Piezoelectric objective lens positioning system and method

Abstract

The invention discloses a piezoelectric objective lens positioning system and method, relates to the technical field of piezoelectric positioning, can realize accurate detection of repeated positioning accuracy of a nanoscale piezoelectric driving system, and comprises an upper computer, a piezoelectric controller, a piezoelectric device and a laser interference assembly. The upper computer sends input information to the piezoelectric controller; the piezoelectric controller generates a corresponding voltage signal according to the input information and inputs the voltage signal to the piezoelectric device; the piezoelectric device is driven by the voltage signal to move to a corresponding target position; the laser interference assembly detects the corresponding actual position when the piezoelectric device moves to the target position; the upper computer obtains a positioning error according to the target position and the actual position; the piezoelectric controller generates a correction voltage signal according to the positioning error; the piezoelectric device is driven to move to the next target position according to the corrected voltage signal and the next voltage signal; and the upper computer determines the repeated positioning precision of the piezoelectric device according to each target position and the detection position corresponding to each target position.

Description

Technical Field

[0001] The present application relates to the field of piezoelectric positioning technology, and in particular to a piezoelectric objective lens positioning system and method. Background Art

[0002] Piezoelectric drive technology is based on the piezoelectric effect, that is, when a piezoelectric material is subjected to an electric field, mechanical deformation occurs inside it, thereby achieving displacement control. Since piezoelectric materials have nanometer-level control accuracy, this type of technology is widely used in nanopositioning systems, especially in scanning probe microscopes (SPMs), atomic force microscopes (AFMs) and other equipment, where piezoelectric actuators are often used to achieve high-precision probe positioning or sample adjustment.

[0003] If the system repeatability positioning accuracy is tested using a dial indicator and a micrometer, the accuracy error data can be obtained by colliding the instrument probe during the system's cyclic motion. However, collisions often lead to cumulative errors. In addition, contact measurement has low accuracy and is inconvenient to read, resulting in poor test accuracy. Summary of the invention

[0004] The present application provides a piezoelectric objective lens positioning system and method, which can realize the detection of repeated positioning accuracy based on a nanometer-level piezoelectric drive system, and at the same time can improve the accuracy of positioning accuracy detection.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect of an embodiment of the present application, a piezoelectric objective lens positioning system is provided, the system comprising: a host computer, a piezoelectric controller, a piezoelectric device and a laser interference component;

[0007] The host computer is used to send input information to the piezoelectric controller, wherein the input information includes stroke information or voltage information;

[0008] The piezoelectric controller is used to generate a corresponding voltage signal according to the input information, and input the voltage signal to the piezoelectric device;

[0009] The piezoelectric device is used to move to a corresponding target position under the drive of the voltage signal;

[0010] The laser interference component is used to detect the actual position corresponding to the displacement of the piezoelectric device to the target position;

[0011] The host computer is further used to obtain a positioning error according to the target position and the actual position;

[0012] The piezoelectric controller is further used to generate a correction voltage signal according to the positioning error;

[0013] The piezoelectric device is further used to drive the downward displacement to the next target position according to the modified voltage signal and the next voltage signal;

[0014] The host computer is also used to determine the repeatability of the piezoelectric device according to each target position and the detection position corresponding to each target position.

[0015] As a possible implementation, the system further includes: an air-floating integrated device, the air-floating integrated device including: an air-floating platform, a metal plate and a first metal rod;

[0016] The metal plate is fixed on the air floating platform, and the first metal rod is fixed on the metal plate;

[0017] The piezoelectric device is fixed on the first metal rod.

[0018] As a possible implementation manner, the piezoelectric device includes: a stator and a mover, the stator is fixed on the first metal rod, and the mover is located on the stator.

[0019] As a possible implementation, the laser interference assembly includes: a laser interferometer, a linear interferometer and a linear reflector;

[0020] The laser interference component is used to use a laser interferometer to generate a detection laser, which passes through the interferometer mirror and the reflector to detect the position of the mover, thereby obtaining the detection position.

[0021] As a possible implementation manner, the linear reflector is fixed on the mover, the linear interferometer is arranged on the linear reflector, and the distance between the linear interferometer and the linear reflector is 1 to 2 mm.

[0022] As a possible implementation manner, the air-floating integrated device further includes: a second metal rod, and the linear interferometer is fixed on the second metal rod.

[0023] As a possible implementation manner, the laser interferometer and the linear interferometer are located at the same horizontal position, and the distance between the laser interferometer and the linear interferometer is 10 to 20 cm.

[0024] As a possible implementation, four corners under the air floating platform are connected with air floating shock absorbers.

[0025] As a possible implementation manner, the air flotation platform is made of marble material.

[0026] In a second aspect of the embodiment of the present application, a piezoelectric objective lens positioning method is provided, which is applied to a piezoelectric objective lens positioning system. The system includes: a host computer, a piezoelectric controller, a piezoelectric device and a laser interference component; the method includes:

[0027] The host computer sends input information to the piezoelectric controller, wherein the input information includes stroke information or voltage information;

[0028] The piezoelectric controller generates a corresponding voltage signal according to the input information, and inputs the voltage signal to the piezoelectric device;

[0029] The piezoelectric device is driven by the voltage signal to move to a corresponding target position;

[0030] The laser interference component detects the actual position corresponding to the displacement of the piezoelectric device to the target position;

[0031] The host computer obtains a positioning error according to the target position and the actual position;

[0032] The piezoelectric controller generates a correction voltage signal according to the positioning error;

[0033] The piezoelectric device drives the lower displacement to the next target position according to the modified voltage signal and the next voltage signal;

[0034] The host computer determines the repeatability of the piezoelectric device according to each target position and the detection position corresponding to each target position.

[0035] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0036] The piezoelectric objective lens positioning system provided in the embodiment of the present application includes: a host computer, a piezoelectric controller, a piezoelectric device and a laser interference component. During the positioning detection process, the host computer sends input information to the piezoelectric controller, and the input information includes travel information or voltage information; the piezoelectric controller generates a corresponding voltage signal according to the input information, and inputs the voltage signal to the piezoelectric device; the piezoelectric device is displaced to the corresponding target position under the drive of the voltage signal; the laser interference component detects the actual position corresponding to the displacement of the piezoelectric device to the target position; the host computer obtains the positioning error according to the target position and the actual position; the piezoelectric controller generates a correction voltage signal according to the positioning error; the piezoelectric device is displaced to the next target position under the drive of the correction voltage signal and the next voltage signal; the host computer determines the repeat positioning accuracy of the piezoelectric device according to each target position and the detection position corresponding to each target position. The piezoelectric objective lens positioning system provided in the embodiment of the present application can accurately and effectively measure and evaluate the repeat positioning accuracy of the piezoelectric nano objective lens positioning system, and can ensure the high precision and high stability of the piezoelectric objective lens positioning system during nanometer-level positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a piezoelectric objective lens positioning system provided in an embodiment of the present application;

[0038] Figure 2 A flow chart of a piezoelectric objective lens positioning method provided in an embodiment of the present application;

[0039] Figure 3 The fluctuation of the piezoelectric device in the piezoelectric objective lens positioning system provided in the embodiment of the present application Figure 1 ;

[0040] Figure 4 The fluctuation of the piezoelectric device in the piezoelectric objective lens positioning system provided in the embodiment of the present application Figure 2 .

[0041] Reference numerals:

[0042] 1-host computer, 2-piezoelectric controller, 3-piezoelectric device, 4-laser interferometer, 5-air floating platform, 6-metal plate, 7-first metal rod, 8-second metal rod, 9-linear interferometer, 10-linear reflector, 11-air floating shock absorber. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0044] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0045] Additionally, the use of “based on” or “according to” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” or “according to” one or more conditions or values ​​may, in practice, be based on additional conditions or beyond values.

[0046] Piezoelectric drive technology is based on the piezoelectric effect, that is, when a piezoelectric material is subjected to an electric field, mechanical deformation occurs inside it, thereby achieving displacement control. Since piezoelectric materials have nanometer-level control accuracy, this type of technology is widely used in nanopositioning systems, especially in scanning probe microscopes (SPMs), atomic force microscopes (AFMs) and other equipment, where piezoelectric actuators are often used to achieve high-precision probe positioning or sample adjustment.

[0047] However, in actual operation, piezoelectric systems are affected by nonlinear effects, hysteresis effects, and creep phenomena, which result in the inability to achieve completely consistent displacements during multiple positioning. This is particularly true during repeated positioning, which may cause large errors and affect the positioning accuracy of the entire system.

[0048] If the system repeatability is tested using a dial indicator and a micrometer, the system will collide with the instrument probe during cyclic motion to obtain the accuracy error data. However, collisions often lead to cumulative errors. In addition, contact measurement has low accuracy and is inconvenient to read, resulting in poor test accuracy. Therefore, in order to address these issues, how to test the repeatability of the nano-piezoelectric drive system requires a simple and accurate repeatability measurement system and method.

[0049] The present application embodiment provides a piezoelectric objective lens positioning system, such as Figure 1 As shown, the system includes: a host computer 1, a piezoelectric controller 2, a piezoelectric device 3 and a laser interference component;

[0050] The host computer 1 is used to send input information to the piezoelectric controller 2, wherein the input information includes stroke information or voltage information;

[0051] The piezoelectric controller 2 is used to generate a corresponding voltage signal according to the input information, and input the voltage signal to the piezoelectric device 3;

[0052] The piezoelectric device 3 is used to move to a corresponding target position under the drive of the voltage signal;

[0053] The laser interference component is used to detect the actual position corresponding to the displacement of the piezoelectric device 3 to the target position;

[0054] The host computer 1 is also used to obtain a positioning error according to the target position and the actual position;

[0055] The piezoelectric controller 2 is further used to generate a correction voltage signal according to the positioning error;

[0056] The piezoelectric device 3 is also used to drive the downward displacement to the next target position according to the modified voltage signal and the next voltage signal;

[0057] The host computer 1 is also used to determine the repeatability of the piezoelectric device 3 according to each target position and the detection position corresponding to each target position.

[0058] Optionally, the piezoelectric controller 2 has built-in piezoelectric ceramics and Wheatstone bridge circuit sensors and a control program, which can adjust the driving voltage in real time to achieve high-precision control of the piezoelectric device 3.

[0059] The laser interference component can accurately measure the position actually reached by the piezoelectric device 3. The laser interference component needs to have nanometer-level resolution to ensure the accuracy of the measurement result.

[0060] The piezoelectric objective lens positioning system provided by the embodiment of the present application comprises: a host computer 1, a piezoelectric controller 2, a piezoelectric device 3 and a laser interference component. In the positioning detection process, the host computer 1 sends input information to the piezoelectric controller 2, and the input information includes travel information or voltage information; the piezoelectric controller 2 generates a corresponding voltage signal according to the input information, and inputs the voltage signal to the piezoelectric device 3; the piezoelectric device 3 is displaced to the corresponding target position under the drive of the voltage signal; the laser interference component detects the actual position corresponding to the displacement of the piezoelectric device 3 to the target position; the host computer 1 obtains the positioning error according to the target position and the actual position; the piezoelectric controller 2 generates a correction voltage signal according to the positioning error; the piezoelectric device 3 is displaced to the next target position under the drive of the correction voltage signal and the next voltage signal; the host computer 1 determines the repeat positioning accuracy of the piezoelectric device 3 according to each target position and the detection position corresponding to each target position. The piezoelectric objective lens positioning system provided by the embodiment of the present application can accurately and effectively measure and evaluate the repeat positioning accuracy of the piezoelectric nano objective lens positioning system, and can ensure the high precision and high stability of the piezoelectric objective lens positioning system in nanometer-level positioning.

[0061] Optionally, the system also includes: an air flotation integrated device, which includes: an air flotation platform 5, a metal plate 6 and a first metal rod 7; the metal plate 6 is fixed on the air flotation platform 5, and the first metal rod 7 is fixed on the metal plate 6; the piezoelectric device 3 is fixed on the first metal rod 7.

[0062] Optionally, four corners under the air floating platform 5 are connected with air floating shock absorbers 11. The air floating platform 5 is made of marble.

[0063] By fixing the piezoelectric device 3 on the air-floating integrated device, the present application can effectively suppress the large temperature drift of the piezoelectric system under static conditions (unenabled state), and can also prevent external factors such as temperature changes, vibrations, noise in the external environment from affecting the accuracy and stability of the system.

[0064] Optionally, the piezoelectric device 3 includes: a stator and a mover, wherein the stator is fixed on the first metal rod 7, and the mover is located on the stator. The mover includes a piezoelectric material, and when the piezoelectric material is subjected to a voltage, mechanical deformation occurs inside the piezoelectric material, thereby achieving displacement control. Figure 1 As shown, the mover can be displaced along the z-axis direction.

[0065] Optionally, the laser interference assembly includes: a laser interferometer 4, a linear interferometer 9 and a linear reflector 10;

[0066] The laser interference component is used to use the laser interferometer 4 to generate a detection laser, which passes through the interferometer mirror and the reflector to detect the position of the mover, thereby obtaining the detection position.

[0067] Specifically, the linear reflector 10 is fixed on the mover, the linear interferometer 9 is arranged on the linear reflector 10, and the vertical distance between the linear interferometer 9 and the linear reflector 10 along the Z axis is 1 to 2 mm.

[0068] Optionally, the air-floating integrated device further comprises: a second metal rod 8, and the linear interferometer 9 is fixed on the second metal rod 8. The laser interferometer 4 and the linear interferometer 9 are located at the same horizontal position, and the distance between the laser interferometer 4 and the linear interferometer 9 along the X-axis direction is 10 to 20 cm.

[0069] The piezoelectric objective lens positioning system provided in the embodiment of the present application can accurately evaluate the repeatability of the nanometer-level piezoelectric positioning system, ensuring its reliability and stability in precision positioning applications. This rigorous testing process is crucial for precision manufacturing, biopharmaceuticals, life sciences, medical diagnosis and other fields, which have extremely high requirements for positioning accuracy.

[0070] The present application also provides a piezoelectric objective lens positioning method, which is applied to a piezoelectric objective lens positioning system, wherein the system includes: a host computer, a piezoelectric controller, a piezoelectric device, and a laser interference component. Figure 2 As shown, the method comprises the following steps:

[0071] Step 201: The host computer sends input information to the piezoelectric controller, where the input information includes stroke information or voltage information.

[0072] Step 202: The piezoelectric controller generates a corresponding voltage signal according to the input information, and inputs the voltage signal to the piezoelectric device.

[0073] Step 203: The piezoelectric device is driven by the voltage signal to move to a corresponding target position.

[0074] Step 204: The laser interference assembly detects the actual position corresponding to the displacement of the piezoelectric device to the target position.

[0075] Step 205: The host computer obtains a positioning error according to the target position and the actual position.

[0076] Step 206: The piezoelectric controller generates a correction voltage signal according to the positioning error.

[0077] Step 207: The piezoelectric device is driven to move downward to a next target position according to the modified voltage signal and the next voltage signal.

[0078] Step 208: The host computer determines the repeatability of the piezoelectric device according to each target position and the detection position corresponding to each target position.

[0079] In one embodiment, the system further includes: an air flotation integrated device, which includes: an air flotation platform, a metal plate and a first metal rod; the metal plate is fixed on the air flotation platform, the first metal rod is fixed on the metal plate; and the piezoelectric device is fixed on the first metal rod.

[0080] In one embodiment, the piezoelectric device includes: a stator and a mover, wherein the stator is fixed on the first metal rod, and the mover is located on the stator.

[0081] In one embodiment, the laser interference assembly includes: a laser interferometer, a linear interferometer and a linear reflector; the method further includes:

[0082] The laser interference component uses a laser interferometer to generate a detection laser, which passes through the interference mirror and the reflector to detect the position of the mover, thereby obtaining the detection position.

[0083] In one embodiment, the linear reflector is fixed on the mover, the linear interferometer is arranged on the linear reflector, and the distance between the linear interferometer and the linear reflector is 1-2 mm.

[0084] In one embodiment, the air-floating integrated device further includes: a second metal rod, and the linear interferometer is fixed on the second metal rod.

[0085] In one embodiment, the laser interferometer and the linear interferometer are located at the same horizontal position, and the distance between the laser interferometer and the linear interferometer is 10-20 cm.

[0086] In one embodiment, four corners under the air floating platform are connected with air floating shock absorbers.

[0087] In one embodiment, the air floating platform is made of marble.

[0088] During the actual test, the host computer sets the stroke or voltage control command and transmits it to the piezoelectric controller. The piezoelectric controller controls the piezoelectric device to position to the specified position along the Z axis. The laser interferometer records the actual position measured by the interferometer at this time. After positioning to the specified position, it positions in the opposite direction to the starting position and repeats the positioning twice. After each positioning, the laser interferometer measures the actual position reached by the system. Record the position data of each measurement, and calculate the standard deviation value of these data through the data processing software in the host computer. The smaller the standard deviation value, the higher the repeatability of the system. Ensure that the environment is stable during the test. Factors such as temperature, humidity, etc. should remain constant. Factors such as vibration and noise should be as close to the ideal value of zero as possible. These factors will affect the performance of the piezoelectric material and increase the disturbance when the system is static, affecting the accuracy of the measurement results. In addition, before testing, the closed-loop control system should be calibrated, and the closed-loop control parameters, low-pass filter, notch filter, PID parameters, etc. should be adjusted to ensure accurate matching of the sensor and controller to achieve the best control effect. Figure 3 As shown in the figure, the fluctuation of the piezoelectric device in the piezoelectric objective lens positioning system of the present application in the static state (not enabled) is tested. The fluctuation is stable at 6-8nm, which solves the problem of large temperature drift of the piezoelectric device. Figure 4 As shown, the fluctuation of the piezoelectric device in the piezoelectric objective lens positioning system of the present application in the dynamic (enabled) state is tested, and the fluctuation is stable at 4-10nm. In addition, through multiple sets of data testing, the repeatability of the piezoelectric objective lens positioning system provided by the present application reaches 10 nanometers, realizing the repeatability measurement of the nanometer-level objective lens positioning system.

[0089] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loading and executing computer execution instructions on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. Computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, etc. that contains one or more servers that can be integrated with a medium. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0090] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A piezoelectric objective lens positioning system, characterized in that: The system comprises: a host computer, a piezoelectric controller, a piezoelectric device and a laser interference component; The host computer is used to send input information to the piezoelectric controller, wherein the input information includes stroke information or voltage information; The piezoelectric controller is used to generate a corresponding voltage signal according to the input information, and input the voltage signal to the piezoelectric device; The piezoelectric device is used to move to a corresponding target position under the drive of the voltage signal; The laser interference component is used to detect the actual position corresponding to the displacement of the piezoelectric device to the target position; The host computer is further used to obtain a positioning error according to the target position and the actual position; The piezoelectric controller is further used to generate a correction voltage signal according to the positioning error; The piezoelectric device is further used to drive the downward displacement to the next target position according to the modified voltage signal and the next voltage signal; The host computer is also used to determine the repeatability of the piezoelectric device according to each target position and the detection position corresponding to each target position.

2. The system according to claim 1, characterized in that The system further comprises: an air-floating integrated device, the air-floating integrated device comprising: an air-floating platform, a metal plate and a first metal rod; The metal plate is fixed on the air floating platform, and the first metal rod is fixed on the metal plate; The piezoelectric device is fixed on the first metal rod.

3. The system according to claim 2, characterized in that The piezoelectric device comprises: a stator and a mover, wherein the stator is fixed on the first metal rod, and the mover is located on the stator.

4. The system according to claim 3, characterized in that The laser interference assembly comprises: a laser interferometer, a linear interferometer and a linear reflector; The laser interference component is used to use a laser interferometer to generate a detection laser, which passes through the interferometer mirror and the reflector to detect the position of the mover, thereby obtaining the detection position.

5. The system according to claim 4, characterized in that The linear reflector is fixed on the mover, the linear interferometer is arranged on the linear reflector, and the distance between the linear interferometer and the linear reflector is 1-2 mm.

6. The system according to claim 5, characterized in that The air-floating integrated device further includes: a second metal rod, and the linear interferometer is fixed on the second metal rod.

7. The system according to claim 4, characterized in that The laser interferometer and the linear interferometer are located at the same horizontal position, and the distance between the laser interferometer and the linear interferometer is 10 to 20 cm.

8. The system according to claim 2, characterized in that The four corners under the air floating platform are all connected with air floating shock absorbers.

9. The system according to claim 2, characterized in that The air floating platform is made of marble material.

10. A piezoelectric objective lens positioning method, characterized in that: Applied to a piezoelectric objective lens positioning system, the system comprises: a host computer, a piezoelectric controller, a piezoelectric device and a laser interference component; the method comprises: The host computer sends input information to the piezoelectric controller, wherein the input information includes stroke information or voltage information; The piezoelectric controller generates a corresponding voltage signal according to the input information, and inputs the voltage signal to the piezoelectric device; The piezoelectric device is driven by the voltage signal to move to a corresponding target position; The laser interference component detects the actual position corresponding to the displacement of the piezoelectric device to the target position; The host computer obtains a positioning error according to the target position and the actual position; The piezoelectric controller generates a correction voltage signal according to the positioning error; The piezoelectric device drives the lower displacement to the next target position according to the modified voltage signal and the next voltage signal; The host computer determines the repeatability of the piezoelectric device according to each target position and the detection position corresponding to each target position.

Images