Research On Self-compensating System Of Installation Error Of Parasitic Time Grating Angle Displacement Sensor

During the using process of parasitic time grating,the measuring head of time grating was distributed uniformly on the circumference of the measured object in a discrete form,so the installation errors of gap value,pitching angle,deflection angle between the measuring head and the measured object caused by the limitation of artificial installation were always unavoidable,and the errors always were changed by relative rotation between the measuring head and the measured object,so no theoretical mathematical model can be built to realize real-time correction and compensation of installation error.In order to realize real-time correction and compensation of installation error of parasitic time grating,the structure of original parasitic time grating measuring head was made better,and a self-compensating system of installation error of parasitic time grating angle displacement sensor was designed.In other words,three sets of eddy current sensor were interconnected into the measuring head by using three point method of error separation in the original parasitic time grating,the gap between the measured object and the discrete head was measured by eddy current sensor,and the relationship equations of the gap,the pitch angle and the measured angle between the discrete head and the measured object were established,so actual rotation angle caused by installation error was measured,the installation error was finally measured and compensated in a form of real-time and on-line integrated synchronous form to achieve more accurate measurement on parasitic time grating.The two parts of the circuit design and the structure design were mainly included in the design of self-compensating system of installation error of parasitic time grating.Since eddy current sensors were embedded,the circuit part should be designed firstly.When the exciting coils were applied to different exciting signals of different frequencies respectively,the induction signals produced by parasitic time grating sensor and eddy current sensor were interfered by each other,which was called the coupling phenomenon.Therefore,the processing circuits were designed to make the induction signals extracted and processed to achieve useful induction signal finally.At the same time,the circuits of the exciting power signal were designed to provide a accurate,stable signal source for self-compensating system of installation error of parasitic time grating.Finally,the circuits were simulated and verified by the simulation softwares of Multisim and ModelSim.It can be seen from the simulation results,the coupled signal of self-compensating system of installation error of parasitic time grating can be processed and extracted,and stable exciting signal source was offered by the designed circuits.In order to demonstrate the feasibility of the design scheme of self-compensating system of installation error of parasitic time grating,the experimental platform was built to verify it in the paper.It can be seen from the experimental results,the excitation signal generated at the core of FPGA can be used as a stable signal source for self-compensating system of installation error of the parasitic time grating.At the same time,the induction signals coupled by eddy current sensor and parasitic time grating can be extracted by the experiment designed in the paper.Finally,the calibration structure of self-compensating system of installation error of parasitic time grating were designed,which included the design of the measuring head,main rotating shaft and transmission device,and the structure was Simulated and analyzed by the simulation software of Ansys to provide an important and theoretical reference for the subsequent structural processing.