A two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure

Abstract

The present invention discloses a two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure. The mechanism comprises a base, four suspension rods, and a working platform. The four suspension rods are fixed to the top plane of the base and are evenly distributed along the circumference. The working platform is coaxial with the base and arranged parallel to each other. Four evenly and obliquely distributed linear actuators, four evenly and obliquely distributed first flexible hinges, and two adjacent, vertically arranged piston rods are installed between the working platform and the base. Four evenly and obliquely distributed second flexible hinges are installed between the four suspension rods and the working platform. By combining the tensegrity structure with the parallel platform, the present invention achieves self-balancing and self-stability, and can achieve a large span while being extremely lightweight.

Description

Technical Field

[0001] The present invention relates to the technical field of space robot structures, and more particularly to a two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure. Background Art

[0002] A parallel mechanism, also known as a parallel robot mechanism, primarily consists of a moving platform (work platform) and a fixed platform (base), connected by two or more branched kinematic chains to form a closed-loop mechanism. Parallel mechanisms are typically composed of a combination of different components. For example, a traditional rigid mechanism uses kinematic pairs to connect several rigid components, which then generate relative motion between them.

[0003] However, the kinematic pair structure of traditional rigid mechanisms is complex, and there are inevitable friction, wear and clearance, as well as errors generated during the mechanical structure processing. These problems cannot meet the design requirements of modern spatial mechanisms well.

[0004] Therefore, providing a two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure with improved motion accuracy is a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure, which eliminates the gap between the kinematic pairs of the parallel mechanism, optimizes the parallel mechanism, and improves the motion accuracy of the tensegrity parallel mechanism.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure comprises a base, four booms and a working platform, wherein the four booms are respectively fixed on the top plane of the base and are evenly distributed along the circumference; the working platform is coaxial with the base and is distributed parallel to each other up and down; four evenly and obliquely distributed linear drives, four evenly and obliquely distributed first flexible hinges and two adjacent and vertically arranged piston rods are installed between the working platform and the base; four evenly and obliquely distributed second flexible hinges are installed between the four booms and the working platform.

[0008] By adopting the above scheme, the beneficial effects of the present invention are:

[0009] Combining the tensegrity structure with the parallel platform achieves self-balancing and self-stability characteristics, and can achieve a large span while being extremely light in weight.

[0010] Furthermore, one end of each of the linear actuators is hinged to the outer circumferential wall of the base, and the other end of each of the linear actuators is hinged to the outer circumferential wall of the working platform.

[0011] Furthermore, one end of each of the first flexible hinges is fixedly connected to the base, and the other end of each of the first flexible hinges is fixedly connected to the work platform.

[0012] Furthermore, one end of each second flexible hinge is fixedly connected to the working platform, and the other end of each second flexible hinge is fixedly connected to the boom near the top; each second flexible hinge is cross-distributed with the corresponding first flexible hinge below it.

[0013] Furthermore, the bottom end of each piston rod is connected to the base through a first rotating pair, and the top end of each piston rod is connected to the working platform through a second rotating pair; the rotation directions of the first rotating pair and the second rotating pair are vertically distributed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0015] Figure 1 A schematic structural diagram of a two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure provided by the present invention;

[0016] Figure 2 This is a structural schematic diagram of the connection relationship between the piston rod, base and working platform provided by the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] like Figure 1 、 2As shown, an embodiment of the present invention discloses a two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure, comprising a base 1, four suspenders 2, and a working platform 3. The four suspenders 2 are fixed to the top plane of the base 1 and evenly distributed along the circumference. The working platform 3 is coaxial with the base 1 and arranged parallel to each other. Four uniformly and obliquely distributed linear actuators 4, four uniformly and obliquely distributed first flexible hinges 5, and two adjacent, vertically arranged piston rods 6 are installed between the working platform 3 and the base 1. Four uniformly and obliquely distributed second flexible hinges 7 are installed between the four suspenders 2 and the working platform 3. By combining a tensegrity structure with a parallel platform, the present invention achieves self-balancing and self-stability, and can achieve a large span while being extremely lightweight.

[0019] Specifically, one end of each linear drive 4 is hinged to the outer circumferential wall of the base 1 , and the other end of each linear drive 4 is hinged to the outer circumferential wall of the working platform 3 .

[0020] Specifically, one end of each first flexible hinge 5 is fixedly connected to the base 1 , and the other end of each first flexible hinge 5 is fixedly connected to the work platform 3 .

[0021] Specifically, one end of each second flexible hinge 7 is fixedly connected to the working platform 3, and the other end of each second flexible hinge 7 is fixedly connected to the boom 2 near the top; each second flexible hinge 7 is cross-distributed with the corresponding first flexible hinge 5 below it.

[0022] Specifically, the bottom end of each piston rod 6 is connected to the base 1 through a first rotating pair 8, and the top end of each piston rod 6 is connected to the working platform 3 through a second rotating pair 9; the rotation directions of the first rotating pair 8 and the second rotating pair 9 are vertically distributed. In this embodiment, the rotating pair is selected to be a rotating shaft and a bearing to achieve relative rotation.

[0023] Of course, in order to ensure that the flip center of the mechanism is fixed during movement, the two piston rods 6 are connected in series through a PU tube. One end of the PU tube is connected to the air inlet end of one piston rod 6, and the other end of the PU tube is connected to the air outlet end of the other piston rod 6. In this way, the extension or shortening of the two piston rods 6 during movement is the same, ensuring that the flip center of the mechanism remains unchanged during the two-degree-of-freedom flip process of rotating around the x' axis and rotating around the y' axis, and at the same time enhancing the coordination of the mechanism.

[0024] The working principle of the present invention is: in the initial state, the four first flexible hinges 5 and the four second flexible hinges 7 are in a tensioned state, providing initial stress for the whole, driving the linear drive 4 to extend or shorten, and realizing the flipping of the working platform 3. When the linear drive 4 returns to the initial length, under the action of the four first flexible hinges 5 and the four second flexible hinges 7, the working platform 3 can quickly return to a stable state.

[0025] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0026] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure, comprising a base, four suspension rods, and a working platform, wherein the four suspension rods are respectively fixed to the top plane of the base and are evenly distributed along the circumference; the working platform is coaxial with the base and is distributed parallel to each other in the upper and lower directions, characterized in that: Four uniformly and obliquely distributed linear actuators, four uniformly and obliquely distributed first flexible hinges, and two adjacent and vertically arranged piston rods are installed between the working platform and the base; four uniformly and obliquely distributed second flexible hinges are installed between the four booms and the working platform; One end of each second flexible hinge is fixedly connected to the work platform, and the other end of each second flexible hinge is fixedly connected to the boom near the top; each second flexible hinge is cross-distributed with the corresponding first flexible hinge below it; The bottom end of each piston rod is connected to the base via a first rotating pair, and the top end of each piston rod is connected to the work platform via a second rotating pair; the rotation directions of the first rotating pair and the second rotating pair are perpendicular to each other; One end of each linear actuator is hinged to the outer circumferential wall of the base, and the other end of each linear actuator is hinged to the outer circumferential wall of the working platform; The two piston rods are connected in series through a PU tube, one end of the PU tube is connected to the air inlet end of one piston rod, and the other end of the PU tube is connected to the air outlet end of the other piston rod.

2. The two-degree-of-freedom parallel adjustment platform mechanism based on a four-bar tensegrity structure according to claim 1, characterized in that: One end of each of the first flexible hinges is fixedly connected to the base, and the other end of each of the first flexible hinges is fixedly connected to the work platform.

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