A long-travel, two-degree-of-freedom compliant precision positioning platform capable of motion decoupling

Abstract

The present invention discloses a long-range, two-degree-of-freedom, compliant precision positioning platform capable of achieving motion decoupling. The platform comprises a fixed platform; a moving platform connected to the fixed platform via a plurality of translation mechanisms; and a plurality of piezoelectric ceramic actuators, each corresponding to the plurality of translation mechanisms. The piezoelectric ceramic actuators apply external forces to the translation mechanisms, causing them to move. The distance the translation mechanisms move is greater than the distance the piezoelectric ceramic actuators extend or retract. The present invention utilizes a hinge replacement approach to design a novel compliant mechanism and a compliant precision positioning platform, achieving in-plane two-degree-of-freedom motion, decoupling motion, and long-range motion.

Description

Technical Field

[0001] The present invention relates to the field of precision mechanical equipment, and more particularly to a large-stroke two-degree-of-freedom compliant precision positioning platform capable of achieving motion decoupling. Background Art

[0002] Compliant mechanisms are a new type of mechanism that relies on its own elastic deformation to transmit energy, force, and motion. This research field builds on the foundations of traditional rigid mechanisms and employs novel approaches to mechanism design and control. Traditional mechanical structures are connected and coordinated through connectors, and the design typically aims to avoid the uncertainty introduced by rod deformation in motion. Compliant mechanisms, however, leverage the deformation of rods or joints to transmit motion. By studying the deformation of compliant hinges and rods, deformation control can be achieved, ultimately enabling the realization of highly precise target motion using compliant mechanisms.

[0003] The advantage of compliant mechanisms is that they are formed in one piece, eliminating the connection and fit between components. There are no friction, lubrication, or wear issues, which reduces the burden of processing, assembly, and maintenance. Therefore, compliant mechanisms are more suitable for micromechanical systems and can achieve high-precision motion. Compliant precision positioning platforms based on compliant mechanism design and modeling control have developed rapidly in recent years. Scholars have designed a variety of compliant precision positioning platforms from the perspectives of mechanism design and platform performance optimization. These platforms range from single to multiple degrees of freedom, from large travel to a combination of macro and micro, and from single to double precision, adapting to different working conditions and meeting different motion requirements. The small travel of piezoelectric ceramics limits the application range of compliant positioning platforms, and the coupling phenomenon in platform motion also interferes with motion accuracy. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0005] Another object of the present invention is to provide a large-stroke two-degree-of-freedom flexible precision positioning platform that can achieve motion decoupling. A new type of flexible mechanism and flexible precision positioning platform are designed using a hinge replacement method to achieve two-degree-of-freedom motion in a plane, and can achieve motion decoupling and large-stroke motion.

[0006] In order to achieve these objects and other advantages according to the present invention, a large-stroke two-degree-of-freedom compliant precision positioning platform capable of achieving motion decoupling is provided, comprising:

[0007] Determine the platform;

[0008] A movable platform connected to the fixed platform via a plurality of translation mechanisms;

[0009] A number of piezoelectric ceramic actuators are provided. The number of piezoelectric ceramic actuators is correspondingly arranged with a number of translation mechanisms. The piezoelectric ceramic actuators apply an external force to the translation mechanisms to make them move, and the distance that the translation mechanisms move is greater than the distance that the piezoelectric ceramic actuators extend or contract.

[0010] Preferably, the fixed platform has an annular structure.

[0011] Preferably, the moving platform has a circular structure, and the fixed platform and the moving platform are of a nested structure.

[0012] Preferably, the translation mechanism includes a lever amplification mechanism and a flexible guiding mechanism. The lever amplification mechanism drives the flexible guiding mechanism to move, thereby causing the moving platform to move.

[0013] Preferably, the lever amplification mechanism includes a first-level lever assembly and a second-level lever assembly. The piezoelectric ceramic actuator applies a force to the first-level lever assembly, causing the first-level lever assembly to move towards the side close to the fixed platform, thereby driving the second-level lever assembly to move towards the side close to the fixed platform.

[0014] Preferably, the first-level lever assembly includes a pair of first support rods and a first flexible rod. The pair of first support rods are horizontally and parallelly fixed inside the fixed platform and are distributed on both sides of the piezoelectric ceramic actuator. The free ends of the pair of support rods fix the first flexible rod. When the piezoelectric ceramic actuator applies a force to the first flexible rod, both ends of the first flexible rod move towards the side close to the fixed platform respectively.

[0015] Preferably, the second-level lever assembly includes a pair of second support rods, a pair of third support rods, and a second flexible rod. Both ends of the first flexible rod respectively fix the pair of second support rods. A pair of third support rods are distributed on the two outer sides of the pair of second support rods and are fixed on the fixed platform. The pair of first support rods, the pair of second support rods, and the pair of third support rods are parallel to each other. The free ends of the pair of second support rods and the free ends of the pair of third support rods fix the second flexible rod, and the second flexible rod connects the flexible guiding mechanism.

[0016] Preferably, the flexible guiding mechanism includes a connecting rod and a "C"-shaped third flexible rod. One end of the connecting rod connects the lever amplification mechanism, and the other end connects the midpoint of the third flexible rod. The free end of the third flexible rod connects the moving platform.

[0017] The present invention has at least the following beneficial effects:

[0018] The precision positioning platform adopts a novel compliant mechanism design, which can achieve the decoupling of planar two-degree-of-freedom motion;

[0019] The lever amplification mechanism is added to the design of the precision positioning platform to achieve long-stroke movement;

[0020] The design of the precision positioning platform changes the traditional platform shape and adopts a circular platform shape, making the platform more adaptable to experimental conditions and more beautiful.

[0021] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of a large-stroke two-degree-of-freedom compliant precision positioning platform that can achieve motion decoupling, according to one of the technical solutions of the present invention;

[0023] Figure 2 This is a working principle diagram of a primary lever assembly according to one of the technical solutions of the present invention;

[0024] Figure 3 This is a working principle diagram of the secondary lever assembly of one of the technical solutions of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0026] In the description of the present invention, the terms "midpoint", "horizontal", "one side", "two sides", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] like Figures 1 to 3 As shown, the present invention provides a large-stroke two-degree-of-freedom compliant precision positioning platform capable of achieving motion decoupling, comprising:

[0028] Fixed platform 1, providing a fixed position for translation mechanism 3;

[0029] The movable platform 2 is connected to the fixed platform 1 through a plurality of translation mechanisms 3. When the translation mechanisms 3 move, the movable platform 2 moves along with the translation mechanisms 3.

[0030] A plurality of piezoelectric ceramic drivers 4 are arranged corresponding to a plurality of translation mechanisms 3. The piezoelectric ceramic drivers 4 apply force to the translation mechanism 3 to make it move. The distance moved by the translation mechanism 3 is greater than the distance extended or retracted by the piezoelectric ceramic driver 4. The translation mechanism 3 has the function of amplifying the moving stroke of the piezoelectric ceramic driver 4.

[0031] In the above technical solution, after the piezoelectric ceramic driver 4 is energized, the piezoelectric ceramic driver 4 applies force to the corresponding translation mechanism 3 to move the translation mechanism 3. The distance the translation mechanism 3 moves is greater than the distance the piezoelectric ceramic driver 4 extends or contracts. The movement of the translation mechanism 3 drives the platform 2 to move in the direction of the translation mechanism 3.

[0032] Based on the above technical solution, the fixed platform 1 is in a circular ring structure, and the piezoelectric ceramic driver 4 is fixed inside the fixed platform 1 , providing a structural basis for fixing the piezoelectric ceramic driver 4 and a plurality of translation mechanisms 3 .

[0033] Based on the above technical solution, the movable platform 2 is a circular structure, the fixed platform 1 and the movable platform 2 are a nested structure, and the movable platform 2 is arranged at the center of the fixed platform 1.

[0034] Based on the above technical solution, the translation mechanism 3 includes a lever amplification mechanism 31 and a flexible guide mechanism 32. The lever amplification mechanism 31 drives the flexible guide mechanism 32 to move, thereby moving the movable platform 2 to achieve multi-directional movement of the movable platform 2.

[0035] Based on the above technical solution, the lever amplification mechanism 31 includes a first-level lever assembly 311 and a second-level lever assembly 312. The piezoelectric ceramic driver 4 applies force to the first-level lever assembly 311, so that the first-level lever assembly 311 moves toward the side close to the fixed platform 1. The distance X' moved by the first-level lever assembly 311 is greater than the distance X extended or retracted by the piezoelectric ceramic driver 4. The movement of the first-level lever assembly 311 drives the second-level lever assembly 312 to move toward the side close to the fixed platform 1, changing the relative position of the moving platform 2 within the fixed platform 1. The lever amplification mechanism 31 plays a role in amplifying the stroke of the piezoelectric ceramic driver 4.

[0036] Based on the above technical solution, the first-level lever assembly 311 includes a pair of first support rods 3111 and a first flexible rod 3112. The pair of first support rods 3111 are horizontally and parallelly fixed on the inner side of the fixed platform 1 and are distributed on both sides of the piezoelectric ceramic driver 4. The free ends of a pair of support rods are fixed to the first flexible rod 3112. When the piezoelectric ceramic driver 4 applies force to the first flexible rod 3112, the two ends of the first flexible rod 3112 move toward the side close to the fixed platform 1 respectively, and the first support rod 3111 becomes the support point for the rotation of the first flexible rod 3112. The distance from the piezoelectric ceramic driver 4 to the first support rod 3111 is less than the distance from the piezoelectric ceramic driver 4 to the end point of the first flexible rod 3112. Therefore, the distance X' moved by the two ends of the first flexible rod 3112 is greater than the distance X moved by the piezoelectric ceramic driver 4, which plays a role in amplifying the moving stroke of the piezoelectric ceramic driver 4.

[0037] Based on the above technical solution, the secondary lever assembly 312 includes a pair of second support rods 3121, a pair of third support rods 3122, and a second flexible rod 3123. A pair of second support rods 3121 are fixed at both ends of the first flexible rod 3112, and a pair of third support rods 3122 are distributed on the two outer sides of the pair of second support rods 3121 and fixed on the fixed platform 1. The pair of first support rods 3111, the pair of second support rods 3121, and the pair of third support rods 3122 are parallel to each other. The free ends of the pair of second support rods 3121 and the free ends of the pair of third support rods 3122 are fixed with the second flexible rod 3123. The middle point of the second flexible rod 3123 is connected to the flexible guide mechanism 32. When the first flexible rod 3112 When the two ends move toward the side close to the fixed platform 1, a pair of second support rods 3121 also move toward the side close to the fixed platform 1, thereby pulling the second flexible rod 3123 toward the side close to the fixed platform 1, and a pair of third support rods 3122 become support points for the rotation of the second flexible rod 3123. The distance from the second support rod 3121 to the third support rod 3122 is smaller than the distance from the middle point of the second flexible rod 3123 to the third support rod 3122. Therefore, the distance X' moved downward by the second support rod 3121 is smaller than the distance X" moved downward by the middle point of the second flexible rod 3123, thereby amplifying the distance X' moved by the two ends of the first flexible rod 3112 toward the side close to the fixed platform 1, thereby further amplifying the moving stroke of the piezoelectric ceramic driver 4.

[0038] Based on the above technical solution, the flexible guiding mechanism 32 includes a connecting rod 321 and a "C"-shaped third flexible rod 322. One end of the connecting rod 321 is connected to the lever amplification mechanism 31, and the other end is connected to the midpoint of the third flexible rod 322. The free end of the third flexible rod 322 is connected to the moving platform 2. The third flexible rod 322 can play a role in deformation. When the lever amplification mechanism 31 moves the moving platform 2 in the direction of the lever amplification mechanism 31, except for the flexible guiding mechanism 32 corresponding to the lever amplification mechanism 31, the other flexible guiding mechanisms 32 are deformed, so as to keep the position of the moving platform 2 relative to the fixed platform 1 in other directions unchanged.

[0039] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated examples here.

Claims

1. A long-travel, two-degree-of-freedom, compliant precision positioning platform capable of achieving motion decoupling, characterized in that: include: Set platform (1); A movable platform (2) connected to the fixed platform (1) via a plurality of translation mechanisms (3); A plurality of piezoelectric ceramic drivers (4), the plurality of piezoelectric ceramic drivers (4) being arranged corresponding to the plurality of translation mechanisms (3), the piezoelectric ceramic drivers (4) applying external force to the translation mechanism (3) to move it, and the translation mechanism (3) moving a distance greater than the distance the piezoelectric ceramic drivers (4) extend or retract; The fixed platform (1) is in a circular ring structure, and the piezoelectric ceramic driver (4) is fixed inside the fixed platform (1); The movable platform (2) is a circular structure, and the fixed platform (1) and the movable platform (2) are a nested structure; There are four translation mechanisms (3), and the four translation mechanisms (3) are evenly spaced and distributed along the periphery of the moving platform (2); The translation mechanism (3) includes a lever amplification mechanism (31) and a flexible guide mechanism (32), wherein the lever amplification mechanism (31) drives the flexible guide mechanism (32) to move, thereby causing the moving platform (2) to move; The lever amplification mechanism (31) includes a primary lever assembly (311) and a secondary lever assembly (312); the piezoelectric ceramic driver (4) applies force to the primary lever assembly (311), causing the primary lever assembly (311) to move toward a side close to the fixed platform (1), thereby driving the secondary lever assembly (312) to move toward a side close to the fixed platform (1); The first-stage lever assembly (311) includes a pair of first support rods (3111) and a first flexible rod (3112). The pair of first support rods (3111) are fixed horizontally and parallel to the inner side of the fixed platform (1) and are distributed on both sides of the piezoelectric ceramic driver (4). The free ends of the pair of first support rods (3111) are fixed to the first flexible rod (3112). When the piezoelectric ceramic driver (4) applies a force to the first flexible rod (3112), the two ends of the first flexible rod (3112) respectively move toward a side close to the fixed platform (1). The distance between the piezoelectric ceramic driver (4) and the first support rod (3111) is smaller than the distance between the piezoelectric ceramic driver (4) and the end point of the first flexible rod (3112); The secondary lever assembly (312) includes a pair of second support rods (3121), a pair of third support rods (3122), and a second flexible rod (3123); a pair of second support rods (3121) are fixed to both ends of the first flexible rod (3112); a pair of third support rods (3122) are distributed on both outer sides of the pair of second support rods (3121) and fixed on the fixed platform (1); the pair of first support rods (3111), the pair of second support rods (3121), and the pair of third support rods (3122) are parallel to each other; the free ends of the pair of second support rods (3121) and the free ends of the pair of third support rods (3122) are fixed to the second flexible rod (3123); and the second flexible rod (3123) is connected to the flexible guide mechanism (32); The distance from the second support rod (3121) to the third support rod (3122) is less than the distance from the midpoint of the second flexible rod (3123) to the third support rod (3122); The flexible guiding mechanism (32) includes a connecting rod (321) and a "C"-shaped third flexible rod (322). One end of the connecting rod (321) is connected to the lever amplification mechanism (31), and the other end is connected to the midpoint of the third flexible rod (322). The free end of the third flexible rod (322) is connected to the moving platform (2).

Images