A humanoid robot parallel driving shoulder and elbow mechanism based on ring limiting module

Abstract

The application relates to a humanoid robot, in particular to a humanoid robot parallel driving shoulder and elbow mechanism based on a ring limiting module. The purpose is to provide a humanoid robot parallel driving shoulder and elbow mechanism based on a ring limiting module, so as to combine the advantages of parallel mechanisms and serial mechanisms, improve the rigidity, load capacity and motion flexibility of the robot shoulder and elbow joints. The technical scheme is a humanoid robot parallel driving shoulder and elbow mechanism based on a ring limiting module, characterized in that the shoulder and elbow mechanism comprises two shoulder mounting frames installed on the left and right sides of the top of the chest cavity, each shoulder mounting frame is provided with a ring sliding rail, a shoulder horizontal rotating shaft, a shoulder vertical rotating shaft and two push rod branches.

Description

Technical Field

[0001] This invention relates to a humanoid robot, specifically to a parallel drive shoulder and elbow mechanism for a humanoid robot based on a ring-shaped limiting module. Background Technology

[0002] Humanoid robots represent a crucial development direction in robotics, and the design of their upper limb structures directly impacts the robot's flexibility and load-bearing capacity during task execution. Existing humanoid robot upper limb joints mostly employ serial mechanisms, where motors, reducers, and other drive components are directly mounted at the joints and connected sequentially via linkages. While this structure simplifies control, it suffers from low stiffness, slow dynamic response, and end-effector positioning accuracy easily affected by the cumulative errors of each joint. Furthermore, placing the drive motor at the joint in a serial structure increases the arm's moment of inertia, hindering the achievement of high-speed, high-precision movements.

[0003] To overcome these shortcomings, some studies have attempted to introduce parallel mechanisms into robot joint design. For example, the "Multi-DOF Redundant Series-Parallel Humanoid Robotic Arm" (CN110524522B) published by Zhejiang University of Technology uses a combination of series mechanisms for the shoulder and elbow joints and a six-DOF parallel mechanism for the wrist joint. However, in this scheme, the shoulder joint still uses a traditional series drive structure, with the drive unit directly mounted at the joint, resulting in a large moment of inertia in the shoulder motion, which limits the improvement of dynamic response performance.

[0004] In summary, existing humanoid robot upper limb mechanisms still suffer from the challenge of balancing stiffness and inertia: serial mechanisms, while simple to control, suffer from low stiffness and high inertia; parallel mechanisms, while offering high stiffness, are mostly limited to wrist or torso applications, and parallel drive schemes for shoulder joints are still immature. Therefore, designing a parallel upper limb mechanism for humanoid robots that combines high stiffness, low inertia, and good mobility, particularly optimizing the structure of the crucial shoulder-elbow joint, is a technical problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a parallel drive shoulder and elbow mechanism for humanoid robots based on a ring-shaped limiting module, so as to combine the advantages of parallel and serial mechanisms and improve the stiffness, load-bearing capacity and motion flexibility of the robot's shoulder and elbow joints.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A parallel drive shoulder and elbow mechanism for a humanoid robot based on a ring-shaped limiting module is characterized in that: the shoulder and elbow mechanism includes two shoulder mounting frames installed on the left and right sides of the top of the chest cavity, and each shoulder mounting frame is equipped with a ring slide rail, a shoulder horizontal rotation axis, a shoulder vertical rotation axis and two push rod branches; The shoulder horizontal rotation axis is fixed on a slider that cooperates with the annular slide rail; the shoulder vertical rotation axis is arranged vertically and its middle part is hinged to the shoulder horizontal rotation axis, the top end of the shoulder vertical rotation axis is connected to the two push rod branches, and the bottom end is connected to the upper arm; The push rod branch is either a UPS push rod branch or a CPS push rod branch; The UPS push rod branch includes a ball joint, an electric push rod, and a universal joint connected in sequence between the shoulder vertical rotation axis and the shoulder mounting bracket; the CPS push rod branch includes a ball joint, an electric push rod, and a cylindrical joint connected in sequence between the shoulder vertical rotation axis and the shoulder mounting bracket.

[0007] One side of the shoulder mount is fixed to the chest cavity, while the rest extends outwards to the left and right sides of the chest cavity. The frame plane of the shoulder mount is also inclined and forms an elevation angle of 10-30° to the left and right sides to facilitate the expansion of the range of motion of the upper arm.

[0008] The shoulder vertical rotation axis is a T-shaped structure formed by connecting the horizontal and vertical sections. The horizontal section is arranged parallel to the front-back direction of the chest cavity. The shaft hole in the middle of the vertical section is hinged to the shoulder horizontal rotation axis, and the axis of the shaft hole is parallel to the horizontal section.

[0009] The two ends of the horizontal section of the vertical rotation axis of the shoulder are respectively connected to one end of two push rod branches, and the other end of the two push rod branches is connected to the end of the shoulder mounting frame near the center of the chest cavity.

[0010] The shoulder arm connector is connected to the bottom end of the vertical rotation shaft of the shoulder, and the main drive motor and the auxiliary drive motor are coaxially mounted on two motor mounting plates connected on its left and right sides; the lower outer sides of the two motor mounting plates are hinged to the top of the two arm protective shells 18, and the bottom ends of the two arm protective shells are hinged to the elbows respectively.

[0011] The elbow includes a circular base plate and three elbow connecting rods standing side by side on the base plate with a distance between them. The three elbow connecting rods have the same structure and each has two hinge holes arranged along the length of the elbow connecting rod. The first hinge shaft is inserted and positioned in the hinge hole at the top of the three elbow connecting rods, and the second hinge shaft is inserted and positioned in the hinge hole in the middle of the three elbow connecting rods. At the same time, the two ends of the second hinge shaft are respectively hinged to the bottom ends of the two large arm protective shells.

[0012] One end of the main drive linkage is fixed to the motor shaft of the main drive motor, thus being directly driven by the motor shaft. The other end is hinged to the second hinge shaft, thus being directly driven by the main drive motor. The motor shaft of the auxiliary drive motor is fixed to one end of the first auxiliary drive linkage, thus being directly driven. The other end of the first auxiliary drive linkage is sequentially hinged to the second hinge shaft via the second auxiliary drive linkage and the elbow-upper arm connecting linkage, thus being driven by the auxiliary drive motor.

[0013] The two cylindrical pairs in the two CPS push rod branches are coaxially arranged, and the two cylindrical pairs share a single slide rod.

[0014] The beneficial effects of this invention are: The shoulder section employs a dual-pushrod branch parallel mechanism, placing the drive unit (electric pushrod) close to the body, significantly improving the stiffness and load-bearing capacity of the shoulder and elbow joints while reducing the inertia at the end of the movement. Through the combined motion of the parallel branches and two rotation axes (horizontal and vertical), it can simulate the complex movements of the human shoulder joint, achieving a wide range of multi-degree-of-freedom spatial rotation. The upper arm section uses a linkage transmission mechanism, placing the drive motor at the rear, making the upper arm structure more compact and reducing the weight of the forearm, which is beneficial for improving dynamic response performance and movement flexibility. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the installation location in Embodiment 1 of the present invention.

[0016] Figure 2 This is a three-dimensional structural diagram of Embodiment 1 of the present invention.

[0017] Figure 3 for Figure 2 A three-dimensional structural diagram of the UPS push rod branch.

[0018] Figure 4 for Figure 1 A three-dimensional structural diagram of the upper arm.

[0019] Figure 5 for Figure 1 A partial schematic diagram of the upper arm.

[0020] Figure 6 This is one of the schematic diagrams illustrating the working principle of Example 1.

[0021] Figure 7 This is the second schematic diagram illustrating the working principle of Example 1.

[0022] Figure 8 This is the third schematic diagram illustrating the working principle of Example 1.

[0023] Figure 9This is a three-dimensional structural diagram of Embodiment 2 of the present invention.

[0024] Figure label: Detailed Implementation

[0025] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.

[0026] The directional setting of this article: The terms "up / down," "left / right," and "front / back" in this article are related to... Figure 1 The mid-thoracic cavity is consistent in its upper and lower, left and right, and front and back dimensions.

[0027] Example 1 like Figure 1 As shown, the humanoid robot's chest cavity 3 is vertically arranged, and the upper left and right sides of the chest cavity 3 are the shoulders 2. The upper arm 1 is connected to the lower side of the shoulders, and the elbow link 17 is connected to the bottom of the upper arm.

[0028] like Figure 2 The humanoid robot parallel drive shoulder and elbow mechanism based on a ring-shaped limiting module shown includes two shoulder mounting brackets 21, four identical UPS push rod branches 22, two ring slide rails 23, two shoulder horizontal rotation axes 24, two shoulder vertical rotation axes 25, and two shoulder upper arm connectors 26.

[0029] Two shoulder mounts 21 are installed on the left and right sides of the chest cavity respectively; each shoulder mount is shaped like a flat frame similar to the letter "H". During installation, part of the shoulder mount 21 is fixed to the chest cavity by bolts, and the rest extends outward in the left and right directions of the chest cavity; the frame plane of the shoulder mount is also inclined and forms an elevation angle of 10 to 30° outward in the left and right directions to expand the range of motion of the upper arm 1.

[0030] Each shoulder mounting bracket is equipped with two identical UPS push rod branches 22 connected by a shoulder vertical rotation axis. The shoulder vertical rotation axis 25 has a T-shaped structure formed by connecting horizontal and vertical sections, with the horizontal section arranged parallel to the anterior-posterior direction of the thoracic cavity. The two UPS push rod branches 22 are installed parallel to each other on the anterior and posterior sides of the thoracic cavity. One end of each UPS push rod branch is mounted on the end of the two shoulder mounting brackets 21 near the thoracic cavity via universal joints, and the other end is connected to the anterior and posterior ends of the horizontal section of the shoulder vertical rotation axis via ball joints. The middle of the shoulder horizontal rotation axis is hinged to the middle of the vertical section of the shoulder vertical rotation axis 25, and the shoulder horizontal rotation axis 24 is parallel to the horizontal section of the shoulder vertical rotation axis. The two ends of the shoulder horizontal rotation axis 24 are fixed on the sliders of the annular slide rail 23 and can rotate with the sliders. The annular slide rail 23 is fixedly installed on the end of the shoulder mounting bracket away from the thoracic cavity. The bottom of the shoulder vertical rotation axis 25 is fixedly connected to the top of the shoulder upper arm connector 26, and the upper arm is fixed to the bottom of the shoulder upper arm connector 26. Thus, the shoulder vertical rotation axis 25, the shoulder horizontal rotation axis 24, and the connected annular slide rail 23 equipped with a slider constitute the annular limiting module.

[0031] like Figure 3 As shown, the UPS push rod branch includes a universal joint 221, an electric push rod 222, and a ball joint 223 connected in sequence; the electric push rod includes a push rod sleeve 224 and a push rod 225 that slides with the push rod sleeve 224; one end of the universal joint 221 is installed at the end of the push rod sleeve 224, and the other end is installed at the end of the shoulder mounting bracket near the chest cavity; the ball joint 223 is installed between the end of the push rod 225 and the end of the horizontal section of the shoulder vertical rotation axis.

[0032] like Figure 4 , Figure 5As shown, the upper arm 1 includes a main drive motor 11, an auxiliary drive motor 12, a motor mounting plate 13, a main drive connecting rod 14, a first auxiliary drive connecting rod 15, a second auxiliary drive connecting rod 16, an elbow connecting rod 17, an upper arm protective shell 18, and an elbow-upper arm connecting rod 19. The two motor mounting plates are parallel to each other and vertically fixed to the left and right sides (i.e., the side closer to the chest cavity and the side farther from the chest cavity) of the shoulder upper arm connector 26 by screws; the main drive motor 11 and the auxiliary drive motor 12 are arranged horizontally and coaxially, and are respectively fixed to the inner side of the two motor mounting plates 13 (the side of the two motor mounting plates facing each other), so that the motor shafts of the two motors are perpendicular to the two motor mounting plates; the lower outer sides of the two motor mounting plates 13 are hinged to one end of the two upper arm protective shells 18, and the other ends of the two upper arm protective shells 18 are respectively hinged to the elbow. The elbow includes a circular base plate and three elbow connecting rods 17 standing side by side on the base plate with a distance between them. The three elbow connecting rods have the same structure and each has two hinge holes arranged along the length of the elbow connecting rod. The first hinge shaft 111 is inserted and positioned in the hinge holes at the top of the three elbow connecting rods. The second hinge shaft 110 is inserted and positioned in the other hinge hole (the hinge hole in the middle of the elbow connecting rod) of the three elbow connecting rods, and both ends are hinged to the bottom ends of the two upper arm protective shells 18.

[0033] One end of the main drive linkage 14 is fixed to the motor shaft of the main drive motor 11, and the other end is hinged to the second hinge shaft 110 through an opening in the shaft hole, so that the main drive motor directly drives the boom. The motor shaft of the auxiliary drive motor 12 is fixed to one end of the first auxiliary drive linkage 15, the other end of the first auxiliary drive linkage 15 is hinged to one end of the second auxiliary drive linkage 16, the other end of the second auxiliary drive linkage 16 is hinged to one end of the elbow boom connecting linkage 19, and the other end of the elbow boom connecting linkage 19 is hinged to the bottom end of the boom protective shell 18 through the second hinge shaft 110 (as mentioned above: the other ends of the two boom protective shells 18 are respectively hinged to the elbow), so that the auxiliary drive motor drives the elbow. The axes of all the aforementioned hinge shafts are parallel to each other.

[0034] like Figure 6 , Figure 7 As shown: The electric actuators 222 in the two identical UPS actuator branches 22 are the power source of the actuator branch. The two electric actuators 222 can drive the boom to rotate in space; when the two electric actuators 222 move in opposite directions, the boom can swing around the vertical rotation axis 25. Figure 6 a, Figure 6 b、 Figure 6 c shows the swinging process of the upper arm around the vertical rotation axis; when the two electric push rods 222 move in the same direction, the swinging of the upper arm around the horizontal rotation axis 24 can be realized. Figure 7 a, Figure 7 b、 Figure 7c shows the swinging process of the upper arm around the horizontal rotation axis.

[0035] like Figure 8 As shown: The auxiliary drive motor 12 drives the first auxiliary drive link 15, which causes the elbow 17 to swing relative to the main drive link 14, thereby realizing the swinging of the human forearm. Figure 8 a, Figure 8 b、 Figure 8 c shows the swinging process of the forearm); the main drive motor 11 drives the main drive linkage 14 to realize the swinging of the human upper arm around the main drive motor shaft; the two can be connected in parallel to control the movement of the human upper arm and forearm.

[0036] Example 2 The only difference between this embodiment and Embodiment 1 is the structure of the push rod branch; all other aspects are the same.

[0037] like Figure 9 As shown, the difference between this embodiment and Embodiment 1 is that the original UPS push rod branch is changed to a CPS push rod branch; that is, the original universal joint 221 is replaced with a cylindrical joint 28, and the two cylindrical joints in the two CPS push rod branches are coaxially arranged; the CPS push rod branch can slide freely on the cylindrical joint.

[0038] In this embodiment, the CPS push rod branch 27 includes a ball joint, an electric push rod, and a cylindrical joint connected in sequence. The electric push rod includes a push rod sleeve and a push rod that slides with the push rod sleeve. The cylindrical joint includes a slide rod and a slide cylinder that slides with the slide rod. The ball joint is installed between the end of the push rod and the end of the horizontal section of the shoulder's vertical rotation axis. The slide cylinder is connected to the push rod, and the axis of the slide cylinder is perpendicular to the axis of the push rod. The slide rod is fixed to one end of the shoulder mounting bracket near the center of the thoracic cavity. In this embodiment, the slide rods of the two cylindrical joints connected to the shoulder mounting bracket are arranged coaxially. Furthermore, the two cylindrical joints share a single slide rod.

[0039] Working principle: This parallel mechanical joint can achieve the degrees of freedom and functions required for biomimetic human arm movement, including three rotational degrees of freedom. The shoulder structure, similar to a Hooke's hinge, connects the chest cavity and the arm, possessing two rotational degrees of freedom, achieved through two motors driving either a UPS push rod branch or a CPS push rod branch (e.g., ...). Figure 6 Figure 7 (As shown); when the two push rod branches cooperate, precise control of shoulder movements can be achieved. Simultaneously, the main drive motor of the upper arm can supplement one degree of rotational freedom of the shoulder, while the auxiliary drive motor can simultaneously operate the rotation of the elbow (e.g., Figure 9 As shown in the figure, this enables precise parallel control of upper limb movements.

Claims

1. A parallel drive shoulder-elbow mechanism for a humanoid robot based on a ring-shaped limiting module, characterized in that: The shoulder-elbow mechanism includes two shoulder mounting brackets (21) installed on the left and right sides of the top of the chest cavity. Each shoulder mounting bracket is equipped with an annular slide rail (23), a shoulder horizontal rotation axis (24), a shoulder vertical rotation axis (25), and two push rod branches. The shoulder horizontal rotation axis is fixed on the slider that cooperates with the annular slide rail; the shoulder vertical rotation axis is arranged vertically and its middle part is hinged to the shoulder horizontal rotation axis, the top end of the shoulder vertical rotation axis is connected to the two push rod branches, and the bottom end is connected to the upper arm (1). The push rod branch is either a UPS push rod branch (22) or a CPS push rod branch (27). The UPS push rod branch includes a ball joint (223), an electric push rod (222), and a universal joint (221) connected in sequence between the shoulder vertical rotation axis and the shoulder mounting frame; the CPS push rod branch includes a ball joint, an electric push rod, and a cylindrical joint (28) connected in sequence between the shoulder vertical rotation axis and the shoulder mounting frame.

2. The humanoid robot parallel drive shoulder-elbow mechanism based on a ring-shaped limiting module according to claim 1, characterized in that: One side of the shoulder mounting bracket (21) is fixed to the chest cavity, and the rest extends outward in the left and right directions of the chest cavity; the frame plane of the shoulder mounting bracket is also arranged at an angle of 10-30° in the left and right directions to facilitate the expansion of the range of motion of the upper arm (1).

3. The humanoid robot parallel drive shoulder-elbow mechanism based on a ring-shaped limiting module according to claim 2, characterized in that: The shoulder vertical rotation axis (25) is a T-shaped structure formed by connecting the horizontal and vertical sections. The horizontal section is arranged parallel to the front-back direction of the chest cavity. The shaft hole in the middle of the vertical section is hinged to the shoulder horizontal rotation axis, and the axis of the shaft hole is parallel to the horizontal section.

4. The humanoid robot parallel drive shoulder-elbow mechanism based on a ring-shaped limiting module according to claim 3, characterized in that: The two ends of the horizontal section of the shoulder vertical rotation axis (25) are respectively connected to one end of two push rod branches, and the other end of the two push rod branches is connected to the end of the shoulder mounting bracket (21) near the center of the chest cavity.

5. The humanoid robot parallel drive shoulder-elbow mechanism based on a ring-shaped limiting module according to claim 4, characterized in that: The shoulder arm connector (26) is connected to the bottom end of the vertical rotation shaft of the shoulder, and the main drive motor (11) and the auxiliary drive motor (12) are coaxially mounted through two motor mounting plates (13) connected on its left and right sides; the lower ends of the two motor mounting plates are hinged to the top ends of the two arm protective shells (18), and the bottom ends of the two arm protective shells are hinged to the elbows respectively.

6. The humanoid robot parallel drive shoulder-elbow mechanism based on a ring-shaped limiting module according to claim 5, characterized in that: The elbow includes a circular base plate and three elbow connecting rods (17) standing side by side on the base plate with a distance between them. The three elbow connecting rods have the same structure and each has two hinge holes arranged along the length of the elbow connecting rod. The first hinge shaft (111) is inserted and positioned in the hinge holes at the top of the three elbow connecting rods. The second hinge shaft (110) is inserted and positioned in the hinge holes in the middle of the three elbow connecting rods. At the same time, the two ends of the second hinge shaft are respectively hinged to the bottom ends of the two upper arm protective shells (18).

7. The humanoid robot parallel drive shoulder-elbow mechanism based on a ring-shaped limiting module according to claim 6, characterized in that: One end of the main drive link (14) is fixed to the motor shaft of the main drive motor (11), and the other end is hinged to the second hinge shaft, so that the main drive motor directly drives the upper arm; the motor shaft of the auxiliary drive motor (12) is fixed to one end of the first auxiliary drive link (15), and the other end of the first auxiliary drive link is hinged to the second hinge shaft through the second auxiliary drive link (16) and the elbow upper arm connecting link (19) in sequence, so that the elbow is driven by the auxiliary drive motor.

8. The humanoid robot parallel drive shoulder-elbow mechanism based on a ring-shaped limiting module according to claim 7, characterized in that: The two cylindrical pairs in the two CPS push rod branches are coaxially arranged, and the two cylindrical pairs share a single slide rod.

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