3T2R high-precision positioning platform based on linear driving

Abstract

The invention provides a 3T2R high-precision positioning platform based on linear driving, which can provide translation capability and rotation capability for a movable platform and increase the application field of a flexible mechanism. The four flexible branch chains of the same structure are symmetrically arranged based on the movable platform, the movable platform is driven to move through the four flexible branch chains of the same structure, and compared with an existing technical scheme, the motion control precision is improved; according to the scheme, Z-axis driving below the movable platform is omitted, the translational freedom degree of the movable platform in the X direction, the Y direction and the Z direction can be achieved through driving of the four T-shaped flexible branch chains, the structure of the flexible platform is optimally designed, the probability of structural failure is reduced, the difficulty of troubleshooting is also reduced once a failure occurs, and the scheme is more practical.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flexible mechanism, in particular to a 3T2R high-precision positioning platform based on linear drive. BACKGROUND

[0002] With the continuous progress of precision machining technology, precision positioning platforms play an increasingly important role in high-precision displacement control, micro-nano manufacturing, three-dimensional imaging and scanning of atomic force microscopes, and other fields. To meet the requirements of high-precision machining, flexible mechanisms are often used as transmission devices for precision positioning platforms. Compared with traditional rigid mechanisms, the design of flexible mechanisms does not require friction pairs or hinges, reducing friction, clearance and wear, and thus they have significant advantages in terms of motion accuracy and reliability. With the continuous improvement of the configuration design theory of flexible mechanisms, new high-precision precision positioning platforms are constantly emerging. For example, patent document with application number CN202010776549.5 discloses a micro-positioning platform based on a 2T3R type flexible kinematic pair, and patent document with application number CN202411439732.0 discloses a high-precision positioning platform based on a flexible kinematic pair. Both of these technical solutions have a driving pair in the Z-axis direction arranged under the moving platform, and the overall structure is relatively complex. When these two solutions are applied, such as in the field of micro-sculpture, the sculpting tool is moved by the moving platform, which can only perform spatial translation, but cannot perform rotation. This significantly limits the application field of flexible mechanisms. SUMMARY

[0003] To solve the problem that existing high-precision positioning platforms only have spatial translation capability and lack spatial rotation freedom, resulting in limited application scenarios, the present application provides a 3T2R high-precision positioning platform based on linear drive, which can provide translation and rotation capabilities for the moving platform, increasing the application field of flexible mechanisms.

[0004] The technical solution of the present application is as follows: a 3T2R high-precision positioning platform based on linear drive, comprising: a base, a cross-shaped moving platform, and four flexible branches; the four flexible branches are symmetrically distributed around the cross-shaped moving platform and located inside the base; characterized in that: the flexible branch is T-shaped, and the flexible branch comprises: a connecting module and three flexible kinematic pairs, the three flexible kinematic pairs are respectively fixedly connected with the connecting module to form a T-shaped structure; the four branches of the cross-shaped moving platform are respectively connected with one connecting module; the flexible kinematic pair comprises: a flexible rod, a kinematic pair frame, a rigid connecting piece one, a rigid connecting piece two, a rigid connecting piece three, and a piezoelectric ceramic actuator; The rigid connecting piece three constitutes the first end of the flexible kinematic pair and is fixedly connected with the driving end of the piezoelectric ceramic actuator, and the bottom end of the piezoelectric ceramic actuator is fixedly connected with the kinematic pair base; The kinematic pair frame comprises a rectangular kinematic pair base and a supporting rigid rod, and one supporting rigid rod is arranged at each of the four vertices of the kinematic pair base; Four rigid connecting pieces two are arranged around the rigid connecting piece three; The rigid connecting piece one is arranged around the rigid connecting piece three and below the rigid connecting piece three, and each rigid connecting piece one is connected with the rigid connecting piece three through one driving connecting flexible rod; The rigid connecting piece one is a rectangular plate, and the bottom end of each flexible rod is connected with one vertex of the rigid connecting piece one; among the flexible rods connected with each vertex of the rigid connecting piece one, two flexible rods on the outer vertices are connected with the kinematic pair frame, and two flexible rods on the inner vertices are connected with the rigid connecting piece two; each rigid connecting piece one is connected with two adjacent rigid connecting pieces two; The rigid connecting piece two constitutes the end of the flexible kinematic pair and is connected with the moving platform through the connecting module.

[0005] Further features are as follows: The rigid connecting piece three is in the shape of a cross, the rigid connecting piece two is in the shape of a cuboid, and four rigid connecting pieces two and four branches of the rigid connecting piece three are arranged in the shape of a Chinese character; A gap is left between the rigid connecting piece two and the rigid connecting piece three, and the top surface of the rigid connecting piece two is higher than the top surface of the rigid connecting piece three; One rigid connecting piece one is arranged below each branch of the cross-shaped rigid connecting piece three; and the two ends of the flexible rods connecting the two are connected with the midpoint of the edge of the rigid connecting piece three and one branch of the cross-shaped rigid connecting piece three; The kinematic pair frame further comprises an L-shaped frame connecting piece; one end of the supporting rigid rod is connected with the vertex of the kinematic pair base, and the other end is connected with the intersection of the L-shaped frame connecting piece; Among the four flexible rods connected with each rigid connecting piece one, the top ends of the two flexible rods on the outer side are connected with one adjacent frame connecting piece; The base comprises a bottom plate arranged horizontally and four vertical support columns, and the four support columns are arranged in a rectangular shape; the bottom ends of the support columns are fixedly connected with the bottom plate; The support columns are parallel to the flexible kinematic pair in the vertical position in the T-shaped flexible branch; The pillar is integrally made with the bottom plate, a threaded hole is formed on the side surface of the pillar, a through hole corresponding to the threaded hole is formed in the pair of kinematic pairs, and the flexible kinematic pairs are fixedly connected with the pillar by screwing a screw in the threaded hole through the through hole. The twenty flexible rods, the first rigid connecting piece, the second rigid connecting piece and the third rigid connecting piece are integrally made.

[0006] The application provides a 3T2R high-precision positioning platform based on linear driving, four flexible branch chains with the same structure are symmetrically arranged on a moving platform, and the four flexible branch chains are used to drive the movement of the moving platform, so that the control precision of movement is improved compared with prior art solutions; the Z-axis driving under the moving platform is cancelled in the application, the four T-shaped flexible branch chains are used to drive, the translational freedom degrees of the moving platform in X, Y and Z directions are realized, the flexible platform structure is optimized, the probability of structural failure is reduced, and the difficulty of troubleshooting is reduced once the failure occurs, so that the application is more practical. Based on the structure of the application, when the movement directions of the flexible branch chains connected to the two ends of the straight line on the cross-shaped moving platform are opposite along a certain axis direction, the moving platform obtains rotational movement based on the axis, the application can convert the linear driving input of the flexible kinematic pair into the rotational output of the moving platform, so that the rotational freedom degree is obtained. The application can make the moving platform have translational ability and rotational ability at the same time through linear driving, and the application of the platform in multifunctional and high-integration application scenarios is promoted and applied. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 It is a schematic view of the overall structure of the positive equal measurement viewing angle of the application; Figure 2 It is a schematic view of the branch chain structure of the positive equal measurement viewing angle of the application; Figure 3 It is a schematic view of the kinematic pair structure of the positive equal measurement viewing angle of the application; Figure 4 It is a Z-direction movement trend graph of the new kinematic pair; Figure 5 It is an X, Y-direction movement trend graph of the new kinematic pair; Figure 6 It is an R-X, R-Y rotation trend graph of the application from the front view; Figure 7 It is an R-X, R-Y rotation trend graph of the application from the positive equal measurement view; Figure 8 It is a comparison simulation example of five kinds of movements.

[0008] Among them, 1-base; 11-base plate; 12-support column; 2-moving platform; 3-flexible branch chain; 31-connecting module; 32-flexible kinematic pair; 321-flexible rod; 322-rigid connector one; 323-rigid connector two; 324-rigid connector three; 325-kinematic pair frame; kinematic pair base 3251; 3252 supporting rigid rod; 3253 frame connector; 326-piezoelectric ceramic actuator. Detailed Implementation

[0009] like Figures 1-8 As shown, the present invention includes a 3T2R high-precision positioning platform based on linear drive, which includes: a base 1, a cross-shaped moving platform 2 and four flexible branches 3; the four flexible branches 3 are symmetrically distributed in pairs around the cross-shaped moving platform 2 and located inside the base 1.

[0010] The flexible branch 3 is T-shaped and includes a connecting module 31 and three flexible kinematic pairs 32. The three flexible kinematic pairs 32 are respectively fixed to the connecting module 31 to form a T-shaped structure; the four branches of the cross-shaped moving platform 2 are respectively connected to a connecting module 31.

[0011] In this design, the flexible branch 3 consists of three flexible kinematic pairs 32. The beginning ends of the three flexible kinematic pairs 32 are connected to the connecting module 31, and their ends are connected to the base 1 respectively. Figure 1 As shown, three flexible kinematic pairs 32 are arranged in a triangular pattern around the connecting module 31. Two of the three flexible kinematic pairs are arranged horizontally on both sides of the connecting module, and one is arranged vertically below the connecting module. One end of the connecting module 31 is connected to the moving platform 2.

[0012] The flexible kinematic pair 32 includes: a flexible rod 321, a rigid connector 1 322, a rigid connector 2 323, a rigid connector 324, a kinematic pair frame 325, and a piezoelectric ceramic actuator 326.

[0013] The motion pair frame 325 includes: a rectangular motion pair base 3251, a supporting rigid rod 3252, and an L-shaped frame connector 3253. A supporting rigid rod 3252 is provided at each of the four vertices of the motion pair base 3251. The motion pair base 3251 is connected to the base 1.

[0014] The rigid connector 324 forms the head end of the flexible kinematic pair 32 and is fixedly connected to the drive end of the piezoelectric ceramic actuator 326. The bottom end of the piezoelectric ceramic actuator 326 is fixedly connected to the kinematic pair base 3251.

[0015] Four rigid connectors 2 323 are arranged around rigid connector 3 324.

[0016] Specifically, the rigid connecting piece three 324 is cross-shaped, the rigid connecting piece two 323 is cuboid structure, and the four rigid connecting piece twos 323 and the four branches of the rigid connecting piece three 324 form a herringbone-shaped arrangement; a gap is left between the rigid connecting piece two 323 and the rigid connecting piece three 324, so that the rigid connecting piece two 323 moves in the moving pair X, Y direction; the top surface of the rigid connecting piece two 323 is higher than the top surface of the rigid connecting piece three 324, and a margin is left for the error of input and output displacement to prevent mutual collision between components. The driving end of the piezoelectric ceramic actuator 326 is connected with the rear end surface of the rigid connecting piece three 324 in the flexible moving pair 32. The flexible moving pair 32 in the application has compact structure, can prevent structural collision and is convenient for processing and manufacturing.

[0017] The rigid connecting piece one 322 surrounds the rigid connecting piece three 324 and is arranged below the rigid connecting piece three 324; each rigid connecting piece one 322 is connected with the rigid connecting piece three 324 through a driving connecting flexible rod 321.

[0018] The rigid connecting piece one 322 is a rectangular plate, and one bottom end of a flexible rod 321 is connected with each vertex; among the flexible rods 321 connected with each vertex of each rigid connecting piece one 322, the two on the outside are connected with the moving pair frame 325, and the two on the inside are connected with the rigid connecting piece two 323; each rigid connecting piece one 322 is connected with two adjacent rigid connecting piece twos 323.

[0019] The rigid connecting piece two 323 constitutes the end of the flexible moving pair 32 and is connected with the moving platform 2 through the connecting module 31.

[0020] Specifically, one rigid connecting piece one 322 is arranged below each branch of the cross-shaped rigid connecting piece three 324; the two ends of the flexible rod 321 connecting the two are connected with the midpoint position of the rectangular edge of the rigid connecting piece three 324 and one branch of the cross-shaped rigid connecting piece three 324 respectively. One end of the supporting rigid rod 3252 is connected with the vertex of the moving pair base 3251, and the other end is connected with the intersection of the L-shaped frame connecting piece 3253. Among the four flexible rods 321 connected with each rigid connecting piece one 322, the top ends of the two flexible rods 321 on the outside are connected with an adjacent frame connecting piece 3253 respectively.

[0021] As Figure 2 and Figure 3As shown, each flexible kinematic pair 32 includes twenty parallel flexible rods 321, and five flexible rods 321 are respectively arranged on each rigid connector 322. The upper ends of the eight flexible rods 321 arranged symmetrically on the outer side of the kinematic pair are fixed to the frame connector 3253 in the kinematic pair frame, and the lower ends are connected to the rigid connector 322. Among the remaining twelve flexible rods 321: the eight outer flexible rods are connected to the rigid connector 323, which constitutes the end of the flexible kinematic pair and is fixed to the moving platform through the connecting module 31; the top ends of the four middle flexible rods 321 are connected to the rigid connector 324, which constitutes the beginning of the flexible kinematic pair and is fixed to the piezoelectric ceramic actuator 326. The piezoelectric ceramic actuator 326 is fixed on the kinematic pair base 3251 of the kinematic pair frame.

[0022] In this design, the flexible kinematic pair 32 consists of twenty flexible rods 321, rigid connector 1 322, rigid connector 2 323, and rigid connector 324, all integrally manufactured to ensure no assembly errors and improve the accuracy and service life of the mechanism.

[0023] The base 1 includes a horizontally arranged base plate 11 and four longitudinally arranged support columns 12, which are integrally formed with the base plate 11. The four support columns 12 are rectangularly distributed, and the lower ends of the support columns 12 are fixed to the base plate 11; the support columns 12 are parallel to the flexible kinematic pairs 32 located in the vertical position within the T-shaped flexible branch chain 3. Figure 1 As shown, the support column 12 is arranged vertically, and the flexible kinematic pairs in the T-shaped flexible chain 3 are arranged in parallel in the vertical direction.

[0024] When the kinematic pair and the base 1 are connected, they are connected by bolts. For example, the support column 12 has a threaded hole on its side (not marked in the figure), and the kinematic pair base 3251 has a through hole corresponding to the threaded hole. After the screw is passed through the through hole, it is screwed into the threaded hole to fix the flexible kinematic pair 32 to the support column 12.

[0025] like Figure 1 As shown, the four branches of the cross-shaped moving platform 2 are each connected to a flexible branch 3. Each flexible branch 3 includes three flexible kinematic pairs 32 in a T-shape. When the four flexible kinematic pairs 32 located in the Z-axis direction (i.e., the four flexible kinematic pairs 32 in the vertical direction) move downwards simultaneously as active pairs, and the remaining kinematic pairs follow suit, the moving platform 2 moves downwards.

[0026] There are two flexible branches 3 along the x-axis, and each flexible branch 3 contains two flexible kinematic pairs 32 located on the x-axis. When all four flexible kinematic pairs 32 on the x-axis of the two flexible branches 3 move in the same direction along the x-axis simultaneously, and the other flexible kinematic pairs 32 on the y-axis and z-axis act as passive pairs, the two connecting modules 31 on the x-axis can move the moving platform 2 in translational motion along the x-axis. Similarly, there are also two flexible branches 3 along the y-axis. When all four flexible kinematic pairs 32 on the y-axis move in the same direction along the y-axis simultaneously, and the flexible kinematic pairs on the x-axis and z-axis act as passive pairs, the two connecting modules 31 on the y-axis can move the moving platform 2 in translational motion along the y-axis.

[0027] The flexible kinematic pair 32 in this application can be used as a passive pair or an active pair. Figure 4 The Z-axis motion trend diagram for the novel kinematic pair; Figure 5 The X and Y direction motion trend diagrams for the novel kinematic pair; Figure 4 and Figure 5 In order to clearly see the relationship between the components, the connecting module 31 is scaled down and displayed together with the rigid connector 323.

[0028] Combination Figure 3 , Figure 4 As shown, when the flexible kinematic pair 32 acts as the active pair, the piezoelectric ceramic actuator 326 inputs displacement to transmit force to the rigid connector 324. The rigid connector 324 transmits force to the rigid connector 1 322 through the four intermediate flexible rods 321 connected to it. The rigid connector 1 322 transmits force to the rigid connector 2 323 through the eight outer flexible rods 321 connected to it, and finally to the moving platform 2. The bending deformation generated by the eight outer flexible rods 321 connected to the rigid connector 1 322 is converted into the platform movement of the moving platform 2. Figure 4 The state in the middle is that the connecting module 31 is moving in the positive Z-axis direction, that is, upward.

[0029] Combination Figure 3 , Figure 5 As shown, when the new kinematic pair 32 is used as a passive pair, the moving platform 2 transmits the force to the rigid connector 2 323 based on the displacement input by the connection module 31. The rigid connector 2 323 transmits the force to the rigid connector 1 322 through the eight flexible rods 321 connected to it in the middle periphery. The rigid connector 1 322 transmits the force to the eight flexible rods 321 connected to it in the outer periphery. Since the undesired movement of the rigid connector 3 324 is suppressed, the force is also transmitted to the four flexible rods 321 connected to it in the middle, which eventually causes the corresponding flexible rods 321 to deform with the moving platform.

[0030] When the platform translates (i.e., moves along the X, Y, and Z directions), combined with Figure 1 ,Figure 3 As shown, when the platform translates along the X direction, the four flexible kinematic pairs 32 driven along the Y direction and the four flexible kinematic pairs 32 driven along the Z direction are all passive pairs and do not provide drive; while the four flexible kinematic pairs 32 driven along the X direction are all active pairs, and the four drive in the same direction along the X-axis, thereby causing the platform to move along the X direction. The same principle applies when the platform translates along the Y and Z directions.

[0031] like Figure 1 As shown, among the four flexible branches 3, there are four flexible kinematic pairs 32 located in the z-axis direction. Two of the flexible kinematic pairs 32 are located on one straight line, and the other two are located on another straight line. Figure 7 The two z-axis kinematic pairs corresponding to connecting modules 31a and 31b are located on the same straight line; connecting modules 31c and 31d are also located on the same straight line. The two z-axis kinematic pairs located on the same straight line are grouped together. One group is designated as the active pair, and the other as the passive pair. Meanwhile, all other kinematic pairs in the x and y axes are designated as passive pairs. If all z-axis flexible kinematic pairs 32 move in the same direction, the moving platform 2 can be moved in the z-axis direction. However, if the two z-axis flexible kinematic pairs 32 in the active pair move in opposite directions, i.e.... Figure 7 In the example shown, connecting module 31a moves vertically upwards, while connecting module 31b moves vertically downwards. If connecting modules 31a and 31b move at the same speed, then the moving platform 2 rotates about the line containing connecting modules 31c and 31d. If connecting modules 31a and 31b move at different speeds, the moving platform will still rotate, but the axis of rotation will leave the plane containing the moving platform.

[0032] The four flexible kinematic pairs 32 in the x-axis direction are located on two flexible branches 3, and the four flexible kinematic pairs 32 in the y-axis direction are located on two other flexible branches 3. If all the flexible kinematic pairs 32 in the y-axis and x-axis not only move along the x-axis or y-axis direction, but also simultaneously move in the same direction clockwise or counterclockwise, theoretically, the moving platform 2 could rotate around the Z-axis. In flexible motion, the micro-motion of the connecting module 31 is the result of the cumulative micro-motion of the flexible components. However, because each connecting module 31 in the x-axis or y-axis direction is simultaneously connected to two opposing flexible kinematic pairs 32 in the structure of this application, the micro-motion generated in either the clockwise or counterclockwise direction is too weak to generate a sufficient rotational angle for practical applications. Therefore, the rotations usable in practical applications are limited to the RX and RY degrees of freedom.

[0033] When the platform rotates (i.e., rotates along both the RX and RY directions), combined with Figure 1 , Figure 3 , Figure 6 , Figure 7 As shown, when the platform rotates around the X direction, the eight flexible kinematic pairs 32 driven along the X and Y directions in the platform all act as passive pairs and do not provide drive. Among the four flexible kinematic pairs 32 below the connecting module 31 that drive along the Z direction, the two flexible kinematic pairs 32 on the same X axis also act as passive pairs and do not provide drive, while the two flexible kinematic pairs 32 on the same Y axis act as driving pairs. They drive in opposite directions along the Z axis, one up and one down, thus causing the platform to rotate. The same principle applies when the platform rotates around the Y direction.

[0034] By using the technical solution of this invention, compared with the prior art, the Z-axis drive pair below the moving platform 2 is eliminated, and the Z-axis drive is distributed to four flexible kinematic pairs 32. Since no structure needs to be designed below the moving platform 2, the moving platform 2 is more flexible in the height direction in practical applications. This solution optimizes the design of the flexible platform structure, so that the moving platform 2 can realize translational degrees of freedom in the X, Y, and Z directions, and also uses the linear drive input of the flexible kinematic pairs to convert into rotational output of the moving platform 2, so that the moving platform 2 can obtain two rotational degrees of freedom, RX and RY.

[0035] For a flexible micro-positioning platform, natural frequencies are an important dynamic characteristic, reflecting the platform's vibration response when subjected to external excitation. Through mathematical modeling and simulation, the technical solution of this application was cross-validated, and the overall trend of the theoretical and simulated values ​​was smooth and consistent. It can be proven that the first five natural frequencies and the sixth natural frequency of the dynamic platform 2 constructed in this scheme have a clear frequency distribution distinction. Simulation results show that the platform has only five vibration modes, including three translational modes and two rotational modes, thus proving that the dynamic platform 2 has 3T2R degrees of freedom. The motion of the 5 degrees of freedom is as follows... Figure 8 As stated above, the simulation in this application is based on the software Abaqus. In the displacement examples in the figure, the order of displacements is such that the higher the color, the greater the displacement. The color map corresponding to the displacement in each mode is arranged from top to bottom according to color. The specific displacement values ​​are slightly different in each modal example.

[0036] Within a driving displacement range of 1 mm, the loss of translational motion along the X, Y, and Z directions is less than 1%. The rotational driving force along the RX and RY directions is slightly greater than the translational driving force along the X, Y, and Z directions, and both are controlled within a small range. This proves that the moving platform 2 has a large stroke, high precision, and 3T2R degrees of freedom.

Claims

1. A linear drive based 3T2R high precision positioning platform comprising: A base, a cross-shaped moving platform and four flexible chains; the four flexible chains are symmetrically distributed around the cross-shaped moving platform and located in the base; In the flexible chain, the flexible chain is T-shaped, and the flexible chain comprises a connecting module and three flexible kinematic pairs, and the three flexible kinematic pairs are fixedly connected with the connecting module to form a T-shaped structure; four branches of the cross-shaped moving platform are respectively connected with one connecting module; The flexible kinematic pair comprises a flexible rod, a kinematic pair frame, a rigid connecting piece one, a rigid connecting piece two, a rigid connecting piece three and a piezoelectric ceramic actuator; The rigid connecting piece three constitutes a first end of the flexible kinematic pair and is fixedly connected with a driving end of the piezoelectric ceramic actuator, and a bottom end of the piezoelectric ceramic actuator is fixedly connected on a kinematic pair base; The kinematic pair frame comprises a rectangular kinematic pair base and a supporting rigid rod, four vertices of the kinematic pair base are respectively provided with one supporting rigid rod, and the kinematic pair base is connected with the base; The four rigid connecting piece twos are arranged around the rigid connecting piece three; The rigid connecting piece one is arranged around the rigid connecting piece three and below the rigid connecting piece three; each rigid connecting piece one is connected with the rigid connecting piece three through one driving connecting flexible rod; The rigid connecting piece one is a rectangular plate, and the bottom end of each flexible rod is connected with one vertex of the rigid connecting piece one; among the flexible rods connected with each vertex of the rigid connecting piece one, two flexible rods on the outer vertices are respectively connected with the kinematic pair frame, and two flexible rods on the inner vertices are respectively connected with the rigid connecting piece two; each rigid connecting piece one is connected with two adjacent rigid connecting piece twos; The rigid connecting piece two constitutes a last end of the flexible kinematic pair and is connected with the moving platform through the connecting module.

2. The linear drive based 3T2R high-precision positioning platform according to claim 1, characterized in that: The rigid connecting piece three is cross-shaped, the rigid connecting piece two is a cuboid structure, and four rigid connecting piece twos and four branches of the rigid connecting piece three form a rice-shaped arrangement; A gap is left between the rigid connecting piece two and the rigid connecting piece three, and the top surface of the rigid connecting piece two is higher than the top surface of the rigid connecting piece three.

3. The linear drive based 3T2R high-precision positioning platform according to claim 2, characterized in that: One rigid connecting piece one is arranged below each branch of the cross-shaped rigid connecting piece three; the two ends of the flexible rod connecting the two are respectively connected with the midpoint position of the rectangular edge of the rigid connecting piece three and one branch of the cross-shaped rigid connecting piece three.

4. The linear drive based 3T2R high-precision positioning platform according to claim 1, characterized in that: The kinematic pair frame further comprises an L-shaped frame connecting piece; one end of the supporting rigid rod is connected with the vertex of the kinematic pair base, and the other end is connected with the intersection of the L-shaped frame connecting piece; Among the four flexible rods connected with each rigid connecting piece one, the top ends of the two flexible rods on the outer side are respectively connected with one adjacent frame connecting piece.

5. The linear drive based 3T2R high-precision positioning platform according to claim 1, characterized in that: The base comprises a horizontally arranged bottom plate and four vertically arranged supporting columns, the four supporting columns are arranged in a rectangular shape, and the bottom ends of the supporting columns are fixedly connected with the bottom plate.

6. The linear drive based 3T2R high-precision positioning platform according to claim 1, characterized in that: The supporting columns are parallel to the flexible kinematic pair in the vertical position of the T-shaped flexible chain.

7. The linear drive based 3T2R high-precision positioning platform according to claim 1, characterized in that: The support is integrally formed with the bottom plate, and a threaded hole is formed in the side surface of the support. A through hole is formed in the pair of motion pair bases corresponding to the threaded hole. A screw is screwed in the threaded hole through the through hole to fix the flexible motion pair with the support.

8. The linear drive based 3T2R high-precision positioning platform according to claim 1, characterized in that: In the flexible motion pair, the twenty flexible rods, the first rigid connecting piece, the second rigid connecting piece and the third rigid connecting piece are integrally formed.

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