Low-temperature closed-loop scanning control method and system, and low-temperature closed-loop scanning device

Abstract

The application discloses a low-temperature closed-loop scanning control method and system and a low-temperature closed-loop scanning device, and relates to the technical field of closed-loop scanning regulation and control. The low-temperature closed-loop scanning control method acquires real-time position data of a table top output by a capacitive sensor in real time during scanning of a sample to be measured, converts the acquired real-time position deviation into a corresponding control voltage value based on a preset position-voltage mapping algorithm, drives a piezoelectric ceramic, simultaneously collects a matching relationship between a piezoelectric ceramic deformation variable and a displacement variable required by a piezoelectric scanning table, dynamically adjusts driving parameters, and ensures that the deformation of the piezoelectric ceramic can be accurately converted into displacement output required by the table top. Then, real-time displacement data of the table top fed back by the capacitive sensor is received, and the effectiveness of a control strategy in the closed-loop control process is quantitatively evaluated, so as to improve dynamic response efficiency in the scanning control process and perform closed-loop feedback, and the problem of low closed-loop scanning control stability in a low-temperature environment in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of closed-loop scanning control technology, and in particular to a low-temperature closed-loop scanning control method, system, and device. Background Technology

[0002] The development of cryogenic closed-loop scanning control technology stems from the urgent need for nanoscale precision measurement in cutting-edge fields such as quantum materials, superconductivity research, and two-dimensional material characterization. Its core is to achieve stable control and accurate feedback of the scanning trajectory under extremely low temperatures and strong magnetic fields. Existing cryogenic closed-loop scanning devices mainly include the following modules and components: This technology system uses a closed-loop cryogenic thermostat as its basic platform, achieving ultra-low vibration isolation and a piezoelectric scanning stage compatible with cryogenic materials and structural designs; the temperature control module of the thermostat keeps temperature fluctuations within a specified range, providing a stable physical environment for the scanning system; subsequently, the piezoelectric drive unit generates a voltage signal according to preset scanning commands, drives mechanical deformation based on digital-to-analog conversion, and moves the sample stage through a flexible metal hinge, ultimately achieving programmable control and data visualization of the scanning process.

[0003] For example, Chinese invention patent CN106773802B discloses a multi-laser radar synchronous scanning control system and method, including: the laser radar slave device acquires its own second closed-loop scanning frequency information, second scanning angle information and the first scanning angle information of the laser radar host; determines the second scanning frequency control information based on the second closed-loop scanning frequency information, angle information and first angle information; controls the scanning frequency of the laser radar slave device according to the second closed-loop scanning frequency information, angle information and first angle information, so that its own scanning frequency is synchronized with the scanning frequency of the laser radar host; and synchronizes the scanning angle of its own device with the scanning angle of the host device.

[0004] For example, Chinese invention patent CN110806689B discloses a closed-loop negative feedback control system based on SSC, including: a pre-made signal module, a comparison circuit, an SSC execution circuit, an output module, and a scanner; wherein the output terminal of the pre-made signal module is connected to the input terminal of the comparison circuit, the output terminal of the SSC execution circuit is connected to the input terminal of the output module, the output terminal of the scanner is connected to the input terminal of the scanner, and its output terminal is connected to the input terminal of the comparison circuit.

[0005] The above-mentioned technology has at least the following technical problems:

[0006] In existing technologies, fluctuations in ambient temperature and the device's own heating can affect the accuracy of piezoelectric displacement. The piezoelectric coefficient of the displacement-sensing piezoelectric ceramic is highly sensitive to temperature changes. In low-temperature scanning environments or environments with ambient heating, the piezoelectric coefficient is prone to fluctuations with each temperature gradient change. This leads to nonlinear deviations in the deformation of the piezoelectric ceramic under the same driving voltage, resulting in a discrepancy between the actual displacement of the stage and the target displacement. Furthermore, the flexible metal hinge in the scanning device, acting as a displacement transmission mechanism, experiences an increase in its elastic modulus at low temperatures, reducing the displacement transmission efficiency for the same deformation. This causes the cumulative displacement deviations during low-temperature closed-loop scanning control to lead to errors in the feedback signal compared to the actual requirements. Consequently, the controller's delayed feedback reception results in lag in closed-loop feedback adjustment, leading to low stability in low-temperature closed-loop scanning control. Summary of the Invention

[0007] To address the technical problem of low stability in closed-loop scanning control under low-temperature environments in existing technologies, embodiments of the present invention provide a low-temperature closed-loop scanning control method, system, and device. The technical solution is as follows:

[0008] On the one hand, a low-temperature closed-loop scanning control method is provided, which includes: S1, during the scanning process of the sample to be tested, acquiring real-time position data of the stage output by the capacitive sensor, and converting the acquired real-time position deviation into the corresponding control voltage value based on a preset position-voltage mapping algorithm to generate a voltage control signal to drive the piezoelectric ceramic. The real-time position data of the stage is used to reflect the actual spatial position of the stage, and the real-time position deviation is used to reflect the difference between the actual position of the stage and the target position; S2, acquiring the matching relationship between the deformation of the piezoelectric ceramic and the displacement required by the piezoelectric scanning stage in real time, and dynamically adjusting the driving parameters to ensure that the deformation energy of the piezoelectric ceramic is accurately converted into the displacement output required by the stage. The deformation of the piezoelectric ceramic represents the amount of expansion or bending deformation generated by the piezoelectric ceramic under the voltage control signal. The driving parameters include the amplification factor of the high-voltage amplifier circuit and the measurement gain of the capacitive sensor; S3, receiving the real-time displacement data of the stage fed back by the capacitive sensor, and simultaneously quantitatively evaluating the effectiveness of the control strategy corresponding to the combination of piezoelectric ceramic and hinge in the closed-loop control process to improve the dynamic response efficiency in the low-temperature closed-loop scanning control process. The real-time displacement data of the stage represents the actual displacement result after being transmitted and amplified by the flexible metal hinge.

[0009] On the other hand, a low-temperature closed-loop scanning control system is provided. This system is applied to the low-temperature closed-loop scanning control method and includes the following modules: a drive voltage control signal generation module, a deformation-displacement matching module, and a control strategy closed-loop feedback module. The drive voltage control signal generation module is used to acquire the real-time position data of the piezoelectric scanning stage during the scanning process of the sample under test from the output of the capacitive sensor. At the same time, based on a preset position-voltage mapping algorithm, the acquired real-time position deviation is converted into the corresponding control voltage value to generate the voltage control signal driving the piezoelectric ceramic. The deformation-displacement matching module is used to acquire the matching relationship between the deformation of the piezoelectric ceramic and the required displacement of the piezoelectric scanning stage in real time, and dynamically adjust the drive parameters to ensure that the deformation energy of the piezoelectric ceramic is accurately converted into the displacement output required by the stage. The control strategy closed-loop feedback module is used to receive the real-time displacement data of the stage fed back by the capacitive sensor, and at the same time, quantitatively evaluate the effectiveness of the control strategy corresponding to the piezoelectric ceramic and hinge combination in the closed-loop control process to improve the dynamic response efficiency in the low-temperature closed-loop scanning control process.

[0010] On the other hand, a low-temperature closed-loop scanning device is provided, which is applied to the low-temperature closed-loop scanning control method. This device includes: an FPGA control unit, a capacitance sensing measurement module, a DA module, a high-voltage amplification module, a channel switching module, and a piezoelectric scanning stage. The FPGA control unit receives real-time stage position data transmitted from the capacitance sensing measurement module and converts the deviation between the real-time stage position and the preset target position into a corresponding driving voltage value according to a preset position-voltage mapping algorithm, and transmits it to the DA module. The capacitance sensing measurement module applies an excitation signal to the capacitance sensor in the piezoelectric scanning stage and reads the feedback signal to obtain real-time xyz axis position data of the stage, achieving a high-speed sampling rate and data transmission with the FPGA control unit. The DA module is used to convert the F... The digital drive voltage input from the PGA control unit is converted into an analog voltage and output to the high-voltage amplifier in the high-voltage amplification module for storage. The high-voltage amplification module receives the analog voltage input from the DA module and amplifies the analog voltage to the required drive voltage for the piezoelectric ceramic by adjusting the amplification factor and signal gain of the high-voltage amplifier. The channel switching module connects multiple piezoelectric scanning stages and the controller, distributing the drive voltage output from the FPGA control unit to the target piezoelectric scanning stage. The piezoelectric scanning stage is the displacement actuator of the cryogenic closed-loop scanning device, containing piezoelectric ceramic and a capacitive sensor. The piezoelectric ceramic receives the drive voltage output from the high-voltage amplification module, causing the flexible metal hinge to deform, while the capacitive sensor monitors the displacement changes of the piezoelectric scanning stage in real time.

[0011] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0012] 1. By constructing a multi-dimensional temperature correlation and dynamic compensation mechanism, the problem of displacement deviation superposition caused by piezoelectric fluctuations of piezoelectric ceramics and elastic changes of flexible metal hinges at low temperatures is solved, improving displacement accuracy and stability. Temperature data is collected simultaneously during curve generation to accurately record the displacement deviation patterns corresponding to the same driving signal at different temperatures. The driving voltage is adjusted in a targeted manner by using effective strategy indicators and displacement conversion deviations to offset the influence of piezoelectric coefficient fluctuations. At the same time, the data in the mapping table is continuously updated during the closed-loop iteration process to make the compensation fit the characteristics of the current low-temperature environment, achieving precise control of displacement fluctuations over a wide temperature range and solving the problem of detection result distortion caused by the superposition of displacement deviations at low temperatures.

[0013] 2. By constructing a dynamic adaptation system for driving parameters consisting of "real-time monitoring - deviation judgment - graded adjustment," the problem of dynamic changes in the characteristics of piezoelectric ceramics and hinges at low temperatures is solved, ensuring efficient and accurate conversion of piezoelectric deformation into stage displacement. By comparing the real-time deformation data score with the actual displacement output score, the matching relationship between the two is determined, and different solutions are provided according to different matching relationships. When the value is greater than the actual displacement output score, it indicates insufficient conversion efficiency, triggering parameter adjustment: the amplification factor of the high-voltage amplifier circuit is adjusted based on the displacement conversion deviation to specifically solve the displacement transmission problem caused by insufficient piezoelectric deformation. Then, the signal gain of the high-voltage amplifier is optimized according to the signal change rate, which can adapt to different low-temperature operating conditions, so that the conversion efficiency of piezoelectric deformation into stage displacement is maintained stably, avoiding closed-loop control failure caused by conversion deviation, and ensuring that the stage displacement always accurately follows the target trajectory during the scanning process.

[0014] 3. By constructing a multi-dimensional quantitative evaluation and closed-loop iteration mechanism, the system addresses the issues of one-sided control strategy evaluation and difficulty in adapting to different low-temperature scenarios and scanning tasks. This enables continuous optimization and efficient adaptation of strategies, quantifies the matching degree between strategies and scanning tasks, accurately matches different task requirements, and categorizes and processes the evaluation results. When a strategy is effective, it is uploaded to the control unit for iterative updates; when a strategy fails to meet the standards, a verification command is triggered to prevent the continuous operation of ineffective strategies. After multiple rounds of data iteration, the performance of strategies for scanning tasks in low-temperature scenarios is improved, enhancing the environmental adaptability and task matching degree of the strategies, and ensuring that optimal control effects can be obtained for different low-temperature scanning requirements.

[0015] 4. Through collaborative modular design, the problem of synchronous control of multiple scanning stages is solved, improving system integration and scalability, adapting to scanning needs in multiple scenarios, forming a complete data flow link between multiple modules, reducing signal transmission loss between modules, and improving overall response speed. In terms of device design, the number of scanning stages can be increased through channel switching modules to adapt to multi-area synchronous scanning scenarios such as semiconductor wafer inspection. Different types of piezoelectric scanning stages can also be replaced to meet the scanning needs of various material samples, reducing system maintenance difficulty. Upgrading a single module does not affect the overall function, providing flexible support for subsequent technology iteration and scenario expansion.

[0016] 5. By constructing a refined control logic of "deviation grading processing - sampling dynamic optimization - rapid voltage regulation", the noise interference caused by the independent operation of position sampling frequency and filtering mode in the existing technology, as well as the closed-loop feedback delay caused by the lag in drive voltage regulation, is solved. This improves the real-time performance and anti-interference capability of closed-loop control. During the deviation adjustment process, different adjustment methods are triggered according to the degree of deviation to avoid the input of erroneous data. The filtering intensity is adapted to specifically filter out high-frequency thermal noise generated by electronic components at low temperatures. Based on the real-time position input, the real-time performance of closed-loop control is improved, the anti-interference capability is enhanced, and the drive voltage regulation responds in a timely manner, avoiding displacement deviation caused by data distortion or regulation lag. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart of the low-temperature closed-loop scanning control method provided in the embodiments of this application;

[0019] Figure 2 A flowchart illustrating the generation process of the drive voltage control signal provided in an embodiment of this application;

[0020] Figure 3 The flowcharts corresponding to the matching relationship determination and closed-loop feedback update provided in the embodiments of this application are as follows;

[0021] Figure 4 This is a schematic diagram of the structure of a flexible metal hinge provided in an embodiment of this application;

[0022] Figure 5 A schematic diagram of the deformation of the scanning stage driven by the flexible metal hinge provided in an embodiment of this application;

[0023] Figure 6This is a schematic diagram of the structure of the low-temperature closed-loop scanning control system provided in the embodiments of this application;

[0024] Figure 7 A schematic diagram of the controller structure of the cryogenic closed-loop scanning control device provided in the embodiments of this application;

[0025] In the figure: 1. Thin part of the metal flexible hinge; 2. Schematic diagram of the metal flexible hinge structure (left is the initial form, right is the deformed form); 3. Moving end; 4. Structure of the metal flexible hinge; 5. Fixed end; 6. Sample to be tested; 7. Piezoelectric scanning stage surface; 8. Piezoelectric ceramic; 9. Metal flexible hinge. Detailed Implementation

[0026] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0027] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0028] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0029] This invention provides a low-temperature closed-loop scanning control method, such as... Figure 1 The flowchart of the low-temperature closed-loop scanning control method shown below includes the following steps:

[0030] S1. During the scanning process of the sample to be tested, the real-time position data of the platform output by the capacitive sensor is acquired in real time and compared with the preset target position data to obtain the real-time position deviation. At the same time, based on the preset position-voltage mapping algorithm, the acquired real-time position deviation is converted into the corresponding control voltage value to generate the voltage control signal driving the piezoelectric ceramic. The real-time position data of the platform is used to reflect the actual spatial position of the platform, and the real-time position deviation is used to reflect the difference between the actual position of the platform and the target position. The sample to be tested usually includes two-dimensional layered materials, superconducting materials, etc.

[0031] The preset position-voltage mapping algorithm is a type of PID (Proportional Integral Derivative) control algorithm. Based on the received real-time position data and the data of the target position and the current position, the internal PID algorithm calculates the response voltage value and transmits it to the digital-to-analog converter.

[0032] S2. Real-time acquisition of the matching relationship between the piezoelectric ceramic deformation and the required displacement of the piezoelectric scanning stage, and dynamic adjustment of the driving parameters to ensure that the deformation energy of the piezoelectric ceramic is accurately converted into the displacement output required by the stage. The piezoelectric ceramic deformation represents the amount of expansion or bending deformation generated by the piezoelectric ceramic under voltage control signal. The piezoelectric scanning stage represents the overall displacement actuator composed of piezoelectric ceramic, metal flexible hinge and stage, which is responsible for driving the sample to achieve high-precision displacement. The driving parameters include the amplification factor of the high voltage amplifier circuit and the measurement gain of the capacitance sensor.

[0033] S3. Receives real-time displacement data of the platform from the capacitive sensor, and simultaneously quantifies and evaluates the effectiveness of the control strategy corresponding to the piezoelectric ceramic and hinge combination in the closed-loop control process, so as to improve the dynamic response efficiency in the low-temperature closed-loop scanning control process. The real-time displacement data of the platform represents the actual displacement result after being transmitted and amplified by the metal flexible hinge.

[0034] It's important to understand that the specific working principle of the low-temperature closed-loop scanning control is as follows: The sample to be tested is mounted on the stage. The controller in the low-temperature closed-loop scanning device, controlled by a PC (Personal Computer), applies an alternating voltage to the piezoelectric ceramic. Due to the inverse piezoelectric effect, the piezoelectric ceramic deforms. The flexible metal hinge, fixed to the piezoelectric ceramic with a high-strength adhesive, amplifies the deformation, causing the piezoelectric scanning stage to displace vertically. A capacitive sensor monitors the stage displacement change and sends the signal to the controller, forming a closed-loop circuit. Simultaneously, the controller dynamically adjusts the voltage applied to the piezoelectric ceramic based on a preset position-voltage mapping algorithm to correct deviations. Furthermore, by combining temperature-displacement deviation mapping data from a temperature database, it predicts and compensates for temperature drift.

[0035] It should be noted that when the sample to be tested (usually including two-dimensional layered materials and superconducting materials) is placed on the stage, a microscope with a high magnification optical lens is placed above the sample to detect it. The sample is mounted on the scanning stage, and the displacement of the sample can be precisely controlled in the three directions of XYZ, so as to obtain the scanning image of the sample.

[0036] Taking the low-temperature atomic-level morphology scanning of graphene in two-dimensional layered materials as a specific scenario, this method rapidly generates a matching piezoelectric ceramic driving voltage signal to avoid positional shifts in the mesa due to minor disturbances in the low-temperature environment. This counteracts the influence of changes in the elastic modulus of the flexible metal hinge on displacement transmission at low temperatures, ensuring that the deformation of the piezoelectric ceramic is accurately converted into mesa displacement. This allows the atomic-level morphology scanning image of graphene to clearly present the lattice structure without distortion caused by displacement deviation or insufficient strategy adaptation.

[0037] like Figure 2The diagram shows a flowchart of the generation of the drive voltage control signal provided in this application embodiment. The real-time coordinate position is compared and judged by interval. If it is within the interval, the position is sampled and adjusted first, and then the drive voltage is regulated. If it is greater than the maximum value of the interval, the real-time position monitoring and warning are performed. If it is less than the minimum value of the interval, the drive voltage is regulated. After that, the digital-to-analog conversion voltage is transferred to the next part.

[0038] Furthermore, the real-time position data of the stage output by the capacitive sensor is acquired in real time. The specific process is as follows: the real-time coordinate position transmitted by the piezoelectric scanning stage is obtained through the capacitive sensor and compared with the preset target coordinate position; in the process of determining the real-time position data of the stage, the sample resolution detected by the optical lens is monitored, and the detection magnification of the optical lens is adjusted according to the obtained sample resolution deviation and combined with the resolution-magnification mapping relationship to avoid position judgment deviation caused by the blurring of the observed sample.

[0039] If the acquired real-time position deviation is greater than the maximum distance within the position deviation range, it indicates that there is an error in the currently acquired real-time position data of the sample under test, and a real-time position detection warning command is sent. If the acquired real-time position deviation is within the position deviation range, it indicates that there is an error in the currently acquired real-time position data of the sample under test, and position sampling adjustment is performed: Based on the acquired real-time position deviation, the control unit sends a sampling parameter adjustment command, specifically: by adjusting the sampling frequency of the capacitive sensor (e.g., increasing the basic sampling frequency from 5kHz to 8-10kHz) and the sampling window duration (e.g., shortening the window duration from 2ms to 0.8-1.2ms), and simultaneously optimizing the filtering algorithm of the sampling data (e.g., using Kalman filtering instead of traditional mean filtering), the sampling accuracy and response speed of the real-time position data of the sample under test are improved, and the interference of error accumulation on subsequent closed-loop control is reduced. The specific values ​​shown in the embodiment are only examples for reference. In actual applications, relevant technical users can make fine adjustments according to the purpose of the current application scenario and the characteristics of the sample under test to meet the needs of the scenario.

[0040] If the acquired real-time position deviation is less than the minimum distance within the position deviation interval, it indicates that the acquired real-time position data of the sample under test is qualified. Then, the driving voltage is adjusted. Specifically, the acquired real-time position deviation of the sample under test is input into the position-voltage mapping algorithm to obtain the driving voltage value controlling the deformation of the piezoelectric ceramic. The FPGA control unit uses digital-to-analog conversion to convert the digital quantity corresponding to the input driving voltage value into an analog voltage quantity, so that the voltage corresponding to the digital quantity obtained after digital-to-analog conversion drives the piezoelectric ceramic to deform, causing the flexible metal hinge fixedly connected to the piezoelectric ceramic to deform. During the position sampling and adjustment process, the deviation between the position of the sample under test and the set position is monitored in real time. If the deviation is within the set allowable range, the driving voltage is adjusted; otherwise, a real-time position detection warning command is sent.

[0041] The specific process of comparing the coordinates with the preset target position is as follows: The real-time coordinate position of the piezoelectric scanning stage obtained by the capacitive sensor is represented by a three-dimensional vector P_real-time = (x1, y1, z1) (e.g., when x1 = 2.5mm, y1 = 3.1mm, z1 = 1.8mm, P_real-time = (2.5, 3.1, 1.8)); the preset target coordinate position is represented by a three-dimensional vector P_target = (x0, y0, z0) (e.g., when the target coordinates x0 = 2.4mm, y0 = 3.0mm, z0 = 1.8mm, P_target = (2.4, 3.0, 1.8)); the difference between the two vectors ΔP = P_real-time - P_target (in the example, ΔP = ...) is calculated. ), and complete the coordinate comparison.

[0042] In this embodiment, by comparing the real-time position with the target position using vector comparison and adjusting the optical lens magnification based on sample resolution deviation, position judgment errors caused by observational ambiguity can be avoided, thus improving the accuracy of position data from the source. When the real-time position deviation is too large, erroneous data is prevented from entering subsequent control stages, preventing closed-loop control from generating deviations based on incorrect information. If the deviation is within the acceptable range, the sampling accuracy and response speed of the position data are enhanced, reducing the interference of error accumulation on closed-loop control and making the acquired position information more consistent with the actual situation. When the deviation is small, direct adjustment of the drive voltage ensures timely voltage adjustment and avoids unnecessary delays. At the same time, real-time monitoring of the degree of deviation during position sampling and adjustment further strengthens the data reliability defense, ultimately ensuring that the entire closed-loop control process operates based on accurate and reliable position data, reducing scanning deviations caused by position judgment errors.

[0043] The preset target position is the real-time position of the sample to be tested obtained by the set calculation method. The sample resolution deviation represents the difference between the acquired sample resolution and the preset sample resolution. The preset sample resolution is set in advance according to the requirements of the sample to be tested. The resolution-magnification mapping relationship stores the mapping relationship between the sample resolution deviation and the optical lens detection magnification. Based on the Gaussian process regression algorithm, it is obtained by training with historical sample resolution and optical lens detection magnification in the process of determining the real-time position data of the platform. The real-time position deviation represents the distance between the acquired real-time coordinate position and the preset target coordinate position. The position deviation interval is a closed interval formed by the maximum and minimum distances of the historical real-time position deviations in the process of determining the real-time position data of the platform.

[0044] During the adjustment of sampling parameters, the sampling frequency, sampling window duration, and corresponding filtering algorithm are selected based on the Bayesian optimization algorithm in hyperparameter optimization to predict the performance of different hyperparameter combinations, and intelligently select the next point most likely to bring performance improvement for trial. In the process of driving voltage regulation, the position-voltage mapping algorithm is a pre-set algorithm, usually the PID control algorithm is selected, and different types of adjustments can be made according to different situations, but the algorithm adjustment is based on the PID control algorithm.

[0045] like Figure 3 The diagram shows a flowchart of the matching relationship determination and closed-loop feedback update provided in this application embodiment. By comparing the obtained actual displacement output score with the real-time deformation data score, it is determined whether to dynamically adjust the driving parameters or to perform a quantitative evaluation of the effectiveness of the control strategy. The dynamic adjustment of the driving parameters includes adjusting the amplification factor and the instruction to adjust the signal gain based on the converted displacement deviation. When the result is satisfactory, a quantitative evaluation of the effectiveness of the control strategy is performed. A target-hinge deformation curve is constructed for temperature compensation, and it is determined whether the strategy is effective. If effective, a closed-loop iteration is performed; if ineffective, the strategy is verified.

[0046] Furthermore, the matching relationship between the real-time acquisition of piezoelectric ceramic deformation and the required displacement of the piezoelectric scanning stage is as follows: Real-time deformation data of the corresponding flexible metal hinge is acquired, specifically the quantified data of the mechanical deformation state generated in real time by the flexible metal hinge under the deformation drive of the piezoelectric ceramic. This mechanical deformation is converted into measurable electrical signal data using a patch-type strain sensor. Simultaneously, the actual displacement output of the piezoelectric scanning stage is acquired, specifically the actual positional change of the piezoelectric scanning stage surface in space used to support the final positional movement of the sample under test. The acquired real-time deformation data is compared with reference real-time deformation data to obtain a real-time deformation data score. This score represents the ratio of the acquired real-time deformation data as the numerator to the reference real-time deformation data as the denominator, and is used to quantify the matching relationship. The process involves determining the degree of deformation deviation of the flexible metal hinge during the process; comparing the acquired actual displacement output with the reference actual displacement output to obtain an actual displacement output score, which represents the ratio of the acquired actual displacement output as the numerator and the reference actual displacement output as the denominator. The actual displacement output score is used to quantify the degree of displacement deviation of the piezoelectric scanning stage during the matching relationship determination process; if the acquired real-time deformation data score is not greater than the actual displacement output score, it indicates that the matching relationship between the real-time deformation data and the actual displacement output is qualified, and the effectiveness of the control strategy is quantitatively evaluated; if the acquired real-time deformation data score is greater than the actual displacement output score, it indicates that the matching relationship between the real-time deformation data and the actual displacement output is unqualified, and the driving parameters are dynamically adjusted to suppress the drift of the matching relationship between deformation and displacement output.

[0047] The dynamic adjustment of driving parameters involves: processing the difference between the acquired real-time deformation data fraction and the acquired actual displacement output fraction to obtain the displacement conversion deviation; based on the displacement conversion deviation, the FPGA control unit generates parameter adjustment instructions to adjust the amplification factor of the high-voltage amplifier circuit; if the displacement conversion deviation re-acquired after amplification factor adjustment is greater than the reference displacement conversion deviation, then based on the re-acquired displacement conversion deviation, it is input into the conversion-gain mapping relationship to generate a signal gain adjustment instruction, specifically: if the acquired rate of change of the electrical signal reflecting the real-time matching relationship between deformation and displacement is greater than the reference rate of change, then the signal gain of the high-voltage amplifier is increased; otherwise, the signal gain of the high-voltage amplifier is decreased to reduce the load on signal transmission; after the signal gain is adjusted, the effectiveness of the control strategy is quantitatively evaluated.

[0048] In this embodiment, if the deviation still does not improve, the signal gain of the high-voltage amplifier is adjusted by combining the rate of change of the deformation-displacement electrical signal. This can improve sensitivity to capture minute matching fluctuations when the signal is actively changing, and reduce the transmission load when the signal is stable, avoiding unnecessary energy consumption and signal distortion. The entire process, from matching judgment to parameter adjustment, forms a targeted logic, and the effectiveness of the control strategy is evaluated simultaneously after adjustment to continuously consolidate the conversion accuracy. Ultimately, it reduces the matching deviation between deformation and displacement, ensuring that the deformation energy of the piezoelectric ceramic is stably and accurately converted into the displacement required by the scanning stage, providing key support for the accuracy of low-temperature closed-loop scanning.

[0049] Real-time deformation data is acquired through strain gauge sensors attached to the surface of the metal hinge, while actual displacement output is acquired through capacitive sensors. Reference real-time deformation data is represented by the summation and averaging of historical real-time deformation data obtained during the historical matching relationship determination process. Reference actual displacement output is represented by the summation and averaging of historical actual displacement outputs obtained during the historical matching relationship determination process. The signal change rate is obtained by acquiring electrical signals based on digital-to-analog conversion and FPGA control unit. The reference change rate is represented by the summation and averaging of historical signal change rates obtained during the historical matching relationship determination process. In the process of adjusting the amplification factor of the high-voltage amplifier circuit, the adjustment of the amplification factor and the conversion-gain mapping relationship are based on the PI feedback control algorithm in Automatic Gain Control (AGC). In the process of determining the matching relationship, historical signal gain and amplification factor adjustment values ​​are obtained through training, enabling the system to obtain optimal overall performance in specific scenarios and long-term operation.

[0050] like Figure 4 The schematic diagram of the metal flexible hinge shown is as follows: Figure 5 The diagram shows the deformation of the scanning stage caused by the flexible metal hinge. The parts enclosed by the blue dashed box are all part of the flexible metal hinge structure. Its connection method and working principle are as follows:

[0051] One end of the flexible metal hinges 1, 4, and 9 is connected to the piezoelectric ceramic 8 as the fixed end 5, and the other end is connected to the piezoelectric scanning stage surface 7 as the movable end 3. This connection allows the flexible metal hinges to transmit deformation to the stage surface under the drive of the piezoelectric ceramic. The piezoelectric ceramic and the piezoelectric scanning stage surface are indirectly connected through the flexible metal hinges. The minute deformation generated by the piezoelectric ceramic is amplified by the flexible metal hinges and transmitted to the piezoelectric scanning stage surface, thereby causing the sample 6 to be tested placed on the stage to move.

[0052] The piezoelectric ceramic 8 is the driving source of the entire system. When the controller applies an alternating voltage to the piezoelectric ceramic, it undergoes a minute deformation according to the inverse piezoelectric effect. This minute deformation is transmitted to the flexible metal hinge, which then undergoes elastic bending (as shown in Figure 2, changing from the initial shape to the deformed shape), amplifying the minute displacement of the piezoelectric ceramic and transmitting it to the piezoelectric scanning stage 7. The piezoelectric scanning stage 7 supports the sample 6 to be tested. Under the displacement transmitted from the flexible metal hinge, it achieves precise displacement, thereby enabling scanning, measurement, or testing of the sample. By precisely controlling the alternating voltage applied to the piezoelectric ceramic, displacement control of the sample in different directions and with varying precision can be achieved, meeting the high-precision requirements of low-temperature closed-loop scanning.

[0053] Furthermore, the effectiveness of the control strategy is quantitatively evaluated. The process is as follows: Real-time displacement data of the stage surface is received from the capacitive sensor, and a motion curve of the target-hinge deformation is constructed to improve the dynamic response efficiency during the low-temperature closed-loop scanning control process. The real-time displacement data of the stage surface represents the actual displacement result after transmission and amplification through the flexible metal hinge. The motion curve of the target-hinge deformation is used to visualize the dynamic transmission relationship between the stage surface displacement and the hinge deformation. The displacement coordinates on the xyz axes of the piezoelectric scanning stage surface are received from the capacitive sensor, with the stage surface as the length and width as the corresponding xy axes, and the stage height as... The z-axis is used to simultaneously acquire the real-time deformation of the flexible metal hinge and perform time axis calibration to generate the target-hinge deformation motion curve. The time axis calibration is represented by time on the horizontal axis and the table displacement and hinge deformation on the vertical axis, respectively. During the generation of the target-hinge deformation motion curve, the real-time temperature value of the corresponding flexible metal hinge when the piezoelectric ceramic is working is acquired simultaneously and marked on the target-hinge deformation motion curve to establish a temperature-displacement deviation mapping table. This table is used to record the displacement deviation value corresponding to the same driving signal at different temperatures, providing data support for subsequent temperature drift compensation.

[0054] The acquired drive signal synchronization error is input into the historical temperature-displacement deviation mapping table to obtain the temperature compensation value. This value is then added to the current real-time temperature value to obtain the actual temperature adjustment value, which is used to compensate for temperature drift during the scanning process of the sample under test. During the temperature adjustment process, if the newly acquired drive signal synchronization error is greater than the reference drive signal synchronization error, it indicates that the sample testing and scanning adjustment strategy under low-temperature conditions is effective, and closed-loop iterative optimization is performed. Otherwise, it indicates that there is an error in the sample testing and scanning adjustment strategy under low-temperature conditions, and a strategy verification command is sent to prompt the preset personnel to check the currently executed scanning process. Specifically, the closed-loop iterative optimization is as follows: the result of the quantitative evaluation of the effectiveness of the control strategy is stored in the historical temperature-displacement deviation mapping table for updating, so as to improve the accuracy of subsequent temperature drift compensation and complete one closed-loop iteration.

[0055] In this embodiment, by constructing the target-hinge deformation motion curve, the dynamic transmission relationship between the table displacement and the hinge deformation can be intuitively presented, clearly showing the real-time correlation between the two, which is beneficial to improving the dynamic response efficiency of the control process. Simultaneously acquiring the real-time temperature of the flexible metal hinge and marking it on the curve, the established temperature-displacement deviation mapping table can provide accurate data for temperature drift compensation, making the compensation measures more closely reflect the actual temperature effect on displacement.

[0056] By combining the synchronization error of the drive signal with a mapping table to obtain temperature compensation values, temperature drift during the scanning process can be specifically offset, reducing displacement deviations caused by temperature changes. Closed-loop iterative optimization, through updating the mapping table, continuously improves the accuracy of subsequent temperature drift compensation, forming a constantly improving compensation mechanism. Meanwhile, strategy verification instructions can promptly detect errors in strategy adjustments, preventing ineffective strategies from continuously affecting scanning results, ensuring the reliability and stability of the low-temperature scanning process, and providing a guarantee for accurately acquiring data from the sample under test.

[0057] The temperature-displacement deviation mapping table is based on a reinforcement learning algorithm. It trains the historical driving signal synchronization error and the corresponding temperature compensation value during the historical quantification evaluation process to obtain the mapping relationship between temperature and displacement deviation. The driving signal synchronization error represents the deviation between the output state of the voltage signal controlling the deformation of the piezoelectric ceramic and the corresponding deformation of the metal flexible hinge and the displacement of the piezoelectric scanning stage, which is used to reflect the degree of deviation between the expected command and the execution result. The reference driving signal synchronization error is represented by the summation and averaging of the driving signal synchronization errors during the historical quantification evaluation process. The closed-loop iteration is based on the Bayesian learning method of Gaussian process regression. It uses a neural network for incremental training, adding the data points obtained in each iteration to the training set to update the network.

[0058] like Figure 6The diagram shown is a schematic representation of the low-temperature closed-loop scanning control system provided in this embodiment of the application. The low-temperature closed-loop scanning control system provided in this embodiment includes the following modules: a drive voltage control signal generation module, a deformation-displacement matching module, and a control strategy closed-loop feedback module. The drive voltage control signal generation module is used to acquire real-time position data of the piezoelectric scanning stage during the scanning process of the sample under test, output by the capacitive sensor. Simultaneously, based on a preset position-voltage mapping algorithm, it converts the acquired real-time position deviation into a corresponding control voltage value to generate a voltage control signal for driving the piezoelectric ceramic. The deformation-displacement matching module is used to acquire the matching relationship between the deformation of the piezoelectric ceramic and the required displacement of the piezoelectric scanning stage in real time, and dynamically adjust the drive parameters to ensure that the deformation energy of the piezoelectric ceramic is accurately converted into the required displacement output of the stage. The control strategy closed-loop feedback module is used to receive real-time displacement data of the stage fed back by the capacitive sensor, and simultaneously quantitatively evaluate the effectiveness of the control strategy corresponding to the piezoelectric ceramic and hinge combination during the closed-loop control process to improve the dynamic response efficiency during the low-temperature closed-loop scanning control process.

[0059] In this embodiment, the voltage control signal generated by the driving voltage control signal generation module acts on the piezoelectric ceramic, providing a basic driving basis for the deformation-displacement matching module. By analyzing the matching relationship between the two, the driving parameters are dynamically adjusted. The adjusted driving parameters are then fed back to the driving voltage control signal generation module, making the subsequently generated voltage control signal more closely match the current deformation-displacement conversion requirements and reducing conversion deviation. Simultaneously, the scanning stage displacement data generated by the collaborative action of the driving voltage control signal generation module and the deformation-displacement matching module is fed back to the control strategy closed-loop feedback module via a capacitive sensor. The feedback module quantitatively evaluates the effectiveness of the control strategy based on this displacement data. The evaluation results are then used to inversely optimize the first two modules: on the one hand, providing a reference for the driving voltage control signal generation module to adjust the position-voltage mapping algorithm; on the other hand, guiding the deformation-displacement matching module to optimize the driving parameter adjustment logic, forming a closed-loop linkage of generation-driving, adjustment-matching, and feedback optimization.

[0060] like Figure 7The diagram shows the controller structure of the cryogenic closed-loop scanning control device provided in this application embodiment, including: an FPGA control unit, a capacitance sensing measurement module, a DA module, a high-voltage amplification module, a channel switching module, and a piezoelectric scanning stage; the FPGA control unit receives the real-time position data of the stage transmitted by the capacitance sensing measurement module, and converts the deviation between the real-time position of the stage and the preset target position into the corresponding driving voltage value according to a preset position-voltage mapping algorithm, and transmits it to the DA module; the capacitance sensing measurement module applies an excitation signal to the capacitance sensor in the piezoelectric scanning stage and reads the feedback signal to obtain the real-time position data of the stage along the xyz axis, achieving a high-speed sampling rate and data transmission with the FPGA control unit; the DA module is used to convert the FPGA signal into a high-voltage amplification module, a channel switching module, and a piezoelectric scanning stage. The digital drive voltage input from the GA control unit is converted into an analog voltage, which is then output to the high-voltage amplifier in the high-voltage amplification module for storage. The high-voltage amplification module receives the analog voltage input from the DA module and amplifies the analog voltage to the required drive voltage for the piezoelectric ceramic by adjusting the amplification factor and signal gain of the high-voltage amplifier. The channel switching module connects multiple piezoelectric scanning stages to the controller and distributes the drive voltage output from the FPGA control unit to the target piezoelectric scanning stage. The piezoelectric scanning stage is the displacement actuator of the cryogenic closed-loop scanning device, containing piezoelectric ceramic and a capacitive sensor. The piezoelectric ceramic receives the drive voltage output from the high-voltage amplification module, causing the flexible metal hinge to deform, while the capacitive sensor monitors the displacement changes of the piezoelectric scanning stage in real time.

[0061] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the flow or function according to the embodiments of the present invention is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. A computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. Available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media. Semiconductor media can be solid-state drives.

[0062] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0063] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0064] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0065] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0066] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0067] In the embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0068] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0069] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0070] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0071] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A low-temperature closed-loop scanning control method, characterized in that, Includes the following steps: S1. During the scanning process of the sample to be tested, the real-time position data of the platform output by the capacitive sensor is acquired in real time. At the same time, based on the preset position-voltage mapping algorithm, the acquired real-time position deviation is converted into the corresponding control voltage value to generate the voltage control signal to drive the piezoelectric ceramic. The real-time position data of the platform is used to reflect the actual spatial position of the platform. The real-time position deviation is used to reflect the difference between the actual position of the platform and the target position. S2. Real-time acquisition of the matching relationship between the piezoelectric ceramic deformation and the required displacement of the piezoelectric scanning stage, and dynamic adjustment of the driving parameters to ensure that the deformation energy of the piezoelectric ceramic is accurately converted into the displacement output required by the stage. The piezoelectric ceramic deformation represents the amount of expansion or bending deformation generated by the piezoelectric ceramic under voltage control signal. The driving parameters include the amplification factor of the high voltage amplifier circuit and the measurement gain of the capacitance sensor. S3. Receive the real-time displacement data of the platform from the capacitive sensor, and simultaneously quantify and evaluate the effectiveness of the control strategy corresponding to the piezoelectric ceramic and hinge combination in the closed-loop control process to improve the dynamic response efficiency in the low-temperature closed-loop scanning control process. The real-time displacement data of the platform represents the actual displacement result after being transmitted and amplified by the metal flexible hinge.

2. The low-temperature closed-loop scanning control method as described in claim 1, characterized in that, The specific process for acquiring the real-time position data of the platform output by the capacitive sensor is as follows: The real-time coordinate position transmitted by the piezoelectric scanning stage is obtained by a capacitive sensor and compared with the preset target coordinate position; During the process of determining the real-time position data of the platform, the sample resolution detected by the optical lens is monitored, and the detection magnification of the optical lens is adjusted according to the obtained sample resolution deviation and the resolution-magnification mapping relationship, so as to avoid position judgment deviation caused by the blurring of the sample under test.

3. The low-temperature closed-loop scanning control method as described in claim 2, characterized in that, The comparison with the preset target coordinate position specifically involves: If the real-time position deviation is greater than the maximum value of the position deviation range, it indicates that there is an error in the real-time position data of the sample to be tested, and a real-time position detection warning command is sent. If the obtained real-time position deviation is within the position deviation range, it indicates that there is an error in the real-time position data of the sample to be tested, and position sampling adjustment is performed. If the real-time position deviation is less than the minimum value of the position deviation range, it means that the real-time position data of the sample to be tested is qualified, and then the driving voltage is adjusted. The position sampling adjustment process is as follows: Based on the acquired real-time position deviation, a sampling parameter adjustment command is sent. Specifically, the sampling frequency and sampling window duration of the capacitive sensor are adjusted, and the filtering algorithm of the sampling data is optimized simultaneously to improve the sampling accuracy and response speed of the real-time position data of the sample under test. After the position sampling is adjusted, the driving voltage is regulated.

4. The low-temperature closed-loop scanning control method as described in claim 3, characterized in that, The position sampling adjustment also includes: During the position sampling and adjustment process, the relationship between the real-time position deviation of the sample under test and the position deviation range is monitored in real time. If the real-time position deviation is less than the minimum value of the position deviation range, the driving voltage is adjusted; otherwise, a real-time position detection warning command is sent. The specific process of driving voltage regulation is as follows: The real-time position deviation of the sample to be tested is input into the position-voltage mapping algorithm to obtain the driving voltage value for controlling the deformation of the piezoelectric ceramic. The digital quantity corresponding to the input driving voltage value is converted into an analog voltage quantity using digital-to-analog conversion to drive the voltage regulation of the metal flexible hinge.

5. The low-temperature closed-loop scanning control method as described in claim 1, characterized in that, The specific process for matching the real-time acquisition of the piezoelectric ceramic deformation with the required displacement of the piezoelectric scanning stage is as follows: Acquire real-time deformation data of the flexible metal hinge connected to the piezoelectric ceramic, and simultaneously acquire the actual displacement output of the piezoelectric scanning stage; The acquired real-time deformation data is compared with the reference real-time deformation data to obtain a real-time deformation data score. The real-time deformation data score is used to quantify the degree of deformation deviation of the metal flexible hinge during the matching relationship determination process. The actual displacement output is compared with the reference actual displacement output to obtain the actual displacement output score. The actual displacement output score is used to quantify the degree of displacement deviation of the piezoelectric scanning stage during the matching relationship determination process. If the score of the real-time deformation data is not greater than the score of the actual displacement output, it indicates that the matching relationship between the real-time deformation data and the actual displacement output is qualified, and the effectiveness of the control strategy is quantitatively evaluated. If the score of the acquired real-time deformation data is greater than the score of the actual displacement output, it indicates that the matching relationship between the real-time deformation data and the actual displacement output is not qualified, and the driving parameters are dynamically adjusted to suppress the drift of the matching relationship between deformation and displacement output.

6. The low-temperature closed-loop scanning control method as described in claim 5, characterized in that, The dynamic adjustment of the driving parameters specifically refers to: The difference between the acquired real-time deformation data score and the acquired actual displacement output score is processed to obtain the displacement conversion deviation; Based on the displacement conversion deviation, parameter adjustment commands are generated to adjust the amplification factor of the high-voltage amplifier circuit. If the displacement conversion deviation reacquired after amplification adjustment is greater than the reference displacement conversion deviation, a signal gain adjustment command is generated based on the reacquired displacement conversion deviation; otherwise, a quantitative evaluation of the effectiveness of the control strategy is performed. The signal gain adjustment command is specifically as follows: If the rate of change of the electrical signal reflecting the real-time matching relationship between deformation and displacement is greater than the reference rate of change, then increase the signal gain of the high-voltage amplifier; otherwise, decrease the signal gain of the high-voltage amplifier to reduce the load on signal transmission. After adjusting the signal gain, a quantitative evaluation of the effectiveness of the control strategy is performed.

7. The low-temperature closed-loop scanning control method as described in claim 6, characterized in that, The process for quantitatively evaluating the effectiveness of the control strategy is as follows: The real-time displacement data of the platform is received from the capacitive sensor, and the deformation motion curve of the target under test-hinge is constructed to improve the dynamic response efficiency in the low-temperature closed-loop scanning control process. The real-time displacement data of the platform represents the actual displacement result after being transmitted and amplified by the metal flexible hinge. The deformation motion curve of the target under test-hinge is used to visualize the dynamic transmission relationship between the platform displacement and the hinge deformation. The construction of the target-hinge deformation motion curve is specifically as follows: By receiving the displacement coordinates on the xyz axis of the piezoelectric scanning stage, simultaneously acquiring the real-time deformation of the metal flexible hinge, and performing time axis calibration, a deformation motion curve of the target under test-hinge is generated. The time axis calibration means that the horizontal axis is time, and the vertical axis is the displacement of the stage and the hinge deformation, respectively. During the generation of the target-hinge deformation motion curve, the real-time temperature value of the corresponding metal flexible hinge when the piezoelectric ceramic is working is simultaneously acquired and marked on the target-hinge deformation motion curve to establish a temperature-displacement deviation mapping table, which is used to record the displacement deviation value corresponding to the same driving signal at different temperatures.

8. The low-temperature closed-loop scanning control method as described in claim 7, characterized in that, The process of quantitatively evaluating the effectiveness of the control strategy also includes: The acquired drive signal synchronization error is input into the historical temperature-displacement deviation mapping table to obtain the temperature compensation value, and then added to the current real-time temperature value to obtain the actual temperature adjustment value, which is used to compensate for the temperature drift during the scanning process of the sample under test. If the synchronization error of the reacquired drive signal is greater than the synchronization error of the reference drive signal during the temperature adjustment process, it indicates that the sample testing and scanning adjustment strategy under low temperature conditions is effective, and closed-loop iterative optimization is performed. Otherwise, it indicates that there is an error in the sample testing and scanning adjustment strategy under low temperature conditions, and a strategy verification instruction is sent to prompt the preset personnel to check the currently executed scanning process; The closed-loop iterative optimization specifically includes: The results of the quantitative evaluation of the effectiveness of the control strategy are stored in the historical temperature-displacement deviation mapping table for updating, so as to improve the accuracy of subsequent temperature drift compensation and complete a closed-loop iteration.

9. A low-temperature closed-loop scanning control system applying the low-temperature closed-loop scanning control method as described in any one of claims 1-8, comprising the following modules: a drive voltage control signal generation module, a deformation-displacement matching module, and a control strategy closed-loop feedback module; The driving voltage control signal generation module is used to acquire the real-time position data of the piezoelectric scanning stage output by the capacitive sensor during the scanning process of the sample to be tested. At the same time, based on the preset position-voltage mapping algorithm, the acquired real-time position deviation is converted into the corresponding control voltage value to generate the voltage control signal driving the piezoelectric ceramic. The deformation-displacement matching module is used to collect the matching relationship between the deformation of the piezoelectric ceramic and the displacement required by the piezoelectric scanning stage in real time, and dynamically adjust the driving parameters to ensure that the deformation energy of the piezoelectric ceramic is accurately converted into the displacement output required by the stage. The control strategy closed-loop feedback module is used to receive real-time displacement data of the platform from the capacitive sensor, and at the same time to quantitatively evaluate the effectiveness of the control strategy corresponding to the piezoelectric ceramic and hinge combination in the closed-loop control process, so as to improve the dynamic response efficiency in the low-temperature closed-loop scanning control process.

10. A cryogenic closed-loop scanning device employing the cryogenic closed-loop scanning control method as described in any one of claims 1-8, comprising: FPGA control unit, capacitance sensing measurement module, DA module, high voltage amplification module, channel switching module and piezoelectric scanning stage; The FPGA control unit is used to receive the real-time position data of the platform transmitted by the capacitive sensing measurement module, and convert the deviation between the real-time position of the platform and the preset target position into the corresponding driving voltage value according to the preset position-voltage mapping algorithm, and transmit it to the DA module. The capacitance sensing measurement module is used to apply an excitation signal to the capacitance sensor in the piezoelectric scanning stage and read the feedback signal to obtain the real-time position data of the stage xyz axis, thereby achieving a high-speed sampling rate and data transmission with the FPGA control unit. The DA module is used to convert the digital value of the drive voltage input from the FPGA control unit into an analog voltage value, and output it to the high voltage amplifier in the high voltage amplifier module for storage. The high-voltage amplifier module is used to receive the analog voltage input from the DA module. By adjusting the amplification factor and signal gain of the high-voltage amplifier, the analog voltage is amplified to the driving voltage required by the piezoelectric ceramic. The channel switching module is used to connect multiple piezoelectric scanning stages and the controller, and distribute the driving voltage output by the FPGA control unit to the target piezoelectric scanning stage; The piezoelectric scanning stage is the displacement actuator of the low-temperature closed-loop scanning device, containing piezoelectric ceramic and capacitive sensor. The piezoelectric ceramic is used to receive the driving voltage output by the high-voltage amplification module, which drives the metal flexible hinge to deform. The capacitive sensor is used to monitor the displacement change of the piezoelectric scanning stage in real time.

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