Research On The Angular Displacement Sensor Based On Alternating Light Field

Angular displacement measurement technology is an important part of geometric measurement technology,which is widely used and plays an important role in the construction of instrumentation,industrial robots,and national defense.At present,there are many types of sensors for angular displacement measurement,which can be divided into contact type and non-contact type according to the measurement method.Due to mechanical displacement loss,contact angular displacement sensors have the disadvantages of low reliability and short service life.Non-contact angular displacement sensors mainly use optical principles,Hall effect,electromagnetic induction principles to achieve non-contact angular displacement Measurements make up for the shortcomings of contact angular displacement sensors.The common non-contact angular displacement sensors are mainly griting sensors.The measurement accuracy of these sensors is inseparable from the high-precision space scoring technology of ultra-precision machining.Grating is currently the most widely used grating sensor,which has the advantages of high measurement accuracy and fast response.However,due to the limitation of light wave wavelength and diffraction limit,the number of grating lines is difficult to be further improved.It can only rely on electronic subdivision,resulting in cost,reliability,anti-jamming and other issues.Based on these,this paper proposes an angular displacement sensor using light field as the measuring medium.The sensor uses the basic principle of time-griting measurement that the theory of space-time conversion to convert the measurement of space into a measurement of time that can be accurately measured.In order to solve the problem of spatial resolution of "grid",using "grid surface" instead of the "grid line" of the grating to reduce the difficulty of scoring the moving ruler and the fixed ruler.In the optical field,the 360° closing principle is used to achieve the entirecircumference measurement,and the circumferential equalization effect is used to reduce the influence of the manufacturing error of a single grating surface on the measurement error.The research content is as follows:1.Based on the basic principle of time grid measurement,a closed whole cycle sensor structure composed of sine transmittance surface is designed by using single alternating variable light field as the measuring medium.A moving alternating light field is constructed by the orthogonal modulation of light intensity in time and space.2.According to the sensor measurement principle,the mathematical model and simulation model are established,the key factors affecting the sensor measurement error are analyzed in detail,and the measurement error rules caused by these factors are analyzed through theoretical derivation and simulation.3.Developed the prototype of the closed sensor for the whole week and built the experimental platform.The experimental results show that the measurement accuracy of±15" for the whole cycle is realized by using 24 groups of 18 opposite poles of the grating plane,and the correctness of the sensor measurement principle and error analysis is verified.To sum up,this paper mainly on the sensor measurement principle is derived,through the establishment of the mathematical model and simulation model,structure design,and a large number of experimental studies based on alternating light field is verified the correctness of the whole week of angular displacement measurement method,and through the simulation and experimental analysis to determine the main source of measurement error,high precision optical field type gate when the angular displacement sensor for the future research laid a solid foundation.