Exoskeleton mechanical arm based on multi-connecting-rod mechanism

Abstract

The invention belongs to the field of exoskeleton mechanical arms, and particularly relates to an exoskeleton mechanical arm based on a multi-connecting-rod mechanism, which comprises a shoulder fixing belt, shoulder joints are arranged at two ends of the shoulder fixing belt, arm structures are arranged below the shoulder joints, and each shoulder joint comprises a driver group and a series connecting rod mechanism which is in driving connection with the driver group and has three rotational degrees of freedom; the lower arm structure can be driven to rotate in the directions of three degrees of freedom; the arm structure comprises a large arm and a small arm, a four-connecting-rod mechanism is connected between the large arm and the small arm in a driving mode, and the arm structure can bend and stretch in a reciprocating mode by driving the four-connecting-rod mechanism. According to the exoskeleton mechanical arm, the driver is arranged at the shoulder joint, so that the overall structure of the mechanical arm is compact, the motion inertia is small, the circular motion of the driver is converted into the flexion and extension motion of the elbow joint by designing the multi-connecting-rod mechanism, and the motion speed and transmission efficiency of the mechanical arm are improved; and in addition, the reasonable motion range of the elbow joint can still be guaranteed under any motion state of the driver, and high reliability and safety are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of exoskeleton robotic arms, and specifically relates to an exoskeleton robotic arm based on a multi-link mechanism. Background Art

[0002] An exoskeleton robotic arm is a wearable intelligent mechanical device that can enhance or assist human motor ability using sensors, actuators, and control systems, and is widely used in fields such as medical rehabilitation, industrial manufacturing, and military defense.

[0003] When designing existing exoskeleton robotic arms, there are problems such as limited or even incorrect joint movement ranges due to unreasonable structural positions and driving directions of the actuators. Summary of the Invention

[0004] In order to solve the above technical problems existing in the prior art, the present invention proposes an exoskeleton robotic arm based on a multi-link mechanism, and its specific technical solution is as follows: An exoskeleton robotic arm based on a multi-link mechanism includes a shoulder fixing strap, with shoulder joints provided at both ends of the shoulder fixing strap, and an arm structure provided below the shoulder joints. The shoulder joints include a set of actuators and a series-link mechanism with three rotational degrees of freedom driven and connected by them, which can drive the lower arm structure to rotate in three degrees-of-freedom directions; the arm structure includes a upper arm and a forearm, and a four-link mechanism is drivingly connected between the upper arm and the forearm, and reciprocating flexion and extension movements are performed by driving the four-link mechanism.

[0005] Further, the set of actuators includes a first shoulder joint actuator, a second shoulder joint actuator, and a third shoulder joint actuator. The first shoulder joint actuator is horizontally fixedly provided at the end of the shoulder fixing strap, and the output shafts of the first shoulder joint actuator, the second shoulder joint actuator, and the third shoulder joint actuator are axially arranged along the X, Y, and Z axes respectively.

[0006] Further, the series-link mechanism includes three arc-shaped links, namely a first shoulder joint link, a second shoulder joint link, and a third shoulder joint link, and the centers of the arcs of the three converge at one point; one end of the first shoulder joint link is connected to the output shaft of the first joint actuator, and the other end is fixedly connected to the second shoulder joint actuator; one end of the second shoulder joint link is connected to the output end of the second shoulder joint actuator, and the other end is fixedly connected to the third shoulder joint actuator; one end of the third shoulder joint link is connected to the output shaft of the third shoulder joint actuator, and the other end is fixedly connected to the upper arm of the arm structure.

[0007] Further, the upper arm includes an upper arm support portion, with a driving hinge portion and a connecting hinge portion provided on the side of the upper arm support portion, and an elbow joint actuator is fixedly installed on the driving hinge portion; the elbow joint actuator is drivingly connected to the four-link mechanism.

[0008] Further, the four-bar linkage mechanism includes a driving link, a large arm link, a small arm link, and a wrist joint link; the rod body of the large arm link is provided with a large arm hinge hole, and the rod body of the small arm link is provided with a small arm hinge hole; one end of the driving link is connected to the output shaft of the elbow joint driver, and the other end is hinged to the upper end of the large arm link; the large arm hinge hole and the small arm hinge hole are hinged and can rotate around the axis; the upper and lower ends of the small arm 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 small arm.

[0009] Further, the rod bodies of the large arm link and the small arm link both have bends, and the large arm hinge hole and the small arm hinge hole are opened at the bends of the corresponding rod bodies.

[0010] Further, the small arm includes a small arm supporting part, and the side part of the small arm supporting part is provided with an upper end small arm hinge hole and a terminal small arm hinge hole. The terminal small arm hinge hole is hinged to the other end of the wrist joint link, and the upper end small arm hinge hole is hinged to the lower end of the large arm link.

[0011] Beneficial effects: The exoskeleton robotic arm of the present invention places the driver at the shoulder joint, making the overall structure of the robotic arm compact and having a small movement inertia. By designing a multi-link mechanism, the circular motion of the driver is converted into the flexion and extension motion of the elbow joint, improving the movement speed and transmission efficiency of the robotic arm. And by adjusting the movement range of the elbow joint through the mechanical structure, a reasonable movement range of the elbow joint is still ensured in any movement state of the driver, having high reliability and safety. Description of the Drawings

[0012] Figure 1 is a schematic diagram of the double-arm structure of an exoskeleton robotic arm based on a multi-link mechanism in this embodiment; Figure 2 is a schematic diagram of the single-arm structure of an exoskeleton robotic arm based on a multi-link mechanism in this embodiment; Figure 3 is an exploded view of the large arm and the small arm in this embodiment; In the figure, 1 - shoulder joint, 2 - arm structure, 3 - shoulder fixing strap; 101 - first shoulder joint link, 102 - first shoulder joint driver, 103 - second shoulder joint driver, 104 - second shoulder joint link, 105 - third shoulder joint link, 106 - third shoulder joint driver; 201 - Upper arm, 202 - Driving link, 203 - Elbow joint driver, 204 - Upper arm link, 205 - Forearm mounting hinge hole, 206 - Forearm hinge hole, 207 - Upper arm end hinge hole, 208 - Forearm link, 209 - Forearm, 210 - Wrist joint link, 211 - Front end hinge hole of wrist joint link, 212 - Upper arm support part, 213 - Driving hinge part, 214 - Connecting hinge part, 215 - Upper arm hinge hole, 216 - Upper end forearm hinge hole, 217 - Forearm support part, 218 - End forearm hinge hole, 219 - End hinge hole of forearm link, 220 - End hinge hole of wrist joint link. Detailed implementation manner

[0013] In order to make the objectives, technical solutions and technical effects of the present invention more clear and understandable, the following further elaborates on the present invention in detail in conjunction with the specification drawings and embodiments.

[0014] As Figures 1 to 3 shown, an exoskeleton robotic arm based on a multi-link mechanism disclosed in an embodiment of the present invention includes a shoulder fixing band 3, with shoulder joints 1 provided at both ends of the shoulder fixing band 3, and an arm structure 2 provided below the shoulder joints 1. The shoulder joint 1 includes a driver group and a series link mechanism with three rotational degrees of freedom driven and connected by the driver group, which can drive the lower arm structure 2 to rotate in three degrees of freedom directions. The arm structure 2 includes an upper arm 201 and a forearm 209, and a four-link mechanism is drivingly connected between the upper arm 201 and the forearm 209, and reciprocating flexion and extension movements are performed by driving the four-link mechanism.

[0015] Specifically, continuing to refer to Figure 2 , the driver group includes a first shoulder joint driver 102, a second shoulder joint driver 103, and a third shoulder joint driver 106. Among them, the first shoulder joint driver 102 is horizontally fixedly provided at the end of the shoulder fixing band 3, and the output shafts of the first shoulder joint driver 102, the second shoulder joint driver 103, and the third shoulder joint driver 106 are axially arranged along the X, Y, and Z axes respectively.

[0016] The series link mechanism includes three arc links, namely a first shoulder joint link 101, a second shoulder joint link 104, and a third shoulder joint link 105. The centers of their arcs converge at one point, which is the center point of the shoulder joint movement. Among them, one end of the first shoulder joint link 101 is connected to the output shaft of the first joint driver 102, and the other end is fixedly connected to the second shoulder joint driver 103; one end of the second shoulder joint link 104 is connected to the output end of the second shoulder joint driver 103, and the other end is fixedly connected to the third shoulder joint driver 106; one end of the third shoulder joint link 105 is connected to the output shaft of the third shoulder joint driver 1, and the other end is fixedly connected to the upper arm 201 of the arm structure 2.

[0017] Continuing to refer toFigure 3 , the four-bar linkage mechanism includes a driving link 202, a large arm link 204, a small arm link 208, and a wrist joint link 210. Among them, a large arm hinge hole 215 is provided at the bent portion of the rod body of the large arm link 204; the upper and lower ends of the small arm link 208 are respectively provided with a small arm mounting hinge hole 205 and a small arm link end hinge hole 219, and a small arm hinge hole 206 is provided at the bent portion of the rod body of the small arm link 208.

[0018] The large arm 201 includes a large arm supporting portion 212, and a driving hinge portion 213 and a connecting hinge portion 214 are provided on the side of the large arm supporting portion 212. An elbow joint driver 203 is fixedly installed on the driving hinge portion 213.

[0019] The small arm 209 includes a small arm supporting portion 217, and an upper end small arm hinge hole 216 and a terminal small arm hinge hole 218 are provided on the side of the small arm supporting portion 217.

[0020] Among them, the output shaft of the elbow joint driver 203 is connected to one end of the driving link 202, the other end of the driving link 202 is hinged to one end of the large arm link 204, the large arm end hinge hole 207 at the other end of the large arm link 204 is hinged to the upper end small arm hinge hole 216, and the large arm hinge hole 215 at the bent portion is hinged to the small arm hinge hole 206 and can rotate through the axis. The small arm mounting hinge hole 205 is hinged to the connecting hinge portion 214, the small arm 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 terminal small arm hinge hole 218.

[0021] The circular motion of the elbow joint driver 203 is transmitted to the large arm link 204 through the driving link 202. Due to the limitation of the hinge connection between the large arm end hinge hole 207 of the large arm link 204 and the upper end small arm hinge hole 216, the small arm 209 makes a reciprocating motion as the driving link 202 rotates. This reciprocating motion is transmitted to the small arm link 208 through the hinge connection of the small arm hinge hole 206. Since the small arm mounting hinge hole 205 of the small arm link 208 is hinged to the connecting hinge portion 214 of the large arm 201, the small arm link 208 makes a flexion and extension motion around the small arm hinge hole 206, and always limits the flexion and extension motion of the elbow joint within a reasonable range of motion.

[0022] In the above mechanism, the driving link 202, the upper half of the large arm 201, the large arm link 204, and the small arm link 208 form a four-bar linkage mechanism. In addition, the wrist joint link 210, the small arm 209, the small arm link 208, and the large arm link 204 form another four-bar linkage mechanism. The bearing capacity of the robotic arm can be improved through the above two four-bar linkage mechanisms.

[0023] The above are only the preferred embodiments of the present invention and do not impose any formal limitations on the present invention. 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 replacements for some of the technical features. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An exoskeleton robotic arm based on a multi-link mechanism, comprising a shoulder fixing strap (3), with shoulder joints (1) provided at both ends of the shoulder fixing strap (3), and an arm structure (2) provided below the shoulder joints (1), characterized in that, The shoulder joint (1) includes a drive unit and a serial linkage mechanism with three rotational degrees of freedom driven and connected thereto, which can drive the lower arm structure (2) to rotate in three degrees of freedom directions; the arm structure (2) includes a large arm (201) and a small arm (209), and a four-bar linkage is driven and connected between the large arm (201) and the small arm (209), and reciprocating flexion and extension movements are performed by driving the four-bar linkage.

2. The exoskeleton robotic arm according to claim 1, characterized in that, The drive unit includes a first shoulder joint driver (102), a second shoulder joint driver (103) and a third shoulder joint driver (106). The first shoulder joint driver (102) is fixedly arranged horizontally at the end of the shoulder fixing belt (3), and the output shafts of the first shoulder joint driver (102), the second shoulder joint driver (103) and the third shoulder joint driver (106) are axially arranged along the X, Y, and Z axes respectively.

3. The exoskeleton robotic arm according to claim 2, characterized in that, The serial linkage mechanism includes three arc-shaped linkages, namely, a first shoulder joint linkage (101), a second shoulder joint linkage (104) and a third shoulder joint linkage (105), and the centers of the arcs of the three converge at one point; one end of the first shoulder joint linkage (101) is connected to the output shaft of the first joint driver (102), and the other end is fixedly connected to the second shoulder joint driver (103); one end of the second shoulder joint linkage (104) is connected to the output end of the second shoulder joint driver (103), and the other end is fixedly connected to the third shoulder joint driver (106); one end of the third shoulder joint linkage (105) is connected to the output shaft of the third shoulder joint driver (106), and the other end is fixedly connected to the large arm (201) of the arm structure (2).

4. The exoskeleton robotic arm according to claim 1, characterized in that, The large arm (201) includes a large arm supporting part (212), and a drive hinge part (213) and a connection hinge part (214) are arranged on the side of the large arm supporting part (212). An elbow joint driver (203) is fixedly installed on the drive hinge part (213); the elbow joint driver (203) is drivingly connected to the four-bar linkage.

5. The exoskeleton robotic arm according to claim 4, wherein The four-bar linkage includes a drive link (202), a large arm link (204), a small arm link (208) and a wrist joint link (210); a large arm hinge hole (215) is provided on the rod body of the large arm link (204), and a small arm hinge hole (206) is provided on the rod body of the small arm link (208); one end of the drive link (202) is connected to the output shaft of the elbow joint driver (203), and the other end is hinged to the upper end of the large arm link (204); the large arm hinge hole (215) is hinged to the small arm hinge hole (206) and can rotate around the axis; the upper and lower ends of the small arm link (208) are respectively hinged to the connection hinge part (214) and one end of the wrist joint link (210), and the other end of the wrist joint link (210) is hinged to the small arm (209).

6. The exoskeleton robotic arm according to claim 5, characterized in that The rod bodies of the large arm link (204) and the small arm link (208) both have bent portions, and the large arm hinge hole (215) and the small arm hinge hole (206) are opened at the bent portions of the corresponding rod bodies.

7. The exoskeleton robotic arm according to claim 5, characterized in that, The forearm (209) includes a forearm supporting portion (217). An upper forearm hinge hole (216) and a terminal forearm hinge hole (218) are provided on the side of the forearm supporting portion (217). The terminal 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).

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