Research On Ultra-Precise Angular Displacement Measurement Method Based On Spatially Correlated Constraint Sensing

With the rapid development of science and technology in recent years,high-end manufacturing,new energy and other national strategic emerging industries and various types of major national projects have put forward new requirements for ultra-highprecision angular measurement capabilities.However,at present,China’s highest precision angle measurement components rely heavily on foreign core technologies and devices,but foreign countries implement price monopoly and technology blockade on China,which seriously restricts the development of China’s ultra-high precision sensors,which is undoubtedly a potential security risk,seriously affecting national economic security and national defense security.At the same time,in the field of ultra-high-precision angle measurement,the development of various countries in the world is generally subject to serious constraints on the working principle of the core measurement device,the level of research has reached the limit,there has been no major breakthrough for many years.In China,due to the lack of original and core technology,the difference between the research level and foreign countries is about 5 times,so the research on the localization of ultra-high precision angular displacement sensing is urgent.In view of the above-mentioned national needs and technology status,this paper proposes to use the original invention of circular time grid sensor as the core measurement device,using the idea of "space-time conversion" to convert the measurement of spatial quantity to the measurement of temporal quantity,from the measurement principle and The key technology is reinvented.Based on this,we explore the full-combination measurement method based on the spatial correlation constraint sensing principle,using two nanocircular time-grid sensors as mutual reference for full-combination measurement,based on the solution of the major scientific problem of "how to improve the measurement accuracy in the absence of higher precision measurement instruments",so as to achieve ultra-high precision This paper is based on solving the major scientific problem of "how to improve the measurement accuracy in the absence of higher precision measurement instruments",and thus achieving ultra-high precision angular displacement measurement.The main contents of this paper are summarized as follows.1)Introduce the theory of "space-time transition",and introduce the principle of double-row structured electric field type circular time grid sensor based on this theory,and further deduce the principle and advantages of single-row structured sensor.On this basis,a spatially correlated constrained sensing method is proposed,in which two sensors are coupled together by spatial correlation to form a new sensing structure.Based on the whole circumference 360° circumferential closure characteristic,the principle of whole circumference angle measurement error and equal to zero is used to realize the axis system error separation and improve the whole circumference angle measurement accuracy through multiple transposition.(2)Systematic analysis of the installation error of the single-row structure nanogrid circular sensor clarifies that the error caused by the installation is mainly reflected in the first harmonic error caused by the deflection and the second harmonic error caused by the tilt,and reveals that the signal pickup with multiple electrodes has harmonic suppression and homogenization effect,which can suppress all frequency harmonic errors except for the integer multiples of the head number while homogenizing the error signal.The signal pickup with multiple electrodes has a harmonic suppression and homogenization effect.And through the combination of theoretical derivation and electric field simulation,the accuracy of the analysis is verified.(3)Build the experimental test platform,design the hardware circuit and the upper computer measurement system,and make the sensor prototype,and conduct the accuracy test on the sensor prototype to verify the correctness of the theoretical analysis.Different installation gaps,different number of readheads and different installation positions are tested to test the influence of different installation cases on the measurement results and to verify the suppression and homogenization effect of the multiple readhead structure on the error generation.Then the spatial correlation constraint sensing method is used to separate the errors of the sensor and calculate the influence of the shaft system errors on the measurement results,which significantly improves the measurement accuracy of the sensor in the whole cycle.In summary,this paper achieves ultra-high precision angular displacement measurement without relying on external higher reference by the spatial correlation constraint measurement method,and achieves ±0.1″ testing accuracy in the range of360° of the full circumference,laying the foundation for the production of China’s selfdeveloped angular reference devices.