A rope-driven test system for a variable stiffness robotic arm and a variable stiffness hand

Abstract

A rope-driven test system for variable stiffness manipulator and variable stiffness gripper includes a two-degree-of-freedom passive motion part, a three-degree-of-freedom active motion part, a pure rigid manipulator, a flexible joint, a variable stiffness manipulator and a variable stiffness gripper, and a frame. The two-degree-of-freedom passive motion part allows manual adjustment of the posture, and the three-degree-of-freedom active motion part realizes accurate operation through motor driving. The pure rigid manipulator provides high stiffness operation, and the flexible joint and the variable stiffness manipulator allow dynamic adjustment of the stiffness to adapt to different tasks. The variable stiffness gripper serves as an end effector and directly contacts objects. The entire system is installed on the frame, realizing structural stability and modular design, and can comprehensively evaluate the performance of the manipulator and the gripper. The invention provides a rope-driven test system that is comprehensive in function, flexible in operation and convenient to maintain, and can effectively test and verify the performance of the variable stiffness manipulator and the gripper, providing important technical support for practical applications.

Description

Technical Field

[0001] This invention relates to robotics technology, and in particular to a rope-driven testing system for variable stiffness robotic arms and variable stiffness grippers. Background Technology

[0002] With the rapid development of robotics technology, robots are being used more and more widely in industries such as manufacturing, healthcare, and services. Traditional robots generally have rigid structures, which makes them perform well in performing high-precision, high-stiffness tasks. However, rigid robots have limitations in certain applications, especially in tasks that require complex interactions with flexible materials or irregular objects. To address these challenges, variable stiffness technology has emerged.

[0003] Variable stiffness robotic arms and grippers can dynamically adjust their stiffness according to task requirements. This adjustable stiffness not only improves the robot's operational flexibility but also effectively enhances its adaptability in complex environments. For example, when operating through narrow spaces or using flexible materials, a variable stiffness robotic arm can soften its structure to avoid collisions or damage to the target object; when performing high-precision operations or fixing targets, the robotic arm can quickly increase its stiffness to ensure the stability and accuracy of the operation.

[0004] Currently, variable stiffness technology still faces many challenges in practical applications, including how to achieve precise control and testing of variable stiffness robotic arms and grippers. Developing a dedicated testing platform is crucial for testing and verifying the performance of such systems. Most existing testing platforms are designed for rigid structures and lack support for variable stiffness systems.

[0005] A variable stiffness rigid-flexible coupling robotic arm is available, combining the high flexibility of a flexible robotic arm with the high precision of a rigid one. Stiffness is dynamically adjusted through the cooperation of a flexible bending arm and a rigidity adjustment component. A rigidity adjustment cavity is incorporated within the flexible bending arm, and the stiffness is controlled by adjusting the insertion depth of the rigidity adjustment rod. This design allows the robotic arm to switch between flexible and rigid modes to adapt to different task requirements. The robotic arm is also equipped with multiple sensors that monitor the bending degree of the flexible arm in real time for negative feedback adjustment, ensuring the accuracy and stability of the robotic arm during task execution. Its disadvantages include: 1. Structural complexity and maintenance cost: The robotic arm relies on a complex rigidity adjustment component and a multi-sensor system, which not only increases the structural complexity of the robotic arm but may also lead to increased manufacturing and maintenance costs. 2. Response speed and control difficulty: The system relies on multi-sensor feedback and pneumatic drive to achieve stiffness adjustment, which may limit the system's response speed and increase control difficulty. Especially when facing rapidly changing task environments, this system may struggle to maintain stable performance. 3. Smoothness of switching between flexibility and rigidity: In this design, stiffness adjustment is achieved by adjusting the insertion depth of the rigidity adjustment rod. This method may not be smooth enough during the switching between flexibility and rigidity, affecting the operation continuity of the robotic arm and the operator's experience.

[0006] Another hybrid-driven, deployable space-age soft robotic arm employs a hybrid drive mode combining rope-driven and pneumatic-driven mechanisms. This robotic arm features a multi-segment structure, composed of multiple modular structural units connected in series. Each modular unit is connected via a central airbag and has drive ropes attached to partitions. These drive ropes are controlled by a drive motor. The central airbag enables the robotic arm's inflation, while the drive ropes provide structural support and motion control. During operation, the robotic arm expands by inflation and folds by tightening the ropes, thus exhibiting variable stiffness and deployability. This design is particularly suitable for space mission applications, significantly reducing volume during storage and providing sufficient stiffness and flexibility during deployment. Its disadvantages include: 1. Complexity and stability of the drive mechanism: This hybrid drive method involves dual control of the airbag and ropes, making the control and coordination of the entire system more complex. Especially crucial is the need to maintain precise synchronization between airbag inflation and rope tightening, which may lead to stability issues when the system responds quickly to demands. 2. Limitations of Applicable Environment: This hybrid-drive robotic arm is primarily designed for space missions and has the advantage of operating in a vacuum environment. However, its application in ground or industrial environments may be limited, especially when facing non-standard or dynamic environments, where the system's adaptability and flexibility may be insufficient. 3. Maintenance and Operation Complexity: The system's multi-segment structure and complex drive modes make maintenance and operation more complex, particularly when maintenance of the airbag or rope system is required, increasing both the difficulty and cost of operation.

[0007] It should be noted that the information disclosed in the background section above is only for understanding the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0008] The main objective of this invention is to overcome the deficiencies in the aforementioned background technology and provide a rope-driven testing system for variable stiffness robotic arms and variable stiffness grippers.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A rope-driven testing system for variable stiffness robotic arms and grippers includes:

[0011] The two-degree-of-freedom passive motion component is used to manually adjust the posture of the robotic arm and gripper.

[0012] The three-degree-of-freedom active motion part, in conjunction with the two-degree-of-freedom passive motion part, achieves precise operation of the robotic arm through motor drive;

[0013] A rigid robotic arm, located below the three-degree-of-freedom active motion section and connected above the flexible joint, is used to provide high rigidity and high precision in operation.

[0014] A flexible joint connects the rigid robotic arm and the variable stiffness robotic arm, allowing the robotic arm to have a certain degree of flexibility during operation.

[0015] A variable stiffness robotic arm, located below the flexible joint and connected to a variable stiffness gripper, can dynamically adjust its stiffness according to task requirements.

[0016] The variable stiffness gripper, located at the bottom of the system, is connected to the variable stiffness robotic arm and is used to directly contact and manipulate objects.

[0017] The frame supports the structure of the entire system and houses the two-degree-of-freedom passive motion part, the three-degree-of-freedom active motion part, the rigid robotic arm, the flexible joint, the variable stiffness robotic arm, and the variable stiffness gripper, providing structural stability and modular design.

[0018] Furthermore, the two-degree-of-freedom passive motion component includes: a connecting plate connected to the frame by screws; a retaining main plate and a retaining bracket for stable support, and interconnected by a tenon and mortise structure and a vertical plate connector; a reinforcing aluminum tube connected to the retaining main plate via an adapter, providing the first passive degree of freedom, allowing rotational adjustment around a certain axis; a fixed bracket fixed between the frame and the retaining main plate, used to fix the first passive degree of freedom, which can be released when removed; and an adapter, allowing rotational adjustment in the direction perpendicular to the first passive degree of freedom, connected to the connecting base plate via a bearing and a rotating shaft, providing the second passive degree of freedom.

[0019] Furthermore, the three-degree-of-freedom active motion component includes: a yaw axis motor drive, which is connected to the base plate via a motor mounting bracket and an aluminum column, outputting rotational torque to the inner ring of a crossed roller bearing to achieve precise and stable rotation of the system in the yaw axis direction; and a degree of freedom for converting rotation into a linear draw rope, driven by two other motors, which are mounted on the base plate via motor mounting brackets and connected to a motor winding reel to drive a steel wire rope, transmitting power to the robotic arm via an intermediate pulley to achieve precise operation of the robotic arm.

[0020] Furthermore, the flexible joint is controlled by pulling or releasing the steel wire rope through the rotation of the motor.

[0021] Furthermore, the flexible joint includes four steel wire ropes, and a motor drives two of the steel wire ropes simultaneously, enabling the joint to move flexibly in different directions.

[0022] Furthermore, it also includes: copper pillars for connecting the rigid robotic arm and the connecting print, providing structural stability; and universal joints for connecting to the lower connecting print, with a threaded shaft embedded in the middle for fixation, a spring in the middle for passing through the steel wire rope, and a pre-tensioning print to pre-tension the steel wire rope, allowing the connected joint to rotate freely in different directions.

[0023] Furthermore, it also includes a shim plate for elevating the pulley mounting bracket, so that the wire ropes are staggered to avoid mutual interference.

[0024] Furthermore, the variable stiffness robotic arm is a mechanism with adjustable mechanical stiffness, which can dynamically adjust its own stiffness according to task requirements.

[0025] Furthermore, the variable stiffness gripper, as an end effector, changes its stiffness through an internal adjustment mechanism such as air extraction or inflation, so as to increase stiffness to firmly grasp the object when in contact with it, and reduce stiffness when not in contact with the object or when flexible adjustment is required.

[0026] Furthermore, the frame is the aluminum profile frame.

[0027] The present invention has the following beneficial effects:

[0028] This invention provides an innovative testing platform for variable stiffness robotic arms and grippers, with its main technical advantages lying in its high flexibility and adaptability. By combining rope-driven technology and multi-degree-of-freedom control, the system can simulate and test various complex operational tasks, thus providing important technical support and reference for the practical application of variable stiffness technology. The system's design allows for dynamic adjustment of the robotic arm and gripper under different stiffness conditions, enabling them to perform precise operations in various environments while maintaining operational safety and flexibility. Furthermore, the system's manual adjustment function allows operators to directly control the position and orientation of the robotic arm and gripper, facilitating real-time adjustments during testing. The modular design makes the entire system easy to assemble, debug, and maintain, and can be adjusted and expanded according to different testing needs. The system design not only simplifies the control process and reduces potential failure points but also improves overall stability and reliability, and reduces manufacturing and maintenance costs. Therefore, the system of this invention is particularly suitable for complex and dynamic applications in ground or industrial environments, providing comprehensive performance evaluation and data support for future technological advancements and practical applications.

[0029] Compared with the aforementioned prior art, the advantages of the present invention are at least as follows: the rope drive technology used is simpler, easier to maintain, and reduces the complexity and cost of the overall system; the system of the present invention can respond to operational needs more quickly through direct rope drive and mechanical structure adjustment, and is also more intuitive and easier to implement in terms of control; the system of the present invention can achieve a smoother transition through rope drive and variable stiffness control, ensuring the continuity and stability of operation.

[0030] Compared with the aforementioned prior art, the advantages of this invention include at least the following: the system uses only rope drive, simplifying the control process, reducing potential failure points, and improving the overall stability and reliability of the system. The system design of this invention is more suitable for various complex and dynamic ground environments, and performs particularly well in ground applications. The system structure of this invention is relatively simple, maintenance is more convenient, operation is more intuitive, and it is suitable for long-term use and rapid deployment.

[0031] Other beneficial effects of the embodiments of the present invention will be further described below. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the rope-driven testing system according to an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the two-degree-of-freedom passive motion part in an embodiment of the present invention.

[0034] Figure 3 This is an exploded view of the two-degree-of-freedom passive motion portion of an embodiment of the present invention.

[0035] Figure 4 This is a schematic diagram of the active shaft, rigid robotic arm, and flexible joint of the three-degree-of-freedom active motion part in an embodiment of the present invention.

[0036] Figure 5 This is an exploded view of the active shaft, rigid robotic arm, and flexible joint of the three-degree-of-freedom active motion part in an embodiment of the present invention.

[0037] Figure 6 This is a partial schematic diagram of a flexible joint according to an embodiment of the present invention.

[0038] Figure 7 This is a diagram showing the winding configuration of a flexible joint according to an embodiment of the present invention.

[0039] Figure 8 This is a layout diagram of the variable stiffness system according to an embodiment of the present invention. Detailed Implementation

[0040] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0041] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for fixing, coupling, or communication.

[0042] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] See Figures 1 to 8This invention provides a rope-driven testing system for a variable stiffness robotic arm 6 and a variable stiffness gripper 7, comprising: a two-degree-of-freedom passive motion part 2 for manually adjusting the posture of the robotic arm and gripper; a three-degree-of-freedom active motion part 3, which cooperates with the two-degree-of-freedom passive motion part 2 to achieve precise operation of the robotic arm via motor drive; a purely rigid robotic arm 4, located below the three-degree-of-freedom active motion part 3 and connected above a flexible joint 5, for providing high stiffness and high precision in operation; and a flexible joint 5, connecting the purely rigid robotic arm 4 and the variable stiffness robotic arm 6, allowing the robotic arm to... Parts of the system possess a certain degree of flexibility during operation; the variable stiffness robotic arm 6, located below the flexible joint 5 and connected to the variable stiffness gripper 7, can dynamically adjust its stiffness according to task requirements; the variable stiffness gripper 7, located at the bottom of the system and connected to the variable stiffness robotic arm 6, is used for direct contact and manipulation of objects; the frame 1, which can be made of aluminum profile, supports the structure of the entire system and houses the two-degree-of-freedom passive motion part 2, the three-degree-of-freedom active motion part 3, the purely rigid robotic arm 4, the flexible joint 5, the variable stiffness robotic arm 6, and the variable stiffness gripper 7, providing structural stability and modular design.

[0045] See Figure 2 and Figure 3 In a preferred embodiment, the two-degree-of-freedom passive motion part 2 includes: a connecting plate 8, connected to the frame 1 by screws; a retaining main plate 9 and a retaining bracket 10, used for stable support, and connected to each other by a tenon and mortise structure and a vertical plate connector 14 to ensure the stability of the structure during adjustment; a reinforcing aluminum tube 12, connected to the retaining main plate 9 by an adapter 13, providing the first passive degree of freedom, allowing rotational adjustment around a certain axis; a fixed bracket 11, fixed between the frame 1 and the retaining main plate 9, used to fix the first passive degree of freedom, which can be released when removed; and an adapter 15, allowing rotational adjustment in the direction perpendicular to the first passive degree of freedom, connected to the connecting base plate 19 by a bushing 16, a bearing 17, and a rotating shaft 18, providing the second passive degree of freedom.

[0046] See Figure 4 and Figure 5 In a preferred embodiment, the three-degree-of-freedom active motion component 3 includes: a yaw-axis motor 20, which is connected to an aluminum column 22 via a motor mounting bracket 21 and mounted on a base plate 23, outputting rotational torque to the inner ring of a crossed roller bearing 37 to achieve precise and stable rotation of the system in the yaw-axis direction; and a linear draw rope degree of freedom, converted from rotation, driven by two other motors 25, which are mounted on another base plate 24 via motor mounting brackets 26 and connected to a motor winding reel 27 to drive a wire rope 28, transmitting power to the robotic arm via an intermediate pulley to achieve precise operation of the robotic arm. The motors may be equipped with a motor speed controller 39.

[0047] See Figures 4 to 7 The flexible joint 5 is controlled by pulling or releasing the steel wire rope 28 through the rotation of a motor. In a preferred embodiment, the flexible joint 5 includes four steel wire ropes 28, and one motor drives two steel wire ropes 28 simultaneously, allowing the joint to move flexibly in different directions. In a preferred embodiment, the system also includes: a copper column for connecting the rigid robotic arm 4 and the connecting printed component 30, providing structural stability; a universal joint 31 for connecting to the lower connecting printed component 30, with a threaded shaft 32 embedded in the middle for fixation, and a spring 38 in the middle for passing through the steel wire rope 28, and pre-tightening the steel wire rope 28 through the pre-tightening printed component 33, allowing the connected joint to rotate freely in different directions. The system also includes a riser plate 34 for raising the pulley fixing frame 29, so that the steel wire ropes 28 are staggered to avoid mutual interference.

[0048] See Figure 8 The variable stiffness robotic arm 6 is a mechanism with adjustable mechanical stiffness, which can dynamically adjust its stiffness according to task requirements. The variable stiffness gripper 7, as an end effector, changes its stiffness through an internal adjustment mechanism such as deflating or inflating, so as to increase stiffness to firmly grasp the object when in contact with it, and reduce stiffness when not in contact with the object or when flexible adjustment is required.

[0049] This invention provides a rope-driven testing system capable of effectively testing the performance of variable stiffness robotic arms and grippers. By combining rope actuation and multi-degree-of-freedom control, this system can simulate and test various complex operational tasks, providing a comprehensive and flexible platform for testing variable stiffness technology. It can effectively test and verify the performance of variable stiffness robotic arms and grippers in various tasks and environments. Through this system, key performance indicators such as stiffness adjustment, operational flexibility, and load capacity of robotic arms and grippers can be comprehensively evaluated, thus providing important technical support for practical applications.

[0050] The features of this invention are as follows: 1. Multi-degree-of-freedom operation: The testing system of this invention has up to three motor-driven degrees of freedom and two manually adjustable degrees of freedom, enabling complex spatial movements and flexibly responding to various testing needs. 2. Rope-driven system: Utilizing rope-driven technology, the system uses dual motors to pull and control the flexible joints, achieving precise operation of the robotic arm and gripper. This design not only simulates various complex operational tasks but also reduces the rigidity of the mechanical system, thereby improving testing safety and flexibility. 3. Testing under variable stiffness conditions: The system supports dynamic adjustment of the stiffness of the robotic arm and gripper, allowing them to perform operations under different stiffness conditions. This feature enables the system to simulate and test the performance of the robotic arm and gripper under different stiffness conditions, providing data support for practical applications. 4. Manual adjustment function: The two axes at the top can be manually adjusted, allowing the operator to directly control the position and posture of the robotic arm and gripper. This function facilitates real-time adjustments during testing, especially in scenarios requiring manual operation or fine adjustment. 5. Modular design: The entire system adopts a modular design, facilitating assembly, debugging, and maintenance. The frame structure built with profiles is lightweight and highly adaptable, and can be adjusted and expanded according to different testing needs. 6. Adaptable to various testing tasks: The system can flexibly cope with various complex environments and task requirements, including flexible operation, operation in confined spaces, and grasping tests of different objects, providing strong support for the practical application of variable stiffness technology.

[0051] The following describes specific embodiments of the present invention.

[0052] Figure 1 This is a schematic diagram of the overall structure of the rope-driven testing system according to an embodiment of the present invention. The rope-driven testing system consists of three main parts: a passive motion part, an active motion part, and a variable stiffness system. Specifically, it includes a two-degree-of-freedom passive motion part 2, a three-degree-of-freedom active motion part 3, a purely rigid robotic arm 4, a flexible joint 5, a variable stiffness robotic arm 6, a variable stiffness gripper 7, and an aluminum profile frame.

[0053] The two-DOF passive motion section 2 is located at the top of the system. This section provides two degrees of freedom for passive motion. These two degrees of freedom can be manually adjusted, allowing the operator to quickly adjust the posture of the robotic arm and gripper without relying on motor drives. This design is particularly suitable for operational scenarios that require frequent changes in posture or fine adjustments, such as manual debugging and calibration tasks.

[0054] The three-DOF active motion section 3 is located below the two-DOF passive motion section 2. This section provides three degrees of freedom for active motion, including rotation of the top YAW axis and two degrees of freedom that convert rotation into linear draw ropes. These degrees of freedom are all driven by motors and can be precisely manipulated by the control system. Their main function is to enable the robotic arm to perform complex tasks within a wider operating range and to automatically adjust its position and posture according to task requirements. Furthermore, this section is the core drive component of the entire system, ensuring high-precision motion control of the robotic arm and gripper.

[0055] The rigid robotic arm 4 is located below the active motion section and connected above the flexible joint 5. This section is made of a purely rigid material, possessing high rigidity and precision, making it suitable for critical tasks requiring strong support and stability. This rigid structure ensures the robotic arm maintains stability when performing tasks with high loads or requiring precise positioning. The rigid robotic arm 4 can withstand significant forces, preventing deformation under high stress conditions and ensuring task reliability.

[0056] A flexible joint 5 connects the rigid robotic arm 4 and the variable stiffness robotic arm 6. This allows the robotic arm portion to have a certain degree of flexibility during operation. Driven by cables, the flexible joint 5 can adjust its posture to adapt to different operational requirements.

[0057] The variable stiffness robotic arm 6 is located below the flexible joint 5 and connected to the variable stiffness gripper 7. The variable stiffness robotic arm 6 can dynamically adjust its stiffness according to task requirements. This design allows the robotic arm to exhibit different characteristics in different scenarios: in some tasks, it can maintain lower stiffness for flexible operation; while in other tasks, it can increase stiffness to enhance stability and load capacity. This variable stiffness capability makes the robotic arm more adaptable to complex tasks.

[0058] The variable stiffness gripper 7 is located at the bottom of the system and connects to the variable stiffness robotic arm 6. The variable stiffness gripper 7 is the end effector of the system, responsible for direct contact and manipulation of the object. The gripper's stiffness can be changed through an internal adjustment mechanism (such as deflating or inflating). When the gripper is in contact with an object, it can increase stiffness to firmly grasp the object and prevent it from slipping; when not in contact with an object or when flexible adjustment is needed, it can decrease stiffness to increase operational flexibility. This design greatly enhances the gripper's maneuverability and adaptability, making it suitable for various gripping and manipulation tasks.

[0059] The aluminum profile frame supports the structural components of the entire system. As the skeleton of the system, the aluminum profile frame is responsible for supporting and protecting all its components. Lightweight yet robust, the aluminum profile provides excellent structural stability while enhancing the system's portability and flexibility. The modular design of frame 1 makes the system easy to assemble, debug, and maintain, and allows for expansion and adjustment to meet different testing needs.

[0060] Figure 2 This is a schematic diagram of the two-degree-of-freedom passive motion part 2 in an embodiment of the present invention. Figure 3 This is an exploded view of the two-degree-of-freedom passive motion part 2 in an embodiment of the present invention.

[0061] This design, through a clever mechanical structure, allows the operator to adjust the connected robotic arm or device along two axes. The connecting plate 8 can be connected to the aluminum profile bracket with screws. The retaining main plate 9 and retaining bracket 10 provide stable support for the rest of the system; they are connected via a mortise and tenon structure and a vertical plate connector 14, ensuring that the structure does not loosen or shift during adjustment. A reinforcing aluminum tube 12 is then connected via an adapter 13, further stabilizing the structure and allowing rotational adjustment around a certain axis, providing the first passive degree of freedom. The aluminum tube is designed to be lightweight yet high-strength, minimizing deformation under external forces while allowing adjustment along the connection direction. Furthermore, a fixing bracket 11 can be fixed between the aluminum profile bracket and the retaining main plate 9, securing the first passive degree of freedom; when removed, this first degree of freedom is released.

[0062] The adapter 15 allows for rotational adjustment in the direction perpendicular to the first passive degree of freedom, and provides a second passive degree of freedom through the connection of the bearing 17, the shaft 18, and the adapter 15 to the connecting base plate 19. A shim 36 is provided along the axial direction.

[0063] Figure 4 This is a schematic diagram of the three-degree-of-freedom active motion part 3, the active shaft, the rigid robotic arm 4, and the flexible joint 5 in an embodiment of the present invention. Figure 5 The exploded view shows the three-degree-of-freedom active motion part 3, the active shaft, the rigid robotic arm 4, and the flexible joint 5 in an embodiment of the present invention. Figure 6 This is a partial schematic diagram of the flexible joint 5 according to an embodiment of the present invention. Figure 7 This is a diagram showing the winding configuration of the flexible joint 5 according to an embodiment of the present invention.

[0064] like Figures 4 to 5 As shown, the yaw axis motor 20 (GM6020 motor) is responsible for driving the rotational motion of the entire system in the yaw axis direction. It is connected to a base plate 23 via a motor mounting bracket 21 and an aluminum column 22, outputting a strong rotational torque to the inner ring of the crossed roller bearing 37, ensuring that the system can rotate accurately and stably in the yaw axis direction.

[0065] Two other motors (M2006 motors) 25 are mounted on another base plate 24 via motor mounting brackets 26. A motor winding reel 27 drives a steel wire rope 28, which transmits power to the lower part via an intermediate pulley. The rigid robotic arm 4 and the connecting printed component 30 are connected by copper pillars 35 and to the lower connecting printed component 30 via a universal joint 31. A threaded shaft 32 is embedded in the center of the universal joint 31 for fixation, and a spring 38 passes through it to pass through the steel wire rope 28. The steel wire rope 28 is pre-tensioned by a pre-tensioning printed component 33. The universal joint 31 allows the connected joints to rotate freely in different directions, providing high flexibility. With the spring 38 passing through, this design allows the flexible joint 5 to adapt to complex motion requirements while maintaining good structural stability.

[0066] The steel wire rope 28 is pulled or released by the rotation of the motor, which can be used to pull or release multiple steel wire ropes 28 (such as...). Figures 6 to 7 Lines 1, 2, 3, and 4 work together, and one motor simultaneously drives two steel wire ropes 28, allowing the joint to move flexibly in different directions. A riser plate 34 elevates one pulley fixing bracket 29, offsetting the positions of lines 2 and 4 to prevent interference.

[0067] This design also ensures the system's stability and durability during operation.

[0068] Figure 8 This is a layout diagram of a variable stiffness system according to an embodiment of the present invention. Figure 8 As shown, the variable stiffness robotic arm 6 is the core component of the system, featuring adjustable mechanical stiffness. This robotic arm changes its stiffness through internal air extraction and other operations, thereby providing optimal operational stability and flexibility under different operating conditions. This design allows the robotic arm to dynamically adjust during task execution to adapt to different loads or operating environments.

[0069] The variable stiffness gripper 7, located at the end of the variable stiffness robotic arm 6, can adjust its stiffness according to the shape and characteristics of the object it contacts. The design of the variable stiffness gripper 7 allows switching between flexible manipulation and rigid grasping; for example, it remains soft when grasping fragile or irregularly shaped objects, and becomes firm when a stable grip is required. Through its collaborative work with the variable stiffness robotic arm 6, the variable stiffness gripper 7 enables the efficient completion of complex tasks. It also adjusts its stiffness by hardening the gripper through air extraction.

[0070] The copper pillar 35 provides robust support and connection for the variable stiffness robotic arm 6 and the variable stiffness gripper 7. High-strength materials and structural design ensure the stability of the entire system during operation, while also allowing for flexible movement of the variable stiffness robotic arm 6 and the variable stiffness gripper 7. The variable stiffness robotic arm 6 and the variable stiffness gripper 7 can be connected via an adapter printout 40.

[0071] The rope-driven testing system of the present invention has the following characteristics in terms of technological innovation mechanism and advantages:

[0072] 1. Multi-degree-of-freedom adjustment mechanism:

[0073] This invention designs a multi-degree-of-freedom adjustment mechanism that includes active and passive adjustment components, providing the robotic arm and gripper with flexibility and adaptability in space. This mechanism ensures the system's precise control capability in complex operating environments, enabling complex spatial movements and meeting various testing requirements.

[0074] 2. Rope-driven and flexible joint control:

[0075] The system employs cable-driven technology combined with flexible joint control to achieve precise manipulation and dynamic adjustment of the robotic arm and gripper. This design improves the system's stability and accuracy when performing various tasks, and enhances its adaptability and operational continuity.

[0076] 3. Dynamic stiffness adjustment:

[0077] This invention supports the operation of robotic arms and grippers under different stiffness conditions, and can dynamically adjust the stiffness according to task requirements. This capability enables the system to adapt to a variety of complex operating scenarios and different load conditions, enhancing the system's practicality and flexibility.

[0078] 4. Modular design:

[0079] The system adopts a modular design, which facilitates the disassembly, replacement, and maintenance of components. This design simplifies the system's operation, extends its service life, reduces maintenance costs, and improves the system's economy and maintainability.

[0080] 5. Manual adjustment function:

[0081] The system is designed with a top-mounted manual adjustment mechanism, allowing operators to quickly adjust the system's attitude and position during testing or operation. This feature enhances the flexibility of system operation, enabling operators to make immediate adjustments, especially in scenarios requiring manual operation or fine-tuning.

[0082] In summary, this invention provides a rope-driven testing system that is comprehensive in function, flexible in operation, and convenient in maintenance. It can effectively test and verify the performance of variable stiffness robotic arms and grippers, providing important technical support for practical applications.

[0083] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A rope-driven testing system for variable stiffness robotic arms and variable stiffness grippers, characterized in that, include: The two-degree-of-freedom passive motion component is used to manually adjust the posture of the robotic arm and gripper. The two-degree-of-freedom passive motion component includes: a connecting plate connected to the frame; a retaining main plate and a retaining bracket connected to each other for stable support; a reinforcing tube connected to the retaining main plate, providing the first passive degree of freedom, allowing rotational adjustment about a certain axis; a fixing bracket fixed between the frame and the retaining main plate, used to fix the first passive degree of freedom, which can be released when removed; and an adapter that allows rotational adjustment in a direction perpendicular to the first passive degree of freedom to provide the second passive degree of freedom. The three-degree-of-freedom active motion part, in conjunction with the two-degree-of-freedom passive motion part, achieves precise operation of the robotic arm through motor drive; the three-degree-of-freedom active motion part includes: a yaw axis motor, which outputs rotational torque to achieve precise and stable rotation of the system in the yaw axis direction; the degree of freedom of rotation converted into a linear draw rope is driven by the other two motors, which transmit power to the robotic arm to achieve precise operation of the robotic arm; A rigid robotic arm, located below the three-degree-of-freedom active motion section and connected above the flexible joint, is used to provide high rigidity and high precision in operation. A flexible joint connects the rigid robotic arm and the variable stiffness robotic arm, allowing the robotic arm to have a certain degree of flexibility during operation. A variable stiffness robotic arm, located below the flexible joint and connected to a variable stiffness gripper, can dynamically adjust its stiffness according to task requirements. The variable stiffness gripper, located at the bottom of the system, is connected to the variable stiffness robotic arm and is used to directly contact and manipulate objects. The frame supports the structure of the entire system and houses the two-degree-of-freedom passive motion part, the three-degree-of-freedom active motion part, the rigid robotic arm, the flexible joint, the variable stiffness robotic arm, and the variable stiffness gripper.

2. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 1, characterized in that, In the two-degree-of-freedom passive motion section: the connecting plate is connected to the frame by screws; the retaining main plate and the retaining bracket are connected to each other by mortise and tenon structure and vertical plate connector; the reinforcing tube is a reinforced aluminum tube, which is connected to the retaining main plate by an adapter; the adapter is connected to the connecting base plate by bearings and a rotating shaft.

3. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 1 or 2, characterized in that, In the three-degree-of-freedom active motion section: the yaw axis motor is connected to the base plate via a motor mounting bracket and an aluminum column, outputting rotational torque to the inner ring of the crossed roller bearing; the other two motors are mounted on the base plate via motor mounting brackets, connected to motor winding reels to drive steel wire ropes, and transmit power to the robotic arm via an intermediate pulley.

4. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 3, characterized in that, The flexible joint is controlled by pulling or releasing the steel wire rope through the rotation of the motor.

5. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 4, characterized in that, The flexible joint includes four steel wire ropes, and a motor drives two of the steel wire ropes simultaneously, enabling the joint to move flexibly in different directions.

6. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 3, characterized in that, Also includes: Copper pillars are used to connect the purely rigid robotic arm and the printed parts, providing structural stability. The universal joint is used to connect to the printed component below. A threaded shaft is embedded in the middle for fixation, and a spring is in the middle for the steel wire rope to pass through. The steel wire rope is pre-tightened by the pre-tightening printed component, allowing the connected joint to rotate freely in different directions.

7. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 3, characterized in that, It also includes a shim plate, used to elevate the pulley mounting bracket, so that the wire ropes are staggered to avoid mutual interference.

8. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 1, characterized in that, The variable stiffness robotic arm is a mechanism with adjustable mechanical stiffness, which can dynamically adjust its stiffness according to task requirements.

9. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 1, characterized in that, The variable stiffness gripper, as an end effector, changes its stiffness through an internal adjustment mechanism to increase stiffness and firmly grasp objects when in contact with them, and to reduce stiffness when not in contact with objects or when flexible adjustment is required.

10. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 9, characterized in that, The internal adjustment mechanism includes either air extraction or air inflation.

11. The rope-driven testing system for variable stiffness robotic arms and grippers as described in claim 1, characterized in that, The frame is an aluminum profile frame.

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