Research On Error Model And Signal Processing Of Multi-reading Head Displacement Sensor

At present,there are two main ways to improve the accuracy of grid-type displacement sensor: increasing the number of grid lines and reading heads to improve the measurement accuracy of the sensor itself;however,increasing the number of grid lines and reading heads will undoubtedly increase the difficulty of processing and installation,and increase the manufacturing cost;By improving the working environment of the sensor to improve the measurement accuracy,the core of this method is to improve the output signal strength of the sensor,the method is difficult to implement,only in the laboratory environment can achieve good results.Aiming at the above problems,this paper studies the new readout head layout and sets up the multi-readout head displacement sensor measurement system.The system can measure the angular displacement.The error is analyzed and the corresponding error model is established.The signal compensation and joint error correction algorithm are proposed.The hardware circuit of signal processing system is designed,and the software of signal processing system is designed according to the modified algorithm and hardware circuit.The main research contents of this paper are as follows:1.This paper studies the construction method of multi-reading head of grid with isometric phase linear,puts forward the displacement sensor with multi-reading head for measuring angular displacement,analyzes the structure and principle of the sensor,and establishes the mathematical model of the sensor.2.Through the error analysis of the sensor,the error of the multi-reading head displacement sensor is obtained.According to the error sources,the error characteristics of the system errors are analyzed,and the errors are divided into high order errors and low order errors.According to the error characteristics,the joint error model of high and low order errors is established,and the method of order determination of errors is studied.3.The design method of hardware circuit of multi-reading head displacement sensor is studied.According to the requirements of sensor and the characteristics of output signal,the excitation signal generation circuit,acquisition circuit and hardware circuit of controller are designed.A circuit which can drive the excitation winding and meet the frequency of the excitation signal of the sensor is realized.4.Studied more reading head displacement sensor signal processing method of software design,according to the signal features and error model to design the signal acquisition,displacement calculation and error characteristic parameter calculation method,and to study its software implementation scheme,design the signal acquisition,displacement calculation and the error characteristic parameters of the software system.5.The test platform of multi-reading head displacement sensor is set up.Through experiments,the signal processing module,data acquisition module and error correction module are verified to realize signal acquisition,error correction and displacement calculation.