A two-dimensional motion platform

Abstract

The present invention provides a two-dimensional motion platform, including a horizontally arranged carrier plate, a driving module for driving the carrier plate to move, a supporting module for supporting the carrier plate, and a control module for controlling the movement of the driving module. The carrier plate is horizontally arranged above the driving module and the supporting module, the carrier plate and the driving module are rigidly connected, and the carrier plate and the supporting module are flexibly hinged. By setting two guide modules, the driving module and the supporting module, to form a differential system, the motion stroke is effectively improved while ensuring the motion accuracy, and high precision and large stroke can be achieved at the same time. At the same time, the various parts of the motion platform are modularized according to function, the motion guide elements are modularized into the driving module and the supporting module; the working carrier plane of the motion platform is modularized into the carrier plate part, each module is a universal component, and some modules can be added or reduced as needed, and the flexibility of secondary development is good.

Description

Technical Field

[0001] The invention relates to a precision platform, in particular to a two-dimensional motion platform. Background Art

[0002] High-precision two-dimensional motion platforms are widely used in various high-precision measurement and processing systems, such as coordinate measuring machines, microscopes, surface profilers, lithography machines, and 3D printing equipment.

[0003] In order to meet high-precision requirements, existing two-dimensional motion platforms usually need to sacrifice moving stroke. Their motion accuracy is heavily dependent on high-precision reference components, such as guide rails and guide planes. The introduction of a large number of guide components easily forms an over-constrained system. In an over-constrained system, in order to avoid the "stuck" phenomenon, the parallelism, coplanarity and other geometric accuracy parameters of the same-direction guide components must be strictly ensured, which makes the assembly and adjustment process of the entire system very complicated.

[0004] In addition, most of the existing two-dimensional motion platforms adopt a self-contained design. After the platform is delivered for use, it is difficult for users to modify its structure. This feature greatly limits the flexibility of secondary development of the system.

[0005] In view of this, the applicant conducted an in-depth study on the structure of a high-precision two-dimensional motion platform, which resulted in this case. Summary of the invention

[0006] The object of the present invention is to provide a two-dimensional motion platform capable of achieving high precision and long travel at the same time.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A two-dimensional motion platform comprises a horizontally arranged carrier plate, a driving module for driving the carrier plate to move, a supporting module for supporting the carrier plate, and a control module for controlling the movement of the driving module, wherein the carrier plate is horizontally arranged above the driving module and the supporting module, the carrier plate and the driving module are rigidly connected, and the carrier plate and the supporting module are flexibly hinged.

[0009] As an improvement of the present invention, the driving module includes a Y-axis linear translation stage and an X-axis linear translation stage installed on the upper surface of the Y-axis linear translation stage, the neutral line of the movement direction of the Y-axis linear translation stage and the neutral line of the movement direction of the X-axis linear translation stage are arranged perpendicular to each other, the Y-axis linear translation stage and the X-axis linear translation stage are both communicatively connected to the control module, and the loading plate is rigidly connected to the upper surface of the X-axis linear translation stage.

[0010] As an improvement of the present invention, the object carrier plate and the upper surface of the X-axis linear translation stage are connected by bolts or welded to each other.

[0011] As an improvement of the present invention, the supporting module includes a Y-axis linear slide rail arranged parallel to the neutral line of the movement direction of the Y-axis linear translation stage and an X-axis linear slide rail arranged parallel to the neutral line of the movement direction of the X-axis linear translation stage. The number of the Y-axis linear slide rails is the same as the number of the X-axis linear slide rails and they are matched one to one. Among the mutually matched Y-axis linear slide rails and the X-axis linear slide rails, the X-axis linear slide rail is arranged on the slide rail surface of the Y-axis linear slide rail, and the loading plate is flexibly hinged on each of the X-axis linear slide rails.

[0012] As an improvement of the present invention, the sliding strokes of the Y-axis linear slide rail and the X-axis linear slide rail are the same and are both greater than the moving strokes of the Y-axis linear translation stage and the X-axis linear translation stage.

[0013] As an improvement of the present invention, the rail surface of each of the X-axis linear rails is respectively provided with a ball-and-socket connection block, and the loading plate is provided with a ball head thread pair that matches each of the ball-and-socket connection blocks one-to-one.

[0014] As an improvement of the present invention, an optical flat crystal is placed on the upper surface of the carrier plate.

[0015] As an improvement of the present invention, a through hole is provided in the middle of the loading plate.

[0016] By adopting the above technical solution, the present invention has the following beneficial effects:

[0017] 1. By setting up two guide modules, the driving module and the supporting module, a differential system is formed, which effectively improves the motion stroke while ensuring the motion accuracy, and can achieve high precision and large stroke at the same time.

[0018] 2. The various parts of the motion platform are modularized according to their functions. The motion guide elements are modularized into drive modules and support modules. The working load plane of the motion platform is modularized into the load plate part. All modules are universal components, and some modules can be added or removed as needed, which has good flexibility in secondary development.

[0019] 3. Only one rigid connection is introduced between the driving module and the loading plate of the motion platform, and the rest are flexible hinges, realizing a zero-time over-constraint design, which is not prone to jamming and the system assembly and adjustment process is relatively simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a two-dimensional motion platform in an embodiment;

[0021] Figure 2 It is a structural schematic diagram of a support module of a two-dimensional motion platform in an embodiment;

[0022] Figure 3 A schematic diagram of the connection between the ball and socket connection block and the ball head thread pair that cooperate with each other in the embodiment;

[0023] Figure 4 It is a schematic diagram of a mechanical model of four components and six guide rails in the embodiment;

[0024] Figure 5 It is a schematic diagram of a mechanical model of six components, six guide rails and two hinges in the embodiment;

[0025] Figure 6 for Figure 5 Schematic diagram after projection onto the reference plane.

[0026] Some parts are omitted in the above figure, and the corresponding parts are marked as follows:

[0027] 10-substrate plate; 11-perforation;

[0028] 12-through hole; 13-ball thread pair;

[0029] 14-optical flat crystal; 20-driving module;

[0030] 21-Y-axis linear translation stage; 22-X-axis linear translation stage;

[0031] 30-support module; 31-Y-axis linear guide rail;

[0032] 32-X-axis linear guide rail; 33-ball and socket connection block.

[0033] 40-Control module. DETAILED DESCRIPTION

[0034] The invention will be further described below in conjunction with specific embodiments:

[0035] The two-dimensional motion platform provided in this embodiment is a high-precision, long-travel and easy-to-assemble two-dimensional motion platform, and is also an easy-to-build modular high-precision two-dimensional motion platform that can be applied to various high-precision measurement and processing systems, such as three-coordinate measuring machines, microscopes, surface profilers, lithography machines, and 3D printing equipment.

[0036] like Figure 1-Figure 3 As shown, the two-dimensional motion platform provided in this embodiment includes a horizontally arranged carrier plate 10, a driving module 20 for driving the carrier plate 10 to move, a supporting module 30 for supporting the carrier plate 10, and a control module 40 for controlling the movement of the driving module 20, wherein the control module 40 is a conventional module that can be purchased directly from the market, is not the focus of this embodiment, and will not be described in detail here.

[0037] The carrier plate 10 is arranged horizontally above the driving module 20 and the supporting module 30, and the driving module 20 and the supporting module 30 are preferably located at positions corresponding to the front half and the rear half of the carrier plate 10, or at positions corresponding to the left half and the right half of the carrier plate 10, respectively. The carrier plate 10 and the driving module 20 are rigidly connected, and the carrier plate 10 and the supporting module 30 are flexibly hinged, and the specific connection structure will be described below. Preferably, an optical flat crystal 14 is placed on the upper surface of the carrier plate 10 as a plane reference to further improve the motion accuracy. In addition, a through hole 11 is opened in the middle position of the carrier plate 10. Since the carrier plate 10 has been lifted up by the driving module 20 and the supporting module 30 to release the space below, the space can be used in conjunction with the through hole 11 to install the processing tools of the processing system or the sensor device of the measuring machine. Specifically, the through hole 11 is a square hole, the diameter of the optical flat crystal 14 is greater than the side length of the square section of the square hole, and the central axis of the optical flat crystal 14 is coaxial with the central axis of the square hole.

[0038] The driving module 20 includes a Y-axis linear displacement stage 21 and an X-axis linear displacement stage 22 installed on the upper surface of the Y-axis linear displacement stage 21, wherein the Y-axis linear displacement stage 21 and the X-axis linear displacement stage 22 are both linear displacement stages that can be directly purchased from the market, the neutral line of the movement direction of the Y-axis linear displacement stage 21 and the neutral line of the movement direction of the X-axis linear displacement stage 22 are arranged perpendicular to each other, and the Y-axis linear displacement stage 21 and the X-axis linear displacement stage 22 are both communicatively connected to the control module 30, and the specific communication connection method can be a conventional method, such as Bluetooth connection or wire connection, etc.; the loading plate 10 is rigidly connected to the upper surface of the X-axis linear displacement stage 22, and the specific rigid connection structure can be a conventional structure, such as welding connection, bolt connection or lock connection, etc. In this embodiment, the upper surface of the loading plate 10 and the X-axis linear displacement stage 22 is connected by bolts or welded to each other as an example for description. The control module 40 can control the driving module 20 to move in the XY plane and try to feedback the movement coordinates of each translation stage. Of course, the XY plane is a horizontal plane, and the X direction and Y direction mentioned in this embodiment refer to two mutually perpendicular directions on the XY plane.

[0039] The support module 30 includes a Y-direction linear guide rail 31 arranged in parallel with the neutral line of the movement direction of the Y-direction linear displacement stage 21 and an X-direction linear guide rail 32 arranged in parallel with the neutral line of the movement direction of the X-direction linear displacement stage 22, that is, the Y-direction linear guide rail 31 and the X-direction linear guide rail 32 are arranged perpendicular to each other, wherein there are more than two Y-direction linear guide rails 31 and more than two X-direction linear guide rails 32, and the number of the Y-direction linear guide rails 31 and the number of the X-direction linear guide rails 32 are the same and matched one to one. In this embodiment, the example of two Y-direction linear guide rails 31 and two X-direction linear guide rails 32 is used for explanation. In the mutually matched Y-direction linear guide rails 31 and X-direction linear guide rails 32, the X-direction linear guide rail 32 is arranged on the guide rail surface of the Y-direction linear guide rail 31. It should be noted that the above-mentioned Y-direction linear guide rails 31 and X-direction linear guide rails 32 are linear guide rails that can be directly purchased from the market. In addition, the sliding strokes of the Y-axis linear guide rail 31 and the X-axis linear guide rail 32 are the same and are both greater than the moving strokes of the Y-axis linear translation stage 21 and the X-axis linear translation stage 22. In this way, the support module 30 can move freely on the XY plane, and the movement range is greater than that of the driving module 20.

[0040] The carrier plate 10 is flexibly hinged on each X-axis linear guide rail 32. Specifically, a ball-and-socket connection block 33 is provided on the surface of each X-axis linear guide rail 32, and a ball-and-socket connection block 33 has a ball socket. Each ball-and-socket connection block 33 is fixed on the corresponding X-axis linear guide rail 32 by a bolted connection structure, and the horizontal plane of each ball-and-socket connection block 33 is lower than the upper surface of the driving module 20. In addition, through holes 12 are respectively provided on the carrier plate 10 at positions corresponding to each ball-and-socket connection block 33, and each through hole 12 is respectively provided with a ball-and-socket thread pair 13 in which a ball head is inserted in a corresponding ball socket, that is, a ball-and-socket thread pair 13 that matches each ball-and-socket connection block 33 one-to-one is provided on the carrier plate 10. It should be noted that before use, the thread needs to be adjusted so that the ball-and-socket thread pair 13 is fully in contact with the corresponding ball socket, and at this time, a gap should be left between the lower surface of the carrier plate 10 and the upper surface of the support module 30.

[0041] When in use, the control module 40 issues a motion command to control the drive module 20 to move according to the command. At this time, the carrier plate 10 moves accordingly, and the supporting module 30 is driven to move through the mutually cooperating ball head thread pair 13 and the ball socket connecting block 33. Since the supporting module 30 does not limit the movement of the carrier plate 10, it only serves to support and stabilize the rental, and thus high-precision two-dimensional large-stroke movement can be achieved.

[0042] The present embodiment is further described below from the perspective of mechanical structure.

[0043] If the flexible hinges in this embodiment are all changed to rigid connections, the two-dimensional motion system formed is similar to the conventional two-dimensional motion system and can be simplified as follows: Figure 4The mechanical structure shown in FIG. 1 is a two-dimensional motion platform. Specifically, the two-dimensional motion platform includes four components, namely, a loading plate 10, a driving module 20, and two groups of Y-axis linear slide rails 31 and X-axis linear slide rails 32 that cooperate with each other. Each component has six original degrees of freedom in three-dimensional space, namely, three linear degrees of freedom of X, Y, and Z and three angular degrees of freedom of rotation around the X, Y, and Z axes, respectively. In addition, the two-dimensional motion platform has six guiding elements, namely, a Y-axis linear displacement table 21, an X-axis linear displacement table 22, two Y-axis linear slide rails 31, and two X-axis linear slide rails 32. Each guiding element can be regarded as a kinematic pair. Since each guiding element only allows linear motion in its guiding direction, five degrees of freedom are constrained, and the system degrees of freedom are:

[0044] Dof = m × 6 - n × 5 = -6

[0045] In the above formula, m is the number of components, and n is the number of guide elements. The calculation result is -6, which means that the motion platform has a high-order super constraint. Only when the X-axis linear displacement table 22 and the two X-axis linear guide rails 32 are strictly arranged in parallel and the Y-axis linear displacement table 21 and the two Y-axis linear guide rails 31 are also strictly parallel, can a virtual constraint be formed, thereby increasing the freedom of the motion platform, which is very difficult in the actual installation process; in addition, when the number of supports increases, the sub-super constraint situation will be more serious, resulting in interference between the various guide elements of the motion platform, resulting in "stuck" phenomenon, or forced deformation of the guide elements;

[0046] In the two-dimensional motion platform provided in this embodiment, since the object carrier 10 has only one rigid connection with the driving module 20 and the rest are flexible hinges, its mechanical structure is as follows: Figure 5 As shown, the two-dimensional motion platform includes six components, namely, a loading plate, a driving module, two ball thread pairs 13, and two sets of Y-axis linear slide rails 31 and X-axis linear slide rails 32 combined components that cooperate with each other. The two-dimensional motion platform includes six guiding elements, namely, a Y-axis linear displacement table 21, an X-axis linear displacement table 22, two Y-axis linear slide rails 31 and two X-axis linear slide rails 32. In addition, there are two flexible hinges, each of which only constrains the three linear degrees of freedom of X, Y, and Z. Then, the system degrees of freedom are:

[0047] Dof = m × 6 - n × 5 - p × 3 = 0

[0048] In the above formula, m is the number of components, n is the number of guide elements, and p is the flexible hinge output. The calculation result is 0. For a two-dimensional motion platform, two degrees of freedom are required, namely, the X and Y degrees of freedom. Therefore, the two-dimensional motion platform provided in this embodiment still has two super constraints, and the two super constraints are released.

[0049] The method for assembling and adjusting the two-dimensional motion platform provided in this embodiment is to place the entire two-dimensional motion platform on a reference plane, such as a horizontal marble plane, and all guide elements only need to be parallel to the reference plane. This method of assembly and adjustment can be completed with only a level or a simple altimeter. When all guide elements are parallel to the reference plane, the mechanical model can be projected onto the reference plane to obtain simplification, such as Figure 6 As shown, each component has 3 degrees of freedom, namely X, Y and one rotational degree of freedom in a plane; each guide element constrains 2 degrees of freedom, retaining only the freedom of motion in the guiding direction; each flexible hinge constrains 2 degrees of freedom, retaining only the rotational degree of freedom in the plane. Substituting the number of components m = 6, the number of guide rails n = 6, and the number of hinges p = 2, the degrees of freedom of the motion platform are:

[0050] Dof = m × 3 - n × 2 - p × 2 = 2

[0051] The motion platform has 2 degrees of freedom, which just meets the two-dimensional plane motion conditions and is a zero-order super-constrained system. In the specific assembly and adjustment process, it is only necessary to ensure that each guide is parallel to the reference plane. The adjustment of line-plane parallelism is very easy to achieve. A level can be used to keep the reference plane and all guide elements horizontal, and an altimeter can be used to adjust several points on the guide element to the same height relative to the reference plane. Each guide element can be placed freely in its own plane parallel to the reference plane. Only rigid connection ends are required in the motion platform, that is, the X-axis linear displacement stage 22 and the Y-axis linear displacement stage 21 are perpendicular to each other to ensure that the XY motion axis of the entire system is vertical.

[0052] Furthermore, when there are more than two moving components in the driven support module 3, each time a moving component is introduced, two components, two guide rails and one hinge are introduced, that is, Figure 6 In the mechanical model shown, m = 2, n = 2, p = 1. Then the newly added degree of freedom of the motion platform is:

[0053] Δ DoF =m×3-n×2-p×2=0

[0054] This indicates that the introduction of new motion components in the support module 30 will not bring about a change in the degrees of freedom of the motion platform, and therefore modular motion components can be freely added.

[0055] The two-dimensional motion platform provided in this embodiment adopts a zero-order super-constraint design, simplifies the assembly requirements of the guide elements, avoids the "stuck" problem of the traditional platform, and realizes high-precision two-dimensional motion of the carrier plate 10 in the XY plane. The driving module 20 and the support module 30 in the platform are composed of universal guide elements, which have good interchangeability and versatility, and have good secondary development space. The hollow design of the carrier plate releases the space below the motion platform, and the differential design is realized in combination with the optical flat crystal 14 reference, which reduces the requirements for the accuracy of the guide parts, so that components with general accuracy can also achieve high-precision three-dimensional measurement and positioning.

[0056] The present invention is described in detail above with reference to the accompanying drawings, but the embodiments of the present invention are not limited to the above embodiments. Those skilled in the art can make various modifications to the present invention based on the prior art, which all belong to the protection scope of the present invention.

Claims

1. A two-dimensional motion platform, characterized in that: The device comprises a horizontally arranged loading board, a driving module for driving the loading board to move, a supporting module for supporting the loading board, and a control module for controlling the movement of the driving module, wherein the loading board is horizontally arranged above the driving module and the supporting module, the loading board and the driving module are rigidly connected, and the loading board and the supporting module are flexibly hinged; The driving module includes a Y-axis linear displacement stage and an X-axis linear displacement stage installed on the upper surface of the Y-axis linear displacement stage, the neutral line of the movement direction of the Y-axis linear displacement stage and the neutral line of the movement direction of the X-axis linear displacement stage are arranged perpendicular to each other, the Y-axis linear displacement stage and the X-axis linear displacement stage are both communicatively connected to the control module, and the object carrier is rigidly connected to the upper surface of the X-axis linear displacement stage; The support module comprises a Y-direction linear slide rail arranged in parallel with the neutral line of the movement direction of the Y-direction linear translation stage and an X-direction linear slide rail arranged in parallel with the neutral line of the movement direction of the X-direction linear translation stage, the number of the Y-direction linear slide rails is the same as the number of the X-direction linear slide rails and they are matched one to one, and in the mutually matched Y-direction linear slide rails and the X-direction linear slide rails, the X-direction linear slide rails are arranged on the slide rail surface of the Y-direction linear slide rail, and the object carrier is flexibly hinged on each of the X-direction linear slide rails; there are more than two Y-direction linear slide rails and more than two X-direction linear slide rails respectively, and the number of the Y-direction linear slide rails is the same as the number of the X-direction linear slide rails and they are matched one to one; The sliding strokes of the Y-axis linear slide rail and the X-axis linear slide rail are the same and are both greater than the moving strokes of the Y-axis linear translation stage and the X-axis linear translation stage; The slide rail surface of each X-axis linear slide rail is respectively provided with a ball-and-socket connection block, and the object carrier is provided with a ball head thread pair that matches each ball-and-socket connection block one-to-one; An optical flat crystal is placed on the upper surface of the carrier plate; A through hole is provided in the middle of the object carrying plate.

2. The two-dimensional motion platform according to claim 1, characterized in that: The object carrier plate and the upper surface of the X-axis linear translation stage are connected by bolts or welded to each other.

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