A tendon-driven robotic arm with S-shaped directional bending function

Abstract

This invention discloses a tendon-driven robotic arm with S-shaped directional bending function, belonging to the field of bionic robotic arms and joint control technology. It includes a main arm body, drive ropes, a base drive assembly, and a mounting base. The main arm body consists of alternating series of a first and second joint with concave structures. The curved surfaces of the two joints are orthogonal and interlock at 90° to achieve single-plane directional bending. The middle part of the main arm body is rotated 180° relative to the upper part, so that the bending direction of the lower part is opposite to that of the upper part. The limiting effect of the joint side baffles restricts ineffective lateral swinging of the joints. Two sets of drive ropes are threaded through a threading boss and driven by symmetrical double wheels on the base for retraction and extension, achieving reverse bending of the upper and lower halves, ultimately forming an S-shaped spatial posture. This invention has a simple structure, good motion stability, and controllable bending direction, making it suitable for applications in bionic continuous robotic arms and spatial bending mechanisms.

Description

Technical Field

[0001] This invention belongs to the field of bionic robotic arms and joint control technology. Background Technology

[0002] With the development of bionic robot technology, tendon-driven robotic arms are widely used in fields such as flexible grasping, bionic motion, and spatial manipulation due to their advantages such as lightweight structure, flexible transmission, and compact layout.

[0003] Existing robotic arm joint structures typically achieve bending through unidirectional cable-driven bending. While this allows for a certain range of posture changes, it falls short in terms of multi-segment continuous bending, bidirectional reverse bending, and overall S-shaped posture construction. The joint chains often employ a uniform directional limiting and driving method, meaning the entire arm can usually only bend to one side, making it difficult to achieve combined deformation with the upper and lower halves deflecting in opposite directions.

[0004] Meanwhile, traditional threading methods often only consider the driving function, while neglecting joint posture stability, lateral sway suppression, and coordinated deformation of the upper and lower segments. This leads to problems such as swaying, uneven stress, or uncontrollable bending trajectory during bending. Therefore, there is an urgent need for a new robotic arm structure that can achieve reverse driving of the upper and lower segments while ensuring joint motion stability, thereby enabling the robotic arm to form an S-shaped bending posture as a whole. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a tendon-driven robotic arm with S-shaped directional bending functionality. This robotic arm achieves opposite bending of the upper and lower halves of the arm body through alternating series connection of the first and second joints, directional limiting via a baffle structure on the second joint, a 180° rotating arrangement in the middle of the arm body, and bidirectional drive via symmetrical handwheels on the base, thereby forming an S-shaped spatial posture. The specific technical solution adopted by this invention is as follows:

[0006] A tendon-driven robotic arm with S-shaped directional bending function includes: a main body 01, a drive rope 02, and a base drive assembly 03.

[0007] The main body 01 of the arm is composed of several first joints 1 and second joints 2 arranged alternately and connected in series. The first joints 1 and second joints 2 are concave joint structures. The cross-section of the first joint 1 is circular, and the main body is cylindrical. The upper and lower surfaces of the main body are symmetrical curved surfaces. The curved surface shape is high on both sides and low in the middle along the X-axis direction, and high in the middle and low on both sides along the Y-axis direction. The second joint 2 has the same main body shape as the first joint 1, and the curved surface shape is rotated horizontally by 90°. When the first joint 1 and the second joint 2 are arranged at 90° staggered, the center points of their curved surfaces match and rotate back and forth in the X-axis direction. The main body 01 of the arm is divided into an upper part and a lower part with the middle as the boundary. The two parts are set with a relative horizontal rotation of 180°, so that the baffles 21 of the two parts are installed in opposite directions.

[0008] The first joint 1 and the second joint 2 are provided with threading bosses 22 on their sides. The drive rope 02 is a flexible high-strength rope. Two sets of drive ropes 02 are threaded through the threading bosses 22 on each joint from both sides. The base drive assembly 03 is retracted and extended through the drive ropes 02. When one set of drive ropes is tightened, the corresponding half of the arm body 01 bends in one direction; the other set of drive ropes drives the other half to bend in the opposite direction, ultimately achieving an S-shaped posture.

[0009] Preferably, the first joint 1 has a protrusion at the center of the upper and lower surfaces of the main body, and the second joint 2 has a groove at the center of the upper and lower surfaces of the main body. The protrusion and the groove cooperate with each other to achieve single-plane bending guidance and retain the bending freedom in the front and back directions.

[0010] Preferably, the side of the first joint 1 is also provided with a baffle 21, which is fixed by screws through the opening in the middle of the side of the first joint 1 and the opening in the middle of the baffle 21; after installation, the baffle 21 is attached to the side of the first joint 1, and its upper and lower extended parts are attached to the second joint 2 to form a relatively fixed structure; the baffle 21 is also provided with a threading boss 22 and a drive rope 02 is threaded through it.

[0011] Preferably, the base drive assembly 03 employs two symmetrically arranged sets of front and rear drive wheels 31, which respectively control the winding and unwinding of two sets of drive ropes 02. Specifically, a symmetrical handwheel or reel structure can be used.

[0012] Preferably, it also includes a mounting base 04, which provides fixation and support for the base drive assembly 03.

[0013] The beneficial effects of this invention are:

[0014] By alternating the cooperation of the first joint 1 and the second joint 2, and the limiting effect of the baffle 21 of the second joint 2, the ineffective lateral swing of the joint is restricted, thus improving motion stability. By rotating the middle of the arm body 01 by 180°, the upper and lower halves have opposite bending directions, achieving an S-shaped posture. The protrusion 22 on the baffle 21 guides the wire threading, taking into account both driving and stabilizing functions. The symmetrical dual-wheel drive of the base drive component 03 enables the reverse movement of the upper and lower ropes, facilitating coordinated structural control. The overall structure is simple, easy to process and assemble, and suitable for applications such as biomimetic continuous robotic arms and spatial bending mechanisms. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the robotic arm described in this invention;

[0016] Figure 2 Views of the first joint: (a) front view, (b) left view, (c) top view, (d) axonometric view;

[0017] Figure 3 Views of the second joint: (a) front view, (b) left view, (c) top view, (d) axonometric view;

[0018] Figure 4 The views are of the baffle: (a) front view, (b) left view, (c) top view, and (d) axonometric view.

[0019] Figure 5 A before-and-after comparison of the motion of the first and second joints after assembly;

[0020] Figure 6 A schematic diagram of the overall assembly of the arm body and drive rope;

[0021] Figure 7 This is a schematic diagram of the base drive assembly.

[0022] Figure 8 This is a schematic diagram of a joint chain structure in which the first and second joints are arranged alternately. Detailed Implementation

[0023] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1 to 8 As shown, this embodiment provides a tendon-driven robotic arm with S-shaped directional bending function, including: arm body 01, drive rope 02, base drive assembly 03 and mounting base 04.

[0025] The main body 01 of the arm is composed of several first joints 1 and second joints 2 arranged alternately and connected in series;

[0026] like Figure 2 and Figure 3 As shown, the first joint 1 and the second joint 2 are concave joint structures. The first joint 1 has a circular cross-section and a cylindrical main body. The upper and lower surfaces of the main body are symmetrical curved surfaces. The curved surface shape is high on both sides and low in the middle along the X-axis direction, and high in the middle and low on both sides along the Y-axis direction. The second joint 2 has the same main body shape as the first joint 1, but its curved surface shape is high on both sides and low in the middle along the Y-axis direction, and high in the middle and low on both sides along the X-axis direction (equivalent to a horizontal rotation of 90°). When the first joint 1 and the second joint 2 are arranged in a 90° staggered arrangement, the center points of their curved surfaces match and rotate back and forth in the X-axis direction.

[0027] The first joint 1 has a protrusion at the center of the upper and lower surfaces of the main body, and the second joint 2 has a groove at the center of the upper and lower surfaces of the main body. The protrusion and the groove cooperate to achieve single-plane bending guidance, thereby limiting the swing amplitude and retaining the bending freedom in the front and back directions, and avoiding ineffective swing of the structure.

[0028] In this embodiment, the arm body 01 has a total of 20 joint units, with 10 joint units in the upper part and 10 joint units in the lower part. Starting from the 11th joint unit, the arm body 01 rotates horizontally 180° relative to the upper part, so that the joint engagement direction of the lower part is opposite to that of the upper part.

[0029] like Figure 4 As shown, a baffle 21 is also provided on the side of the first joint 1. The baffle 21 is fixed with screws through the opening in the middle of the side of the first joint 1 and the opening in the middle of the baffle 21. After installation, the baffle 21 is attached to the side of the first joint 1, and its upper and lower extended parts are attached to the second joint 2 to form a relatively fixed structure.

[0030] The first joint 1 and the second joint 2 are provided with threading bosses 22 on their sides and on the baffle 21. The drive rope 02 is a flexible high-strength rope, which is threaded through the threading bosses 22 on each joint and the baffle 21.

[0031] In the upper part, the baffle 21 is set on one side of the second joint 2; in the lower part, due to the overall rotation of 180°, the baffle 21 is arranged on the opposite side of the original baffle position of the second joint 2. The drive rope 02 of the upper part is guided by the threading boss 22 on the baffle 21 of the lower part to ensure overall stability; the drive rope 02 of the lower part is arranged in a conventional manner to achieve the corresponding reverse bending, so that the force and bending direction of the upper and lower parts are opposite.

[0032] like Figure 7 As shown, the base drive assembly 03 uses two sets of drive wheels 31 arranged symmetrically at the front and rear, which control the winding and unwinding of two sets of drive ropes 02 respectively.

[0033] When one set of drive ropes is tightened, the corresponding half of the arm body 01 bends in one direction; the other set of drive ropes drives the other half to bend in the opposite direction, ultimately achieving an S-shaped posture.

[0034] like Figure 5 As shown, the robotic arm is initially arranged in a straight line; when the base drive assembly 03 applies reverse tension to the upper and lower drive ropes 02 respectively, the upper part deflects to one side and the lower part deflects in the opposite direction, thus forming an S-shaped curved curve for the entire arm body 01.

[0035] This embodiment, through the alternating arrangement of the first joint 1 and the second joint 2, the directional limiting of the baffle 21, and the reverse driving of the upper and lower partitions, not only restricts the lateral swing but also makes the bending direction controllable. It is suitable for continuous robotic arms, bionic arms, and tendon-driven mechanisms that require spatial directional deformation.

[0036] It should be noted that the above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A tendon-driven robotic arm with S-shaped directional bending function, characterized in that, The robotic arm includes: a main body (01), a drive rope (02), and a base drive assembly (03); The arm body (01) is composed of several first joints (1) and second joints (2) arranged alternately and connected in series; The first joint (1) and the second joint (2) are concave joint structures. The first joint (1) has a circular cross-section and a cylindrical body. The upper and lower surfaces of the body are symmetrical curved surfaces. The curved surfaces are high on both sides and low in the middle along the X-axis direction, and high in the middle and low on both sides along the Y-axis direction. The second joint (2) has the same body shape as the first joint (1). The curved surface shape is rotated horizontally by 90° so that when the first joint (1) and the second joint (2) are arranged at 90° staggered, the center points of their curved surfaces match and rotate back and forth in the X-axis direction. The arm body body (01) is divided into an upper part and a lower part with the middle as the boundary. The two parts are set with a horizontal rotation of 180° relative to each other so that the baffles (21) of the two parts are installed in opposite directions. The first joint (1) and the second joint (2) are provided with threading bosses (22) on their sides. The drive rope (02) is a flexible high-strength rope. Two sets of drive ropes (02) are threaded through the threading bosses (22) on each joint from both sides. The base drive assembly (03) is retracted and extended through the drive ropes (02). When one set of drive ropes is tightened, the corresponding half of the arm body (01) bends in one direction; the other set of drive ropes (02) drives the other half to bend in the opposite direction, ultimately achieving an S-shaped posture.

2. The tendon-driven robotic arm with S-shaped directional bending function according to claim 1, characterized in that, The first joint (1) has a protrusion at the center of the upper and lower surfaces of the main body, and the second joint (2) has a groove at the center of the upper and lower surfaces of the main body. The protrusion and the groove cooperate to achieve single-plane bending guidance and retain the bending freedom in the front and back directions.

3. The tendon-driven robotic arm with S-shaped directional bending function according to claim 1, characterized in that, The first joint (1) is also provided with a baffle (21) on the side, which is fixed by screws through the opening in the middle of the side of the first joint (1) and the opening in the center of the baffle (21); after installation, the baffle (21) fits against the side of the first joint (1), and its upper and lower extended parts fit against the second joint (2) to form a relatively fixed structure; the baffle (21) is also provided with a threading boss (22) and a drive rope (02) is threaded through it.

4. The tendon-driven robotic arm with S-shaped directional bending function according to claim 1, characterized in that, The base drive assembly (03) uses two sets of drive wheels (31) arranged symmetrically in the front and rear, which respectively control the release and retraction of two sets of drive ropes (02).

5. The tendon-driven robotic arm with S-shaped directional bending function according to claim 4, characterized in that, The front and rear drive wheels (31) adopt a symmetrical handwheel or winding wheel structure.

6. The tendon-driven robotic arm with S-shaped directional bending function according to claim 1, characterized in that, The robotic arm also includes a mounting base (04) which provides fixation and support for the base drive assembly (03).

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