Novel four-degree-of-freedom 3-PRPaRRUPUR space series-parallel manipulator and working method

Abstract

The invention relates to a novel four-degree-of-freedom 3-PRPaRamp and a preparation method thereof. The invention discloses an RUPUR space series-parallel manipulator and a working method, and belongs to the technical field of space kinematic pair rigid-flexible series-parallel machinery. The RUPUR space series-parallel manipulator comprises a fixed platform, a movable platform, a PRPaR driving branch and an RUPUR series branch chain; the two ends of the PRPaR driving branch and the two ends of the RUPUR series-connection branch chain are connected with the fixed platform and the movable platform, and under the action of the PRPaR driving branch and the RUPUR series-connection branch chain, translation of the movable platform in the three-dimensional direction and rotation of the movable platform in the vertical direction are achieved, so that the movable platform has four degrees of freedom. Meanwhile, the three PRPaR driving branches and the RUPUR series branch chain enable the mechanism to have larger bearing capacity, the mechanism can effectively avoid singular positions under kinematics interference among the four mechanisms and influence of rotating pairs in the mechanisms, the working space of the whole mechanism is increased, and the overall rigidity and flexibility of the mechanism are improved.

Description

Technical Field

[0001] The present invention relates to a novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator and a working method thereof, belonging to the technical field of rigid-flexible hybrid machinery with spatial kinematic pairs. Background Art

[0002] A manipulator is a mechanical device with some functions of human hands, capable of imitating humans to quickly and accurately complete operations such as grasping, transporting, and placing items. With the continuous improvement of industrial automation, since the manipulator can operate in postures that are difficult for humans to achieve, and has the advantages of a compact structure, small floor area, high speed, high flexibility, strong load-bearing capacity, and large stiffness, it is widely used in the industrial field and has become an important automation device in the industrial field.

[0003] With the rapid development of the industrial level, the requirements for the working accuracy of the manipulator are getting higher and higher, and in most working environments, the manipulator as a whole is required to carry a certain mass of heavy objects and move in a large range in three-dimensional space and frequently change directions. Whether the manipulator has high degrees of freedom, a large working space, and high stiffness has a huge impact on the manipulator field. The serial manipulator has the advantages of a large working space, high flexibility, simple control, and low cost, but has poor rigidity and weak load-bearing capacity; the parallel manipulator has the advantages of high stiffness, high precision, high dynamic performance, and strong load-bearing capacity, but has a small working space, complex control, and will also have singular configurations; therefore, combining the parallel mechanism with the serial mechanism increases the degrees of freedom of the mechanism, enabling the mechanism to have four degrees of freedom. At the same time, the parallel module combines the characteristics of the serial module to increase the working space of the mechanism, avoid singular configurations, and retain the advantages of high precision, high stiffness, and strong load-bearing capacity of the parallel module; for this reason, it is very necessary to propose a four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator. Summary of the Invention

[0004] To overcome the deficiencies in the above background art, the present invention provides a four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator, which can combine the advantages of the parallel module and the serial module, increase the working space of the entire mechanism, avoid singular positions, and improve the overall accuracy and flexibility of the mechanism.

[0005] The technical solution of the present invention is as follows: A novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator includes a fixed platform, a moving platform, a PRPaR driving branch, and a RUPUR serial chain; both ends of the PRPaR driving branch and the RUPUR serial chain are connected to the fixed platform and the moving platform; The fixed platform includes a linear module and an upper motor support plate; the linear module includes two horizontal linear modules and a vertical linear module. The two horizontal linear modules are arranged in parallel in the same plane, and the vertical linear module is vertically placed in the vertical plane of the symmetry line of the two horizontal linear modules; the upper motor support plate is located between the two horizontal linear modules and connects the two horizontal linear modules; The linear module includes a precision linear ball screw slide module and a servo motor as the drive. The linear ball screw slide module includes a drive slider and a linear guide rail. The drive slider makes a reciprocating linear motion on the linear guide rail. One end of the PRPaR drive branch is connected to the drive slider of the linear module, and the other end of the PRPaR drive branch is connected to the moving platform. The movement of the drive slider drives the PRPaR drive branch to perform three-dimensional translation; a servo motor is provided at the middle position of the upper motor support plate. The servo motor is connected to one end of the RUPUR series chain, and the other end of the RUPUR series chain is connected to the moving platform. When the servo motor starts, it drives the RUPUR series chain to move in three dimensions and rotate in the vertical direction.

[0006] Preferably, there are three PRPaR drive branches in total, which are divided into a first PRPaR drive branch, a second PRPaR drive branch connected to the horizontal linear module, and a third PRPaR drive branch connected to the vertical linear module. The three PRPaR drive branches have the same structure but are non-uniformly distributed.

[0007] Further preferably, the PRPaR drive branch includes a second revolute pair, a T-shaped swing rod, a parallelogram hinge, and a first revolute pair; the second revolute pair includes a drive slider shaft hole, an upper end shaft hole of the T-shaped swing rod that rotates in cooperation with it, and a pin connecting the two; the T-shaped swing rod is a T-shaped rod, one end of which is used as one side of the parallelogram hinge, and the other end is connected to the drive slider through the second revolute pair. The four sides of the parallelogram hinge are the lower end of the T-shaped swing rod, two identical Pa-chain swing rods, and a shaft pin. The four sides are connected by pins to form a Pa-chain revolute pair, and the two connected sides can rotate; the first revolute pair includes a shaft pin as the revolute pair shaft and a moving platform shaft hole as the revolute pair bearing.

[0008] Further preferably, among the three PRPaR drive branches, the lengths of the T-shaped swing rods in the first PRPaR drive branch and the second PRPaR drive branch connected to the parallel linear modules are the same, but different from the length of the T-shaped swing rod in the third PRPaR drive branch connected to the vertical linear module. At the same time, the lengths of the Pa-chain swing rods in the three drive branches have the same characteristics as the T-shaped swing rods; the lengths of the Pa-chain swing rods of the parallelogram hinge in the first PRPaR drive branch and the second PRPaR drive branch are the same, and different from the length of the Pa-chain swing rod of the parallelogram hinge in the third PRPaR drive branch.

[0009] Further preferably, the axes of the first revolute pair and the second revolute pair in the PRPaR driving branch are parallel to each other and perpendicular to the axes of the pins connected to the two sides of the parallelogram hinge, so that the swing rod and the parallelogram hinge can swing in different directions to achieve the three-dimensional rotation of the moving platform.

[0010] Further preferably, the axles pins connected to the moving platform in the first PRPaR driving branch and the second PRPaR driving branch are parallel to each other in the same plane, and both are perpendicular to the axle pin connecting the third PRPaR driving branch to the moving platform.

[0011] Preferably, the RUPUR series chain includes a first Hooke's joint, a RUPUR sliding pair, and a second Hooke's joint connected in sequence between the servo motor and the moving platform; the RUPUR series chain is located at the central axis of the three PRPaR driving branches, and can achieve movement along the three-dimensional direction and rotation around the vertical direction with the three PRPaR branches; the RUPUR sliding pair includes two telescopical rods connected in series; one end of the first Hooke's joint is connected to the output shaft of the servo motor on the upper motor support plate, and the other end of the first Hooke's joint is connected to the upper telescopic rod. There is a cross shaft between the other end of the first Hooke's joint and the middle of the upper telescopic rod. The cross shaft forms a revolute pair with the hole at the end of the first Hooke's joint and the hole at the end of the upper telescopic rod respectively, and the axis of the formed revolute pair is perpendicular to the axis of the RUPUR sliding pair; the lower telescopic rod is connected to one end of the second Hooke's joint, and the other end of the second Hooke's joint is connected to the moving platform. There is a cross shaft between the middle of the lower telescopic rod and one end of the second Hooke's joint. The cross shaft forms a revolute pair with the hole at the end of the second Hooke's joint and the hole at the end of the upper telescopic rod respectively, and the axis of the formed revolute pair is perpendicular to the axis of the RUPUR sliding pair.

[0012] Further preferably, the servo motor is located on the upper surface of the upper motor support plate. The upper motor support plate is provided with a through hole, and the output shaft of the servo motor passes through the through hole and is connected to one end of the first Hooke's joint. The hole of the upper motor support plate serves as a bearing, and the shaft end of the first Hooke's joint serves as a shaft to form a revolute pair, and the axis of the formed revolute pair is perpendicular to the axis of the RUPUR sliding pair.

[0013] Further preferably, a hole is provided at the center of the moving platform. The central hole of the moving platform serves as a bearing, and the shaft end of the second Hooke's joint serves as a shaft to form a revolute pair, and the axis of the formed revolute pair is perpendicular to the axis of the RUPUR sliding pair.

[0014] Further preferably, the diameter of the upper telescopic rod is larger than that of the lower telescopic rod. The upper telescopic rod is a hollow rod, and the lower telescopic rod is a solid rod.

[0015] A working method of a novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator includes the following steps: During use, when only one servo motor in the horizontal linear module is used and only the driving slider in this linear module is close to the coupling, the servo motor drives the driving slider to slide to the other side, and the T-shaped swing rod in the first PRPaR driving branch connected to it moves accordingly. Under the action of the rotating pair of the Pa chain, the two Pa chain swing rods in the parallelogram hinge tilt to the same side. Before the first PRPaR driving branch and the second PRPaR driving branch are completely symmetric, the moving platform is driven to lower its height, and the lower telescopic rod slides downward in the upper telescopic rod. The driving slider and the Pa chain swing rod in the second PRPaR driving branch move in the opposite direction; After the first PRPaR driving branch and the second PRPaR driving branch are symmetric, the height of the moving platform rises, the lower telescopic rod slides upward, and the two driving branches move in the same direction; during this time, the movement direction of the third driving branch is the same as that of the moving platform; During use, when only the servo motor in the vertical linear module is used, the servo motor drives the driving slider to perform reciprocating linear motion in the linear guide rail, and the third PRPaR driving branch swings up and down accordingly, driving the moving platform to translate only in a two-dimensional plane within a certain range. The first and second PRPaR driving branches move in the same direction; when exceeding this range, the moving platform will not only translate in the two-dimensional plane but also translate up and down. At this time, the first and second PRPaR driving branches move in opposite directions; During use, when none of the servo motors in the three linear modules are used, only the servo motor on the upper motor support plate is working. The servo motor on the upper motor support plate drives the RUPUR series chain to rotate in three-dimensional space, but due to the mutual interference between components, the rotation range is limited; During use, when the servo motors in the three linear modules are used simultaneously, the movement directions of the first, second, and third PRPaR driving branches are related to the motor directions. At this time, the moving platform will not only translate in a two-dimensional plane or rotate in three-dimensional space. It will perform both rotation and translation in three-dimensional space.

[0016] The beneficial effects of the present invention are as follows: During the use of the present invention, through the motor provided in the linear module, the driving slider performs reciprocating linear motion in the guide rail, and then, under the action of the PRPaR driving branch connected to the slider and the RUPUR series chain provided at the central axis of the 3-PRPaR parallel mechanism, the moving platform realizes translational motion in three-dimensional directions and rotational motion around the vertical direction, enabling the moving platform to have four degrees of freedom; at the same time, the three PRPaR driving branches and one RUPUR series chain enable the mechanism to have a greater load-bearing capacity. Under the influence of kinematic interference among the four mechanisms and the rotating pairs in the mechanism, the mechanism can effectively avoid singular positions, increasing the working space of the entire mechanism and improving the overall stiffness and flexibility of the mechanism. Description of the Drawings

[0017] Figure 1 This is a schematic diagram of the overall structure of a novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator provided by the present invention; Figure 2 This is a schematic diagram of the PRPaR drive branch in the novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator provided by the present invention; Figure 3 This is a schematic diagram of the RUPUR series chain in the novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator provided by the present invention; Wherein: 1. Moving platform, 2. Axle pin, 3. First rotating pair, 4. Pa chain swing rod, 5. Pa chain rotating pair, 6. T-shaped swing rod, 7. Second rotating pair, 8. Driving slider, 9. Linear module, 10. Linear guide rail, 11. Coupling, 12. Servo motor, 13. Upper motor support plate, 14. First Hooke's joint, 15. Cross shaft, 16. Upper telescopic rod, 17. Lower telescopic rod, 18. Second Hooke's joint; 401. Pa chain swing rod of the first PRPaR drive branch, 402. Pa chain swing rod of the second PRPaR drive branch, 403. Pa chain swing rod of the third PRPaR drive branch; 601. T-shaped swing rod of the first PRPaR drive branch, 602. T-shaped swing rod of the second PRPaR drive branch, 603. T-shaped swing rod of the third PRPaR drive branch; 801. Driving slider of the first horizontal linear module, 802. Driving slider of the second horizontal linear module, 803. Driving slider of the third horizontal linear module; 901. First horizontal linear module, 902. Second horizontal linear module, 903. Third vertical linear module; 121. Servo motor of the first horizontal linear module, 122. Servo motor of the second horizontal linear module, 123. Servo motor of the third vertical linear module, 124. Servo motor of the upper motor support plate. Detailed Embodiment

[0018] The following further describes the specific embodiments of the present invention in conjunction with the embodiments shown in the drawings. Those skilled in the art can understand other advantages and functions of the present invention by reading this specification. It should be noted that the described embodiments are only a part of the embodiments of the present invention, and the protection scope of the present invention is not limited to the following embodiments.

[0019] The orientation or ordinal numbers such as "upper, lower, left, right, front, back, first, second, third" etc. appearing in this specification and the claims are only for convenience of description, rather than limiting the protection scope of the present invention; without changing the technical essence, the adjustment or change of relevant relative relationships shall all fall within the implementable scope of the present invention.

[0020] Embodiment 1: A novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator, as Figures 1-3 shown, comprising a fixed platform, a moving platform (1), a PRPaR driving branch, and a RUPUR series chain; the two ends of the PRPaR driving branch and the RUPUR series chain are connected to the fixed platform and the moving platform.

[0021] The fixed platform includes a linear module (9) and an upper motor support plate (13); the linear module includes two horizontal linear modules and one vertical linear module. The two horizontal linear modules are arranged in parallel in the same plane, and the vertical linear module is vertically placed in the vertical plane of the symmetry line of the two horizontal linear modules; the upper motor support plate is located between the two horizontal linear modules and connects the two horizontal linear modules. The upper ends of the three linear modules are connected to a frame (omitted in the figure).

[0022] The linear module includes a precision linear ball screw slide module and a servo motor as the drive. The linear ball screw slide module includes a drive slider (8) and a linear guide rail (10). The drive slider makes a reciprocating linear motion on the linear guide rail. One end of the PRPaR driving branch is connected to the drive slider of the linear module, and the other end of the PRPaR driving branch is connected to the moving platform. The movement of the drive slider drives the PRPaR driving branch to perform three-dimensional translation; between the servo motor (12) and the linear guide rail (10) in the linear module, torque and motion are transmitted through a coupling (11).

[0023] A servo motor is provided at the middle position of the upper motor support plate (13). The output end of the servo motor is connected to one end of the RUPUR series chain, and the other end of the RUPUR series chain is connected to the moving platform. When the servo motor starts, it drives the RUPUR series chain to perform three-dimensional movement and vertical rotation.

[0024] There are three PRPaR driving branches in total, which are divided into a first PRPaR driving branch, a second PRPaR driving branch connected to the horizontal linear module, and a third PRPaR driving branch connected to the vertical linear module. The three PRPaR driving branches have the same structure but are non-uniformly distributed. The corresponding linear modules are respectively named the first horizontal linear module (901), the second horizontal linear module (902), and the third vertical linear module (903).

[0025] The PRPaR driving branch includes a second rotating pair (7), a T-shaped swing rod (6), a parallelogram hinge, and a first rotating pair (3); the second rotating pair includes a driving slider shaft hole, an upper end shaft hole of the T-shaped swing rod rotatably matched therewith, and a pin connecting the two; the T-shaped swing rod (6) is a T-shaped rod, one end of which serves as one side of the parallelogram hinge, and the other end is connected to the driving slider through the second rotating pair. The four sides of the parallelogram hinge are the lower end of the T-shaped swing rod, two identical Pa-chain swing rods (4), and a shaft pin (2). The four sides are connected by pins to form four Pa-chain rotating pairs (5). The two connected sides can rotate. The Pa-chain swing rod is a straight rod; the first rotating pair includes a shaft pin (2) as the rotating pair shaft and a moving platform (1) shaft hole as the rotating pair bearing.

[0026] Among the three PRPaR driving branches, the lengths of the T-shaped swing rods in the first PRPaR driving branch and the second PRPaR driving branch connected to the linearly arranged linear modules placed in parallel are the same, but different from the length of the T-shaped swing rod in the third PRPaR driving branch connected to the linearly arranged linear module placed vertically. At the same time, the lengths of the Pa-chain swing rods in the three driving branches have the same characteristics as those of the T-shaped swing rods; the lengths of the Pa-chain swing rods of the parallelogram hinges in the first PRPaR driving branch and the second PRPaR driving branch are the same, different from the length of the Pa-chain swing rod of the parallelogram hinge in the third PRPaR driving branch. The lengths of the Pa-chain swing rods and the T-shaped swing rods in the first and second PRPaR driving branches are slightly longer.

[0027] The axes of the first rotating pair and the second rotating pair in the PRPaR driving branch are parallel to each other and perpendicular to the axes of the pins connecting the two sides of the parallelogram hinge (i.e., the axes of the Pa-chain rotating pairs), so that the swing rod and the parallelogram hinge can swing in different directions to realize the three-dimensional rotation of the moving platform.

[0028] The shaft pins connected to the moving platform in the first PRPaR driving branch and the second PRPaR driving branch are parallel to each other in the same plane, and both are perpendicular to the shaft pin connecting the moving platform in the third PRPaR driving branch. The arrangement of the third PRPaR driving branch is different from that of the first and second PRPaR driving branches. The shaft pin ( Figure 1 is blocked) in the third PRPaR driving branch is perpendicular to the shaft pins of the first and second PRPaR driving branches. When the mechanism operates, the swing rods (601-602) of the first and second PRPaR driving branches swing up and down, and the Pa-chain swing rods (401-402) swing left and right. The swing rod (603) of the third PRPaR driving branch swings left and right, and the Pa-chain swing rod (403) swings up and down.

[0029] The RUPUR series branch chain comprises a first Hooke's joint (14), a RUPUR moving pair, and a second Hooke's joint (18) which are sequentially connected between the servo motor and the moving platform; the RUPUR series branch chain is located at the central axis of the three PRPaR drive branches, and can realize movement along the three-dimensional direction and rotation around the vertical direction along with the three PRPaR branches; the RUPUR moving pair comprises two telescopic rods connected in series; one end of the first Hooke's joint (14) is connected to the output shaft of the servo motor (124) of the upper motor support plate, and the other end of the first Hooke's joint (14) is connected to the upper telescopic rod (16); a cross shaft (15) is provided between the other end of the first Hooke's joint and one end of the upper telescopic rod to form a universal joint; the cross shaft forms a rotation pair with the hole at the end of the first Hooke's joint and the hole at the end of the upper telescopic rod respectively; the long axis of the cross shaft forms a rotation pair with the upper telescopic rod, and the short axis forms a rotation pair with the first Hooke's joint, so that the telescopic rod can swing in four directions: forward, backward, left, and right; and the formed rotation pair axis is perpendicular to the RUPUR moving pair axis. The lower telescopic rod (17) is connected to one end of the second Hooke's joint (18), and the other end of the second Hooke's joint (18) is connected to the moving platform (1). A cross shaft is provided between one end of the lower telescopic rod and one end of the second Hooke's joint to form a universal joint, so that the moving platform can also move in four directions, front, back, left, and right. The cross shaft forms a revolute pair with the hole at the end of the second Hooke's joint and the hole at the end of the upper telescopic rod, respectively. The axis of the revolute pair formed is perpendicular to the axis of the RUPUR moving pair.

[0030] The servo motor (124) is located on the upper motor support plate. The upper motor support plate is provided with a through hole. The output shaft of the servo motor (124) passes through the through hole and is connected to one end of the first Hooke's hinge (14). The hole of the upper motor support plate serves as a bearing, and the shaft end of the first Hooke's hinge serves as an axis to form a rotation pair. The formed rotation pair axis is perpendicular to the RUPUR moving pair axis.

[0031] A hole is provided at the center of the moving platform (1), the center hole of the moving platform serves as a bearing, and the shaft end of the second Hooke's hinge (18) serves as an axis to form a revolute pair, wherein the axis of the revolute pair is perpendicular to the axis of the RUPUR moving pair.

[0032] Embodiment 2: A novel four-DOF 3-PRPaR&RUPUR spatial hybrid manipulator, whose structure is as described in Example 1, except that the diameter of the upper telescopic rod is larger than that of the lower telescopic rod, the upper telescopic rod is a hollow rod, and the lower telescopic rod is a solid rod, and the two are connected in series; the RUPUR moving pair includes a lower telescopic rod as a moving pair guide rail and an upper telescopic rod slidably matched with the lower telescopic rod.

[0033] Embodiment 3: A working method using the novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator described in Example 2 comprises the following steps: In use, when only one servo motor (121) in the horizontal linear module (901) is used and only the driving slider (801) in this linear module is close to the coupling, the servo motor (121) drives the driving slider (801) to slide to the other side. The T-shaped swing rod (601) in the first PRPaR driving branch connected thereto moves accordingly. Under the action of the Pa chain rotating pair (5), the two Pa chain swing rods (401) in the parallelogram hinge tilt to the same side. Before the first PRPaR driving branch and the second PRPaR driving branch are completely symmetrical, the moving platform (1) is driven to lower in height, and the lower telescopic rod (17) slides downward in the upper telescopic rod (16). The driving slider and the Pa chain swing rod (402) in the second PRPaR driving branch move in the opposite direction.

[0034] After the first PRPaR driving branch and the second PRPaR driving branch are symmetrical, the height of the moving platform increases, the lower telescopic rod slides upward, and the two driving branches move in the same direction; during this time, the movement direction of the third driving branch is the same as that of the moving platform.

[0035] In use, when only the servo motor (123) in the third vertical linear module (903) is used, the servo motor (123) drives the driving slider (803) to perform reciprocating linear motion in the linear guide rail. The third PRPaR driving branch swings up and down accordingly, and drives the moving platform (1) to only translate in a two-dimensional plane within a certain range. The first and second PRPaR driving branches move in the same direction; when exceeding this range, the moving platform will not only translate in a two-dimensional plane, but also translate up and down. At this time, the first and second PRPaR driving branches move in opposite directions.

[0036] In use, when none of the servo motors (121 - 123) in the three linear modules (901 - 903) are used, only the servo motor (124) on the upper motor support plate (13) is working. The servo motor (124) on the upper motor support plate drives the RUPUR series chain to rotate in three-dimensional space, but due to the mutual interference between components, the rotation range is limited.

[0037] In use, when the servo motors (121 - 123) in the three linear modules (901 - 903) are used simultaneously, the movement directions of the first, second, and third PRPaR driving branches are related to the motor directions. At this time, the moving platform (1) will not only translate in a two-dimensional plane or rotate in three-dimensional space. It will perform rotation and translation simultaneously in three-dimensional space.

[0038] It can be seen from the embodiments that the four usage methods show that the present invention not only has the advantages of a parallel mechanism, but also combines the advantages of a series mechanism, increasing the working space of the mechanism and avoiding the occurrence of singular positions.

[0039] Although the present invention has been described in detail above through general descriptions and specific embodiments, based on the present invention, those skilled in the art can make some modifications or improvements to it, and these modifications or improvements are obvious. Therefore, any modifications or improvements made without departing from the spirit of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator, characterized in that, It includes a fixed platform, a moving platform, a PRPaR driving branch, and a RUPUR series chain; both ends of the PRPaR driving branch and the RUPUR series chain are connected to the fixed platform and the moving platform. The fixed platform includes a linear module and an upper motor support plate; the linear module includes two horizontal linear modules and a vertical linear module. The two horizontal linear modules are arranged in parallel in the same plane, and the vertical linear module is vertically placed in the vertical plane of the symmetry line of the two horizontal linear modules; the upper motor support plate is located between the two horizontal linear modules and connects the two horizontal linear modules. The linear module includes a linear ball screw slide module and a servo motor. The linear ball screw slide module includes a driving slider and a linear guide rail. The driving slider makes a reciprocating linear motion on the linear guide rail. One end of the PRPaR driving branch is connected to the driving slider of the linear module, and the other end of the PRPaR driving branch is connected to the moving platform; a servo motor is provided at the middle position of the upper motor support plate. One end of the servo motor is connected to the RUPUR series chain, and the other end of the RUPUR series chain is connected to the moving platform.

2. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 1, wherein There are three PRPaR driving branches in total, which are the first PRPaR driving branch connected to the horizontal linear module, the second PRPaR driving branch, and the third PRPaR driving branch connected to the vertical linear module. The three PRPaR driving branches have the same structure but are non-uniformly distributed.

3. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 2, characterized in that, The PRPaR driving branch includes a second rotating pair, a T-shaped swing rod, a parallelogram hinge, and a first rotating pair; the second rotating pair includes a driving slider shaft hole, an upper end shaft hole of the T-shaped swing rod that rotates in cooperation with it, and a pin connecting the two; the T-shaped swing rod is a T-shaped rod. One end of it serves as one side of the parallelogram hinge, and the other end is connected to the driving slider through the second rotating pair. The four sides of the parallelogram hinge are the lower end of the T-shaped swing rod, two identical Pa chain swing rods, and a pin. The four sides are connected by pins to form a Pa chain rotating pair, and the two connected sides can rotate; the first rotating pair includes a pin as the rotating pair shaft and a moving platform shaft hole as the rotating pair bearing.

4. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 3, wherein Among the three PRPaR driving branches, the lengths of the T-shaped swing rods in the first PRPaR driving branch and the second PRPaR driving branch are the same, but different from the length of the T-shaped swing rod in the third PRPaR driving branch; the lengths of the Pa chain swing rods of the parallelogram hinge in the first PRPaR driving branch and the second PRPaR driving branch are the same, different from the length of the Pa chain swing rod of the parallelogram hinge in the third PRPaR driving branch.

5. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 3, characterized in that, The axes of the first rotating pair and the second rotating pair in the PRPaR driving branch are parallel to each other and perpendicular to the axes of the pins connecting the two sides in the parallelogram hinge.

6. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 3, characterized in that, The pins connected to the moving platform in the first PRPaR driving branch and the second PRPaR driving branch are parallel to each other in the same plane, and both are perpendicular to the pin connecting the moving platform in the third PRPaR driving branch.

7. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 1, characterized in that The RUPUR series chain includes a first Hooke's joint, a RUPUR prismatic pair, and a second Hooke's joint that are sequentially connected between the servo motor and the moving platform; the RUPUR series chain is located at the central axis of the three PRPaR drive branches; the RUPUR prismatic pair includes two telescopical rods connected in series; one end of the first Hooke's joint is connected to the output shaft of the servo motor on the upper motor support plate, and the other end of the first Hooke's joint is connected to the upper telescopic rod. A cross shaft is provided between the other end of the first Hooke's joint and the middle of the upper telescopic rod. The cross shaft forms a revolute pair with the hole at the end of the first Hooke's joint and the hole at the end of the upper telescopic rod respectively, and the axis of the formed revolute pair is perpendicular to the axis of the RUPUR prismatic pair; The lower telescopic rod is connected to one end of the second Hooke's joint, and the other end of the second Hooke's joint is connected to the moving platform. A cross shaft is provided between the lower telescopic rod and one end of the second Hooke's joint. The cross shaft forms a revolute pair with the hole at the end of the second Hooke's joint and the hole at the end of the upper telescopic rod respectively, and the axis of the formed revolute pair is perpendicular to the axis of the RUPUR prismatic pair; Preferably, the diameter of the upper telescopic rod is larger than that of the lower telescopic rod. The upper telescopic rod is a hollow rod, and the lower telescopic rod is a solid rod.

8. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 7, wherein The servo motor is located above the upper motor support plate. The upper motor support plate is provided with a through hole. The output shaft of the servo motor passes through the through hole and is connected to one end of the first Hooke's joint. The hole on the upper motor support plate serves as a bearing, and the shaft end of the first Hooke's joint serves as a shaft, forming a revolute pair. The axis of the formed revolute pair is perpendicular to the axis of the RUPUR prismatic pair.

9. The novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator according to claim 7, wherein A hole is provided at the center of the moving platform. The central hole of the moving platform serves as a bearing, and the shaft end of the second Hooke's joint serves as a shaft, forming a revolute pair. The axis of the formed revolute pair is perpendicular to the axis of the RUPUR prismatic pair.

10. A working method of a novel four-degree-of-freedom 3-PRPaR&RUPUR spatial hybrid manipulator, characterized in that, It includes the following steps: During use, when only one servo motor in the horizontal linear module is used and only the drive slider in this linear module is close to the coupling, the servo motor drives the drive slider to slide to the other side, and the T-shaped swing rod in the first PRPaR drive branch connected thereto moves accordingly. Under the action of the revolute pair of the Pa chain, the two Pa chain swing rods in the parallelogram hinge tilt to the same side. Before the first PRPaR drive branch and the second PRPaR drive branch are completely symmetric, the height of the moving platform is driven to decrease, and the lower telescopic rod slides downward in the upper telescopic rod. The drive slider and the Pa chain swing rod in the second PRPaR drive branch move in the opposite direction; After the first PRPaR drive branch and the second PRPaR drive branch are symmetric, the height of the moving platform increases, and the lower telescopic rod slides upward. The two drive branches move in the same direction; during this time, the movement direction of the third drive branch is the same as that of the moving platform; During use, when only the servo motor in the vertical linear module is used, the servo motor drives the drive slider to reciprocate linearly in the linear guide rail, and the third PRPaR drive branch swings up and down accordingly, driving the moving platform to translate only in a two-dimensional plane within a certain range. The first and second PRPaR drive branches move in the same direction; when exceeding this range, the moving platform will not only translate in the two-dimensional plane but also translate up and down. At this time, the first and second PRPaR drive branches move in the opposite direction; In use, when the servo motors in all three linear modules are not in use, only the servo motor on the upper motor support plate is operating, and the servo motor on the upper motor support plate drives the RUPUR series chain to rotate in three-dimensional space; In use, when the servo motors in all three linear modules are used simultaneously, the movement directions of the first, second, and third PRPaR drive branches are related to the motor directions. At this time, the moving platform will not only translate in a two-dimensional plane or rotate in three-dimensional space. Instead, it will simultaneously rotate and translate in three-dimensional space.

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