New time-grating displacement sensor and harmonic wave error-correction

Firstly through studying inductive mechanism of time-grating sensor, a new type of displacement sensor - two-phase unequal-pitch time-grating displacement sensor is proposed. It greatly enhanced the number of pole-pairs and sensor precision without increasing the number of the engraving groove. Secondly, it studied that composition of the sensor error and harmonic wave correction method for error is presented. The new error correction method based on non-equidistant sampling is proposed. It is the same effect of error correction through compared with the non-equidistant sampling and the whole cycle of sampling error correction method, but its sampling points must be more less. Finally experiments validated that both methods can greatly enhance the accuracy of the sensor.