579 results about "Laser interferometry" patented technology

The invention relates to the technical field of numerical control machining, in particular to a CAM post-optimization method and system for geometric error compensation of a multi-axis linkage numerical control machine tool. The method comprises the following steps: firstly, carrying out kinematics analysis and geometric error modeling on a target machine tool, and deploying the target machine tool in a CAM post-optimization module; then actual state parameters of the target machine tool in the machining process are collected in real time through a laser interferometer; a motion instruction of a target machine tool and a detection result of a laser interferometer are synchronously obtained through a CAM post-optimization module, and then geometric errors of a linear axis and a rotating axis in the operation process of the target machine tool are calculated in real time through a kinematic model and a geometric error model. According to the method, different linear axis compensation modes are adopted for different instructions; and a cutter shaft attitude vector error and a cutter cutting point position error are calculated in combination with inverse kinematics, and are corrected step by step. The problem that the error compensation precision of a controller in an existing numerical control machine tool is insufficient can be solved.

The invention discloses a high-precision three-degree-of-freedom attitude adjustment platform for a spectrometer, which is based on a simplified design of a Stewart platform and comprises a movable platform, a static platform and a three-degree-of-freedom driving mechanism connected between the movable platform and the static platform. The driving mechanism is composed of three sets of servo electric cylinders, telescopic rods and servo motors and is driven by a ball screw, and posture adjustment of the platform is achieved. According to the platform, a laser interferometer is adopted as a high-precision sensor, a closed-loop feedback control system is combined, and submicron displacement measurement and attitude control are achieved. The platform can achieve translation in the Z-axis direction and rotation around the X axis and the Y axis, the rotation angle can reach + / -15 degrees, and the precision can reach 0.02 mm. According to the invention, the device ensures high precision and stability in a complex working environment, has the characteristics of stable movement, quick response, easy maintenance and the like, and is suitable for the fields of optical experiments, spectral analysis and attitude adjustment and error compensation of precise instruments.

Various implementations of implants and implant surfaces for clinical rehabilitation or enhancement of a patient, related systems, and computer programs and methods for the design and manufacturing of implants are disclosed. A macroscale shape, a microscale surface texture, and a nanoscale surface topography are overlaid to increase, condition, and thereby functionalize an implant surface. A thin-film coating and / or laser interferometry is utilized to overlay on a machined implant substrate a nanoscale surface topography. Manufacturing the macroscale shape and the microscale texture may be performed with an ultrashort pulsed laser system in separate process steps. The design of a dental implant may be assisted by a self-learning computer program product, based on trained coupled shape models including, for example, mesh-based statistical shape and orientation models.

The invention discloses a noise reduction method and system for a high-performance TWS Bluetooth audio chip, and relates to the technical field of acoustoelectric integration, and the method comprises the steps: collecting an environment noise signal, synchronously obtaining a Bluetooth radio frequency interference signal, converting the Bluetooth radio frequency interference signal into a digital signal through a 24-bit analog-to-digital converter, and outputting a multi-modal noise feature matrix; performing noise separation and reverse sound wave generation on the multi-modal noise characteristic matrix by using a pre-trained lightweight CycleGAN model, and outputting a reverse sound wave signal; monitoring auditory meatus tightness parameters in real time, dynamically adjusting phase offset and frequency response balance parameters of the mixed noise reduction signals, and outputting optimized noise reduction signals adaptive to the current wearing state; and performing parameter calibration on the optimized noise reduction signal through anechoic chamber scene simulation and laser interferometer phase detection to generate a noise reduction control instruction set. According to the invention, the noise interference problem of the TWS earphone in a complex environment is effectively solved.

The invention relates to the technical field of optical detection, in particular to an aspheric lens laser interference detection adjustment error separation system and method, and the method comprises the steps: placing an aspheric lens on a clamping platform, carrying out the multiple laser interference measurement through adjusting different pitch angles and azimuth angles, and collecting a multi-angle interference fringe image; for different installation and adjustment error types, key features of typical error fringe images are extracted and compared with current interference fringe images, and identification of the installation and adjustment error types and levels is achieved; a mathematical model of various installation and adjustment errors is constructed, polynomial parameterization representation is adopted, installation and adjustment compensation parameters are reversely solved according to an identification result, and installation and adjustment are completed; and repeating the measurement and analysis process, and constructing an error adjustment frequency optimization model until the precision requirement is met. The method provided by the invention can improve the adjustment efficiency and precision of the aspherical lens.

A frequency stabilization method and system for tunable light sources based on characteristic curve reconstruction are provided, which relate the field of frequency stabilization technologies of modulation absorption spectrum. A set of frequency stabilization control method and system based on internal modulation absorption spectroscopy of light source is constructed, and a high-precision laser frequency stabilization method under large-amplitude and high-bandwidth frequency modulation based on frequency discrimination curve reconstruction is proposed to solve a problem that it is difficult for micro-probe laser interferometry measurement benchmark to balance large-amplitude and high-bandwidth frequency modulation, and high-precision frequency stabilization, resulting in that it is difficult to obtain high relative accuracy measurement under large-range measurement. Under the large-amplitude and high-bandwidth frequency modulation, a distortion model of the frequency discrimination curve and a distortion correction model are constructed, which is used for feedback adjustment of phase compensation and reconstructing the frequency discrimination curve.

Various implementations of implants and implant surfaces for clinical rehabilitation or enhancement of a patient, related systems, and computer programs and methods for the design and manufacturing of implants are disclosed. A macroscale shape, a microscale surface texture, and a nanoscale surface topography are overlaid to increase, condition, and thereby functionalize an implant surface. A thin-film coating and / or laser interferometry is utilized to overlay on a machined implant substrate a nanoscale surface topography. Manufacturing the macroscale shape and the microscale texture may be performed with an ultrashort pulsed laser system in separate process steps. The design of a dental implant may be assisted by a self-learning computer program product, based on trained coupled shape models including, for example, mesh-based statistical shape and orientation models.

The invention discloses a feedback control method for laser welding, and relates to the technical field of laser welding, and the method comprises the following steps: obtaining target design information of a target assembly part and a target sub-design information set of a sub-component set; carrying out clamping positioning analysis to obtain a clamping feature point set and a workpiece alignment vector set; welding control analysis is conducted, and welding path control is obtained; pre-constructing a welding repair analysis module; clamping the sub-components of the sub-component set to obtain a to-be-welded entity; in the automatic welding process of a to-be-welded entity, the laser interferometer collects and feeds back a real-time interference fringe sequence to the welding repair analysis module; and welding repair analysis is conducted according to the real-time interference fringe sequence to obtain repair path control, and the target welding assembly executes feedback control optimization on the to-be-welded entity with the repair path control as a constraint. The technical problems that in the prior art, laser welding control precision is insufficient, and stability is poor are solved, and the technical effect of improving welding quality and efficiency is achieved.

The invention relates to the technical field of measurement of mechanical vibration or ultrasonic waves, water sound waves or infrasonic waves, in particular to a vibration liquid column hydrophone calibration device and method based on laser interferometry, and the device comprises a laser vibration meter, a hydrophone to be measured, a liquid column cavity for suspending the hydrophone to be measured, and a vibration table connected with the liquid column cavity. The to-be-measured hydrophone is detachably connected with an adjusting and positioning mechanism, the adjusting and positioning mechanism is connected with a laser vibration measuring instrument for executing vibration measurement, the adjusting and positioning mechanism and the laser vibration measuring instrument are introduced, the problem that accurate calibration of the low-frequency hydrophone cannot be achieved in the prior art is solved, and through sound field modeling calculation and correction, accurate calibration of the low-frequency hydrophone is achieved. The technical problem that the uncertainty and deviation of a hydrophone sensitivity calibration result caused by a non-uniform sound field cannot be effectively reduced in the prior art is solved.

Various implementations of implants and implant surfaces for clinical rehabilitation or enhancement of a patient, related systems, and computer programs and methods for the design and manufacturing of implants are disclosed. A macroscale shape, a microscale surface texture, and a nanoscale surface topography are overlaid to increase, condition, and thereby functionalize an implant surface. A thin-film coating and / or laser interferometry is utilized to overlay on a machined implant substrate a nanoscale surface topography. Manufacturing the macroscale shape and the microscale texture may be performed with an ultrashort pulsed laser system in separate process steps. The design of a dental implant may be assisted by a self-learning computer program product, based on trained coupled shape models including, for example, mesh-based statistical shape and orientation models.

Various implementations of implants and implant surfaces for clinical rehabilitation or enhancement of a patient, related systems, and computer programs and methods for the design and manufacturing of implants are disclosed. A macroscale shape, a microscale surface texture, and a nanoscale surface topography are overlaid to increase, condition, and thereby functionalize an implant surface. A thin-film coating and / or laser interferometry is utilized to overlay on a machined implant substrate a nanoscale surface topography. Manufacturing the macroscale shape and the microscale texture may be performed with an ultrashort pulsed laser system in separate process steps. The design of a dental implant may be assisted by a self-learning computer program product, based on trained coupled shape models including, for example, mesh-based statistical shape and orientation models.

The invention discloses a rapid positioning and punching device and method for a precision die, and relates to the technical field of precision die and die casting machining equipment. The device comprises a workbench and an air floatation-vibration suppression and vacuum pre-fixing integrated platform at the bottom of a positioning groove of the workbench, and the air floatation-vibration suppression and vacuum pre-fixing integrated platform can be switched between a vacuum adsorption pre-fixing mode and an air floatation vibration suppression mode. Y-axis modules are arranged on the two sides of the workbench and drive the X-axis module and the Z-axis lifting mechanism to move. The intelligent drilling unit adopts an inner cooling type drill bit with a built-in phase change microcapsule, and the position error is compensated in real time through a laser interferometer. The method integrates the devices and sequentially comprises the steps of workpiece vacuum pre-fixing, air floatation vibration suppression, self-adaptive balanced clamping, vision and laser composite positioning, drilling and phase change self-cooling, laser dynamic error compensation and the like. The problems of positioning drifting, short service life of a drill bit and clamping unbalance during drilling of high-hardness die steel and large die castings (such as electric control boxes of new energy automobiles) are effectively solved.

The invention relates to a data acquisition and analysis system and method for laser interference measurement, and aims to solve the problem of limited measurement precision caused by asynchronous signal acquisition, imperfect environmental interference compensation and algorithm errors of the existing system. The system comprises a photoelectric conversion unit, a signal conditioning unit, a high-speed synchronous acquisition unit, a real-time processing unit and an error compensation module. The photoelectric conversion unit adopts a four-quadrant PIN photodiode array to receive interference light signals and convert the interference light signals into analog electric signals; the signal conditioning unit performs gain adjustment and bandwidth limitation on the signal; the high-speed synchronous acquisition unit realizes femtosecond-level synchronous acquisition of signals; the real-time processing unit performs phase solution and eliminates harmonic errors based on an improved arc tangent algorithm; and the error compensation module fuses temperature sensor data and accelerometer data to realize thermal drift and vibration compensation.

The invention provides a laser interference measurement precision traceability system and method. The system comprises an atomic clock, a femtosecond optical frequency comb, a spectrum spreading and frequency doubling module, a beat frequency module and a traceability processing module. The repetition frequency of a spectrum output by a femtosecond optical frequency comb and the frequency reference of an atomic clock are locked, frequency beating is carried out on a femtosecond laser spectrum and an interference measurement light source through spectrum broadening, optical frequency doubling and frequency beating detection, and traceability comparison is carried out on an obtained frequency beating signal and laser interference measurement data. The measurement precision of the to-be-measured laser interferometer is traced to the atomic clock frequency reference, and the traceability of laser interference measurement data is realized. Compared with the prior art, the laser interference measurement precision traceability system measures the wavelength by using the atomic clock frequency reference, has higher precision and resolution, and can realize on-site traceability of laser interference measurement data precision. And through precision traceability, the precision and stability of laser interference measurement are also improved.

The invention belongs to the technical field of precision part machining, and discloses a precision part machining precision error compensation technology, high-precision measuring equipment comprises a laser interferometer and a coordinate measuring machine, a numerical control system calculates the compensation amount of each axis of a machine tool according to a model and carries out dynamic adjustment, and an online tool measuring system comprises a tool compensation probe. The laser interferometer carries out interference measurement through reflection of a laser beam and a machine tool measuring part so as to obtain the measurement precision, and through cooperation of the laser interferometer, the coordinate measuring machine and the cutter compensation probe, the numerical control system calculates the compensation amount of each axis of the machine tool according to a model and carries out dynamic adjustment. The laser interferometer performs interference measurement through reflection of a laser beam and a machine tool measuring part, ensures parallelism and perpendicularity, checks error changes of the machine tool at different working temperatures, detects motion errors of the machine tool at different temperatures by using the laser interferometer, and compensates the errors according to the temperature changes.

The invention discloses an interference displacement measuring device based on a Sagnac structure, and solves the problems that in the prior art, the displacement measurement error of a right-angle prism is large, and the interference displacement measuring device cannot be applied to displacement measurement of a plane mirror and the right-angle prism at the same time. The influence of original reflection of multi-order ghost reflection light is avoided, under the condition that quadruple optical subdivision is obtained, compared with laser interferometers visible in the current market and reported in literatures, a to-be-measured right-angle prism is utilized to form a Sagnac structure, a phase decoupling form formed by a measurement structure and a reference structure is utilized, and the measurement accuracy is improved. The periodic nonlinear error of the measurement system is reduced by using the measurement basis of the to-be-measured rectangular prism, and the measurement error in the phase shift of the to-be-measured rectangular prism is weakened by using the phase coupling of reference and measurement, so that the displacement measurement precision is improved.

The present invention discloses a position error calibration device and a calibration method for an industrial robot. The position error calibration device in the present invention includes a laser ranging component for measuring the three-dimensional coordinates of the target ball at the end of the robot. The laser ranging component includes a laser interferometer, a beam splitter, a two-dimensional position sensitive detector, and a housing; a two-dimensional moving platform for moving the laser ranging component in the X-axis and Y-axis directions. The two-dimensional moving platform includes a lead screw slider module and a grating scale in the X-axis and Y-axis directions; a supporting device for fixing and supporting the two-dimensional moving platform so that it can work stably in three-dimensional space. Compared with a laser tracker, the present invention does not require transformation between a spherical coordinate system and a rectangular coordinate system, thereby avoiding the amplification effect of the angle error of the inner circle grating in the laser tracker. The present invention can directly measure the three-dimensional coordinate values of the reflecting target ball in the measurement coordinate system, has a good calibration effect, and can meet the calibration requirements of industrial robots.

The invention discloses a surface defect height quantitative detection method and device based on all-optical laser ultrasound. The method comprises the following steps: respectively exciting and detecting ultrasonic Rayleigh waves in a state that a pulse laser and a laser interferometer are arranged on the same side and different sides of a surface defect of a detected sample piece, extracting the transit time of an incident Rayleigh wave and the transit time of a transmission Rayleigh wave, and obtaining the height of the surface defect on the basis of the transit time of the incident Rayleigh wave and the transit time of the transmission Rayleigh wave. According to the invention, the detection of incident ultrasonic Rayleigh waves, reflected ultrasonic Rayleigh waves and transmitted ultrasonic Rayleigh waves is realized by moving the sample piece or the pulse laser and the laser interferometer through the linear motion platform, the height of the surface defect is calculated, the detected sample piece does not need to be clamped for the second time in the detection process, and high-efficiency in-situ quantitative detection is realized. In addition, nondestructive testing of the tested sample piece is achieved under a thermoelastic mechanism, the contact type defect of traditional ultrasonic testing is overcome, and the device is suitable for special environments such as high temperature, high pressure, intense radiation and strong corrosion.

The invention discloses an error compensation method for a double-end driving gantry machine tool. The method comprises the following steps: 1, establishing a theoretical transformation matrix of a double-end driving gantry machine tool cutter end, and comparing the theoretical transformation matrix with an actual transformation matrix to obtain an error transmission model of the cutter end; 2, instructions are applied to the two ends of the double-end-drive gantry machine tool at the same time, and a double-drive X-axis, a Y-axis and a Z-axis are driven to move; 3, installing a laser interferometer probe and a reflector at a specified position of each shaft, and measuring by an interferometer to obtain a geometric error; 4, substituting the measured geometric error into the error transfer model, and calculating to obtain a cutter end error; and 5, performing error compensation on the cutter end according to the calculated cutter end error. According to the method, the influence of the double-end driving error on the positioning precision of the tail end of the cutter can be quantitatively evaluated through the error transfer model, the position error is compensated, the machining precision of the double-end driving gantry machine tool is improved, and the problem that the machining precision is insufficient in actual machining is solved.

The invention discloses a medical vaporizer verification system, and relates to the technical field of medical instrument detection. Comprising an environment perception acquisition module, an environment data preprocessing and structuring module, a condensation risk feature extraction and risk value quantification module, a deep learning driven condensation risk intelligent determination module and a particle dynamic identification and condensate droplet elimination module. Multi-dimensional physical parameters of environmental conditions are obtained in real time through a multi-type high-sensitivity sensor array arranged in a detection cabin. According to the invention, environmental changes are monitored in real time through a multi-sensor array, condensation risk features are extracted, and an intervention mechanism is triggered in advance by using deep learning intelligent pre-judgment; ultrasonic excitation and a laser interferometer are combined to collect particle vibration characteristics, and machine learning is matched to quickly distinguish drug particles and condensate drops, so that errors are effectively eliminated, the verification accuracy of an atomizer and the intelligent level of the system are improved, and the detection reliability and clinical safety are ensured.

The invention discloses a wear state and precision degradation prediction method for a ball screw drive system, and the method comprises the steps: employing a dual-label obtaining strategy, and constructing a'strong label + weak label 'mixed label sequence covering a whole life cycle; mapping a macroscopic working condition into a contact interface micromechanical state quantity, and converting a time domain signal into a travel domain / space domain stable sequence by adopting equal travel synchronous resampling, so as to weaken the influence of speed fluctuation on feature extraction; a double-flow physical guidance neural network is further constructed, and a physical attention mechanism is introduced to realize data feature and physical prior fusion; training is completed based on supervision loss and physical consistency constraint, and online recursive correction is carried out by using sparse laser interferometer calibration data. By adopting the method, the prediction deviation caused by equipment aging and working condition change can be reduced, and stable prediction of the wear state and the repeated positioning error degradation trend is realized.

The invention relates to the technical field of five-axis numerical control machining error detection, in particular to a high-precision geometric error detection method and system for five-axis numerical control machining, and the method comprises the steps: obtaining a height error value and a height error matrix of a measurement point on the surface of a workbench through a laser interferometer; determining the final possibility that the height error matrix deforms in a corresponding area on the surface of the workbench; determining the deformation quantity of the surface of the workbench measured each time; determining the most recently measured deformation quantity change rate of the surface of the workbench; determining the final deformation quantity of the position of the workpiece on the surface of the workbench at each moment; and compensating the five-axis numerical control machine tool according to the final deformation quantity. The dynamic influence that the surface deformation of the workbench is gradually increased along with time accumulation and the influence of the self weight of the workpiece on the surface of the workbench are reduced, and the overall machining performance of the five-axis numerical control machine tool is improved.

The invention discloses a double-path laser interferometer, a grating measurement method and an optical detection system, and relates to the technical field of optical detection.The double-path laser interferometer comprises a laser light source for providing a laser beam, the light splitting module is used for splitting the laser beam into a first light beam and a second light beam, and the first light path module is used for enabling the first light beam to enter a measured grating and receiving first diffraction light emitted by the measured grating to form a first interferogram; the second light path module is used for enabling the second light beam to enter the measured grating and receiving second diffraction light emitted by the measured grating to form a second interferogram; the imaging acquisition modules are arranged on the light emitting sides of the first light path module and the second light path module respectively, and the imaging acquisition modules are set to determine the measurement result of the measured grating according to the first interference pattern and the second interference pattern, so that the measurement efficiency of the uniformity of the grating is improved on the premise that the measurement precision is not sacrificed.

The invention discloses a dynamic calibration control method for the detection precision of a non-standard automatic testing fixture, and particularly relates to the field of industrial automation and control, which comprises the following steps of: constructing a real-time dynamic error field model of the testing fixture; a distributed optical fiber sensing network and a miniature laser interferometer cooperatively collect real-time detection data and spatial-temporal variation errors under a multi-physics coupling effect, a precision degradation track is predicted based on spatial-temporal variation error data, a pre-compensation signal is generated, and a self-adaptive Kalman filtering algorithm is adopted to generate a precision compensation parameter. Environment temperature, vibration and electromagnetic interference data are monitored in real time, environment disturbance data are generated, a hybrid controller combining nonlinear model predictive control and reinforcement learning is adopted, multi-source data are fused, a calibration instruction is generated through multi-target optimization, and an execution mechanism is driven to achieve online dynamic calibration. And digital threads and transfer learning are integrated to realize full-life-cycle data closed-loop management and continuous optimization.

Provided are a laser interferometer capable of reducing the frequency of a signal calculated and processed in a demodulation circuit and reducing the cost of the demodulation circuit, and a spectroscopic device provided with the laser interferometer. A laser interferometer is provided with: an optical modulator that adds a modulation signal to laser light using a resonator element; a light receiving element that detects a change in the intensity of the laser light including the sampled signal and the modulated signal, and outputs a laser reception signal; a signal oscillation unit that generates a reference signal of a first frequency with the vibration element as a source vibration; and a demodulation circuit that demodulates the sampled signal from the laser reception signal on the basis of the reference signal, the demodulation circuit comprising: a DC offset removal unit that removes the offset; a first phase regulator that regulates the phase of the reference signal; a first multiplier that multiplies the laser reception signal by a reference signal; a first filter; a second multiplier multiplying the first multiplication signal by a reference signal; a second filter; and a phase calculator that calculates a phase.

The invention relates to a global measurement field construction method for a complex scene, and the method comprises the steps: fixedly arranging a plurality of target seats which are suitable for the placement of laser reflection target balls of a laser tracker in the scene, and enabling the target seats to serve as visual reference points; laying a laser tracker station; measuring three-dimensional coordinate values of the laser tracker stations and the visual reference point and laser interference ranging values of the laser tracker stations and the visual reference point, and obtaining measurement data of the visual reference point under different laser tracker stations; the method comprises the following steps: constructing a spatial transformation relationship among station coordinate systems of laser trackers, converting measurement data of the laser trackers to a global coordinate system, and constructing a global measurement field; and carrying out adjustment optimization on the obtained global measurement field. According to the method provided by the invention, high-precision measurement field construction oriented to large-size complex-structure parts is realized, the precision and robustness of coordinate calculation are improved, and the problem that traditional measurement field construction in a complex scene is easy to block is effectively solved.

The invention relates to an anti-falling device integration method and system based on light guide rail coupling and deformation control, and the method comprises the following steps: carrying out the stress distribution scanning of a light guide rail through a laser interference measurement system, and obtaining a guide rail stress distribution map; based on the guide rail stress distribution map, carrying out dynamic rigidity analysis on the light guide rail to obtain a guide rail rigidity characteristic curve; carrying out coupling calculation on the light guide rail based on the guide rail rigidity characteristic curve to obtain guide rail coupling parameters; based on the guide rail coupling parameters, structural design and layout optimization are conducted on the anti-falling device, and an anti-falling device integration scheme is obtained; and performing virtual assembly and performance simulation on the integration scheme of the anti-falling device to obtain a performance evaluation report of the anti-falling system, thereby solving the technical problem that the integrated design of the anti-falling system generally lacks in-depth analysis on the mechanical characteristics of the guide rail body, so that potential safety hazards are difficult to find and correct in time.

The invention provides a laminated piezoelectric ceramic displacement and output force test tool and a test method, and belongs to the field of piezoelectric ceramic detection. The problems that no tool for detecting the output force and the displacement of the laminated piezoelectric ceramic at the same time exists at present, and the tool for detecting the output force of the laminated piezoelectric ceramic at present is not accurate enough and cannot obtain accurate output force are solved. The device comprises a marble platform, an output force testing tool and a displacement testing tool, a force sensor of the output force testing tool comprises laminated piezoelectric ceramic used in the sensor and a strain gauge sensor, and the laminated piezoelectric ceramic used in the sensor and laminated piezoelectric ceramic to be tested are made of the same material. The strain gauge sensor is attached to the surface of the laminated piezoelectric ceramic used in the sensor; a laser interferometer measuring head of the displacement testing tool can detect the displacement of the laminated piezoelectric ceramic to be tested. The tool can measure the output force of the to-be-measured laminated piezoelectric ceramic more accurately, and can detect the displacement and the output force of the to-be-measured laminated piezoelectric ceramic at the same time.

The invention discloses a nanoscale high-precision positioning method based on a multi-degree-of-freedom motion workbench, and relates to the field of large-stroke and high-precision positioning, and the method comprises the steps: S1, initializing the motion workbench, and guaranteeing that a system is in a zero position state; s2, sending a target position instruction by the upper computer, and driving the macro moving platform to quickly move to a position near a target; s3, acquiring the current position, calculating the deviation from the target position according to the target displacement and the current actual feedback displacement value, and generating micropositioner control parameters; s4, a control instruction is generated, and nanoscale displacement compensation is executed; and S5, iteratively correcting the displacement of the micropositioner until the deviation fed back by the laser interferometer meets the requirement. According to the invention, the positioning precision of large-stroke (hundred millimeters) movement is improved to a nanometer level, the device is suitable for the fields of photoetching machines, ultra-precision machining, biological micromanipulation and the like, and the equipment performance and the process level are improved. In addition, the system adopts a modular design, can adapt to different driving and sensing units according to requirements, and has strong expansibility.

The invention discloses an ultralow-temperature cascade refrigeration device, belongs to the technical field of refrigeration devices, and solves the problems that when a low-temperature screw compressor continuously operates below-80 DEG C, organic acid generated by hydrolysis of trace moisture and ester lubricating oil and metal chips form colloidal deposition, the resistance of a slide valve is increased, displacement lag is caused, and the service life of the slide valve is prolonged. However, the sensor only feeds back an instruction signal and cannot be monitored by a control system, and finally bearing wear or energy efficiency reduction is caused. Comprising a screw compressor and a slide valve state monitoring circuit arranged in the screw compressor. The actual displacement of the slide valve is measured in real time through double-frequency laser interference, the thickness of jelly is analyzed in combination with acoustic surface wave frequency shift, the fault index is calculated after dynamic compensation, early warning is conducted when the limit is exceeded, a blind area of a traditional sensor is eliminated, diagnosis is conducted in advance, and compressor bearing abrasion is avoided.