A five-degree-of-freedom serial-parallel hybrid robot

Abstract

A five-degree-of-freedom serial-parallel hybrid robot includes a redundant drive parallel mechanism, a linear guide worktable, a bed support and an end actuator, wherein the redundant drive parallel mechanism body contains three motion branches, each motion branch contains two drive sources, wherein the first motion branch contains a mobile pair, a ball pair and two rotation pairs, the second motion branch is completely identical to the third motion branch structure, and contains a mobile pair, two rotation pairs and a Hooke's hinge, the redundant drive parallel mechanism has two rotational and one mobile degrees of freedom, the linear guide worktable is installed at the bottom of the bed support, has two mobile degrees of freedom, can adjust the position of the clamped workpiece in two directions, and the end actuator is installed on the moving platform at the lower end of the redundant drive parallel mechanism. The present invention constitutes a five-degree-of-freedom serial-parallel hybrid robot in the form of serial-parallel hybrid integration, has a small cumulative error influence, high processing dexterity, and can meet the processing requirements of complex special-shaped components.

Description

Technical Field

[0001] The invention relates to the field of serial-parallel hybrid robots, in particular to a robot device composed of a five-degree-of-freedom serial-parallel hybrid robot for machine tool processing and manufacturing. Background Art

[0002] Today's society is developing rapidly in terms of industrial level. Machine tools are important equipment in the entire manufacturing field. With the continuous rise of industries such as automobiles, aircraft, and ships, the structure and shape of processed parts are becoming increasingly complex, and the requirements for the rigidity and dexterity of processing machine tools are bound to become higher and higher. Therefore, as an important branch of the development of the processing and manufacturing field, machine tools must meet the design concepts of structural diversification, high efficiency, and high reliability when designing processing machine tools. It is necessary to develop processing machine tools with the advantages of large working space, high rigidity, high precision, and high dexterity to promote the rapid development of the manufacturing industry.

[0003] In the field of processing and manufacturing, traditional three-coordinate machine tools, traditional five-coordinate machine tools or parallel robots are usually used for workpiece processing. Traditional five-coordinate machine tools use serial mechanisms as the main actuators, which can achieve higher processing quality when processing small workpieces. Due to the serial structure characteristics of such processing machine tools, they have five degrees of freedom, and the movements between coordinate axes are independent of each other. They have outstanding advantages in processing dexterity and system control. However, serial mechanisms have certain shortcomings in load-bearing capacity, dynamic responsiveness and dexterity. In addition, it is found in actual engineering applications and research that it is difficult to overcome cumulative errors, and it is difficult to meet the high-efficiency, high-precision and high-quality processing technology requirements of workpieces. Compared with traditional five-coordinate machine tools with serial mechanisms as the main actuators, another type of processing equipment is to use parallel mechanisms in machine tool design and application, integrating the advantages of serial and parallel machine tools in workspace, rigidity, dexterity and static / dynamic characteristics, and providing new solutions for the processing of complex and special-shaped workpieces.

[0004] However, the existing processing machine tools with parallel mechanisms as the main actuators still have deficiencies in stability, reliability and working dexterity. With further research on such processing machine tools, redundant drive parallel mechanisms have the advantages of fewer singular postures, higher rigidity and dexterity, and can be designed into serial-parallel hybrid robot processing equipment with better load capacity and dynamic stability. Therefore, the invention of serial-parallel hybrid robot processing equipment with independent intellectual property rights is not only conducive to enriching and expanding the practical engineering applications of parallel mechanisms, but also has very important significance for promoting the development of my country's manufacturing industry. Summary of the invention

[0005] Based on the above technical problems, the present invention provides a five-degree-of-freedom serial-parallel hybrid robot, with the purpose of designing a brand-new redundant drive parallel mechanism, using the parallel mechanism as the main actuator to solve the problem of processing complex and special-shaped workpieces, making the processing process more efficient and improving the processing quality of the workpiece.

[0006] The present invention adopts the following technical scheme: a five-degree-of-freedom serial-parallel hybrid robot, which is characterized by: a redundant drive parallel mechanism 1, a linear guide worktable 2, a bed frame 3 and an end actuator 4. The redundant drive parallel mechanism 2 of the robot has three degrees of freedom, namely one degree of freedom of movement and two degrees of freedom of rotation, and the linear guide worktable 3 has two degrees of freedom of movement. The five-degree-of-freedom serial-parallel hybrid robot is formed by serial-parallel hybrid integration. The driving source of the redundant drive parallel mechanism of the robot is six servo motors, and the driving source of the linear guide worktable is two servo motors.

[0007] The redundant drive parallel mechanism 2 includes a static platform, a dynamic platform and three motion branches connecting the static and dynamic platforms; wherein the first motion branch chain is connected in sequence by a moving pair, a ball pair and two rotating pairs to form a PSRR type motion branch chain, the upper end of the motion branch chain is connected to the sliding guide rail branch chain base through a ball pair, the motion branch chain hinge point can slide relatively along the guide rail direction, and the lower end of the motion branch chain is connected to the dynamic platform through a rotating pair; the second and third motion branches have exactly the same composition and connection sequence of the motion pairs, and are connected in sequence by a moving pair, two rotating pairs and a Hooke's hinge to form a PRRU type motion branch chain, the upper end of the motion branch chain is connected to the sliding guide rail branch chain base through a rotating pair, the motion branch chain hinge point can slide relatively along the guide rail direction, and the lower end of the motion branch chain is connected to the dynamic platform through a Hooke's hinge; the upper ends of the three motion branches are indirectly connected to the static platform through the sliding guide rail, and the three sliding guide rails are installed and fixed on the static platform in an axially symmetrical manner.

[0008] The lower end of the motion branch chain is connected to the moving platform, wherein the coordinates of the hinge points connecting the motion branch chain and the moving platform are arranged in an isosceles right triangle, the lower end of the first motion branch chain is connected to the moving platform at the right-angled end point of the isosceles right triangle in the plane where the moving platform is located, the lower ends of the second motion branch chain and the third motion branch chain are respectively connected to the two end points of the base of the isosceles right triangle in the plane where the moving platform is located in an axially symmetrical manner; the upper end of the motion branch chain is indirectly connected to the static platform through a sliding guide rail, the moving axis of the sliding guide rail connected to the first motion branch chain is perpendicular to the base of the isosceles right triangle in the plane where the static platform is located, the moving axis of the sliding guide rail connected to the second motion branch chain and the third motion branch chain are collinear, and the moving axis coincides with the base of the isosceles right triangle in the plane where the static platform is located, wherein the three sliding guide rails The connection between the moving guide rail and the static platform is axially symmetrical; the moving pair at the upper end of the first moving branch chain and the moving pair in the ball pair parallel to the base of the isosceles right triangle in the plane where the static platform is located is the driving pair of the first moving branch chain, and the two rotating pair axes at the lower end of the first moving branch chain are parallel to the base of the isosceles right triangle in the plane where the moving platform is located; the moving pair and the upper end rotating pair of the second and third moving branches are the driving pairs of their respective moving branches, and the two rotating pair axes of the moving branches are parallel to the perpendicular bisector of the base of the isosceles right triangle in the plane where the static platform is located, and the two rotating axes of the Hooke's joint are perpendicular to each other, one of the rotating axes is parallel to the perpendicular bisector of the base of the isosceles right triangle in the plane where the static platform is located, and the other rotating axis is parallel to the base of the isosceles right triangle in the plane where the moving platform is located.

[0009] The linear guide workbench consists of a workbench fixed base, a mobile platform, a drive motor and a clamp, wherein the fixed base is fixedly connected to the bed support, the mobile platform is installed above the fixed base, the clamp is installed above the mobile platform, and two drive motors are respectively installed at the ends of the fixed base and the mobile platform; the end actuator is installed on the lower moving platform, and it can rotate around the normal direction of the plane where the moving platform is located when working.

[0010] The present invention is a five-degree-of-freedom serial-parallel hybrid robot, which uses a new type of redundant drive parallel mechanism as the main actuator, combines a two-degree-of-freedom serial worktable module with a three-degree-of-freedom redundant drive parallel mechanism module, and realizes the dexterous movement and stable and reliable operation of machine tool processing. Compared with the existing machine tool processing technology, the five-degree-of-freedom serial-parallel hybrid robot of the present invention has the following advantages: (1) a combined motion similar to circular motion is provided by rotation and translation, wherein the parallel mechanism part can complete rotational motion in two directions and translational motion in one direction, and the processing dexterity in the robot workspace is high; (2) the combination of serial module and parallel module is adopted, which reduces the influence of cumulative error compared with the traditional machine tool with serial mechanism as the main actuator, and improves the workpiece processing accuracy; (3) the redundant drive parallel mechanism improves the overall stiffness and load capacity of the robot, and has advantages in avoiding singular postures; (4) the linear guide worktable can increase the robot's mobile workspace. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall composition of a five-degree-of-freedom serial-parallel hybrid robot of the present invention;

[0012] Figure 2 It is a schematic diagram of the structure of a redundant drive parallel mechanism of a five-degree-of-freedom serial-parallel hybrid robot of the present invention;

[0013] Figure 3 It is a schematic diagram of the structure of a linear guide rail workbench of a five-degree-of-freedom serial-parallel hybrid robot of the present invention;

[0014] Figure 4 It is a schematic diagram of the structure of a bed support of a five-degree-of-freedom serial-parallel hybrid robot of the present invention;

[0015] Figure 5 This is a schematic diagram of the first kinematic branch structure of a five-degree-of-freedom serial-parallel hybrid robot of the present invention;

[0016] Figure 6 This is a schematic diagram of the second kinematic branch structure of a five-degree-of-freedom serial-parallel hybrid robot of the present invention;

[0017] Figure 7 It is a structural schematic diagram of a static platform linear slide module of a five-degree-of-freedom serial-parallel hybrid robot of the present invention;

[0018] in:

[0019] Figure 1 Middle: 1. Redundant drive parallel mechanism; 2. Linear guide worktable; 3. Bed frame; 4. End actuator;

[0020] Figure 2Middle: 110. static platform; 120. dynamic platform; 130. first motion branch chain; 140. second motion branch chain; 150. third motion branch chain;

[0021] Figure 3 Middle: 210. Workbench fixed base; 211. First smooth guide rod; 212. Second smooth guide rod; 213. First ball screw; 214. First drive motor; 220. Mobile platform; 221. Third smooth guide rod; 222. Fourth smooth guide rod; 223. Second ball screw; 224. Second drive motor; 230. Clamp;

[0022] Figure 4 Middle: 310. Frame base; 320. Fixed hanger; 330. Frame body; 340. Reinforcement ribs;

[0023] Figure 5 Middle: 131. First moving pair; 132. Ball pair; 133. First rotating pair; 134. Second rotating pair; 135. Third driving motor; 136. Fourth driving motor;

[0024] Figure 6 Middle: 141. Second moving pair; 142. Third rotating pair; 143. Fourth rotating pair; 144. Hooke hinge; 145. Fifth driving motor; 146. Sixth driving motor;

[0025] Figure 7 In the figure: 111. servo motor; 112. motor support; 113. coupling; 114. bearing; 115. ball screw; 116. nut pair; 117. kinematic pair fixed base; 118. slide rail; 119. bearing support. DETAILED DESCRIPTION

[0026] In order to further illustrate the present invention, the present invention will be described in detail below in conjunction with specific embodiments. The specific embodiments described below are only for illustrating the present invention, which will help those skilled in the art to further understand the present invention, but the protection scope of the present invention is not limited to the embodiments.

[0027] Figure 1It is a schematic diagram of the overall composition of a five-degree-of-freedom serial-parallel hybrid robot of the present invention, which includes a redundant drive parallel mechanism 1, a linear guide worktable 2, a bed frame 3 and an end actuator 4. The redundant drive parallel mechanism 1 of the robot is controlled by six drive motors, and the processing of the workpiece installed on the linear guide worktable 2 is realized by combining the serial and parallel structures, and the processing process of the workpiece is controlled by adjusting the rotation direction and rotation angle of the motor. In order to improve the overall rigidity of the robot and expand the mobile working space, the present invention selects a redundant drive parallel mechanism 1 with two rotational degrees of freedom and one mobile degree of freedom as the main actuator, and integrates a linear guide worktable 2 with two mobile degrees of freedom at the lower end of the bed frame 3 to form a five-degree-of-freedom serial-parallel hybrid robot. The posture of the end actuator 4 is adjusted by the redundant drive parallel mechanism 1, which can meet the high-quality and high-efficiency processing technology requirements of complex and special-shaped workpieces in space.

[0028] Figure 2 It is a structural schematic diagram of a redundant drive parallel mechanism of a five-degree-of-freedom serial-parallel hybrid robot of the present invention. The redundant drive parallel mechanism 1 includes a static platform 110, a dynamic platform 120, a first motion branch 130, a second motion branch 140 and a third motion branch 150. The upper end of the first motion branch is connected to the static platform 110 through a first moving pair 131, and the lower end is connected to the dynamic platform 120 through a second rotating pair 134. The composition and connection sequence of the motion pairs of the second and third motion branches are exactly the same. The upper end of the second motion branch is connected to the static platform 110 through a second moving pair 141, and the lower end is connected to the dynamic platform 120 through a Hooke's hinge 144. In order to facilitate the explanation of the spatial position relationship of each kinematic pair, a moving coordinate system p-xyz and a reference coordinate system O-XYZ are set on the static platform, wherein the coordinates of the hinge points where the moving branches connect the dynamic and static platforms are arranged in an isosceles right triangle, the origin of the moving coordinate system is p, the normal direction of the plane where the moving platform 120 is located is the y-axis, the axis of the base of the isosceles right triangle passing through the plane where the moving platform 120 is located is the x-axis, and the z-axis follows the right-hand rule. The origin of the reference coordinate system is O, the normal direction of the plane where the static platform 110 is located is the Y-axis, the axis of the base of the isosceles right triangle passing through the plane where the static platform 110 is located is the X-axis, and the Z-axis direction follows the right-hand rule.

[0029] Figure 3The present invention is a schematic diagram of the structure of a linear guide workbench of a five-degree-of-freedom serial-parallel hybrid robot. The linear guide workbench that moves relative to the base of the bed support 3 is composed of a workbench fixed base 210, a first smooth guide rod 211, a second smooth guide rod 212, a first ball screw 213, a first drive motor 214, a mobile platform 220, a third smooth guide rod 221, a fourth smooth guide rod 222, a second ball screw 223, a second drive motor 224 and a clamp 230. The first smooth guide rod 211 and the second smooth guide rod 212 are symmetrically installed on the workbench fixed base 210 to assist the first ball screw 213 in moving in the horizontal direction, thereby improving the guiding ability of the driving process as well as the reliability and accuracy of the work. A mobile platform 220 is installed on the upper end of the linear guide workbench, and the installation direction of the second ball screw 223 is perpendicular to the first ball screw 213 at the bottom. The clamp 230 is installed on the upper side of the mobile platform 220. By clamping the workpiece 230 with the clamp, the coordinates of the workpiece can be accurately adjusted along the x-axis and z-axis, and the redundant drive parallel mechanism 1 is coordinated and cooperated during the processing to complete the processing task.

[0030] Figure 4 It is a schematic diagram of the bed support structure of a five-degree-of-freedom serial-parallel hybrid robot of the present invention. The bed support structure includes a fixed base 310, a fixed hanger 320, a frame body 330 and reinforcing ribs 340. A plurality of reinforcing ribs 340 are arranged at the right-angle bends of the bed support to improve the stability of the bed support structure. The installation and fixation of the machine tool is realized through the combination of the screw and the fixing pin in the support fixing assembly, so that the bed support is simplified and has good practicality.

[0031] Figure 5 It is a schematic diagram of the first kinematic branch structure of a five-degree-of-freedom serial-parallel hybrid robot of the present invention. The first kinematic branch is connected in sequence by the first moving pair 141, the ball pair 132, the first rotating pair 133 and the second rotating pair 134 to form a PSRR type kinematic branch. The first moving pair 141 and the ball pair 132 serve as the driving pair of the first kinematic branch, and the third driving motor 135 and the fourth driving motor 136 serve as their driving sources. The first moving pair 141 can slide along the Z axis. Due to the constraint relationship between the kinematic pairs, the rotation axis of the ball pair is parallel to the rotation center line of the Z axis and the X axis, and the rotation axis of the first rotating pair 133 and the second rotating pair 134 is parallel to the rotation center line of the x axis.

[0032] Figure 6It is a schematic diagram of the second kinematic branch structure of a five-degree-of-freedom serial-parallel hybrid robot of the present invention. The composition and connection order of the kinematic pairs of the second kinematic branch and the third kinematic branch are exactly the same. The second kinematic branch is connected in sequence by the second mobile pair 141, the third rotating pair 142, the fourth rotating pair 143 and the Hooke's hinge 144 to form a PRRU type kinematic branch. The second mobile pair 141 and the third rotating pair 142 serve as the driving pair of the second kinematic branch, and the fifth driving motor 145 and the sixth driving motor 146 serve as their driving sources. The second mobile pair 141 can slide along the X-axis, the axes of the third rotating pair and the fourth rotating pair are parallel to the rotation center line of the Z-axis, and the two rotation axes of the Hooke's hinge 144 are perpendicular to each other, one of the rotation axes is parallel to the rotation center line of the x-axis, and the other rotation axis is parallel to the rotation center line of the z-axis.

[0033] Figure 7 It is a structural schematic diagram of a static platform linear slide module of a five-degree-of-freedom serial-parallel hybrid robot of the present invention. The static platform linear slide module includes a servo motor 111, a motor support 112, a coupling 113, a bearing 114, a ball screw 115, a nut pair 116, a kinematic pair fixed base 117, a slide rail 118 and a bearing support 119.

[0034] In order to improve the overall rigidity of the robot, the present invention selects a redundant drive parallel mechanism as the main actuator and integrates a linear guide worktable. At the same time, the series mechanism can make up for the shortcoming of the small working space of the parallel mechanism, and can increase the moving space of the redundant drive parallel mechanism. The advantages of the two mechanisms can be complementary. The present invention adjusts the posture of the end actuator through the redundant drive parallel mechanism, which is easy to realize the modularization and interchangeability of the processing equipment, has the advantages of high precision and high flexibility, and can meet the high-quality processing task requirements of complex and special-shaped workpieces.

[0035] The above description in combination with the accompanying drawings is only an embodiment of a five-degree-of-freedom serial-parallel hybrid robot of the present invention. The protection scope of the present invention is not limited to the above embodiment. Various non-substantial improvements made without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A five-degree-of-freedom serial-parallel hybrid robot, the characteristics of which include: A redundant drive parallel mechanism, a linear guide worktable, a bed frame and an end actuator. The redundant drive parallel mechanism of the robot has three degrees of freedom, namely one mobile degree of freedom and two rotational degrees of freedom. The linear guide worktable has two mobile degrees of freedom. A five-degree-of-freedom processing robot is formed by serial-parallel hybrid integration. The driving source of the redundant drive parallel mechanism of the robot is six servo motors, and the driving source of the linear guide worktable is two servo motors. The redundant drive parallel mechanism includes a static platform, a dynamic platform and three motion branches of specific configurations connecting the static and dynamic platforms. The first motion branch is a PSRR type, consisting of a moving pair, a ball pair and two The rotating pairs are connected in sequence, the upper end of the motion branch chain is connected to the sliding guide branch chain base through a ball pair, the hinge point of the motion branch chain can slide relatively along the guide direction, and the lower end of the motion branch chain is connected to the moving platform through a rotating pair; the second and third motion branch chains are PRRU type, each of which is composed of a moving pair, two rotating pairs and a Hooke's hinge connected in sequence, the upper end of the motion branch chain is connected to the sliding guide branch chain base through a rotating pair, the hinge point of the motion branch chain can slide relatively along the guide direction, and the lower end of the motion branch chain is connected to the moving platform through a Hooke's hinge; the upper ends of the three motion branch chains are indirectly connected to the static platform through the sliding guide, and the three sliding guides are installed and fixed on the static platform in an axially symmetrical manner.

2. A five-degree-of-freedom serial-parallel hybrid robot according to claim 1, characterized in that: The lower end of the motion branch chain is connected to the moving platform, wherein the coordinates of the hinge points connecting the motion branch chain and the dynamic and static platforms are arranged in an isosceles right triangle, the lower end of the first motion branch chain is connected to the moving platform at the right-angled end point of the isosceles right triangle on the plane where the moving platform is located, the lower ends of the second motion branch chain and the third motion branch chain are respectively connected to the two end points of the base of the isosceles right triangle on the plane where the moving platform is located in an axially symmetrical manner; the upper end of the motion branch chain is indirectly connected to the static platform through a sliding guide rail, the moving axis of the sliding guide rail connected to the first motion branch chain is perpendicular to the base of the isosceles right triangle on the plane where the static platform is located, the moving axis of the sliding guide rail connected to the second motion branch chain and the third motion branch chain are collinear, and the moving axis coincides with the base of the isosceles right triangle on the plane where the static platform is located, wherein the three The connection between the sliding guide rail and the static platform is axially symmetrical; the moving pair at the upper end of the first motion branch chain and the motion pair in the ball pair parallel to the base of the isosceles right triangle in the plane where the static platform is located is the driving pair of the first motion branch chain, and the two rotation pair axes at the lower end of the first motion branch chain are parallel to the base of the isosceles right triangle in the plane where the moving platform is located; the moving pair and the upper end rotation pair of the second and third motion branches are the driving pairs of their respective motion branches, and the two rotation pair axes of the motion branches are parallel to the bisector of the base of the isosceles right triangle in the plane where the static platform is located, and the two rotation axes of the Hooke's joint are perpendicular to each other, one of the rotation axes is parallel to the bisector of the base of the isosceles right triangle in the plane where the static platform is located, and the other rotation axis is parallel to the base of the isosceles right triangle in the plane where the moving platform is located.

3. A five-degree-of-freedom serial-parallel hybrid robot according to claim 1, characterized in that: The linear guide workbench consists of a workbench fixed base, a mobile platform, a drive motor and a clamp, wherein the fixed base is fixedly connected to the bed support, the mobile platform is installed above the fixed base, the clamp is installed above the mobile platform, and two drive motors are respectively installed at the ends of the fixed base and the mobile platform; the end actuator is installed on the lower moving platform, and it can rotate around the normal direction of the plane where the moving platform is located when working.

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