Seven-degree-of-freedom series-parallel structure mechanical arm for biped robot

Abstract

The invention discloses a seven-degree-of-freedom series-parallel structure mechanical arm for a biped robot, and relates to the field of robots, the seven-degree-of-freedom series-parallel structure mechanical arm is installed on a supporting body, and the supporting body is located on an installation fixing base. Comprising a five-degree-of-freedom series arm and a two-degree-of-freedom parallel wrist structure which is located at the front end of the series arm and connected with the series arm. According to the mechanical arm with the series-parallel connection structure, the rigidity and the bearing capacity of the mechanical arm are improved, the working space is expanded to adapt to more complex operation tasks, the stability and the reliability of operation are enhanced, error accumulation is reduced, and the accuracy of overall operation is improved.

Description

Technical Field

[0001] The invention relates to the field of robots, and in particular to a seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot. Background Art

[0002] Bipedal robots can simulate the way humans walk and perform tasks in complex and ever-changing environments. However, the mechanical arms of existing bipedal robots mostly adopt traditional series or parallel structures. These structures have certain limitations in positioning accuracy, workspace range, and structural stiffness. Although the series structure has a large workspace and flexible movements, it has problems of cumulative error and low structural stiffness; although the parallel structure has high accuracy and strong load-bearing capacity, it has a small workspace and strong coupling problems.

[0003] Therefore, technicians in this field are committed to developing a new type of robotic arm structure that can have the advantages of both series and parallel mechanisms, and can overcome the problems of cumulative errors and low structural stiffness in the series structure and small working space and coupling in the parallel structure. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is how to design a new type of mechanical arm for a bipedal robot, which not only has the advantages of both series and parallel mechanisms, but also overcomes the defects of the series mechanism and the parallel mechanism themselves, and can improve the stability, flexibility and load capacity of the bipedal robot, expand the working space of the bipedal robot and improve its adaptability in complex environments.

[0005] To achieve the above objectives, the present invention explores a new type of serial-parallel hybrid robotic arm structure, which combines the advantages of serial and parallel mechanisms and can provide a larger workspace and higher flexibility while maintaining high precision and high rigidity, especially in the field of micro-manipulation. The performance and applicability of the bipedal robot are improved through the innovative design of the serial-parallel robotic arm.

[0006] The present invention provides a seven-degree-of-freedom serial-parallel structure mechanical arm for a bipedal robot, which is installed on a supporting body, and the supporting body is located on a mounting fixed seat. The invention is characterized in that it includes a five-degree-of-freedom serial arm and a two-degree-of-freedom parallel wrist structure located at the front end of the serial arm and connected to the serial arm.

[0007] Furthermore, the tandem arm includes a one-axis mounting flange, a one-axis motor, a one-axis to two-axis transition flange, a two-axis motor, a three-axis motor, a three-axis connecting flange, a large arm connecting rod, a four-axis motor, a four-axis to five-axis transition flange, and a five-axis motor, which are connected in sequence, wherein the tandem arm is mounted on the supporting body through a robotic arm mounting flange.

[0008] Furthermore, the tandem arm also includes a first-axis housing, a second-axis housing, a third-axis housing, a fourth-axis housing and a fifth-axis end cover, which are respectively covered on the corresponding axis motors.

[0009] Furthermore, the parallel wrist structure is connected to the series arm via a forearm connecting flange, wherein the parallel wrist structure includes two UPS units and one U unit, which together realize two degrees of freedom control of terminal pitch and yaw.

[0010] Furthermore, the two UPS units are arranged in parallel in the wrist support flange, and one end is connected to the forearm connection flange, and the other end is connected to the wrist connection shaft.

[0011] Furthermore, the two UPS units each include a first universal joint, a translational joint and a ball hinge connected in sequence; wherein the first universal joint is mounted on the forearm connecting flange through a cylindrical pin, and the ball hinge is connected to the wrist connecting shaft.

[0012] Furthermore, the translational joint is a linear motion joint, comprising a rotating motor, a screw, a screw nut, a guide rod, a linear motion joint cylinder, and a guide slip ring connected in sequence, wherein the rotating motor is mounted on a linear joint motor mounting flange and connected to the first universal joint; the linear motion joint cylinder is connected to the ball joint via the guide slip ring.

[0013] Furthermore, the U unit is a second universal joint.

[0014] Furthermore, the U unit is connected to the wrist support flange via a pin.

[0015] Furthermore, the U unit is connected to the end flange via a pin.

[0016] The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot provided by the present invention has at least the following technical effects: The serial-parallel structure manipulator provided by the present invention provides significant advantages for its mechanical properties, kinematics and dynamic algorithms, including improving the stiffness and load-bearing capacity of the manipulator, expanding the workspace to adapt to more complex operation tasks, and enhancing the stability and reliability of the operation. In addition, due to the high-precision characteristics of the parallel mechanism, the error accumulation is reduced and the accuracy of the overall operation is improved. The optimized kinematic analysis simplifies the parameter observation and analysis, making the establishment of the kinematic positive solution equation more efficient. At the same time, through singularity research and workspace analysis, it is ensured that the manipulator operates within an effective workspace, avoiding singular configurations and improving the robustness of the algorithm. The optimization of structural parameters further reduces the condition number of the Jacobian matrix and improves the efficiency and accuracy of the kinematic algorithm. Finally, the structure supports multiple motion modes, enhances the flexibility and adaptability of the manipulator, and enables it to maintain efficient and precise operation when facing a changing working environment.

[0017] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of installation of a preferred embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the structure of the mechanical arm of the illustrated embodiment; Figure 3 yes Figure 1 UPS+U wrist structure schematic diagram of the embodiment shown; Figure 4 yes Figure 1 Schematic diagram of the linear motion joint structure of the illustrated embodiment.

[0019] Among them, 1-mounting base, 2-support body, 3-robotic arm 1, 4-robotic arm 2, robotic arm mounting flange 5, mounting flange 6, one-axis motor 7, one-axis housing 8, one-axis two-axis adapter flange 9, two-axis motor 10, two-axis housing 11, three-axis housing 12, three-axis motor 13, three-axis connecting flange 14, big arm connecting rod 15, four-axis housing 16, four-axis motor 17, four-axis five-axis adapter flange 18, five-axis end cover 19, five-axis motor 20, UPS+U wrist 2 degree of freedom structure 21, forearm connecting flange 22, translation joint 23, wrist connecting shaft 24, end flange 25, wrist universal joint center connecting flange 26, wrist support flange 27, ball hinge 28, guide slip ring 29, linear motion joint cylinder 30, guide rod 31, screw nut 32, screw 33, rotating motor 34, linear joint motor mounting flange 35, first universal joint 36. DETAILED DESCRIPTION

[0020] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0021] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0022] The embodiment of the present invention proposes a robotic arm design for a bipedal robot, in particular, a robotic arm that combines a 5-DOF series structure and a 2UPS+U parallel wrist structure, wherein UPS refers to a combination of a universal joint, a prismatic joint, and a spherical joint, and U refers to a universal joint. The purpose of this design is to improve the flexibility, accuracy, stability, and load capacity of the bipedal robot wrist through an innovative robotic arm design, while expanding its workspace and improving its adaptability in complex environments, so that it can adapt to more complex operating tasks. The design also takes into account the carrying capacity of the wrist. Through optimized design, the wrist can withstand a large load while maintaining high precision. This robotic arm design is suitable for occasions that require high-precision and high-stability operations, such as precision assembly, medical surgery assistance, detection in complex environments, etc.

[0023] In particular, the serial part of the robot arm has 5 degrees of freedom, which enables the robot arm to perform a variety of basic movements in space, such as extension, bending, rotation, etc. This structure can simulate a variety of movements of the human hand due to its large working range and flexibility, and is particularly suitable for application scenarios that require operation in a large space.

[0024] In particular, the parallel structure of the wrist consists of two UPS units and one U unit, where the UPS unit consists of a universal joint, a translational joint and a ball hinge. This structural design allows the wrist to be precisely controlled in two degrees of freedom, so that the end of the robotic arm can complete pitch and yaw movements, providing additional support and control, thereby enhancing the rigidity and load-bearing capacity of the wrist. The universal joint enables multi-directional rotational movement, the translational joint provides linear motion along a certain axis, and the ball hinge allows the wrist to perform spherical motion in space. Through the design of this parallel structure, with the help of the synergy of multiple kinematic pairs, the accuracy and rigidity of the wrist are significantly improved, especially when performing delicate operations, it can provide more stable posture control.

[0025] In general, the bipedal robot arm design provided in the embodiment of the present invention provides a flexible and precise wrist movement solution with broad application prospects by combining a 5-DOF series structure and a 2-DOF 2UPS+U parallel wrist structure.

[0026] Example 1 like Figure 1 As shown, an embodiment of the present invention provides a seven-degree-of-freedom serial-parallel structure robotic arm for a bipedal robot, including two robotic arms, which are respectively installed on both sides of a supporting body 2, and the supporting body 2 is located on a mounting fixed seat 1, each robotic arm includes a five-degree-of-freedom serial arm and a two-degree-of-freedom parallel wrist structure located at the front end of the serial arm and connected to the serial arm.

[0027] Example 2 like Figure 2 As shown, on the basis of Example 1, the five-degree-of-freedom tandem arm realizes multi-directional movement through a precisely designed gear and connecting rod mechanism, including a one-axis mounting flange 6, a one-axis motor 7, a one-axis-two-axis transition flange 9, a two-axis motor 10, a three-axis motor 13, a three-axis connecting flange 14, a large arm connecting rod 15, a four-axis motor 17, a four-axis-five-axis transition flange 18, and a five-axis motor 20 connected in sequence, wherein the tandem arm is mounted on the support body 2 through the robot arm mounting flange 5.

[0028] The tandem arm further includes a first axis housing 8, a second axis housing 11, a third axis housing 12, a fourth axis housing 16 and a fifth axis end cover 19, which are respectively covered on the corresponding axis motors.

[0029] In particular, the two-degree-of-freedom parallel wrist structure is a UPS+U wrist 2-degree-of-freedom structure 21.

[0030] Example 3 like Figure 3 As shown, on the basis of Example 1 or 2, the parallel wrist structure is connected to the serial arm through the forearm connection flange 22, wherein the parallel wrist structure includes two UPS units and one U unit, which together realize the two-degree-of-freedom control of the end pitch and yaw. The two UPS units are arranged in parallel in the wrist support flange 27, and one end is connected to the forearm connection flange 22, and the other end is connected to the wrist connection shaft 24. The two UPS units each include a first universal joint 36, a translation joint 23 and a ball hinge 28 connected in sequence; wherein the first universal joint 36 is installed on the forearm connection flange 22 through a cylindrical pin, and the ball hinge 28 is connected to the wrist connection shaft 24.

[0031] Example 4 like Figure 4As shown, based on Examples 1, 2 or 3, the translational joint 23 is also a linear motion joint, including a rotating motor 34, a screw 33, a screw nut 32, a guide rod 31, a linear motion joint cylinder 30, and a guide slip ring 29 connected in sequence, wherein the rotating motor 34 is mounted on the linear joint motor mounting flange 35 and is connected to the first universal joint 36; the linear motion joint cylinder 30 is connected to the ball joint 28 via the guide slip ring 29.

[0032] In particular, the U unit is a second universal joint. The U unit is connected to the wrist support flange 27 through a pin. The U unit is connected to the end flange 25 through a pin. The U unit is connected to the wrist universal joint center connection flange 26 through a pin.

[0033] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot, mounted on a support body, the support body being located on a mounting base, characterized in that: The invention comprises a series arm with five degrees of freedom and a parallel wrist structure with two degrees of freedom which is located at the front end of the series arm and connected with the series arm.

2. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot according to claim 1, characterized in that: The tandem arm includes a one-axis mounting flange, a one-axis motor, a one-axis to two-axis transition flange, a two-axis motor, a three-axis motor, a three-axis connecting flange, a large arm connecting rod, a four-axis motor, a four-axis to five-axis transition flange, and a five-axis motor, which are connected in sequence, wherein the tandem arm is mounted on the supporting body via a robotic arm mounting flange.

3. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot as claimed in claim 2, characterized in that: The series arm also includes a first-axis housing, a second-axis housing, a third-axis housing, a fourth-axis housing and a fifth-axis end cover, which are respectively covered on the corresponding axis motors.

4. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot according to claim 1, characterized in that: The parallel wrist structure is connected to the series arm via a small arm connecting flange, wherein the parallel wrist structure includes two UPS units and one U unit, which together realize two degrees of freedom control of terminal pitch and yaw.

5. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot as claimed in claim 4, characterized in that: The two UPS units are arranged in parallel in the wrist support flange, and one end is connected to the forearm connection flange, and the other end is connected to the wrist connection shaft.

6. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot as claimed in claim 5, characterized in that: The two UPS units each include a first universal joint, a translation joint and a ball hinge which are connected in sequence; wherein the first universal joint is mounted on the forearm connection flange via a cylindrical pin, and the ball hinge is connected to the wrist connection shaft.

7. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot as claimed in claim 6, characterized in that: The translation joint is a linear motion joint, including a rotating motor, a screw, a screw nut, a guide rod, a linear motion joint cylinder, and a guide slip ring connected in sequence, wherein the rotating motor is mounted on the linear joint motor mounting flange and connected to the first universal joint; the linear motion joint cylinder is connected to the ball joint via the guide slip ring.

8. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot as claimed in claim 4, characterized in that: The U unit is a second universal joint.

9. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot as claimed in claim 5, characterized in that: The U unit is connected to the wrist support flange via a pin.

10. The seven-degree-of-freedom serial-parallel structure mechanical arm for a biped robot as claimed in claim 5, characterized in that: The U unit is connected to the end flange via a pin shaft.

Images