Research On Embedded Angular Displacement Sensor Based On Orthogonally Electromagnetic Field Coupling Of Time And Space

Heavy-duty precision machine tools as ships,aerospace rockets,nuclear power plants,and other ‘pillars of a great power’ parts of the workhorse,its development is one of the important symbols of national infrastructure capacity.Accurate angular displacement measurement of large-diameter hollow structures,which are often used at the end turntable of machine tools,is a key aspect of machine positioning accuracy.To date,most angular displacement detection uses grating sensors,whose accuracy depends on the definition and homogeneity of the grating line edges.Achieving some success in angular displacement measurement,however,this type of sensor still relies on external sensors for indirect measurement,thus limiting its accuracy.An embedded angular displacement sensor,which utilizes orthogonal electromagnetic field coupling of time and space,presents a new idea for accurate angular displacement measurement of end turntables on heavy-duty precision machine tools.To achieve direct measurement of angular displacements using large-diameter hollow rotating mechanical components as the measurement unit,and to develop research around the goal of achieving accurate angular displacement measurement of such components.The main research elements are as follows.(1)Based on the principle of coupling of time and space and electromagnetic induction,a large-diameter hollow rotating mechanical component of a machine tool end turntable was used as the object of research,and orthogonally electromagnetic field coupling of time and space was constructed in its local spatial area.The sensing signal formation method was proposed,the embedded angular displacement sensor model was constructed,the relationship between spatial angular displacement information and the sensing signal was established by incorporating the high-frequency clock pulse interpolation technique,and the mechanism of embedded angular displacement sensing was elucidated.(2)Based on the sensing mechanism,the design of the mechanical and electrical structure of the sensor was carried out,and the correctness of the sensing mechanism and the feasibility of the structural design were verified by simulation analysis in conjunction with the structural model of the sensor.The error characteristics of the sensor were also analyzed from the electrical point of view with the simulation results,the mathematical model of the error was established,and the accuracy of the model was verified by simulation.Finally,the optimization of the sensing signal was achieved by setting the compensation winding.(3)Based on the sensor structure model,a precision experimental platform was built,prototypes were developed and sensor performance tests were carried out,including sensor repeatability tests,stability tests,and accuracy tests.Proposing an error correction method based on Gaussian process regression to address the issue of a large measurement error of the sensor,the error correction experimental research was carried out,and compared with the classical Fourier error correction method.The results showed that the stability over the entire measurement range was 0.5 ";the forward repeatability was 0.46",the reverse repeatability was 0.48 ";the final measurement error corrected by Gaussian process regression was 1.75",with an average reduction of 98.1%,which was worked significantly better than the classical Fourier.In consideration of the above,based on the group’s previous research,an embedded angular displacement sensor based on the spatial-temporal coupling of alternating magnetic fields was developed for the accurate angular displacement measurement of the end turntable of heavy precision machine tools in the thesis.The sensing mechanism was elucidated through a combination of theoretical analysis,simulation and experiments,a sensor model was constructed,error characteristics were analysed,an error correction method based on Gaussian process regression was proposed and experimental verification was carried out.The results showed that the research had the theoretical and engineering value for achieving accurate angular displacement measurement of large-diameter hollow rotating mechanical components and improving the positioning accuracy of heavy-duty precision machine tools.