Exoskeleton robotic arm based on multi-link mechanism

Abstract

This invention belongs to the field of exoskeleton robotic arms, specifically an exoskeleton robotic arm based on a multi-link mechanism. It includes a shoulder fixation strap with shoulder joints at both ends. An arm structure is located below the shoulder joints. Each shoulder joint includes a actuator assembly and a series linkage mechanism with three rotational degrees of freedom, enabling the arm structure to rotate in three directions. The arm structure includes an upper arm and a forearm, connected by a four-bar linkage, which drives the reciprocating flexion and extension movements of the arm structure. This invention places the actuators at the shoulder joints, resulting in a compact overall structure and low inertia. By designing a multi-link mechanism, the circular motion of the actuators is transformed into flexion and extension movements of the elbow joint, improving the arm's movement speed and transmission efficiency. Furthermore, it maintains a reasonable range of motion for the elbow joint even under arbitrary actuator motion conditions, exhibiting high reliability and safety.

Description

Technical Field

[0001] This invention belongs to the field of exoskeleton robotic arms, specifically an exoskeleton robotic arm based on a multi-link mechanism. Background Technology

[0002] An exoskeleton is a wearable intelligent mechanical device that uses sensors, actuators, and control systems to enhance or assist the human body's motor abilities. It is widely used in fields such as medical rehabilitation and industrial manufacturing.

[0003] Existing exoskeleton robotic arms have problems in their design, such as limited joint range of motion or even errors due to unreasonable structural positions and driving directions of the actuators. Summary of the Invention

[0004] To address the aforementioned technical problems in the existing technology, this invention proposes an exoskeleton robotic arm based on a multi-link mechanism, the specific technical solution of which is as follows:

[0005] An exoskeleton robotic arm based on a multi-link mechanism includes a shoulder fixation strap with shoulder joints at both ends. An arm structure is located below the shoulder joints. The shoulder joints include a driver assembly and a series linkage mechanism with three rotational degrees of freedom connected to it, which can drive the lower arm structure to rotate in three directions. The arm structure includes an upper arm and a forearm, and a four-bar linkage is driven between the upper arm and the forearm, and the arm structure performs reciprocating flexion and extension movements by driving the four-bar linkage.

[0006] Furthermore, the actuator group includes shoulder joint actuator one, shoulder joint actuator two, and shoulder joint actuator three. Shoulder joint actuator one is laterally fixed at the end of the shoulder fixing strap, and the output shafts of shoulder joint actuator one, shoulder joint actuator two, and shoulder joint actuator three are respectively set along the X, Y, and Z axes.

[0007] Furthermore, the series linkage mechanism includes three arc-shaped links, namely shoulder joint link one, shoulder joint link two, and shoulder joint link three, and the centers of their arcs converge at a single point; one end of shoulder joint link one is connected to the output shaft of shoulder joint actuator one, and the other end is fixedly connected to shoulder joint actuator two; one end of shoulder joint link two is connected to the output end of shoulder joint actuator two, and the other end is fixedly connected to shoulder joint actuator three; one end of shoulder joint link three is connected to the output shaft of shoulder joint actuator three, and the other end is fixedly connected to the upper arm of the arm structure.

[0008] Furthermore, the boom includes a boom support portion, and the side of the boom support portion is provided with a drive hinge portion and a connecting hinge portion. An elbow joint driver is fixedly installed on the drive hinge portion; the elbow joint driver drives and connects to the four-bar linkage mechanism.

[0009] Furthermore, the four-bar linkage includes a drive link, an upper arm link, a forearm link, and a wrist joint link; the upper arm link has an upper arm hinge hole, and the forearm link has a forearm hinge hole; one end of the drive link is connected to the output shaft of the elbow joint actuator, and the other end is hinged to the upper end of the upper arm link; the upper arm hinge hole is hinged to the forearm hinge hole and can rotate through the axis; the upper and lower ends of the forearm link are respectively hinged to the connecting hinge part and one end of the wrist joint link, and the other end of the wrist joint link is hinged to the forearm.

[0010] Furthermore, both the upper arm connecting rod and the lower arm connecting rod have bends, and the upper arm hinge holes and the lower arm hinge holes are opened at the corresponding bends of the rods.

[0011] Furthermore, the forearm includes a forearm support portion, the side of which is provided with an upper forearm hinge hole and an end forearm hinge hole. The end forearm hinge hole is hinged to the other end of the wrist joint connecting rod, and the upper forearm hinge hole is hinged to the lower end of the upper arm connecting rod.

[0012] Beneficial effects: The exoskeleton robotic arm of the present invention places the actuator at the shoulder joint, making the overall structure of the robotic arm compact and with low motion inertia. By designing a multi-link mechanism, the circular motion of the actuator is transformed into the flexion and extension motion of the elbow joint, which improves the movement speed and transmission efficiency of the robotic arm. Furthermore, by adjusting the range of motion of the elbow joint through the mechanical structure, the reasonable range of motion of the elbow joint is still guaranteed even in any motion state of the actuator, which has high reliability and safety. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a dual-arm structure of an exoskeleton robotic arm based on a multi-link mechanism according to this embodiment;

[0014] Figure 2 This is a schematic diagram of a single-arm structure of an exoskeleton robotic arm based on a multi-link mechanism in this embodiment;

[0015] Figure 3 This is an exploded structural diagram of the upper arm and forearm in this embodiment;

[0016] In the diagram, 1-shoulder joint, 2-arm structure, 3-shoulder fixation strap;

[0017] 101-Shoulder joint linkage 1, 102-Shoulder joint actuator 1, 103-Shoulder joint actuator 2, 104-Shoulder joint linkage 2, 105-Shoulder joint linkage 3, 106-Shoulder joint actuator 3;

[0018] 201-Upper arm, 202-Drive linkage, 203-Elbow joint actuator, 204-Upper arm linkage, 205-Forearm mounting hinge hole, 206-Forearm hinge hole, 207-Upper arm end hinge hole, 208-Forearm linkage, 209-Forearm, 210-Wrist joint linkage, 211-Wrist joint linkage front hinge hole, 212-Upper arm support, 213-Drive hinge, 214-Connecting hinge, 215-Upper arm hinge hole, 216-Upper forearm hinge hole, 217-Forearm support, 218-End forearm hinge hole, 219-Forearm linkage end hinge hole, 220-Wrist joint linkage end hinge hole. Detailed Implementation

[0019] To make the objectives, technical solutions, and technical effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] like Figures 1 to 3 As shown in the figure, an exoskeleton robotic arm based on a multi-link mechanism disclosed in this invention includes a shoulder fixing strap 3, with shoulder joints 1 at both ends of the shoulder fixing strap 3, and an arm structure 2 disposed below the shoulder joints 1. The shoulder joint 1 includes a driver assembly and a series linkage mechanism with three rotational degrees of freedom connected to it, which can drive the arm structure 2 below to rotate in three directions of freedom. The arm structure 2 includes an upper arm 201 and a forearm 209, and a four-bar linkage is driven between the upper arm 201 and the forearm 209, and reciprocating flexion and extension movements are performed by driving the four-bar linkage.

[0021] For details, please refer to [link / reference]. Figure 2 The actuator assembly includes a shoulder joint actuator 102, a shoulder joint actuator 2 103, and a shoulder joint actuator 3 106. The shoulder joint actuator 102 is laterally fixed at the end of the shoulder fixing strap 3, and the output shafts of the shoulder joint actuator 102, shoulder joint actuator 2 103, and shoulder joint actuator 3 106 are respectively arranged along the X, Y, and Z axes.

[0022] The series linkage mechanism includes three arc-shaped links: shoulder joint link one 101, shoulder joint link two 104, and shoulder joint link three 105. The centers of their arcs converge at a single point, which is the center of the shoulder joint movement. One end of shoulder joint link one 101 is connected to the output shaft of shoulder joint actuator one 102, and the other end is fixedly connected to shoulder joint actuator two 103. One end of shoulder joint link two 104 is connected to the output end of shoulder joint actuator two 103, and the other end is fixedly connected to shoulder joint actuator three 106. One end of shoulder joint link three 105 is connected to the output shaft of shoulder joint actuator three 106, and the other end is fixedly connected to the upper arm 201 of the arm structure 2.

[0023] Continue to refer to Figure 3 The four-bar linkage includes a drive link 202, an upper arm link 204, a forearm link 208, and a wrist joint link 210. The upper arm link 204 has an upper arm hinge hole 215 at its bend; the forearm link 208 has a forearm mounting hinge hole 205 at its upper end and a forearm link end hinge hole 219 at its lower end, and a forearm hinge hole 206 at its bend.

[0024] The upper arm 201 includes an upper arm support 212. The upper arm support 212 has a drive hinge 213 and a connecting hinge 214 on its side. An elbow joint driver 203 is fixedly installed on the drive hinge 213.

[0025] The forearm 209 includes a forearm support portion 217, and the side of the forearm support portion 217 is provided with an upper forearm hinge hole 216 and an end forearm hinge hole 218.

[0026] In this design, the output shaft of the elbow joint actuator 203 is connected to one end of the drive link 202, and the other end of the drive link 202 is hinged to one end of the upper arm link 204. The upper arm end hinge hole 207 at the other end of the upper arm link 204 is hinged to the upper forearm hinge hole 216, while the upper arm hinge hole 215 at the bend is hinged to the forearm hinge hole 206 and can rotate through the axis. The forearm mounting hinge hole 205 is hinged to the connecting hinge part 214, the forearm link end hinge hole 219 is hinged to the wrist joint link end hinge hole 220 at one end of the wrist joint link 210, and the wrist joint link front hinge hole 211 at the other end of the wrist joint link 210 is hinged to the end forearm hinge hole 218.

[0027] The circular motion of the elbow joint actuator 203 is transmitted to the upper arm linkage 204 via the drive link 202. Due to the hinge restriction between the upper arm end hinge hole 207 and the upper forearm hinge hole 216 of the upper arm linkage 204, the forearm 209 reciprocates with the rotation of the drive link 202. This reciprocating motion is transmitted to the forearm linkage 208 via the hinge of the forearm hinge hole 206. Since the forearm mounting hinge hole 205 of the forearm linkage 208 is hinged to the connecting hinge part 214 of the upper arm 201, the forearm linkage 208 performs flexion and extension movements around the forearm hinge hole 206, always limiting the flexion and extension movements of the elbow joint within a reasonable range of motion.

[0028] In the aforementioned mechanism, the upper part of the drive link 202, upper arm 201, upper arm link 204, and forearm link 208 constitutes a four-bar linkage. Furthermore, the wrist joint link 210, forearm 209, forearm link 208, and upper arm link 204 constitute another four-bar linkage. These two four-bar linkages enhance the load-bearing capacity of the robotic arm.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Although the implementation process of the present invention has been described in detail above, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-link mechanism-based exoskeleton robot arm comprising a shoulder fixing belt (3) provided with a shoulder joint (1) at both ends, and an arm structure (2) provided below the shoulder joint (1), characterized in that, The shoulder joint (1) includes a driver assembly and a series linkage mechanism with three rotational degrees of freedom connected to it, which can drive the lower arm structure (2) to rotate in three directions; the arm structure (2) includes an upper arm (201) and a forearm (209), and a four-bar linkage is driven between the upper arm (201) and the forearm (209), and reciprocating flexion and extension movements are performed by driving the four-bar linkage. The upper arm (201) includes an upper arm support (212), and the upper arm support (212) has a drive hinge (213) and a connecting hinge (214) on its side. An elbow joint driver (203) is fixedly installed on the drive hinge (213); the elbow joint driver (203) drives the four-bar linkage. The four-bar linkage includes a drive link (202), an upper arm link (204), a forearm link (208), and a wrist joint link (210). The upper arm link (204) has an upper arm hinge hole (215), and the forearm link (208) has a forearm hinge hole (206). One end of the drive link (202) is connected to the output shaft of the elbow joint actuator (203), and the other end is hinged to the upper end of the upper arm link (204). The upper arm hinge hole (215) is hinged to the forearm hinge hole (206) and can rotate through the axis. The upper and lower ends of the forearm link (208) are respectively hinged to the connecting hinge part (214) and one end of the wrist joint link (210). Both the upper arm connecting rod (204) and the lower arm connecting rod (208) have bends, and the upper arm hinge hole (215) and the lower arm hinge hole (206) are opened at the bends of the corresponding rods. The forearm (209) includes a forearm support (217), and the side of the forearm support (217) is provided with an upper forearm hinge hole (216) and an end forearm hinge hole (218). The end forearm hinge hole (218) is hinged to the other end of the wrist joint link (210), and the upper forearm hinge hole (216) is hinged to the lower end of the upper arm link (204).

2. The exoskeleton robotic arm of claim 1, wherein, The actuator group includes shoulder joint actuator one (102), shoulder joint actuator two (103) and shoulder joint actuator three (106). Shoulder joint actuator one (102) is fixedly mounted laterally at the end of the shoulder fixing strap (3), and the output shafts of shoulder joint actuator one (102), shoulder joint actuator two (103) and shoulder joint actuator three (106) are respectively set along the X, Y and Z axes.

3. The exoskeleton robotic arm of claim 2, wherein, The series linkage mechanism includes three arc-shaped links, namely shoulder joint link one (101), shoulder joint link two (104) and shoulder joint link three (105), and the arc centers of the three links converge at one point; one end of shoulder joint link one (101) is connected to the output shaft of shoulder joint actuator one (102), and the other end is fixedly connected to shoulder joint actuator two (103); one end of shoulder joint link two (104) is connected to the output end of shoulder joint actuator two (103), and the other end is fixedly connected to shoulder joint actuator three (106); one end of shoulder joint link three (105) is connected to the output shaft of shoulder joint actuator three (106), and the other end is fixedly connected to the upper arm (201) of the arm structure (2).

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