High-precision axial fine adjustment structure

Abstract

The application discloses a high-precision axial fine adjustment structure, which is used for realizing high-frequency response and high-precision positioning of axial displacement in a dynamic following process. The structure is composed of a fine adjustment structure main body and a driving control circuit. The main body part is slidably connected to a bottom plate through a guide piece and a transmission connection support. A piezoelectric actuator and an elastic force balance mechanism abut against the support from opposite directions, so that the support is in a pre-tightening force balance state and generates axial micro-displacement in response to driving. The driving control circuit integrates a multi-core heterogeneous control unit and a signal acquisition module containing a power amplification circuit. The signal acquisition module acquires displacement parameters fed back by a position detection assembly in real time, the multi-core heterogeneous control unit calculates the deviation of real-time displacement and a target height instruction according to the displacement parameters, and generates a compensation control quantity. Finally, the power amplification circuit converts the control quantity into a dynamic driving voltage and outputs the dynamic driving voltage to the piezoelectric actuator, so that the support executes precise displacement adjustment.

Description

Technical Field

[0001] This application relates to the field of precision motion control, and more particularly to a high-precision axial micro-adjustment structure. Background Technology

[0002] In precision inspection, precision machining, and autofocus equipment, actuators typically need to complete high-precision displacement adjustments in an extremely short time to meet the demands of applications such as high-speed scanning, dynamic tracking, and real-time focusing. As the operating speed and precision requirements of equipment continue to increase, displacement actuators face even greater challenges in terms of response speed, positioning accuracy, and operational stability.

[0003] Existing precision displacement actuators typically employ electric drive or other fast-response actuation methods to achieve minute displacement control. However, under conditions of high-speed dynamic operation and load bearing, the actuator is susceptible to various factors, leading to displacement fluctuations, unstable response, or decreased accuracy during operation, thereby affecting the overall performance and long-term operational reliability of the equipment. Summary of the Invention

[0004] To address the aforementioned technical issues, this application provides a high-precision axial micro-motion adjustment structure for achieving high-frequency response and high-precision positioning of axial displacement during dynamic following.

[0005] The technical solution provided in this application is described below:

[0006] This application provides a high-precision axial micro-adjustment structure, including: The main body of the micro-adjustment structure and the drive control circuit; The main body of the micro-motion adjustment structure includes: a base plate, a guide component, a transmission connection bracket, a piezoelectric actuator, a position detection component, and an elastic force balancing mechanism; The transmission connection bracket is slidably connected to the base plate through the guide member. The output end of the piezoelectric actuator and the elastic force balancing mechanism abut against the transmission connection bracket from opposite directions, so that the transmission connection bracket is in a pre-tightening force balance state and generates a small axial displacement in response to the drive of the piezoelectric actuator in the pre-tightening force balance state. The drive control circuit includes: a multi-core heterogeneous control unit, a signal acquisition module, and a power amplifier circuit built into the signal acquisition module; The signal acquisition module connects the position detection component and the multi-core heterogeneous control unit. The signal acquisition module is used to acquire and transmit the real-time displacement parameters of the axial displacement of the transmission connection bracket output by the position detection component, and feed them back to the multi-core heterogeneous control unit through a feedback signal. The multi-core heterogeneous control unit calculates the compensation control quantity based on the displacement deviation between the real-time displacement feedback signal and the target height command, wherein the target height command includes the initially calibrated compliance height; The compensation control quantity is converted into a dynamic drive voltage by the power amplifier circuit, and the dynamic drive voltage is output to the piezoelectric actuator to drive the transmission connection bracket to perform displacement adjustment.

[0007] Optionally, the elastic force balancing mechanism includes: Disc spring assembly and preload adjustment component; The elastic force balancing mechanism is integrally disposed below the base plate; The disc spring assembly sets the preload amount through the preload adjustment component, and applies a constant preload force to the transmission connection bracket in the opposite direction to the output direction of the piezoelectric actuator, so that the transmission connection bracket always keeps in close contact with the output end of the piezoelectric actuator, and cooperates with the piezoelectric actuator to clamp the transmission connection bracket.

[0008] Optionally, the position detection component includes: Optical measuring scale and measuring head; The optical measuring ruler is fixed to the base plate, and the measuring head is fixed to the side edge of the transmission connection bracket; The detection head moves synchronously with the transmission connection bracket, generates a differential position signal by sensing the grid displacement of the optical detection ruler, and feeds it back to the signal acquisition module so that the signal acquisition module can acquire the differential position signal in real time and convert it into real-time displacement parameters in digital state.

[0009] Optionally, the structure further includes: A ranging component, which is disposed on the base plate, includes a laser emitter and a laser receiver; The laser emitter and the laser receiver are symmetrically and obliquely arranged on both sides of the transmission connection bracket; The laser emitter projects a laser beam onto the surface of the target to be detected. The laser receiver obtains the current surface height of the target in real time by capturing the reflection signal of the laser beam, and obtains a target height correction command. The target height correction command is then dynamically input to the multi-core heterogeneous control unit in real time.

[0010] Optionally, the multi-core heterogeneous control unit includes: Logic processing core and general processing core; The logic processing core is used to execute the real-time closed-loop control algorithm, perform deviation calculation based on the real-time displacement parameters of the digital state, and output the compensation control quantity. The general-purpose processing core is used for task scheduling and external communication; The logic processing core is electrically connected to the signal acquisition module, and the general processing core and the logic processing core interact with each other via an on-chip bus.

[0011] Optionally, the logic processing core integrates an error compensation module and a signal filtering module. The signal filtering module performs noise reduction processing on the real-time displacement parameters of the digital state using a Kalman filtering algorithm, and the error compensation module performs nonlinear correction on the compensation control quantity according to a preset hysteresis model.

[0012] Optionally, the power amplifier circuit is a two-stage series-connected high-voltage power amplifier circuit, which is used to linearly amplify the low-voltage logic signal output by the multi-core heterogeneous control unit into a dynamic drive voltage of 0-120V.

[0013] Optionally, the drive control circuit further includes: The hardware protection module includes a hardware comparison circuit, which is connected in parallel to the real-time drive current signal of the piezoelectric actuator and the real-time displacement parameter. The hardware protection module is used to monitor the parameter relationship between the drive current or the real-time displacement parameter and the preset safety threshold, so as to execute the corresponding protection logic according to the parameter relationship.

[0014] Optionally, the hardware protection module executes tiered trigger protection logic: When the drive current or the real-time displacement parameter exceeds the first safety threshold, the multi-core heterogeneous control unit performs a software reset protection. When the drive current or the real-time displacement parameter exceeds a second safety threshold that is higher than the first safety threshold, the hardware comparison circuit performs a hardware circuit shutdown.

[0015] Optionally, an image acquisition device is connected and installed on the transmission connection bracket, and the multi-core heterogeneous control unit synchronously adjusts the operating frequency of the piezoelectric actuator according to the exposure frequency of the image acquisition device, so that the image acquisition device driven by the transmission connection bracket can achieve displacement adjustment during the movement.

[0016] As can be seen from the above technical solutions, this application has the following advantages: First, an antagonistic preload state is established on the transmission connection bracket by a piezoelectric actuator and an elastic force balancing mechanism, eliminating mechanical backlash and hysteresis at the physical level. Second, a multi-core heterogeneous control unit is used to achieve functional decoupling, with the logic processing core handling the high-frequency closed-loop algorithm, and using real-time displacement parameters acquired by the signal acquisition module for deviation compensation. Finally, a power amplifier circuit converts the compensation command into a high-dynamic drive voltage, enabling rapid energy injection. This structure achieves deep coupling between mechanical rigidity and electronic control, not only eliminating the mechanical hysteresis of traditional micro-motion mechanisms but also significantly improving the system's control bandwidth through heterogeneous parallel computing, ensuring high-frequency response speed and high-precision positioning performance during dynamic tracking of axial displacement adjustment. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the main body of the high-precision axial micro-motion adjustment structure in this application; Figure 2 This is a front view of the main body of the high-precision axial micro-adjustment structure in this application; Figure 3 This is a schematic diagram of the elastic force balance mechanism of the high-precision axial micro-motion adjustment structure in this application; Figure 4 This is a schematic diagram of the piezoelectric actuator with the high-precision axial micro-motion adjustment structure in this application; Figure 5 This is a schematic diagram of the position detection component of the high-precision axial micro-motion adjustment structure in this application; Figure 6 This is a schematic diagram of the guide component of the high-precision axial micro-motion adjustment structure in this application; Figure 7 This is a schematic diagram of the drive control circuit for the high-precision axial micro-motion adjustment structure in this application. Detailed Implementation

[0019] In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and other terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to describe the relative positional relationship between the components or parts and do not specifically limit the specific installation orientation of each component or part.

[0020] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0021] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] Furthermore, the structures, proportions, sizes, etc., drawn in the accompanying drawings of this application are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0023] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Please see Figures 1 to 7 This application first provides an embodiment of a high-precision axial micro-adjustment structure, which includes: The main body of the micro-adjustment structure and the drive control circuit; The main body of the micro-motion adjustment structure includes: a base plate 11, a guide member 12, a transmission connection bracket 13, a piezoelectric actuator 14, a position detection component 15, and an elastic force balancing mechanism 16; The transmission connection bracket 13 is slidably connected to the base plate 11 through the guide member 12. The output end of the piezoelectric actuator 14 and the elastic force balancing mechanism 16 abut against the transmission connection bracket 13 from opposite directions, so that the transmission connection bracket 13 is in a pre-tightening force balance state, and generates a small axial displacement in response to the drive of the piezoelectric actuator 14 in the pre-tightening force balance state. The drive control circuit includes: a multi-core heterogeneous control unit 21, a signal acquisition module 22, and a power amplifier circuit 221 built into the signal acquisition module 22; The signal acquisition module 22 connects the position detection component 15 and the multi-core heterogeneous control unit 21. The signal acquisition module 22 is used to acquire and transmit the real-time displacement parameters of the axial displacement of the transmission connection bracket 13 output by the position detection component 15, and feed them back to the multi-core heterogeneous control unit 21 through feedback signals. The multi-core heterogeneous control unit 21 calculates the compensation control quantity based on the displacement deviation between the real-time displacement feedback signal and the target height command, wherein the target height command includes the initially calibrated compliance height; The compensation control quantity is converted into a dynamic driving voltage by the power amplifier circuit 221, and the dynamic driving voltage is output to the piezoelectric actuator 14 to drive the transmission connection bracket 13 to perform displacement adjustment.

[0025] In this embodiment, the micro-motion adjustment structure serves as the execution terminal for high-frequency actions, and the drive control circuit serves as the calculation and power output terminal; the two are electrically connected.

[0026] The main body of the micro-adjustment structure includes a base plate 11, a guide component 12, a transmission connection bracket 13, a piezoelectric actuator 14, a position detection component 15, and an elastic force balancing mechanism 16. Specifically, the guide component 12 is a precision crossed ball bearing guide, which consists of a V-shaped raceway guide, a roller cage, and staggered cylindrical rollers. This provides high-rigidity, low-friction linear guidance for axial movement, ensuring that the transmission connection bracket 13 does not wobble during high-speed reciprocating motion.

[0027] The piezoelectric actuator 14 is a stacked piezoelectric actuator that uses the inverse piezoelectric effect to generate deformation. It has the characteristics of large thrust, fast response and resolution down to the nanometer level. In this embodiment, the piezoelectric actuator is a set of two, which are respectively set on both sides of the transmission connection bracket 13 on the base plate 11 to meet the force balance of the transmission connection bracket 13 when the displacement occurs.

[0028] In this embodiment, the main parameters of the piezoelectric actuator 14 are as follows: stroke range 50-100μm±10%, resolution 1-5nm, repeatability 0.2%FS, no-load resonant frequency ≥2000Hz±20%, thrust ≤1200N, tension ≤200N, and driving voltage 0-120V. The front push rod (output end) of the piezoelectric actuator 14 abuts against the transmission connection bracket 13, while the elastic force balancing mechanism 16 applies a constant preload in the opposite direction to the front push rod of the piezoelectric actuator 14, so that the transmission connection bracket 13 is in a state of force balance.

[0029] The transmission connection bracket 13 is equipped with an image acquisition device 131. In this embodiment, the image acquisition device 131 is specifically a high-speed acquisition CCD (charge-coupled device) used to capture microscopic defect images of the surface of an OLED (organic light-emitting diode) panel (the surface to be inspected) in real time during the inspection process. Its overall weight together with the weight of the bracket constitutes the inertial load of the system.

[0030] The drive control circuit adopts a modular hardware architecture, including a multi-core heterogeneous control unit 21, a signal acquisition module 22, and a power amplifier circuit 221. The signal acquisition module 22 connects the position detection component 15 to the multi-core heterogeneous control unit 21. It integrates a 16-bit high-precision D / A converter to convert the digital control commands directly generated by the multi-core heterogeneous control unit 21 into extremely low-noise continuous analog control signals, ensuring high precision and high-speed dynamic response when driving the actuator. The multi-core heterogeneous control unit 21 calculates the compensation control quantity based on the displacement deviation between the real-time displacement feedback signal and the target height command, which includes the initially calibrated compliance height. The calculated control signal undergoes two-stage linear amplification through the power amplifier circuit 221, converting it into a 0-120V dynamic drive voltage and outputting it to the piezoelectric actuator 14. This drive voltage can generate a dynamic thrust of up to 1200N, driving the transmission connection bracket 13 to perform displacement adjustment within microseconds, thereby ensuring that the module's no-load resonant frequency remains above 2000Hz, fundamentally supporting millisecond-level real-time focusing response.

[0031] Optionally, the elastic force balancing mechanism 16 includes: Disc spring assembly 161 and preload adjustment component 162; The elastic force balancing mechanism 16 is integrally disposed below the base plate 11; The disc spring assembly 161 sets the preload amount through the preload adjustment member 162, and applies a constant preload force to the transmission connection bracket 13 that is opposite to the output direction of the piezoelectric actuator 14, so that the transmission connection bracket 13 always keeps in close contact with the output end of the piezoelectric actuator 14, and cooperates with the piezoelectric actuator 14 to clamp the transmission connection bracket 13.

[0032] Specifically, the preload adjustment component 162 uses a micro-adjustment bolt. The disc spring assembly 161 is composed of multiple stacked disc spring plates, which passes through the base plate 11 and abuts against the bottom of the transmission connection bracket 13 via the preload adjustment component 162. During assembly, the preload of the disc spring assembly 161 is compressed by manually tightening the micro-adjustment bolt, which acts as the preload adjustment component 162, thereby applying a reverse constant preload force to the transmission connection bracket 13. The design principle of this mechanism is based on utilizing the stiffness characteristics of the disc spring assembly 161 to ensure that the system satisfies the balance formula: the sum of the axial load and thrust of the piezoelectric actuator 14 is equal to the sum of the tension of the piezoelectric actuator 14 and the elastic force of the disc spring assembly 161.

[0033] It should be noted that in practice, in order to ensure the structural lifespan, a safety factor is usually set when performing calculations. For example, in this embodiment, the safe stroke of the disc spring assembly 161 is 75% of the total stroke. Also, when calculating the balance formula, the tension of the piezoelectric actuator 14 and the elasticity of the disc spring assembly 161 should have a 30% margin to avoid loss of control, that is, take 70% of the maximum value.

[0034] Taking specific application parameters as an example, the parameters of the piezoelectric actuator 14 are: stroke range 50-100μm±10%, resolution 1-5nm, repeatability 0.2%FS, no-load resonant frequency ≥2000Hz±20%, thrust ≤1200N, tension ≤200N, driving voltage 0-120V, the displacement range of the disc spring assembly 161 is 0.2-1.1mm, the applied force range is 105N-10767N, the initial elastic force caused by the preload of the elastic force balancing mechanism 16 is 2926N, and the initial compression stroke is 0.55mm.

[0035] Based on the above initial conditions, when the axial stroke requirement of the piezoelectric actuator 14 is 65μm, the axial load of the piezoelectric actuator is 220N, and the current thrust of the piezoelectric actuator is 100N, the required spring force of the disc spring assembly 161 in conjunction with the output of the piezoelectric actuator 14 is calculated as follows: First, convert the axial travel unit: 65μm / 1000=0.065mm.

[0036] Based on the converted axial travel and the initial parameters of 75% of the spring's full travel, the coefficients for the displacement required by the disc spring assembly 161 when moving 65μm are calculated as follows: 0.065mm / 0.55mm. 75% = 0.0886.

[0037] After determining the coefficients, the change in initial elastic force is calculated based on the coefficients, which is 0.0886. 2926N=259N, meaning that without the influence of other conditions, the thrust required by the piezoelectric actuator 14 to achieve a displacement elastic force balance mechanism 16 of 65μm is 259N.

[0038] At this point, the balance formula must be satisfied: the sum of the axial load (220N) and thrust (100N) of the piezoelectric actuator 14 must equal the sum of the initial maximum tension (200N) of the piezoelectric actuator 14 and the elastic force (259N) of the disc spring assembly 161, that is: 220N + 100N and 200N 0.7+259N The calculated value of 0.7 is equivalent (should be understood as equal or very close), that is, the initial elastic force of 2926N achieved by the preload of the current elastic force balancing mechanism 16 can cooperate with the piezoelectric actuator 14 to make its thrust and pull reach a balanced state in the dynamic process. This ensures that there is no physical backlash between the transmission connection bracket 13 and the piezoelectric actuator 14, thereby eliminating the backlash of the mechanical transmission and thus cooperating with the high-precision displacement of the piezoelectric actuator 14.

[0039] Optionally, the position detection component 15 includes: Optical measuring scale 151 and measuring head 152; The optical detection ruler 151 is fixed to the base plate 11, and the detection reading head 152 is fixed to the side edge of the transmission connection bracket 13; The detection head 152 moves synchronously with the transmission connection bracket 13. It generates a differential position signal by sensing the grid displacement of the optical detection ruler 151 and feeds it back to the signal acquisition module 22, so that the signal acquisition module 22 can acquire the differential position signal in real time and convert it into real-time displacement parameters in digital state.

[0040] Specifically, the optical measuring scale 151 is a high-precision grating scale with periodic engravings, and its body is firmly mounted on the reference surface of the base plate 11. The measuring head 152 is fixed to the side of the transmission connecting bracket 13 and keeps synchronized with the image acquisition device 131 in the axial movement direction. When the transmission connecting bracket 13 drives the measuring head 152 to move relative to the optical measuring scale 151 fixed on the base plate 11, the light-emitting element inside the measuring head 152 emits a light signal and projects it onto the engraving surface. It uses the moiré fringe effect to generate a coherent signal that changes with displacement and converts the light signal into an electrical signal with a specific phase relationship. Then, the electrical signal is output to the signal acquisition module 22, which performs electronic subdivision technology. Through the acquisition and conversion processing of the waveform signal, the physical engraving period is refined into a high-precision resolution, thereby generating high-precision digital real-time displacement parameters. This allows the linear displacement of the transmission connecting bracket 13 to be fed back to the control circuit in real time and accurately, ensuring that the high-speed acquisition CCD can achieve high-response autofocus operation based on accurate position feedback during movement.

[0041] Optionally, the structure further includes: A ranging component 17 is disposed on the base plate 11, and the ranging component 17 includes a laser emitter 171 and a laser receiver 172. The laser emitter 171 and the laser receiver 172 are symmetrically and obliquely arranged on both sides of the transmission connection bracket 13; The laser emitter 171 projects a laser beam onto the surface of the target to be detected. The laser receiver 172 obtains the current surface height of the target in real time by capturing the reflection signal of the laser beam. Based on the height information, the receiver calculates and processes the height to obtain a target height correction command, and then dynamically inputs the target height correction command to the multi-core heterogeneous control unit 21 in real time.

[0042] The ranging component 17 is fixed to the base plate 11 by a bracket and is used to detect the undulations of the surface to be inspected in real time. Specifically, a modulated laser pulse or continuous wave is emitted to the surface to be inspected by a laser emitter 171, and a laser receiver 172 captures the reflected echo. Then, by calculating the time difference or phase difference between the laser emission and reception, and combining it with the speed of light, the precise axial distance can be calculated. Accordingly, the ranging component 17 can acquire the surface height information of the target to be inspected in real time. Based on this height information, a target height correction command is generated after calculation and processing, and the target height correction command is dynamically input to the multi-core heterogeneous control unit 21 in real time, so that the system adjusts the displacement of the transmission connection bracket 13 in real time according to the actual shape of the surface to be inspected. This enables the high-speed acquisition CCD to achieve dynamic tracking and real-time focusing during flight inspection, ensuring that a clear image is always captured during the movement.

[0043] In addition, the ranging component 17 also has the following functions: Communication function: The data (digital or analog signal) to be transmitted is loaded onto the laser beam, for example, by encoding it by adjusting the intensity, frequency, or phase of the laser. After the laser receiver 172 detects this modulated optical signal, it restores the original data through photoelectric conversion and signal demodulation, thereby realizing high-bandwidth data transmission.

[0044] Synchronization function: A high-precision clock signal is encoded into the laser pulse sequence. When the laser receiver 172 receives each characteristic pulse, it generates a corresponding synchronization electrical signal. By comparing the clock signals of the laser transmitter 171 and the laser receiver 172, clock drift can be calibrated and compensated, thereby achieving microsecond or even nanosecond-level time synchronization and ensuring collaborative operation between devices.

[0045] Specifically, the multi-core heterogeneous control unit 21 includes: Logic processing core 211 and general processing core 212; The logic processing core 211 is used to execute the real-time closed-loop control algorithm, perform deviation calculation based on the real-time axial displacement parameters of the transmission connection bracket 13, and output the compensation control quantity; the general processing core 212 is used for task scheduling and external communication. The logic processing core 211 is electrically connected to the signal acquisition module 22, and the general processing core and the logic processing core 211 interact with each other via an on-chip bus.

[0046] The multi-core heterogeneous control unit 21 adopts a heterogeneous architecture of FPGA (Field-Programmable Gate Array) and ARM SOC (ARM System-on-Chip). The logic processing core 211 is specifically an FPGA, which uses its real-time hardware processing capabilities to build the core control logic and directly connects to the signal acquisition module 22. It completes real-time calculation and deviation correction of position information in each control cycle, ensuring the microsecond-level response of the control loop. The general-purpose processing core 212 is specifically an ARM SOC, which is responsible for running system-level tasks, including receiving and parsing external instructions, managing communication interfaces, and performing non-real-time task scheduling for the entire adjustment process.

[0047] In the heterogeneous architecture, the general-purpose processing core 212 and the logic processing core 211 work closely together via an on-chip bus. The general-purpose processing core 212 is responsible for upper-layer logic and global state management, issuing target height instructions and algorithm parameters to the logic processing core 211 via the on-chip bus. The logic processing core 211, on the other hand, independently runs the closed-loop algorithm at the lower level and transmits real-time displacement status and monitoring data back to the general-purpose processing core 212 via the on-chip bus. This clearly defined heterogeneous design enables the system to achieve high-frequency, high-precision real-time displacement adjustment without consuming the computing resources of the general-purpose processing core 212.

[0048] Optionally, the logic processing core 211 integrates an error compensation module 2111 and a signal filtering module 2112. The signal filtering module 2112 performs noise reduction processing on the real-time displacement parameters using a Kalman filtering algorithm, and the error compensation module 2111 performs nonlinear correction on the compensation control quantity according to a preset hysteresis model.

[0049] The signal filtering module 2112 constructs a state-space model in the logic processing core 211 and uses the Kalman filter algorithm to calculate the optimal estimate of the real-time displacement parameters containing random noise from the digital state fed back by the position detection component 15. Through iterative operations of prediction updates and correction updates, the algorithm removes measurement noise introduced by mechanical vibration or electromagnetic interference in real time in the time domain, thereby extracting high signal-to-noise ratio true displacement data and providing a stable feedback basis for closed-loop control.

[0050] The error compensation module 2111 is specifically designed to correct the inherent nonlinear hysteresis effect of the piezoelectric material used in the piezoelectric actuator 14. The logic processing core 211 has a pre-set hysteresis model based on experimental data, which describes the nonlinear mapping relationship between the driving voltage and the output displacement, as well as the hysteresis loop characteristics. The error compensation module 2111 performs inverse nonlinear correction on the calculated compensation control quantity according to this hysteresis model, offsetting the inconsistency in deformation of the piezoelectric material during voltage increase and decrease.

[0051] By using Kalman filtering for noise reduction and hysteresis model correction, the multi-core heterogeneous control unit 21 effectively solves the problems of nonlinear distortion and dynamic interference in precision displacement control. This enables the module to maintain extremely high trajectory tracking accuracy even in high-frequency reciprocating motion, supporting the module to achieve an idle resonant frequency of up to 2000Hz and meeting the technical requirements of millisecond-level high-response autofocus.

[0052] Optionally, the power amplifier circuit 221 is a two-stage series-connected high-voltage power amplifier circuit; the power amplifier circuit 221 is used to linearly amplify the low-voltage logic signal output by the multi-core heterogeneous control unit 21 into a dynamic drive voltage of 0-120V.

[0053] The power amplifier circuit 221 employs a two-stage series amplification architecture to achieve a balance between high gain and high current output. The first stage, acting as a preamplifier, pre-amplifies the milliwatt-level low-voltage logic control signal output from the multi-core heterogeneous control unit 21. The second stage, acting as a high-voltage power stage, further linearly boosts the pre-amplified signal to a 0-120V high-voltage drive signal.

[0054] The power amplifier circuit 221 provides sufficient dynamic drive current to the piezoelectric actuator 14 with capacitive characteristics, ensuring that the piezoelectric actuator 14 can generate dynamic thrust of up to 1200N.

[0055] Through a two-stage amplification design, the power amplifier circuit 221 maintains excellent output linearity and bandwidth, enabling the transmission connection bracket 13 to closely follow the control commands issued by the multi-core heterogeneous control unit 21 and complete high-frequency micro-displacement adjustments. This circuit layout not only improves the system's driving capability but also effectively isolates the logic circuit and the high-voltage drive circuit through staged amplification, enhancing the operational stability of the control circuit 2 in complex electromagnetic environments.

[0056] Optionally, the drive control circuit further includes: Hardware protection module 23, the hardware protection module 23 includes a hardware comparison circuit, the hardware comparison circuit is connected in parallel to the real-time drive current signal of the piezoelectric actuator 14 and the real-time displacement parameter; When the hardware protection module 23 monitors the parameter relationship between the drive current or the displacement parameter and the preset safety threshold, it executes corresponding protection logic according to the parameter relationship.

[0057] The hardware protection module 23 monitors the system's operating status in real time through hardware circuitry. The hardware comparison circuit simultaneously acquires the real-time operating current data of the piezoelectric actuator 14 and the physical displacement data returned by the position detection component 15 via the sensor feedback interface.

[0058] When the hardware comparator circuit detects an abnormal increase in the instantaneous current value, or when the displacement parameter shows that the transmission connection bracket 13 has exceeded the preset safety threshold, the hardware comparator circuit immediately outputs a low-level blocking signal. The blocking signal directly acts on the hardware enable terminal of the power amplifier circuit 221. Through hardware-level logic interlocking, the output of the dynamic drive voltage is forcibly cut off within a period of nanosecond-level time units.

[0059] Optionally, the hardware protection module 23 executes hierarchical trigger protection logic: When the drive current or the displacement parameter exceeds the first safety threshold, the multi-core heterogeneous control unit 21 performs a software reset protection. When the drive current or the displacement parameter exceeds a second safety threshold that is higher than the first safety threshold, the hardware comparison circuit performs a hardware circuit shutdown.

[0060] Specifically, the hardware protection module 23 establishes a layered defense mechanism. When the hardware protection module 23 detects that the drive current or displacement parameter exceeds the first safety threshold, it determines that the current state is an abnormal fluctuation requiring intervention. At this time, the hardware protection module 23 sends a trigger signal to the multi-core heterogeneous control unit 21, which executes a software reset protection program. By re-initializing the control algorithm and clearing the abnormal register, it attempts to restore the module to normal working state, and the general-purpose processing core 212 reports the current fluctuation record to the host computer.

[0061] When the drive current or displacement parameter rises further and exceeds the second safety threshold, which is higher than the first safety threshold, the hardware comparator circuit determines that the current state is a critical fault that endangers hardware safety. At this time, the hardware comparator circuit no longer relies on the logic judgment of the multi-core heterogeneous control unit 21, but directly outputs a blocking signal to the power amplifier circuit 221 through the level switching of the physical circuit, and forcibly shuts down the voltage output of the power amplifier circuit 221.

[0062] The hardware protection module 23 performs hierarchical monitoring, and the multi-core heterogeneous control unit 21 performs software reset and the hardware comparison circuit performs physical shutdown, which ensures the safety and reliability of the micro-adjustment structure under different fault levels.

[0063] Optionally, an image acquisition device 131 is connected and installed on the transmission connection bracket 13. The multi-core heterogeneous control unit 21 synchronously adjusts the operating frequency of the piezoelectric actuator 14 according to the exposure frequency of the image acquisition device 131, so that the image acquisition device 131 driven by the transmission connection bracket 13 can achieve displacement adjustment during the movement.

[0064] A high-speed CCD, serving as an image acquisition device 131, is mounted on the transmission connection bracket 13. During the dynamic detection process, the multi-core heterogeneous control unit 21 acts as the execution entity, receiving the exposure synchronization signal from the image acquisition device 131 in real time. The multi-core heterogeneous control unit 21 calculates the spatial position deviation of the image acquisition device 131 at the current exposure frequency in real time using its internal logic, and dynamically adjusts the driving frequency sent to the piezoelectric actuator 14 based on this, ensuring precise alignment between the extension and retraction movement of the piezoelectric actuator 14 and the exposure shutter timing of the image acquisition device 131.

[0065] Through this frequency synchronization mechanism, the multi-core heterogeneous control unit 21 drives the transmission connecting bracket 13 to counteract focal length changes caused by external vibrations or surface undulations of the object being measured at the moment of each image exposure. This displacement adjustment method ensures that the image acquisition device 131 remains within the preset focal plane range during the reciprocating motion with the transmission connecting bracket 13, thereby eliminating imaging blurring during the motion process and ensuring that the defect images captured by the high-speed acquisition CCD have extremely high clarity and contrast, providing high-quality raw data support for subsequent algorithm analysis.

[0066] The overall implementation process of this structure in actual use is as follows: First, the multi-core heterogeneous control unit 21 serves as the control core, and its general processing core 212 receives target height instructions from external sources or preset ones. These target height instructions are the heights obtained by manually focusing on preset initial detection targets on the same batch of target surfaces. Manual focusing enables the high-speed acquisition CCD to obtain clear images. The target height instructions carry data including at least the initially calibrated compliance height.

[0067] In practice, the physical height of the target surface to be detected within the same batch relative to the image acquisition device 131 varies with the placement coordinates of the target surface, resulting in non-unique heights for the same batch of target surfaces. Therefore, when switching target surfaces, a deviation will occur between the height of the high-speed acquisition CCD and the corresponding height of the next target surface and the target height command. At this time, the ranging component 17 projects a laser beam onto the target surface through the laser emitter 171, and the laser receiver 172 captures the reflected signal to obtain the current surface height of the target in real time. The multi-core heterogeneous control unit 21 dynamically corrects the target height command based on this real-time height information to achieve feedforward control.

[0068] The logic processing core 211 of the multi-core heterogeneous control unit 21 acquires the corrected instructions through the on-chip bus and synchronously receives the real-time displacement parameters of the digital state fed back by the signal acquisition module 22. The real-time displacement parameters of the digital state are generated by the detection head 152 sensing the moiré fringe displacement of the optical detection scale 151, and then electronically subdivided by the signal acquisition module 22 to generate high-precision position information.

[0069] The signal filtering module integrated inside the logic processing core 211 uses the Kalman filtering algorithm to reduce noise in the data. Then, the error compensation module 2111 performs nonlinear correction on the control quantity according to the preset hysteresis model and calculates the accurate compensation control quantity.

[0070] The low-voltage logic signal output from the logic processing core 211 enters the power amplifier circuit 221. Through the two-stage series-connected power amplifier circuit 221, the signal is linearly amplified to a dynamic drive voltage of 0-120V, driving the piezoelectric actuator 14 to generate a thrust of up to 1200N. Under this thrust, the transmission connection bracket 13 overcomes the constant preload applied by the disc spring assembly 161 and the preload adjustment component 162, causing the image acquisition device 131 on it to press down for micro-displacement adjustment.

[0071] During the motion, the multi-core heterogeneous control unit 21 adjusts the operating frequency of the piezoelectric actuator 14 in real time according to the exposure frequency of the image acquisition device 131, so as to ensure that the image acquisition device 131 is in the optimal focal plane at the moment of each frame exposure.

[0072] Throughout the process, the hardware protection module 23 performs parallel real-time monitoring. When the drive current or displacement parameter exceeds the first safety threshold, the multi-core heterogeneous control unit 21 performs software reset protection; if the drive current or displacement parameter further exceeds the second safety threshold, the hardware comparison circuit immediately outputs a blocking signal to forcibly shut down the output of the power amplifier circuit 221, thereby achieving physical protection of the main body of the micro-adjustment structure.

[0073] It should be noted that when the target height command was initially confirmed by manually focusing the high-speed acquisition CCD, the focal length of the high-speed acquisition CCD was already fixed. Subsequently, the high-speed acquisition CCD was axially displaced in the Z-axis direction to achieve continuous focusing when the working height changed.

[0074] This embodiment achieves a balance between algorithm response and task scheduling through the collaborative division of labor between the logic processing core 211 and the general-purpose processing core 212 of the multi-core heterogeneous control unit 21. Combining the feedforward control of the ranging component 17 and the optical feedback of the position detection component 15, Kalman filtering and hysteresis models effectively eliminate the nonlinear effects of the piezoelectric actuator 14, ensuring sub-micron level control accuracy. Through the constant preload provided by the disc spring assembly 161, the module completely eliminates the backlash of mechanical transmission. Combined with the synchronized action logic of the multi-core heterogeneous control unit 21 and the exposure frequency of the image acquisition device 131, displacement adjustment under high-speed motion is achieved. Furthermore, the software reset and hardware physical shutdown graded triggering mechanism established by the hardware protection module 23 improves the stability and imaging quality of the module during long-term operation in complex industrial environments.

[0075] In the several embodiments provided in this application, it should be understood that the disclosed structures can be implemented in various ways in terms of control logic. For example, the embodiments described above are merely illustrative, and the division of units is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0076] 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.

[0077] Furthermore, the functional units in the various embodiments of this application 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. The integrated unit can be implemented in hardware or as a software functional unit.

Claims

1. A high-precision axial micro-adjustment structure, characterized in that, The structure includes: The main body of the micro-adjustment structure and the drive control circuit; The main body of the micro-motion adjustment structure includes: a base plate, a guide component, a transmission connection bracket, a piezoelectric actuator, a position detection component, and an elastic force balancing mechanism; The transmission connection bracket is slidably connected to the base plate through the guide member. The output end of the piezoelectric actuator and the elastic force balancing mechanism abut against the transmission connection bracket from opposite directions, so that the transmission connection bracket is in a pre-tightening force balance state and generates a small axial displacement in response to the drive of the piezoelectric actuator in the pre-tightening force balance state. The drive control circuit includes: a multi-core heterogeneous control unit, a signal acquisition module, and a power amplifier circuit built into the signal acquisition module; The signal acquisition module connects the position detection component and the multi-core heterogeneous control unit. The signal acquisition module is used to acquire and transmit the real-time displacement parameters of the axial displacement of the transmission connection bracket output by the position detection component, and feed them back to the multi-core heterogeneous control unit through a feedback signal. The multi-core heterogeneous control unit calculates the compensation control quantity based on the displacement deviation between the real-time displacement feedback signal and the target height command, wherein the target height command includes the initially calibrated compliance height; The compensation control quantity is converted into a dynamic drive voltage by the power amplifier circuit, and the dynamic drive voltage is output to the piezoelectric actuator to drive the transmission connection bracket to perform displacement adjustment.

2. The structure according to claim 1, characterized in that, The elastic force balancing mechanism includes: Disc spring assembly and preload adjustment component; The elastic force balancing mechanism is integrally disposed below the base plate; The disc spring assembly sets the preload amount through the preload adjustment component, and applies a constant preload force to the transmission connection bracket in the opposite direction to the output direction of the piezoelectric actuator, so that the transmission connection bracket always keeps in close contact with the output end of the piezoelectric actuator, and cooperates with the piezoelectric actuator to clamp the transmission connection bracket.

3. The structure according to claim 1, characterized in that, The position detection component includes: Optical measuring scale and measuring head; The optical measuring ruler is fixed to the base plate, and the measuring head is fixed to the side edge of the transmission connection bracket; The detection head moves synchronously with the transmission connection bracket, generates a differential position signal by sensing the grid displacement of the optical detection ruler, and feeds it back to the signal acquisition module so that the signal acquisition module can acquire the differential position signal in real time and convert it into real-time displacement parameters in digital state.

4. The structure according to claim 1, characterized in that, The structure also includes: A ranging component, which is disposed on the base plate, includes a laser emitter and a laser receiver; The laser emitter and the laser receiver are symmetrically and obliquely arranged on both sides of the transmission connection bracket; The laser emitter projects a laser beam onto the surface of the target to be detected. The laser receiver obtains the current surface height of the target in real time by capturing the reflection signal of the laser beam, and obtains a target height correction command. The target height correction command is then dynamically input to the multi-core heterogeneous control unit in real time.

5. The structure according to claim 1, characterized in that, The multi-core heterogeneous control unit includes: Logic processing core and general processing core; The logic processing core is used to execute the real-time closed-loop control algorithm, perform deviation calculation based on the real-time displacement parameters, and output the compensation control quantity. The general-purpose processing core is used for task scheduling and external communication; The logic processing core is electrically connected to the signal acquisition module, and the general processing core and the logic processing core interact with each other via an on-chip bus.

6. The structure according to claim 5, characterized in that, The core logic processing module integrates an error compensation module and a signal filtering module. The signal filtering module performs noise reduction processing on the real-time displacement parameters using a Kalman filtering algorithm, and the error compensation module performs nonlinear correction on the compensation control quantity according to a preset hysteresis model.

7. The structure according to claim 1, characterized in that, The power amplifier circuit is a two-stage series-connected high-voltage power amplifier circuit, which is used to linearly amplify the low-voltage logic signal output by the multi-core heterogeneous control unit into a dynamic drive voltage of 0-120V.

8. The structure according to claim 1, characterized in that, The drive control circuit also includes: The hardware protection module includes a hardware comparison circuit, which is connected in parallel to the real-time drive current of the piezoelectric actuator and the real-time displacement parameter. The hardware protection module is used to monitor the parameter relationship between the drive current or the real-time displacement parameter and the preset safety threshold, so as to execute the corresponding protection logic according to the parameter relationship.

9. The structure according to claim 8, characterized in that, The hardware protection module executes hierarchical trigger protection logic: When the drive current or the real-time displacement parameter exceeds the first safety threshold, the multi-core heterogeneous control unit performs a software reset protection. When the drive current or the real-time displacement parameter exceeds a second safety threshold that is higher than the first safety threshold, the hardware comparison circuit performs a hardware circuit shutdown.

10. The structure according to any one of claims 1 to 9, characterized in that, An image acquisition device is connected and installed on the transmission connection bracket. The multi-core heterogeneous control unit synchronously adjusts the operating frequency of the piezoelectric actuator according to the exposure frequency of the image acquisition device, so that the image acquisition device driven by the transmission connection bracket can achieve displacement adjustment during the movement.

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