Micro-displacement platform integrated with capacitive displacement sensor

Abstract

The invention relates to a micro-displacement platform integrated with a capacitive displacement sensor. The micro-displacement platform comprises a base, a load platform, a piezoelectric actuator mechanism arranged between the base and the load platform, and a capacitive displacement sensor mechanism, the piezoelectric actuator mechanisms are uniformly distributed in the circumferential direction of the load platform, the piezoelectric actuator mechanisms are used for driving the load platform to move in multiple directions, and the capacitance displacement sensor mechanism is used for detecting the moving distance of the load platform; according to the technical scheme, the load platform is integrated on the base, the piezoelectric actuator mechanism used in cooperation with the load platform is integrally installed on the base, and the capacitance displacement sensor mechanism is installed between the base and the load platform. When the piezoelectric actuator mechanism moves or rotates to adjust the load platform, the capacitive displacement sensor mechanism can accurately measure and feed back the load platform, and accurate and reliable positioning during operation of the load platform is ensured.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision measuring devices, and more specifically to a micro-displacement platform integrating a capacitive displacement sensor. Background Technology

[0002] A micro-displacement platform is a device used for high-precision positioning and scanning, widely applied in optical experiments, dynamic image stabilization, and airborne imaging. It achieves nanometer-level displacement control through actuators such as piezoelectric ceramics, and features a compact structure and fast response speed.

[0003] With the rapid development of ultra-precision positioning technology, the requirements for positioning accuracy are becoming increasingly stringent in fields such as nanolithography, high-end microscopic scanning imaging, optical image stabilization, nanoimprinting, optical communication, and nanometry. Existing micro-displacement platforms or devices based on micro-displacement platforms generally adopt an asymmetric structure, which cannot provide real-time feedback when the platform is moved and adjusted, thus compromising the accuracy of the adjustment. Furthermore, since the platform typically involves the adjustment of multiple degrees of freedom during use, it is essential to ensure that effective measurements can be obtained after adjusting each degree of freedom of the micro-displacement platform.

[0004] Therefore, to solve the above problems, a micro-displacement platform integrating a capacitive displacement sensor is needed. Summary of the Invention

[0005] This technical solution integrates a capacitive displacement sensor into a micro-displacement platform. By integrating the load platform onto a base, and simultaneously integrating and installing a piezoelectric actuator mechanism that works with the load platform on the base, as well as a capacitive displacement sensor mechanism between the base and the load platform, it ensures that the capacitive displacement sensor mechanism can accurately measure and provide feedback on the load platform when the piezoelectric actuator mechanism moves or rotates, thus ensuring accurate and reliable positioning of the load platform during operation.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] A micro-displacement platform integrating a capacitive displacement sensor includes a base, a load platform that is adjusted and installed in conjunction with the base, a piezoelectric actuator mechanism disposed between the base and the load platform, and a capacitive displacement sensor mechanism; the piezoelectric actuator mechanism is provided in multiple parts and the multiple piezoelectric actuator mechanisms are evenly distributed in the circumferential direction of the load platform, the piezoelectric actuator mechanism is used to drive the load platform to move in multiple degrees of freedom, and the capacitive displacement sensor mechanism is used to detect the moving distance of the load platform.

[0008] Furthermore, the capacitive displacement sensor mechanism includes a sensor mounting base fixedly installed with the base, a sensing electrode plate fixedly installed with the sensor mounting base, and a shielding electrode plate fixedly installed on the load platform. The shielding electrode plate moves synchronously with the load platform and works with the sensing electrode plate to perform distance detection.

[0009] Furthermore, the capacitive displacement sensor mechanism is configured in groups of two, with multiple groups in total, and the multiple groups of capacitive displacement sensor mechanisms are evenly distributed in the circumferential direction of the load platform.

[0010] Furthermore, a set of the capacitive displacement sensor mechanisms is arranged symmetrically relative to the piezoelectric actuator mechanism, and the sensing plate and the shielding plate are arranged parallel to each other.

[0011] Furthermore, the piezoelectric actuator mechanism includes a compliant lever amplification component and a piezoelectric ceramic assembly fixedly installed in conjunction with the compliant lever amplification component; one end of the compliant lever amplification component is fixedly installed in conjunction with a base, and the other end of the compliant lever amplification component is fixedly installed in conjunction with a load platform; the piezoelectric ceramic assembly extends and retracts to drive the compliant lever amplification component to drive the load platform to move.

[0012] Furthermore, the compliant lever amplification assembly includes a support arm, a vertical arm, a mounting arm formed on the support arm, and a flexible straight beam disposed at the end of the mounting arm, all of which are fixedly mounted to the base. The mounting arm is provided with a flexible hinge, and the piezoelectric ceramic assembly is arranged between the flexible hinge and the vertical arm.

[0013] Furthermore, the end of the flexible straight beam is formed with a straight beam positioning block that is fixedly installed with the load platform, and a hinge beam is provided between the mounting arm and the support arm.

[0014] Furthermore, the load platform is generally rectangular, and a right-angle flexible hinge is provided between the load platform and the base.

[0015] Furthermore, an amplification circuit board is mounted on the base, and the amplification circuit board is electrically connected to the capacitive displacement sensor mechanism.

[0016] Furthermore, a top cover is provided on the base for proper installation.

[0017] The beneficial effects of this technical solution are:

[0018] This technical solution integrates a capacitive displacement sensor into a micro-displacement platform. By integrating the load platform onto a base, and simultaneously integrating and installing a piezoelectric actuator mechanism that works with the load platform on the base, as well as a capacitive displacement sensor mechanism between the base and the load platform, it ensures that the capacitive displacement sensor mechanism can accurately measure and provide feedback on the load platform when the piezoelectric actuator mechanism moves or rotates, thus ensuring accurate and reliable positioning of the load platform during operation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall exploded structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the overall installation of the present invention;

[0021] Figure 3 This is a schematic diagram of the mounting on the back of the base of the present invention;

[0022] Figure 4 This is a top view of the interior of the base of the present invention;

[0023] Figure 5 This is a schematic diagram of the piezoelectric actuator mechanism of the present invention;

[0024] Figure 6 For the present invention Figure 3 Enlarged view of point A in the middle;

[0025] Figure 7 This is a schematic diagram of the load platform adjustment of the present invention.

[0026] The attached diagram lists the components represented by each number as follows:

[0027] 1-Load platform; 2-Base; 3-Piezoelectric actuator mechanism; 4-Amplifier circuit board; 5-Capacitive displacement sensor mechanism; 6-Top cover; 7-Right-angle flexible hinge; 8-Piezoelectric ceramic assembly; 9-Support arm; 10-Induction plate; 11-Shielding plate; 12-Sensor mounting base; 13-Flexible hinge; 14-Flexible straight beam; 15-Straight beam positioning block; 71-Inner gap; 72-Outer gap; 91-Upright arm; 92-Mounting arm; 93-Hinge beam. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0029] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] like Figures 1 to 4 As shown in the embodiment of this application, a micro-displacement platform integrating a capacitive displacement sensor includes a base 2, a load platform 1 that is adjusted and installed in conjunction with the base 2, a piezoelectric actuator mechanism 3 disposed between the base 2 and the load platform 1, and a capacitive displacement sensor mechanism 5; the piezoelectric actuator mechanism 3 is provided in multiples and the multiple piezoelectric actuator mechanisms 3 are evenly distributed in the circumferential direction of the load platform 1, the piezoelectric actuator mechanism 3 is used to drive the load platform 1 to move in multiple degrees of freedom, and the capacitive displacement sensor mechanism 5 is used to detect the moving distance of the load platform 1.

[0033] This technical solution integrates a capacitive displacement sensor-based micro-displacement platform. By integrating a load platform 1 onto a base 2, and simultaneously integrating and installing a piezoelectric actuator mechanism 3 for use with the load platform 1 on the base 2, and a capacitive displacement sensor mechanism 5 between the base 2 and the load platform 1, it ensures that the capacitive displacement sensor mechanism 5 can accurately measure and provide feedback on the load platform 1 when the piezoelectric actuator mechanism 3 moves or rotates, ensuring accurate and reliable positioning of the load platform 1 during operation. Multiple integrated capacitive displacement sensors 5 are used to simultaneously measure the load platform's displacement in the X-axis or Y-axis direction and its deflection angle around the Z-axis (perpendicular to the XY plane). Closed-loop control is achieved using the capacitive displacement sensors 5, improving the dynamic scanning trajectory tracking performance of the micro-displacement platform.

[0034] In this embodiment, the capacitive displacement sensor mechanism 5 includes a sensor mounting base 12 fixedly installed with the base 2, a sensing electrode plate 10 fixedly installed with the sensor mounting base 12, and a shielding electrode plate 11 fixedly installed on the load platform 1. The shielding electrode plate 11 moves synchronously with the load platform 1 and cooperates with the sensing electrode plate 10 to perform distance detection.

[0035] like Figure 1-4As shown, the sensor mounting base 12 is fixedly installed on the base 2, serving as the mounting fulcrum for the sensing electrode plate 10. The shielding electrode plate 11 is correspondingly fixedly installed in conjunction with the load platform 1. A platform positioning groove for positioning and installing the shielding electrode plate 11 is provided on the outer surface of the load platform. After the shielding electrode plate 11 is fixedly installed in conjunction with the load platform 1, the two move synchronously. Through the cooperative arrangement of the sensing electrode plate 10 and the shielding electrode plate 11, it is convenient to detect the change in the distance between the base 2 and the load platform 1.

[0036] In this embodiment, the capacitive displacement sensor mechanism 5 is configured as a group of two, with a total of multiple groups, and the multiple groups of capacitive displacement sensor mechanisms 5 are evenly distributed in the circumferential direction of the load platform 1.

[0037] like Figure 1 , Figure 4 As shown, the capacitive displacement sensor mechanism 5 is set in pairs, with a total of four sets of structures. The four sets of capacitive displacement sensor mechanisms 5 are respectively arranged around the load platform 1. Taking the load platform 1 as a hollow cuboid structure as an example, by setting multiple sets of capacitive displacement sensor mechanisms 5, the moving distance of the load platform 1 can be accurately detected, which facilitates precise control.

[0038] In this embodiment, a set of capacitive displacement sensor mechanisms 5 are arranged symmetrically relative to the piezoelectric actuator mechanism 3, and the sensing plate 10 and the shielding plate 11 are arranged parallel to each other.

[0039] like Figure 1-4 As shown, the induction plate 10 and the shielding plate 11 are arranged parallel to each other and face each other. The two capacitive displacement sensor mechanisms 5 in the set are symmetrically arranged with respect to the piezoelectric actuator mechanism 3. With this arrangement, when the load platform 1 moves with a single degree of freedom, it can measure multiple data and perform calculations to improve measurement accuracy. When the load platform 1 rotates, the corresponding rotation angle can be calculated by detecting the values ​​of the two capacitive displacement sensor mechanisms 5.

[0040] In this embodiment, the piezoelectric actuator mechanism 3 includes a compliant lever amplification component and a piezoelectric ceramic assembly 8 that is fixedly installed in conjunction with the compliant lever amplification component; one end of the compliant lever amplification component is fixedly installed in conjunction with the base 2, and the other end of the compliant lever amplification component is fixedly installed on the load platform 1. The piezoelectric ceramic assembly 8 extends and retracts to drive the compliant lever amplification component to drive the load platform 1 to move.

[0041] like Figure 1-5As shown, the piezoelectric actuator mechanism 3 is fixedly installed on the base 2 and in conjunction with the load platform 1. The piezoelectric actuator mechanism 3 includes a compliant lever amplification component and a piezoelectric ceramic assembly 8 that is installed in conjunction with it. The piezoelectric ceramic assembly 8 is used to drive the compliant lever amplification component to move the load platform 1. Multiple piezoelectric actuator mechanisms 3 are provided, such as... Figure 4 As shown, the piezoelectric actuator mechanisms 3 installed on the parallel sides of the load platform 1 are identical. The two piezoelectric actuator mechanisms 3 are symmetrically arranged relative to the load platform 1, thereby achieving motion adjustment of the load platform 1 along the X and Y directions. When two adjacent piezoelectric actuator mechanisms 3 act simultaneously on the load platform 1, the load platform 1 rotates, thus achieving rotational adjustment and multi-degree-of-freedom adjustment. When the distance between the shielding plate 11 and the sensing plate 10 changes, the capacitance value formed by them changes accordingly. The capacitive displacement sensor mechanism 5 detects this capacitance change and converts it into an electrical signal corresponding to the displacement of the load platform 3. This electrical signal is sent to the control system as a feedback signal. The control system adjusts the driving voltage applied to the piezoelectric actuator assembly 3 accordingly (the specific control technologies involved in this technical solution all use existing technologies and are not elaborated here), thereby changing the output force or displacement of the piezoelectric actuator assembly 3 and achieving closed-loop control of the position of the load platform 1.

[0042] In this embodiment, the compliant lever amplification assembly includes a support arm 9, a vertical arm 91, a mounting arm formed on the support arm 9, and a flexible straight beam 14 disposed at the end of the mounting arm. A flexible hinge 13 is disposed on the mounting arm 92 (the distance from the processing position of the flexible hinge 13 to the hinge beam 93 is la, and the distance from the hinge beam 93 to the flexible straight beam 14 is le, which together with the other components form a compliant lever structure). The piezoelectric ceramic assembly 8 is arranged between the flexible hinge 13 and the vertical arm 91.

[0043] like Figure 5 As shown, the compliant lever amplification assembly adopts a one-piece molding process to ensure the accuracy of product use. The support arm 9 is fixedly installed with the base 2. The support arm 9 has a raised vertical arm 91 and a mounting arm 92. The right end of the mounting arm 92 is integrally formed into a flexible hinge 13. The stacked piezoelectric ceramic group 8 is arranged between the vertical arm 91 and the flexible hinge 13. The upper end of the mounting arm 92 has a raised flexible straight beam 14 that is connected and installed with the load platform 1. When the overall structure is in use, it is used to provide power input to the load platform 1. When the load platform 1 needs to be moved with a single degree of freedom, the two piezoelectric actuator mechanisms 3 arranged in parallel on the load platform 1 act on the load platform 1 at the same time to ensure its stable and reliable operation and prevent rotation.

[0044] In this embodiment, the end of the flexible straight beam 14 is formed with a straight beam positioning block 15 that is fixedly installed with the load platform 1, and a hinge beam 93 is provided between the mounting arm 92 and the support arm 9.

[0045] The hinge beam 93, mounting arm 92, and support arm 9 are also integrally molded to ensure the structural performance. The straight beam positioning block 15 is used to cooperate with the load platform 1 for fixed installation and to provide a power input point.

[0046] In this embodiment, the load platform 1 is generally rectangular, and a right-angle flexible hinge 7 is provided between the load platform 1 and the base 2.

[0047] like Figure 3 Figure 6 As shown, right-angle flexible hinges 7 are disposed between the load platform 1 and the base 2, and are located at the four corners of the cuboid load platform 1. After the load platform 1 and the base 2 are integrally processed by wire cutting, an inner gap 71 and an outer gap 72 are formed. The right-angle flexible hinges 7 are formed between the inner gap 71 and the outer gap 72, which serves to connect the load platform 1 and the base 2. The four right-angle flexible hinges 7 ensure that the load platform moves linearly along the X-axis and Y-axis, thereby achieving motion decoupling and ensuring the scanning and positioning accuracy of the micro-displacement platform.

[0048] In this embodiment, an amplification circuit board 4 is mounted on the base 2, and the amplification circuit board 4 is electrically connected to the capacitive displacement sensor mechanism 5.

[0049] like Figure 1 As shown, the capacitive displacement sensor mechanism 5 and the amplification circuit board 4 are integrated within the limited space of the micro-displacement platform to improve integration and the anti-interference capability of the sensing signal.

[0050] In this embodiment, a top cover 6 is provided on the base 2 for proper installation.

[0051] like Figure 7 As shown, the dashed line represents the position of the load platform 1 after it has moved. Based on the principle of average reading, the capacitive displacement sensor... and or capacitive displacement sensor and The average value of the displacement measurement results is taken as the micro-displacement measurement result of the load platform along the X-axis direction; similarly, the capacitive displacement sensor and or capacitive displacement sensor and The average value of the displacement measurement results is taken as the micro-displacement measurement result of the load platform along the Y-axis. When the deflection angle is small, it is based on the capacitive displacement sensor. and Output displacement difference or capacitive displacement sensor and The output displacement difference can be used as a measurement of the deflection angle of the load platform around the Z-axis.

[0052] The capacitive displacement sensor assembly is integrated between the load platform and the base. Its sensing plate is fixed to the sensor base, which in turn is fixed to the platform base. The shielding plate is fixed to the side of the load platform and is grounded. When the sensing plate and shielding plate are vertically aligned, the measured capacitance of the parallel plate capacitor formed by the sensing and shielding plates of the capacitive displacement sensor is:

[0053]

[0054] In the formula, This represents the measured capacitance value of a parallel-plate capacitor. The dielectric constant between the shielding plate and the inductive plate is... The area of ​​the shielding electrode and the sensing electrode facing each other. The radius of the circular sensing electrode on the sensing plate (the plate is circular in this example). and These represent the initial and varying distances between the shielding plate and the sensing plate, respectively.

[0055] A sensing signal line is led out from the sensing electrode plate and connected to the amplifier circuit board. The signal is then transmitted to the capacitive displacement sensing demodulation circuit module outside the micro-displacement platform. As the load platform moves, the distance between the shielding electrode plate and the sensing electrode plate changes, causing a corresponding change in capacitance. This detects the displacement of the load platform and uses it as a feedback signal. By controlling the change in the driving voltage, the output force or displacement of the stacked piezoelectric ceramic is changed, thus achieving closed-loop control.

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A micro-displacement platform integrating a capacitive displacement sensor, characterized in that: It includes a base (2), a load platform (1) that is adjusted and installed in conjunction with the base (2), a piezoelectric actuator mechanism (3) disposed between the base (2) and the load platform (1), and a capacitive displacement sensor mechanism (5); the piezoelectric actuator mechanism (3) is provided with multiple piezoelectric actuator mechanisms (3) evenly distributed in the circumferential direction of the load platform (1), the piezoelectric actuator mechanism (3) is used to drive the load platform (1) to move in multiple degrees of freedom, and the capacitive displacement sensor mechanism (5) is used to detect the moving distance of the load platform (1).

2. The micro-displacement platform with integrated capacitive displacement sensor according to claim 1, characterized in that: The capacitive displacement sensor mechanism (5) includes a sensor mounting base (12) fixedly installed with the base (2), a sensing electrode plate (10) fixedly installed with the sensor mounting base (12), and a shielding electrode plate (11) fixedly installed on the load platform (1). The shielding electrode plate (11) moves synchronously with the load platform (1) and cooperates with the sensing electrode plate (10) to perform distance detection.

3. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 2, characterized in that: The capacitive displacement sensor mechanism (5) is set in pairs, with a total of multiple groups, and the multiple groups of capacitive displacement sensor mechanisms (5) are evenly distributed in the circumferential direction of the load platform (1).

4. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 3, characterized in that: A set of capacitive displacement sensor mechanisms (5) are arranged symmetrically relative to the piezoelectric actuator mechanism (3), and the sensing plate (10) and the shielding plate (11) are arranged parallel to each other.

5. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 1, characterized in that: The piezoelectric actuator mechanism (5) includes a compliant lever amplification component and a piezoelectric ceramic assembly (8) fixedly installed in conjunction with the compliant lever amplification component; one end of the compliant lever amplification component is fixedly installed in conjunction with the base (2), and the other end of the compliant lever amplification component is fixedly installed in conjunction with the load platform (1). The piezoelectric ceramic assembly extends and retracts to drive the compliant lever amplification component to drive the load platform (1) to move.

6. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 5, characterized in that: The compliant lever amplification assembly includes a support arm (9) fixedly installed with a base (2), a vertical arm (91), a mounting arm (92) formed on the support arm (9), and a flexible straight beam (14) disposed at the end of the mounting arm (9). A flexible hinge (13) is provided on the mounting arm (9), and the piezoelectric ceramic assembly (8) is arranged between the flexible hinge (13) and the vertical arm (9).

7. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 6, characterized in that: The flexible straight beam (14) has a straight beam positioning block (15) formed at its end to cooperate with the load platform (1) for fixed installation, and a hinge beam (93) is provided between the mounting arm (92) and the support arm (9).

8. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 1, characterized in that: The load platform (1) is in the shape of a cuboid, and a right-angle flexible hinge (7) is provided between the load platform (1) and the base (2).

9. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 1, characterized in that: An amplifier circuit board (4) is mounted on the base (2), and the amplifier circuit board (4) is electrically connected to the capacitive displacement sensor mechanism (5).

10. The micro-displacement platform with an integrated capacitive displacement sensor according to claim 1, characterized in that: The base (1) is provided with a top cover (6) for matching installation.

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