Study On Dynamic Calibration Method & Error Separation And Tracing Of Embedded Round Time Grating Sensors

In recent years,with rapid development of wind power energy,nuclear power energy,hydropower energy,locomotive,aerospace etc.in our country,the demand for large and high-precision gear transmission pairs has further increased.Therefore,there is an urgent demand for machine tools processing large and precision gears.Whereas one of the challenges faced by machine tools manufacturing large gears is the indexing precision of large turntable at the end of transmission chain of machine tool,the level of product's quality directly depends on positioning accuracy of large turntable.While the technical requirements for large turntable are extreme,such as bigger turntable is better,the degree of setting position is more accurate the better,turntable is in high-speed and supports heavy loads,and turntable is hollow.All above technology requirements indeed restrict the use of traditionally high-precision displacement sensors.In view of above problems of position detection in extreme conditions and on the basis of field-mode time grating technology,a new type of embedded round time grating sensor is designed based on the new traveling-wave forming method in this paper.The new type sensor makes a component(such as a gear)with equally divided property of transmission mechanism as the rotor.And then,with the external small size measuring part and signal processing circuit,it can achieve angular displacement measurement.Because of advantage of no formal rotor and external measuring part embedding in transmission mehcanism,the sensor can be used in extreme,severe,special working conditions above.Additionally,the sensor is resistant to vibration and oil,high-precision with economy.Therefore,it's significant to study on embedded time grating sensors.The main innovations of this paper are as follows:(1)On the basis of previous magnetic field-mode time grating technology,a new type of embedded round time grating sensor is designed based on the new traveling-wave forming method,and the mathematical model of measuring principle is established.(2)A comparative calibration algorithm based on wavelet transform and linear interpolation is proposed to calibrate the embedded round time grating sensor.A self-calibration model based on differential of measured values is used in sensor's self-calibration.(3)Error characteristic of embedded round time grating sensor is analyzed,Fourier transform is used to achieve error tracing,and then corresponding error-control measures are proposed to deal with error source which has great influence on accuracy of sensor.Above all,designs a new type of embedded round time grating sensor based on the new traveling-wave forming method,establishes the mathematical model of measuring principle of new type sensors,proposes using Fourier transform to achieve error tracing based on errors' characteristic of embedded time grating sensors.Puts forward comparative calibration algorithm based on wavelet transform and linear interpolation to calibrate sensor's error;uses self-calibration model based on differential of measured values to correct sensor's values,lastly,the accuracy of sensor is significantly improved by using two calibaration means above.