Three-movement one-rotation four-degree-of-freedom redundant drive parallel mechanism

Abstract

The invention belongs to the technical field of industrial robots, and discloses a three-movement one-rotation four-degree-of-freedom redundant drive parallel mechanism which comprises a fixed platform and a movable platform. A plurality of motion branch chains are arranged between the fixed platform and the movable platform; the motion branch chain comprises a first arc-shaped connecting rod and a second arc-shaped connecting rod which are bent reversely, and the first arc-shaped connecting rod and the second arc-shaped connecting rod are connected in a sliding mode; one end of the first arc-shaped connecting rod is matched with the fixed platform, and the first arc-shaped connecting rod can rotate around the axis perpendicular to the fixed platform; one end of the second arc-shaped connecting rod is movably connected with the movable platform; the first arc-shaped connecting rod is provided with a first driving motor used for driving the first arc-shaped connecting rod to rotate around the axis parallel to the fixed platform. The second arc-shaped connecting rod is provided with an auxiliary motor used for driving the second arc-shaped connecting rod to slide relative to the first arc-shaped connecting rod. The operation stability and precision of the parallel mechanism can be improved, the bearing capacity of a kinematic pair is improved, and the overall performance of the mechanism is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial robots, and particularly relates to a three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism. Background Art

[0002] The parallel mechanism is in the form of multiple degrees of freedom in space. Its main feature is that it connects the fixed platform and the moving platform through two or more branch chains to form a multi-closed-loop structure. Compared with the serial mechanism, the parallel mechanism has advantages such as greater structural stiffness and load-bearing capacity, higher positioning accuracy, and easier control. Among them, the redundant drive parallel mechanism refers to a parallel mechanism in which the number of its mechanism drive devices is more than the number of degrees of freedom. It has local symmetry, effectively eliminates the singular configurations inside the working space, and improves the force characteristics of the mechanism. Therefore, it is often applied to fields with large loads or high dynamic performance requirements, such as simulators, machine tools, and positioning platforms.

[0003] Currently, among the existing redundant drive parallel mechanisms with few degrees of freedom, the invention patent with the publication number CN115592653B proposes a planar three-degree-of-freedom redundant drive parallel mechanism. Its four parallel branch chains are evenly distributed along the outer peripheral side of the moving platform, that is, arranged in a regular quadrilateral to connect the moving platform. By rotating the rotating rod in the parallel branch chain and driving the telescopic rod to expand and contract, a redundant drive overconstrained parallel mechanism is formed, enabling the moving platform to move in the x-axis and y-axis of the plane and rotate around the z-axis; the patent application with the publication number CN110181487A proposes a two-rotation and one-translation redundant drive parallel mechanism with high dexterity. It uses 4 completely identical RPRU branch chains, greatly improving the stability performance, stiffness, and fault tolerance of the mechanism; the invention patent with the publication number CN114654454B proposes a three-branch motion redundant parallel mechanism driven by a moving pair. It uses 3 identical hybrid branches, making the parallel mechanism of this mechanism have the characteristic of a large rotation angle.

[0004] An existing three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism has low stiffness, small precision, poor flexibility and load-bearing capacity, and is not easy to control. In addition, the kinematic pairs of the mechanism adopt rotational pairs and translational pairs, and the axes of these kinematic pairs are parallel or coplanar. Most of the connections between two adjacent linkages use one kinematic pair (rotational pair / translational pair), resulting in excessive load-bearing capacity of these mechanism kinematic pairs, limited working space and flexibility, and difficulty in avoiding singular points, further affecting the overall performance of the mechanism. Summary of the Invention

[0005] The purpose of the present invention is to provide a three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism, which can improve the operation smoothness and precision of the parallel mechanism, improve the load-bearing capacity of the kinematic pairs, and improve the overall performance of the mechanism.

[0006] To achieve the above object, the present invention is implemented by the following technical solutions: A three-shift-one-rotation four-degree-of-freedom redundant drive parallel mechanism, comprising a fixed platform and a moving platform; the fixed platform and the moving platform are arranged in parallel; At least two kinematic chains are provided between the fixed platform and the moving platform; The kinematic chain includes a first arc-shaped link and a second arc-shaped link that are bent in the opposite direction. One end of the first arc-shaped link is slidably connected to one end of the second arc-shaped link; the end of the first arc-shaped link away from the second arc-shaped link cooperates with the fixed platform, and the first arc-shaped link can rotate around an axis perpendicular to the fixed platform; the end of the second arc-shaped link away from the first arc-shaped link is connected to the moving platform, and the second arc-shaped link is movably connected to the moving platform; A first drive motor is arranged at the end of the first arc-shaped link away from the second arc-shaped link for driving the first arc-shaped link to rotate around an axis parallel to the fixed platform; an auxiliary motor is arranged at the end of the second arc-shaped link away from the moving platform for driving the second arc-shaped link to slide relative to the first arc-shaped link.

[0007] By adopting the above technical solutions, the second arc-shaped link is driven by the auxiliary motor to interact with the first arc-shaped link. At the same time, the first arc-shaped link can slide relative to the second arc-shaped link, so that the kinematic chain can perform elongation or contraction movement in its length direction; similarly, the first drive motor drives the corresponding first arc-shaped link to rotate around the axis of the output shaft of the first drive motor, which will also cause the first arc-shaped link to slide relative to the second arc-shaped link, and then drive the second arc-shaped link to slide relative to the first arc-shaped link, thereby causing the kinematic chain to perform elongation or contraction movement in its length direction. In addition, the first arc-shaped link can rotate around an axis perpendicular to the fixed platform. In this way, the moving platform can realize the movement of four degrees of freedom along the X, Y, and Z axes and rotation around the Z axis, and the axis is not fixed when it rotates around the Z axis.

[0008] The first arc-shaped link and the second arc-shaped link are mutually coupled, and there are two kinematic pairs between them, so that the load-bearing capacity of the kinematic pairs can be further improved. The setting of the auxiliary motor forms a redundant drive, which also helps to improve the load-bearing capacity of multiple movable joint points in the parallel mechanism. The second arc-shaped link is movably connected to the moving platform. Combining with the arc-shaped structures of the first arc-shaped link and the second arc-shaped link, and the two kinematic pairs existing between the first arc-shaped link and the second arc-shaped link, the working space of the parallel mechanism can be further expanded, the flexibility can be improved, and the singular points can be avoided.

[0009] When a singularity occurs, the first arc-shaped connecting rod can rotate around an axis perpendicular to the fixed platform, which can eliminate the influence of the singularity, expand the working space, and improve the operation stability of the parallel mechanism. Driven by the first drive motor and the auxiliary motor, the first arc-shaped connecting rod and the second arc-shaped connecting rod slide relative to each other. During this process, their arcs guide and restrict each other's movement trajectories, which helps to improve the operation accuracy of the parallel mechanism.

[0010] According to an embodiment of the present invention, the first arc-shaped connecting rod is provided with a first arc-shaped groove, and the first arc-shaped groove extends along the arc length direction of the first arc-shaped connecting rod; the second arc-shaped connecting rod is provided with a second arc-shaped groove, and the second arc-shaped groove extends along the arc length direction of the second arc-shaped connecting rod; one end of the first arc-shaped connecting rod away from the fixed platform is slidably matched with the second arc-shaped groove; one end of the second arc-shaped connecting rod away from the moving platform is slidably matched with the first arc-shaped groove.

[0011] Furthermore, a first pin shaft is arranged at the end of the first arc-shaped connecting rod and the second arc-shaped connecting rod in sliding fit, and the first pin shaft is slidably matched with the second arc-shaped groove. A second pin shaft is arranged at the end of the second arc-shaped connecting rod and the first arc-shaped connecting rod in sliding fit, and the second pin shaft is slidably matched with the first arc-shaped groove. Further, the second pin shaft is the output shaft of the auxiliary motor.

[0012] Thus, by using the first arc-shaped groove and the second arc-shaped groove to strengthen the guidance, limitation, and restriction of the movement trajectories of the second arc-shaped connecting rod and the first arc-shaped connecting rod, the operation stability of the parallel mechanism can be further improved; moreover, the first arc-shaped groove and the second arc-shaped groove extend along the arc lengths of the first arc-shaped connecting rod and the second arc-shaped connecting rod respectively, which can ensure the maximization of the working space of the parallel mechanism.

[0013] Furthermore, the radii and arcs of the first arc-shaped connecting rod and the second arc-shaped connecting rod are equal.

[0014] Furthermore, the radii of the first arc-shaped connecting rod and the second arc-shaped connecting rod are not equal, and the arc lengths are not equal.

[0015] In this way, according to the requirements for the working space, the radii and arc lengths of the first arc-shaped connecting rod and the second arc-shaped connecting rod can be set to be equal or unequal, so as to adjust the moving space of the parallel mechanism.

[0016] According to an embodiment of the present invention, the output shaft of the auxiliary motor is sleeved inside the first arc-shaped groove, and a gear is arranged at the end of the output shaft of the auxiliary motor. The first arc-shaped connecting rod is provided with a rack extending along the arc length, and the gear meshes with the rack.

[0017] Driven by the auxiliary motor, the arc-shaped rack cooperates with the gear. The gear rotates under the drive of the auxiliary motor and drives the end of the second arc-shaped connecting rod to slide in the first arc-shaped groove, so that the moving branch chain expands or contracts in its length direction. The cooperation structure of the gear and the rack can improve the smoothness and lubricity of this operation process, avoid operation jams and eliminate singular points.

[0018] According to an embodiment of the present invention, a support frame is provided in the direction of the first arc-shaped connecting rod away from the second arc-shaped connecting rod. One end of the first arc-shaped connecting rod away from the second arc-shaped connecting rod cooperates with the support frame, and the support frame can rotate around an axis perpendicular to the fixed platform.

[0019] Furthermore, the output shaft of the first driving motor is sleeved on the support frame and is arranged parallel to the fixed platform; the end of the first arc-shaped connecting rod away from the second arc-shaped connecting rod is sleeved on the output shaft of the first driving motor. In this way, the output shaft of the first driving motor can drive the first arc-shaped connecting rod to rotate around an axis parallel to the fixed platform.

[0020] In this way, the support frame is used to realize the connection between the first driving motor and the first arc-shaped connecting rod. Moreover, the support frame is rotationally matched with the fixed platform, and the support frame can drive the first arc-shaped connecting rod to rotate around an axis perpendicular to the fixed platform. In this way, singular points can be further avoided and the flexibility of the parallel mechanism can be improved.

[0021] According to an embodiment of the present invention, the support frame includes two symmetrically arranged support arms, and the two support arms extend towards the moving platform; the output shaft of the first driving motor is inserted inside the two support arms in parallel, and one end of the first arc-shaped connecting rod away from the second arc-shaped connecting rod is arranged between the two support arms and is sleeved on the output shaft of the first driving motor.

[0022] According to an embodiment of the present invention, the fixed platform is configured with a second driving motor, and at least one support frame cooperates with the output end of the second driving motor. The second driving motor is used to drive the connected support frame and the first arc-shaped connecting rod to rotate around an axis perpendicular to the fixed platform.

[0023] According to an embodiment of the present invention, a support rod is provided between the second arc-shaped connecting rod and the moving platform. Both ends of the support rod are rotationally matched with the second arc-shaped connecting rod and the moving platform respectively.

[0024] In this way, singular points can be further avoided through the support rod, and the smoothness of the operation of the parallel mechanism can be improved; and the working space and flexibility of the parallel mechanism can be further expanded.

[0025] Furthermore, rotating shafts are inserted through both ends of the support rod, and the two rotating shafts are respectively connected to the second arc-shaped connecting rod and the moving platform; the support rod can rotate relative to the axis of the rotating shaft.

[0026] Furthermore, the moving platform is configured with a first connecting member. The first connecting member includes two symmetrically arranged connecting arms that extend towards the fixed platform. The rotating shaft away from the second arc-shaped connecting rod penetrates inside the two connecting arms of the first connecting member.

[0027] Thus, by means of the cooperation of components such as the support rod and the rotating shaft, the flexibility of the movement between the second arc-shaped connecting rod and the moving platform is improved, and the movement space of the moving platform is further expanded. The cooperation of components such as the support rod and the rotating shaft can also further eliminate the singular points during the operation of the first arc-shaped connecting rod and the second arc-shaped connecting rod, and improve the smoothness of the operation of the moving platform.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The first arc-shaped connecting rod and the second arc-shaped connecting rod are coupled to each other, and there are two kinematic pairs between them. In this way, the load-bearing capacity of the kinematic pairs can be further improved, and the setting of the auxiliary motor forms a redundant drive, which also helps to improve the load-bearing capacity of multiple moving joint points in the parallel mechanism.

[0029] 2. The second arc-shaped connecting rod is movably connected to the moving platform. In combination with the arc-shaped structures of the first arc-shaped connecting rod and the second arc-shaped connecting rod, and the two kinematic pairs existing between the first arc-shaped connecting rod and the second arc-shaped connecting rod, the working space of the parallel mechanism can be further expanded and the flexibility can be improved, and singularities can also be avoided. The first arc-shaped connecting rod and the second arc-shaped connecting rod slide relative to each other, and during this process, their respective arcs guide and restrict each other's movement trajectories, which helps to improve the accuracy of the operation of the parallel mechanism.

[0030] 3. The first arc-shaped connecting rod is configured with a rack extending along the arc length and meshes with the gear at the end of the second arc-shaped connecting rod, which can improve the smoothness and smoothness of the operation of the first arc-shaped connecting rod and the second arc-shaped connecting rod, avoid operation jams, and eliminate singularities. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The schematic diagrams in the specification that form a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 is a schematic diagram of the overall structure of a three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to Embodiment 1 of the present invention; Figure 2 is a schematic diagram of the structure of the kinematic chain of a three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to Embodiment 1 of the present invention; Figure 3 is a schematic diagram of the structure of the first arc-shaped connecting rod of a three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to Embodiment 1 of the present invention; Figure 4Schematic structural diagram of the second arc link of the three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to Embodiment 1 of the present invention; Figure 5 Schematic structural diagram of the extended state of the kinematic chain of the three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to Embodiment 1 of the present invention; Figure 6 Schematic structural diagram of the contracted state of the kinematic chain of the three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to Embodiment 1 of the present invention.

[0032] Reference numerals: fixed platform 10; moving platform 20; kinematic chain 30; first arc link 41; second arc link 42; support rod 43; first arc groove 44; second arc groove 45; first pin shaft 46; rack 47; gear 48; support frame 50; support arm 51; rotating shaft 52; first connecting member 53; connecting arm 54; second connecting member 55; first driving motor 61; second driving motor 62; auxiliary motor 63. Detailed implementation manners

[0033] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0034] The following detailed descriptions are all exemplary descriptions, aiming to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms adopted by the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the present invention are only for the purpose of describing specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention.

[0035] Embodiment 1 A three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism, as Figures 1 - 6 shown, includes a fixed platform 10 and a moving platform 20 arranged in parallel; at least two kinematic chains 30 are provided between the fixed platform 10 and the moving platform 20; in this embodiment, three kinematic chains 30 are arranged in a circumferential array between the fixed platform 10 and the moving platform 20.

[0036] The kinematic chain 30 includes a first arc link 41, a second arc link 42, and a support rod 43 connected in sequence; the first arc link 41 is movably matched with the second arc link 42, and the two are bent in opposite directions; one end of the first arc link 41 away from the second arc link 42 is connected to the fixed platform 10, and at least one first arc link 41 can rotate around an axis perpendicular to the fixed platform 10, and one end of the second arc link 42 away from the first arc link 41 is rotatably matched with the support rod 43, and one end of the support rod 43 away from the second arc link 42 is rotatably matched with the moving platform 20 through the support rod 43.

[0037] One end of the first arc-shaped connecting rod 41 away from the second arc-shaped connecting rod 42 is provided with a first driving motor 61 for driving the first arc-shaped connecting rod 41 to rotate around an axis parallel to the fixed platform 10; one end of the second arc-shaped connecting rod 42 away from the support rod 43 is provided with an auxiliary motor 63 for driving the second arc-shaped connecting rod 42 to slide relative to the first arc-shaped connecting rod 41.

[0038] By driving the second arc-shaped connecting rod 42 to interact relative to the first arc-shaped connecting rod 41 by the auxiliary motor 63, and at the same time, the first arc-shaped connecting rod 41 can slide relative to the second arc-shaped connecting rod 42, so that the movement branch chain 30 can perform elongation or contraction movement in its length direction; similarly, when the first driving motor 61 drives the corresponding first arc-shaped connecting rod 41 to rotate around the axis of the output shaft of the first driving motor 61, it will also cause the first arc-shaped connecting rod 41 to slide relative to the second arc-shaped connecting rod 42, and then drive the second arc-shaped connecting rod 42 to slide relative to the first arc-shaped connecting rod 41, thereby causing the movement branch chain 30 to perform elongation or contraction movement in its length direction. In addition, the first arc-shaped connecting rod 41 can rotate around an axis perpendicular to the fixed platform 10. In this way, the moving platform 20 can realize the movement of four degrees of freedom along the X, Y, and Z axes and the rotation around the Z axis, and the axis is not fixed when it rotates around the Z axis.

[0039] The first arc-shaped connecting rod 41 and the second arc-shaped connecting rod 42 are mutually coupled, and there are two kinematic pairs between them, which can further improve the load-bearing capacity of the kinematic pairs. The setting of the auxiliary motor 63 forms a redundant drive, which also helps to improve the load-bearing capacity of multiple moving joint points in the parallel mechanism. The second arc-shaped connecting rod 42 is movably connected to the moving platform 20. Combining with the arc-shaped structures of the first arc-shaped connecting rod 41 and the second arc-shaped connecting rod 42, and the two kinematic pairs existing between the first arc-shaped connecting rod 41 and the second arc-shaped connecting rod 42, it can further expand the working space of the parallel mechanism and improve the flexibility, and can also avoid singular points.

[0040] When a singular point appears, the first arc-shaped connecting rod 41 can rotate around an axis perpendicular to the fixed platform 10, which can eliminate the influence of the singular point and improve the operation smoothness of the parallel mechanism while expanding the working space. Driven by the first driving motor 61 and the auxiliary motor 63, the first arc-shaped connecting rod 41 and the second arc-shaped connecting rod 42 slide relative to each other. During this process, their arcs guide and restrict each other's movement trajectories, which helps to improve the operation accuracy of the parallel mechanism.

[0041] Further, the first arc-shaped link 41 is configured with a first arc-shaped groove 44, and the first arc-shaped groove 44 extends along the arc length direction of the first arc-shaped link 41; the second arc-shaped link 42 is configured with a second arc-shaped groove 45, and the second arc-shaped groove 45 extends along the arc length direction of the second arc-shaped link 42; one end of the first arc-shaped link 41 away from the fixed platform 10 is in sliding fit with the second arc-shaped groove 45; one end of the second arc-shaped link 42 away from the support rod 43 is in sliding fit with the first arc-shaped groove 44.

[0042] Both the first arc-shaped groove 44 and the second arc-shaped groove 45 are through grooves, thereby reducing the mass of the moving branch chain 30.

[0043] In this embodiment, the radii and arcs of the first arc-shaped link 41 and the second arc-shaped link 42 are equal. In other embodiments, according to the requirements of the working space, the radii and arc lengths of the first arc-shaped link 41 and the second arc-shaped link 42 can be set to be equal or unequal, so as to adjust the moving space of the parallel mechanism.

[0044] Further, a first pin shaft 46 is arranged at the end of the first arc-shaped link 41 in sliding fit with the second arc-shaped link 42, and the first pin shaft 46 is in sliding fit with the second arc-shaped groove 45. The end of the second arc-shaped link 42 in sliding fit with the first arc-shaped link 41 is sleeved on the output shaft of the auxiliary motor 63, and the output shaft of the auxiliary motor 63 is sleeved inside the first arc-shaped groove 44 and is in sliding fit with the first arc-shaped groove 44. The auxiliary motor 63 can drive the second arc-shaped link 42 to rotate around the axis of the output shaft of the auxiliary motor 63, thereby driving the second arc-shaped link 42 to slide in the first arc-shaped groove 44.

[0045] A gear 48 is arranged at the end of the output shaft of the auxiliary motor 63, and the first arc-shaped link 41 is configured with a rack 47 extending along the arc length. The gear 48 meshes with the rack 47. Driven by the auxiliary motor 63, the arc-shaped rack 47 cooperates with the gear 48. The gear 48 rotates driven by the auxiliary motor 63 and drives the end of the second arc-shaped link 42 to slide in the first arc-shaped groove 44, so that the moving branch chain 30 undergoes elongation or contraction movement in its length direction. The cooperation structure of the gear 48 and the rack 47 can improve the smoothness and smoothness of this operation process, avoid operation jams and eliminate singularities.

[0046] A support frame 50 is arranged in the direction of the first arc-shaped link 41 away from the second arc-shaped link 42. One end of the first arc-shaped link 41 away from the second arc-shaped link 42 is matched with the support frame 50, and the support frame 50 can rotate around an axis perpendicular to the fixed platform 10.

[0047] Furthermore, the output shaft of the first driving motor 61 is sleeved on the support frame 50 and is arranged parallel to the fixed platform 10; the end of the first arc-shaped connecting rod 41 far from the second arc-shaped connecting rod 42 is sleeved on the output shaft of the first driving motor 61. In this way, the output shaft of the first driving motor 61 can drive the first arc-shaped connecting rod 41 to rotate around the axis parallel to the fixed platform 10.

[0048] The support frame 50 includes two symmetrically arranged support arms 51, and the two support arms 51 extend towards the moving platform 20; the output shaft of the first driving motor 61 is inserted through the interiors of the two support arms 51 in parallel, and one end of the first arc-shaped connecting rod 41 far from the second arc-shaped connecting rod 42 is arranged between the two support arms 51 and is sleeved on the output shaft of the first driving motor 61.

[0049] The fixed platform 10 is configured with a second driving motor 62, and at least one support frame 50 is matched with the output end of the second driving motor 62. The second driving motor 62 is used to drive the connected support frame 50 and the first arc-shaped connecting rod 41 to rotate around the axis perpendicular to the fixed platform 10.

[0050] The connection between the first driving motor 61 and the first arc-shaped connecting rod 41 is realized by using the support frame 50. Moreover, the support frame 50 is rotationally matched with the fixed platform 10, and the support frame 50 can drive the first arc-shaped connecting rod 41 to rotate around the axis perpendicular to the fixed platform 10. Especially under the drive of the second driving motor 62, the connected moving chain 30 rotates around the axis perpendicular to the fixed platform 10 and drives the other two moving chains 30 to also rotate around the axis perpendicular to the fixed platform 10, which can further avoid singular points and improve the flexibility of the parallel mechanism.

[0051] A support rod 43 is provided between the second arc-shaped connecting rod 42 and the moving platform 20. The two ends of the support rod 43 are respectively rotationally matched with the second arc-shaped connecting rod 42 and the moving platform 20.

[0052] In this way, the singular points can be further avoided through the support rod 43, and the smoothness of the operation of the parallel mechanism can be improved; and the working space and flexibility of the parallel mechanism can be further expanded.

[0053] Furthermore, rotating shafts 52 are inserted through the two ends of the support rod 43, and the two rotating shafts 52 are respectively connected to the second arc-shaped connecting rod 42 and the moving platform 20; the support rod 43 can rotate relative to the axis of the rotating shaft 52.

[0054] Furthermore, the moving platform 20 is configured with a first connecting member 53. The first connecting member 53 includes two symmetrically arranged connecting arms 54, and the connecting arms 54 extend towards the fixed platform 10; the rotating shaft 52 arranged at the end of the support rod 43 far from the second arc-shaped connecting rod 42 is inserted through the interiors of the two connecting arms 54 of the first connecting member 53.

[0055] Furthermore, a second connecting member 55 is disposed at one end of the second arc-shaped connecting rod 42 close to the support rod 43. The second connecting member 55 can be configured to have the same structure as the first connecting member 53 or a different structure from the first connecting member 53. In combination Figure 2 , in this embodiment, the second connecting member 55 is a block structure and has a different structure from the first connecting member 53. The rotating shaft 52 disposed at the end of the support rod 43 away from the moving platform 20 penetrates through the inside of the second connecting member 55, and this rotating shaft 52 penetrates through the end of the support rod 43 away from the moving platform 20. The support rod 43 can also rotate around the rotating shaft 52 away from the moving platform 20.

[0056] Thus, by using the cooperation of the support rod 43 and the two rotating shafts 52, two movable joints are formed between the second arc-shaped connecting rod 42 and the moving platform 20, improving the movement flexibility between the second arc-shaped connecting rod 42 and the moving platform 20, and further expanding the movement space of the moving platform 20. The cooperation of the support rod 43 and components such as the rotating shaft 52 can further eliminate the singular points in the operation process of the first arc-shaped connecting rod 41 and the second arc-shaped connecting rod 42, and improve the operation smoothness of the moving platform 20.

[0057] The three-translation-one-rotation four-degree-of-freedom redundant drive parallel mechanism of this embodiment realizes translational motion in three directions and rotation in one direction, and the axis of rotation is not unique, and can be applied to fields such as virtual-axis machine tools, aviation simulation equipment, and medical equipment.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism, comprising a fixed platform (10) and a moving platform (20); characterized in that, At least two kinematic chains (30) are provided between the fixed platform (10) and the moving platform (20); The kinematic chain (30) includes a first arc-shaped connecting rod (41) and a second arc-shaped connecting rod (42) that are bent in the opposite direction, and the first arc-shaped connecting rod (41) and the second arc-shaped connecting rod (42) are slidably connected to each other; one end of the first arc-shaped connecting rod (41) away from the second arc-shaped connecting rod (42) is matched with the fixed platform (10), and the first arc-shaped connecting rod (41) can rotate around an axis perpendicular to the fixed platform (10); one end of the second arc-shaped connecting rod (42) away from the first arc-shaped connecting rod (41) is movably connected to the moving platform (20); One end of the first arc-shaped connecting rod (41) away from the second arc-shaped connecting rod (42) is provided with a first driving motor (61) for driving the first arc-shaped connecting rod (41) to rotate around an axis parallel to the fixed platform (10); one end of the second arc-shaped connecting rod (42) away from the moving platform (20) is provided with an auxiliary motor (63) for driving the second arc-shaped connecting rod (42) to slide relative to the first arc-shaped connecting rod (41).

2. The three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to claim 1, characterized in that, The first arc-shaped connecting rod (41) is provided with a first arc-shaped groove (44), and the first arc-shaped groove (44) extends along the arc length direction of the first arc-shaped connecting rod (41); the second arc-shaped connecting rod (42) is provided with a second arc-shaped groove (45), and the second arc-shaped groove (45) extends along the arc length direction of the second arc-shaped connecting rod (42); One end of the first arc-shaped connecting rod (41) away from the fixed platform (10) is slidably matched with the second arc-shaped groove (45); one end of the second arc-shaped connecting rod (42) away from the moving platform (20) is slidably matched with the first arc-shaped groove (44).

3. The three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to claim 2, characterized in that, The output shaft of the auxiliary motor (63) is sleeved inside the first arc-shaped groove (44), and a gear (48) is arranged at the end of the output shaft of the auxiliary motor (63), and the first arc-shaped connecting rod (41) is provided with a rack (47) extending along the arc length, and the gear (48) is meshed with the rack (47).

4. The three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to claim 1, characterized in that, One end of the first arc-shaped connecting rod (41) away from the second arc-shaped connecting rod (42) is provided with a support frame (50), and the support frame (50) can rotate around an axis perpendicular to the fixed platform (10).

5. The three-translation and one-rotation four-degree-of-freedom redundant drive parallel mechanism according to claim 4, characterized in that, The output shaft of the first driving motor (61) is sleeved on the support frame (50) and is arranged parallel to the fixed platform (10); The output shaft of the first driving motor (61) can drive the first arc-shaped connecting rod (41) to rotate around an axis parallel to the fixed platform (10).

6. The three-translation-one-rotation four-degree-of-freedom redundant driving parallel mechanism according to claim 4, wherein the support frame (50) includes two symmetrically arranged support arms (51), and the two support arms (51) extend towards the moving platform (20); The output shaft of the first driving motor (61) is inserted parallelly inside the two support arms (51), and one end of the first arc-shaped connecting rod (41) away from the second arc-shaped connecting rod (42) is arranged between the two support arms (51) and sleeved on the output shaft of the first driving motor (61).

7. The three-translation-one-rotation four-degree-of-freedom redundant driving parallel mechanism according to claim 4, wherein the fixed platform (10) is configured with a second driving motor (62), at least one support frame (50) is matched with the output end of the second driving motor (62), and the second driving motor (62) is used to drive the connected support frame (50) and the first arc-shaped connecting rod (41) to rotate around an axis perpendicular to the fixed platform (10).

8. The three-translation-one-rotation four-degree-of-freedom redundant driving parallel mechanism according to claim 1, wherein a support rod (43) is provided between the second arc-shaped connecting rod (42) and the moving platform (20), and both ends of the support rod (43) are rotationally matched with the second arc-shaped connecting rod (42) and the moving platform (20) respectively.

9. The three-translation-one-rotation four-degree-of-freedom redundant driving parallel mechanism according to claim 8, wherein rotation shafts (52) are inserted through both ends of the support rod (43), and the two rotation shafts (52) are respectively connected to the second arc-shaped connecting rod (42) and the moving platform (20); the support rod (43) can rotate relative to the axis of the rotation shaft (52).

10. The three-translation-one-rotation four-degree-of-freedom redundant driving parallel mechanism according to claim 9, wherein the moving platform (20) is configured with a first connecting member (53), the first connecting member (53) includes two symmetrically arranged connecting arms (54), and the connecting arms (54) extend towards the fixed platform (10); The rotation shaft (52) away from the second arc-shaped connecting rod (42) is inserted inside the two connecting arms (54) of the first connecting member (53).

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