robot, enabling it to cope with a variety of environments and task requirements.

[0081] The robot of the present application can use a variety of movement modes, including fixed-base movement, cable movement, and grip-free movement, to achieve more functions. Through tendon-air hybrid drive, the robot of the present application has a variety of movement modes, which expands its application scenarios. Specifically, the robot can perform precise movements on a fixed base, can be remotely operated by cable when performing tasks, and can also move freely without external constraints. In the fixed-base movement mode, the robot can accurately locate and perform tasks; in the cable movement mode, the robot can effectively expand the working range and perform precise operations in complex environments; and in the cable-free movement mode, the robot has a high degree of freedom and can easily complete tasks in complex and uncertain environments. The combination of these three movement modes makes the robot more adaptable and can be flexibly used in a variety of application scenarios.

[0082] The present application can achieve stiffness changes, can be more adaptable to a variety of environments, and has higher flexibility and compliance. The robot's stiffness is adjustable, and the robot can adjust its stiffness through a pneumatic drive system. The ability to change stiffness allows the robot to exhibit different hardness and flexibility in different tasks, thereby adapting to various different working environments. In some tasks that require delicate operations, the robot can be adjusted to a lower stiffness to ensure smooth manipulation of objects; when it needs to withstand greater forces or perform complex interactions, the robot can improve its mechanical properties and enhance its stability by increasing its stiffness. This technical feature gives the robot greater flexibility and compliance than traditional robots, and enables it to better perform tasks in uncertain or dynamically changing environments.

[0083] In the description of this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or mutual communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0084] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0085] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0086] It should be noted that, in this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0087] The terms "first," "second," "third," "fourth," etc. (if any) in the specification and claims of the present application and in the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or apparatus.

[0088] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-morph variable stiffness continuum robot, characterized in that: The polymorphic variable stiffness continuum robot comprises a continuum module, a variable drive module and an air pump; The continuum module includes a base, a first flexible component, and a tendon drive component. The first end of the first flexible component is disposed on the base. The tendon drive component is disposed on the base and connected to the end of the first flexible component via a drive rope. The first flexible component is formed with a receiving cavity. The variable drive module includes a plurality of head motion units, a tail motion unit, an actuator box and a plurality of second flexible components, wherein the plurality of second flexible components are respectively connected to the head motion unit and the tail motion unit, the actuator box is connected to the plurality of second flexible components, and the air pump is detachably connected to the plurality of second flexible components via an air pipe; When the multi-morphological variable stiffness continuum robot performs fixed base movement, the tendon drive component is used to drive the first flexible component to perform bending and / or telescopic movement through the drive rope, and the air pump is used to control the plurality of second flexible components through the air tube, so that the variable drive module moves in the accommodating cavity, thereby completing the variable stiffness adjustment of the multi-morphological variable stiffness continuum robot; When the multi-morph variable stiffness continuum robot performs cable motion, the air pump is used to control the plurality of second flexible components through the air pipe so that the variable drive module moves outside the accommodating cavity; When the multi-morph variable stiffness continuum robot performs cable-free motion, the actuator box is used to control the plurality of second flexible components so that the variable drive module moves outside the accommodating cavity.

2. The multi-morph variable stiffness continuum robot according to claim 1, characterized in that: The first flexible component includes multiple flexible ring structures and multiple unit fixing plates, the flexible ring structures and the unit fixing plates are arranged at intervals, and the unit fixing plate at the head end is connected to the base, the driving rope passes through the multiple unit fixing plates, and the end of the driving rope is connected to the unit fixing plate at the end.

3. The multi-morph variable stiffness continuum robot according to claim 2, characterized in that: The tendon drive assembly includes multiple motors and multiple winding devices, and the multiple motors are connected to the multiple winding devices in a one-to-one correspondence. The multiple motors and the multiple winding devices are respectively connected to the base, and the corresponding driving ropes are respectively wound around the multiple winding devices. The ends of the multiple driving ropes are evenly distributed on the unit fixing plate at the end.

4. The multi-morph variable stiffness continuum robot according to claim 2, characterized in that: Each of the flexible ring structures includes an annular sponge and two spacer discs, the two spacer discs are respectively arranged on both sides of the annular sponge, the unit fixing plate is connected to the spacer disc, and the unit fixing plate and the spacer disc are correspondingly provided with multiple through holes, and the multiple drive ropes correspond one-to-one to the multiple through holes on each unit fixing plate and each spacer disc.

5. The multi-morphological variable stiffness continuum robot according to claim 3, characterized in that: There are three motors and three winding devices, and the three winding devices are arranged on the base in the shape of an equilateral triangle.

6. The multi-morphological variable stiffness continuum robot according to any one of claims 1 to 5, characterized in that: The head movement unit includes a top plate and a first friction structure, the top plate is connected to a plurality of the second flexible components, and the first friction structure is arranged on the top plate; The tail motion unit includes a tail plate and a second friction structure, wherein the tail plate is connected to a plurality of the second flexible components, and the second friction structure is provided on the tail plate; The first friction structure and the second friction structure are arranged opposite to each other, and a friction coefficient of the first friction structure is greater than a friction coefficient of the second friction structure.

7. The multi-morphological variable stiffness continuum robot according to any one of claims 1 to 5, characterized in that: Each of the second flexible components includes a head flexible tube, a tail flexible tube and a tee joint, wherein two ends of the tee joint are respectively connected to the head flexible tube and the tail flexible tube; The actuator box includes a driving box, multiple negative pressure pumps, multiple air pipe joints and multiple solenoid valves. The multiple negative pressure pumps, multiple air pipe joints and multiple solenoid valves are arranged in the driving box, and the multiple negative pressure pumps, multiple air pipe joints and multiple solenoid valves correspond to each other one by one. The negative pressure pump is connected to one air port corresponding to the air pipe joint, the second air port of the air pipe joint is connected to one air port corresponding to the solenoid valve, the third air port of the air pipe joint is connected to the third end corresponding to the three-way joint, and the two ports of the solenoid valve are connected to the atmosphere.

8. The multi-morph variable stiffness continuum robot according to claim 7, characterized in that: The head flexible tube and the tail flexible tube both include multiple sponge tubes, multiple constraint sheets and a film structure. Every two sponge tubes are connected by the constraint sheet, and the film structure is wrapped around the outside of the multiple sponge tubes and the multiple constraint sheets.

9. The multi-morphological variable stiffness continuum robot according to claim 7, characterized in that: There are three second flexible components, and there are three negative pressure pumps, three trachea connectors, and three solenoid valves respectively. The trachea connector is a three-way trachea connector, and the solenoid valve is a two-way solenoid valve.

10. A control method based on the multi-morphological variable stiffness continuum robot according to any one of claims 1 to 9, characterized in that: The control method includes: When the multi-morph variable stiffness continuum robot performs fixed base movement, the tendon drive component drives the first flexible component to perform bending and / or telescopic movement through the drive rope, and the air pump controls the plurality of second flexible components through the air pipe, so that the variable drive module moves in the accommodating cavity, thereby completing the variable stiffness adjustment of the multi-morph variable stiffness continuum robot; When the multi-morph variable stiffness continuum robot performs cable motion, the air pump controls the plurality of second flexible components through the air pipe, so that the variable drive module moves outside the accommodating cavity; When the multi-morph variable stiffness continuum robot performs cable-free motion, the actuator box controls the plurality of second flexible components to enable the variable drive module to move outside the accommodating cavity.

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