Active vibration reduction sample table suitable for low-temperature environment
By combining active vibration damping units and passive vibration isolation structures, the problems of insufficient vibration and detection accuracy of low-temperature sample stages are solved, realizing high-precision vibration control and displacement detection in low-temperature environments, and meeting high-precision testing requirements.
Patent Information
- Application Number
- CN202512030177.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-03-03
AI Technical Summary
Existing low-temperature sample stages are unable to effectively suppress cold source vibrations in low-temperature environments, resulting in large residual vibrations and insufficient displacement detection accuracy, which affects high-precision testing.
An active vibration reduction system is formed by adopting an active vibration reduction unit, a low-temperature load-bearing unit, a cold source adaptation unit, and a collaborative control unit, combined with non-contact displacement detection, a low-temperature resistant piezoelectric actuator, and a closed-loop control module. Combined with an air-bearing passive vibration isolation structure and flexible connection, it achieves dual vibration attenuation and real-time compensation for displacement detection.
The residual vibration of the sample stage is reduced from the micrometer level to the nanometer level to meet the requirements of high-precision low-temperature testing. The displacement detection accuracy is stabilized at the nanometer level, avoiding the detection device from occupying the optical window and ensuring that the optical testing function is not affected.
Smart Images
Figure CN121595464A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of precision instruments and mechanical engineering technology, and in particular to an active vibration damping sample stage suitable for low-temperature environments. Background Technology
[0002] In cryogenic testing scenarios in fields such as cryogenic physics and cryogenic optics, cryogenic sample stages must simultaneously meet the requirements of cryogenic environment and low vibration control, while also being compatible with optical testing functions. However, existing cryogenic sample stage technologies have significant shortcomings and are difficult to adapt to high-precision applications. First, they rely on passive vibration reduction methods such as rubber bellows and flexible supports, which cannot effectively suppress vibrations generated by the operation of the cold source. The sample stage still has significant residual vibrations, failing to meet the low vibration standards required for high-precision testing. Second, displacement detection schemes in cryogenic environments are not perfect. For example, there are problems such as insufficient detection accuracy due to the influence of low temperature, and the detection device occupying the optical window and affecting optical testing functions. These issues prevent meeting the stringent temperature requirements of high-precision testing and limit the accuracy and applicability of cryogenic testing. Summary of the Invention
[0003] The purpose of this invention is to provide an active vibration damping sample stage suitable for low-temperature environments, thereby solving the aforementioned technical problems.
[0004] To achieve the above objectives, the present invention provides an active vibration damping sample stage suitable for low-temperature environments, comprising an active vibration damping unit, a low-temperature bearing unit, a cold source adaptation unit, a low-temperature unit, and a collaborative control unit; The active vibration damping unit includes a non-contact displacement detection module, a low-temperature piezoelectric actuator assembly, and a closed-loop control module, all electrically connected in sequence. The low-temperature load-bearing unit includes a vacuum chamber and a sample stage body. The cold source adaptation unit includes a low-temperature refrigerator, a low-rigidity flexible connection structure, and an integrated cold-conducting and vibration-isolation assembly. The low-temperature unit includes a secondary cold plate, a low-temperature compatible heater, and a temperature sensor. The low-temperature refrigerator is connected to the vacuum chamber and the sample stage body through the flexible connection structure. An air-floating passive vibration isolation structure is provided between the low-temperature refrigerator and the mounting surface of the sample stage body. The secondary cold plate is connected to the sample stage body and the cold head of the low-temperature refrigerator through a flexible cold-conducting assembly. The coordination control unit is connected to each unit via signal.
[0005] Preferably, the non-contact displacement detection module of the active vibration damping unit adopts any one or more of the following combinations to collect the vibration displacement of the sample stage body: Option 1: Includes 3 laser interferometers arranged along the X, Y, and Z axes respectively, and a reflector fixed on the main body of the sample stage. The laser interferometers are installed on the outer wall of the vacuum cavity or on the vibration isolation platform, and the laser beam path avoids the cold screen and flexible cooling components inside the vacuum cavity. Option 2: Includes an inertial sensor installed on the main body of the sample stage, which collects acceleration signals and integrates them to obtain displacement signals; Option 3: Includes a microscope imaging component, which acquires sample images in real time and processes them using image algorithms to obtain the relative displacement of the sample. When acquiring sample images, one imaging camera or a combination of two or more stereo imaging cameras can be used.
[0006] Preferably, the low-temperature resistant piezoelectric actuator assembly of the active vibration damping unit adopts any of the following configurations to compensate for the displacement generated by vibration in the reverse direction: Configuration 1: The sample stage body, Z-axis piezoelectric actuator, Y-axis piezoelectric actuator, X-axis piezoelectric actuator, and mounting base plate are connected in the vertical direction in that order. The X-axis and Y-axis each use two opposing piezoelectric actuators, and the two opposing actuators use a push-pull drive method with opposite polarities to compensate for the overturning deviation of the sample stage body caused by vibration. The Z-axis uses one piezoelectric actuator to compensate for vertical vibration. Configuration 2: The X-axis and Y-axis each use one piezoelectric actuator, and the Z-axis uses one piezoelectric actuator. They are connected in the vertical direction in the following order: sample stage body, Z-axis piezoelectric actuator, Y-axis piezoelectric actuator, X-axis piezoelectric actuator, and mounting base plate. Configuration 3: A 6-degree-of-freedom control structure is formed by using 6 piezoelectric actuators.
[0007] Preferably, the closed-loop control module of the active vibration damping unit receives the vibration displacement signal transmitted by the non-contact displacement detection module, and generates a drive control signal after filtering and phase analysis to drive the low-temperature resistant piezoelectric actuator assembly to move. At the same time, the closed-loop control module also receives the real-time temperature signal of the sample stage body collected by the low-temperature unit, and corrects the detection error caused by low-temperature strain in the optical elements, inertial elements or gratings in the non-contact displacement detection module through a PID temperature compensation algorithm.
[0008] Preferably, the vacuum cavity of the low-temperature bearing unit is provided with one top optical window and four to eight side optical windows for multi-dimensional optical testing; the top surface of the sample stage body is reserved with a sample fixing slot for placing the sample to be tested, and the volume of the sample fixing slot is adapted to the installation space of the low-temperature piezoelectric actuator assembly.
[0009] Preferably, the low-rigidity flexible connection structure of the cold source adapter unit includes a flexible corrugated pipe, a flexible cold-conducting component, and an optional gas heat exchange pipeline. The room temperature end of the cryogenic refrigerator is sealed to the vacuum chamber through the flexible corrugated pipe, the 40K cold end of the cryogenic refrigerator is connected to the cold screen in the vacuum chamber through the flexible cold-conducting component, and the 4K cold end of the cryogenic refrigerator is connected to the sample stage body through the flexible cold-conducting component or the gas heat exchange pipeline.
[0010] Preferably, the flexible cooling component of the cold source adapter unit includes multiple oxygen-free copper strips arranged in parallel. The oxygen-free copper strips are wrapped with a polytetrafluoroethylene low-temperature compatible coating layer. The connection end between the flexible cooling component and the secondary cold plate adopts an embedded structure and is embedded in the pre-set cooling groove of the secondary cold plate.
[0011] Preferably, the cryogenic refrigeration unit of the cold source adapter unit is provided with vibration damping feet at the bottom. The vibration damping feet and the air-float passive vibration isolation structure form a dual passive vibration damping system. At the same time, the vacuum chamber sidewall of the cryogenic bearing unit is reserved with an electrical vacuum connection for the wires of the active vibration damping unit and the cryogenic unit to be led out through the cavity.
[0012] Preferably, the microscope imaging assembly is rigidly fixed to the mounting surface of the sample stage body by a support arm, and its objective lens faces the top optical window of the vacuum cavity.
[0013] Preferably, the collaborative control unit has a built-in microprocessor-like chip, and the elastic vibration isolation joint of the integrated cooling-vibration isolation component adopts a variable stiffness structure. The collaborative control unit receives the temperature signal from the low-temperature unit, the vibration signal from the non-contact displacement detection module, and the vibration transmission status signal from the cold source adaptation unit. Through analysis using a fuzzy PID hybrid control algorithm, when the vibration signal exceeds the preset range, the stiffness of the elastic vibration isolation joint is increased; when the temperature signal deviates from the set value, the cold energy transfer efficiency of the cooling chain is adjusted; when the two are coupled, the adjustment priority of cooling efficiency and vibration isolation stiffness is dynamically balanced to achieve collaborative adaptation of cooling, vibration isolation, and active vibration reduction.
[0014] Therefore, the present invention employs the above-mentioned active vibration damping sample stage suitable for low-temperature environments, which has the following beneficial effects: 1. By combining the air-float passive vibration isolation structure with the low-temperature refrigerator vibration damping feet, a dual passive vibration damping foundation is formed, which initially attenuates the vibration of the cold source and the external environment. Then, combined with the non-contact displacement detection module to capture vibration signals in real time, the low-temperature resistant piezoelectric actuator to compensate for displacement and the closed-loop control module, an active vibration damping system is formed. This system can reduce the residual vibration of the sample stage from the micron level of existing technologies to the nanometer level, solving the problem that passive vibration damping cannot eliminate the inherent vibration of the cold source, and meeting the stringent requirements of low vibration for high-precision low-temperature testing of quantum materials, semiconductor devices, etc.
[0015] 2. The closed-loop control module has a built-in PID temperature compensation algorithm, which can receive the real-time temperature signal of the low-temperature unit, correct the error caused by low-temperature strain in the displacement detection module, and solve the problem of insufficient accuracy of the existing detection scheme due to low temperature.
[0016] 3. The displacement detection module does not require the use of optical windows, and the vacuum cavity is designed with one top optical window and four to eight expandable side windows. Even if detection methods that require windows, such as laser interferometers, are used, the remaining windows can still meet the optical testing requirements, avoiding functional conflicts between the detection device and optical testing.
[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of an active vibration damping sample stage suitable for low-temperature environments according to the present invention; Figure 2 This is a schematic diagram of the active vibration damping sample stage of the present invention; Figure 3 This is a schematic diagram of an embodiment of the integration of the low-temperature thermostat and the active vibration isolator of the present invention; Figure 4 This is a flowchart of the active vibration reduction closed-loop control signal of the present invention; Figure 5 This is a flowchart illustrating the connection relationships between the various units of the present invention. Attached Figure Description
[0019] 1. Glass window; 2. Vacuum chamber; 3. Sample stage body; 4. Cold shield; 5. Secondary cold plate; 6. Active vibration damper; 7. Microscope assembly; 8. Vacuum bellows; 9. Flexible cooling assembly; 10. Table screen; 11. Inertial sensor; 12. Cryogenic refrigerator cold head; 13. Cryogenic refrigerator support; 14. Vibration-damping feet. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.
[0021] It should be noted that the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as a process, method, system, product, or server that includes a series of steps or units, not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or device.
[0022] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
[0023] like Figures 1-5As shown, the present invention proposes an active vibration damping sample stage suitable for low-temperature environments, which has excellent adaptability to low-temperature environments and compatibility with low-temperature system integration. It can be matched with commonly used cryogenic refrigerators and achieve efficient integration with existing low-temperature systems. At the same time, it takes into account the integration requirements of maintaining a low-temperature vacuum environment and various types of low-temperature high-precision testing. It includes an active vibration damping unit, a low-temperature bearing unit, a cold source adapter unit, a low-temperature unit, and a collaborative control unit. The active vibration damping unit includes a non-contact displacement detection module, a low-temperature resistant piezoelectric actuator assembly, and a closed-loop control module connected in sequence. The low-temperature bearing unit includes a vacuum chamber 2 and a sample stage body 3. The cold source adapter unit includes a cryogenic refrigerator, a low-stiffness flexible connection structure, and an integrated cold conduction-vibration isolation assembly. The low-temperature unit includes a secondary cold plate 5, a low-temperature compatible heater, and a temperature sensor. The cryogenic refrigerator is connected to the vacuum chamber 2 and the sample stage body 3 through the flexible connection structure. An air-floating passive vibration isolation structure is provided between the mounting surface of the cryogenic refrigerator and the sample stage body 3. The secondary cold plate 5 is connected to the sample stage body 3 and the cryogenic refrigerator cold head 12 through a flexible cold conduction assembly 9. The collaborative control unit is connected to each unit via signal.
[0024] Specifically, the non-contact displacement detection module of the active vibration damping unit adopts one or more of the following combinations: Option 1: Includes three laser interferometers arranged along the X, Y, and Z axes respectively, and a reflector fixed on the sample stage body 3. The laser interferometers are installed on the outer wall of the vacuum cavity 2 or the vibration isolation platform, and the laser beam path avoids the cold screen 4 and the flexible cooling component 9 inside the vacuum cavity 2. The cryogenic refrigerator cold head 12 can be set as an eccentric structure to reserve a window at the bottom of the vacuum cavity 2. Option 2: Obtains acceleration signals through an inertial sensor 11 installed on the sample stage body 3 and integrates them to obtain displacement signals. Option 3: Obtains sample images in real time through a microscope component 7 and processes them using an algorithm to obtain... For sample relative displacement, sample image acquisition can be performed using one imaging camera or a combination of two or more stereo imaging cameras, requiring only one optical window, such as glass window 1. Furthermore, the microscope assembly 7 is rigidly fixed to the mounting surface of the sample stage body 3 via a support arm, with its objective lens facing the top glass window 1 of the vacuum chamber 2. The microscope assembly 7 acquires images of the sample on the sample stage body 3 in real time, assisting in the observation and verification of the vibration control effect of the sample stage body 3. Real-time image observation directly verifies the vibration control effect, such as transforming a blurry image of micron-level vibration into a clear image of nanometer-level vibration, eliminating the need for additional verification devices and improving the ease of use and reliability of the test results. Among the three solutions mentioned above, their advantages are as follows: Solution 1 avoids interference between the laser optical path and the cold source components through an eccentric cold head design, adapting to high-precision displacement detection requirements; Solution 2 does not require occupying glass window 1, retaining all windows for optical testing, resolving the conflict between detection and testing window space; Solution 3 reduces reliance on sample markings through stereo imaging, extending to testing scenarios with unmarked samples. These three solutions cover different testing conditions, improving equipment adaptability.
[0025] The low-temperature resistant piezoelectric actuator assembly of the active vibration damping unit adopts any of the following configurations. Specifically, Configuration 1: The sample stage body 3, Z-axis piezoelectric actuator, Y-axis piezoelectric actuator, X-axis piezoelectric actuator, and mounting base plate are connected vertically in the order of sample stage body 3, Z-axis piezoelectric actuator, Y-axis piezoelectric actuator, X-axis piezoelectric actuator, and mounting base plate. The X-axis and Y-axis each use two opposing piezoelectric actuators, and the two opposing actuators use a push-pull drive method with opposite polarities to reduce the overturning deviation of the sample stage body 3 caused by vibration. The Z-axis uses one piezoelectric actuator. Two other configurations are also possible: Configuration 2: The X-axis and Y-axis each use one piezoelectric actuator, and the Z-axis uses one piezoelectric actuator, connected vertically in the order of sample stage body 3, Z-axis piezoelectric actuator, Y-axis piezoelectric actuator, X-axis piezoelectric actuator, and mounting base plate. Configuration 3: Six piezoelectric actuators form a 6-DOF control structure to achieve multi-dimensional attitude adjustment and vibration compensation of the sample stage body 3. The advantages of the above three configurations are as follows: Configuration 1 solves the flipping problem of the sample stage body 3 through opposing push-pull drive, which is suitable for high-precision testing scenarios such as quantum materials; Configuration 2 simplifies the structure and reduces costs, meeting the vibration control requirements of conventional low-temperature testing; Configuration 3 realizes multi-degree-of-freedom adjustment, which can cope with complex attitude control scenarios such as atomic force microscopy and improve the cost performance of the equipment.
[0026] The closed-loop control module of the active vibration reduction unit receives the real-time temperature signal of the sample stage body 3 collected by the low-temperature unit. Through the built-in temperature compensation algorithm, it corrects the detection errors caused by low-temperature strain of optical elements, inertial elements or gratings in the non-contact displacement detection module. It covers the low-temperature error problem of various detection elements such as grating ruler, laser interferometer, and inertial sensor 11, avoids detection deviation caused by thermal contraction in the 4-40K environment, ensures that the displacement detection accuracy is stable at the nanometer level, and provides accurate signal input for active vibration reduction.
[0027] The vacuum chamber 2 of the cryogenic bearing unit has one glass window 1 and four basic side glass windows 1 on the top, which can be expanded to eight side glass windows 1 according to the testing requirements for multi-dimensional optical testing. The top surface of the sample stage body 3 has a reserved sample fixing groove for stable placement of the sample to be tested, and its volume is adapted to the installation space of cryogenic piezoelectric actuator components, such as active shock absorbers 6. Through the design of basic windows plus expandable windows, it not only meets the window requirements of conventional optical testing, but also adapts to the multi-window requirements of multi-dimensional combined testing, avoiding functional limitations caused by a fixed number of windows and improving the versatility of the equipment.
[0028] The low-temperature resistant flexible connection structure of the cold source adapter unit includes a vacuum bellows 8, a flexible heat conduction component 9, and an optional gas heat exchange pipeline. When the test requires high heat conduction efficiency, the oxygen-free copper strip is a good conductor with a heat conduction efficiency far higher than that of the gas medium, so there is no need to use the gas heat exchange pipeline. The room temperature end of the cryogenic refrigerator is sealed to the vacuum chamber 2 through the vacuum bellows 8. The 40K cold end of the cryogenic refrigerator is connected to the cold screen 4 in the vacuum chamber 2 through the flexible heat conduction component 9. The 4K cold end of the cryogenic refrigerator is connected to the sample stage body 3 through the flexible heat conduction component 9 or the gas heat exchange pipeline. The flexible cooling component 9 of the cold source adapter unit includes multiple oxygen-free copper strips arranged in parallel. The connection end between the flexible cooling component 9 and the secondary cold plate 5 adopts an embedded structure and is embedded in the pre-set cooling groove of the secondary cold plate 5. The oxygen-free copper strips can be selectively wrapped with a polytetrafluoroethylene low-temperature compatible coating layer, and the coating layer does not cover the contact area between the cooling chain and the secondary cold plate 5 and the sample stage body 3, so as to ensure the efficiency of cold transfer and keep the temperature of the sample stage body 3 relatively stable.
[0029] The cryogenic refrigerator support 13 of the cold source adapter unit is equipped with vibration-damping feet 14 at its bottom. An air-floating passive vibration isolation structure is installed between the sample stage body 3 (located on the tabletop 10) and the ground. The vibration-damping feet 14 and the air-floating passive vibration isolation structure together form a dual passive vibration reduction system to weaken the vibration transmitted to the sample stage body 3 during cryogenic refrigerator operation. Simultaneously, the vacuum chamber 2 of the cryogenic bearing unit has a pre-installed electrical vacuum connection on its side wall for the wires of the active vibration reduction unit and the cryogenic unit to pass through the chamber, ensuring the airtightness of the vacuum chamber 2. The dual passive vibration reduction first reduces the vibration of the cryogenic refrigerator by 50%-70% from its initial level, laying the foundation for subsequent active vibration reduction and reducing the compensation load of the active vibration reduction unit. The vacuum connection design ensures vacuum sealing while preventing vibration transmission caused by wire exits, thus balancing cryogenic maintenance and vibration isolation.
[0030] The collaborative control unit incorporates a microprocessor-like chip, such as the STM32H7 series high-performance microcontroller. The elastic vibration isolation joint of the integrated cooling-vibration isolation component adopts a variable stiffness structure, which is a composite of laminated rubber and piezoelectric ceramics. The stiffness can be continuously adjusted according to the working conditions, balancing flexible vibration isolation and structural stability. The collaborative control unit receives temperature signals from the low-temperature unit, vibration signals from the non-contact displacement detection module, and vibration transmission status signals from the cold source adaptation unit. Through fuzzy PID hybrid control algorithm analysis, the three types of signals are first filtered, denoised, and normalized. Then, the precise signals are converted into fuzzy linguistic variables such as "large / medium / small deviation," and combined with preset expert rules for reasoning and judgment. When the vibration signal exceeds the preset range, it is determined that vibration should be suppressed first, and the output signal increases the stiffness of the elastic vibration isolation joint. When the temperature signal deviates from the set value, it is determined that the temperature should be stabilized first, and the cold energy transfer efficiency of the cooling chain should be adjusted. When the two are coupled, the algorithm balances the priority of cooling and vibration isolation by dynamically allocating adjustment weights, avoiding conflicting adjustment actions, and ultimately achieving coordinated adaptation of cooling, vibration isolation, and active vibration reduction.
[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. An active vibration damping sample stage suitable for low-temperature environments, characterized in that: Includes active vibration damping unit, low temperature load-bearing unit, cold source adaptation unit, low temperature unit and collaborative control unit; The active vibration damping unit includes a non-contact displacement detection module, a low-temperature piezoelectric actuator assembly, and a closed-loop control module, all electrically connected in sequence. The low-temperature load-bearing unit includes a vacuum chamber and a sample stage body. The cold source adaptation unit includes a low-temperature refrigerator, a low-rigidity flexible connection structure, and an integrated cold-conducting and vibration-isolation assembly. The low-temperature unit includes a secondary cold plate, a low-temperature compatible heater, and a temperature sensor. The low-temperature refrigerator is connected to the vacuum chamber and the sample stage body through the flexible connection structure. An air-floating passive vibration isolation structure is provided between the low-temperature refrigerator and the mounting surface of the sample stage body. The secondary cold plate is connected to the sample stage body and the cold head of the low-temperature refrigerator through a flexible cold-conducting assembly. The coordination control unit is connected to each unit via signal.
2. The active vibration damping sample stage suitable for low-temperature environments according to claim 1, characterized in that: The non-contact displacement detection module of the active vibration damping unit uses any one or more of the following combinations to collect the vibration displacement of the sample stage body: Option 1: Includes 3 laser interferometers arranged along the X, Y, and Z axes respectively, and a reflector fixed on the main body of the sample stage. The laser interferometers are installed on the outer wall of the vacuum cavity or on the vibration isolation platform, and the laser beam path avoids the cold screen and flexible cooling components inside the vacuum cavity. Option 2: Includes an inertial sensor installed on the main body of the sample stage, which collects acceleration signals and integrates them to obtain displacement signals; Option 3: Includes a microscope imaging component, which acquires sample images in real time and processes them using image algorithms to obtain the relative displacement of the sample. When acquiring sample images, one imaging camera or a combination of two or more stereo imaging cameras can be used.
3. The active vibration damping sample stage suitable for low-temperature environments according to claim 1, characterized in that: The low-temperature resistant piezoelectric actuator assembly of the active vibration damping unit adopts any of the following configurations to compensate for the displacement caused by vibration in the reverse direction: Configuration 1: The sample stage body, Z-axis piezoelectric actuator, Y-axis piezoelectric actuator, X-axis piezoelectric actuator, and mounting base plate are connected in the vertical direction in that order. The X-axis and Y-axis each use two opposing piezoelectric actuators, and the two opposing actuators use a push-pull drive method with opposite polarities to compensate for the overturning deviation of the sample stage body caused by vibration. The Z-axis uses one piezoelectric actuator to compensate for vertical vibration. Configuration 2: The X-axis and Y-axis each use one piezoelectric actuator, and the Z-axis uses one piezoelectric actuator. They are connected in the vertical direction in the following order: sample stage body, Z-axis piezoelectric actuator, Y-axis piezoelectric actuator, X-axis piezoelectric actuator, and mounting base plate. Configuration 3: A 6-degree-of-freedom control structure is formed by using 6 piezoelectric actuators.
4. The active vibration damping sample stage suitable for low-temperature environments according to claim 3, characterized in that: The closed-loop control module of the active vibration damping unit receives the vibration displacement signal transmitted by the non-contact displacement detection module. After filtering and phase analysis, it generates a drive control signal to drive the low-temperature piezoelectric actuator assembly. At the same time, the closed-loop control module also receives the real-time temperature signal of the sample stage body collected by the low-temperature unit. Through the PID temperature compensation algorithm, it corrects the detection error caused by low-temperature strain in the optical elements, inertial elements or gratings in the non-contact displacement detection module.
5. The active vibration damping sample stage suitable for low-temperature environments according to claim 1, characterized in that: The vacuum chamber of the low-temperature bearing unit is equipped with one top optical window and four to eight side optical windows for multi-dimensional optical testing; the top surface of the sample stage body is reserved with a sample fixing slot for placing the sample to be tested, and the volume of the sample fixing slot is adapted to the installation space of the low-temperature piezoelectric actuator assembly.
6. The active vibration damping sample stage suitable for low-temperature environments according to claim 1, characterized in that: The low-rigidity flexible connection structure of the cold source adapter unit includes a flexible corrugated pipe, a flexible cold-conducting component, and an optional gas heat exchange pipeline. The room temperature end of the cryogenic refrigerator is sealed to the vacuum chamber through the flexible corrugated pipe. The 40K cold end of the cryogenic refrigerator is connected to the cold shield in the vacuum chamber through the flexible cold-conducting component. The 4K cold end of the cryogenic refrigerator is connected to the sample stage body through the flexible cold-conducting component or the gas heat exchange pipeline.
7. The active vibration damping sample stage suitable for low-temperature environments according to claim 6, characterized in that: The flexible cooling component of the cold source adapter unit includes multiple oxygen-free copper strips arranged in parallel. The oxygen-free copper strips are wrapped with a polytetrafluoroethylene low-temperature compatible coating layer. The connection end between the flexible cooling component and the secondary cold plate adopts an embedded structure and is embedded in the pre-set cooling groove of the secondary cold plate.
8. The active vibration damping sample stage suitable for low-temperature environments according to claim 7, characterized in that: The cryogenic refrigeration unit of the cold source adapter unit is equipped with vibration damping feet at the bottom of the support. The vibration damping feet and the air-float passive vibration isolation structure form a dual passive vibration damping system. At the same time, the vacuum chamber sidewall of the cryogenic bearing unit is reserved with an electrical vacuum connection for the wires of the active vibration damping unit and the cryogenic unit to be led out through the cavity.
9. The active vibration damping sample stage suitable for low-temperature environments according to claim 2, characterized in that: The microscope imaging assembly is rigidly fixed to the mounting surface of the sample stage body by a support arm, and its objective lens faces the top optical window of the vacuum cavity.
10. An active vibration damping sample stage suitable for low-temperature environments according to claim 1, characterized in that: The collaborative control unit has a built-in microprocessor-like chip, and the elastic vibration isolation joint of the integrated cooling-vibration isolation component adopts a variable stiffness structure. The collaborative control unit receives the temperature signal from the low-temperature unit, the vibration signal from the non-contact displacement detection module, and the vibration transmission status signal from the cold source adaptation unit. Through analysis using a fuzzy PID hybrid control algorithm, when the vibration signal exceeds the preset range, the stiffness of the elastic vibration isolation joint is increased; when the temperature signal deviates from the set value, the cold energy transfer efficiency of the cooling chain is adjusted; when the two are coupled, the adjustment priority of cooling efficiency and vibration isolation stiffness is dynamically balanced to achieve collaborative adaptation of cooling, vibration isolation, and active vibration reduction.