High-precision time-grating displacement sensor based on harmonic wave correcting method

摘要

Time-grating displacement sensor is a new type angular displacement sensor with initial invention. In the research of time-grating sensor, it is found that the cost of high precision only dependent on the high-precision machining and fitting technology is very high generally, and it is very difficult to achieve it. In terms of special structure of time-grating sensor including multi-probes and multi-poles, harmonic wave correcting method is firstly proposed for error correction and compensation of sensors. The data acquired system acquires data from time-grating sensor and the raster at scores of evenly spaced data points in the range of one pole synchronously. These data is input computer to achieve spectrum analysis of the error, and to obtain the best-fitting curve including the main harmonic wave component. The best-fitting curve can be utilized to correct the error curve associated with the special algorithm. Numeric experiments on time-grating sensor of different size are devised to verify the effectiveness of the method, and experimental results coming out from applications confirm the validity of the proposed method. The precision of time-grating angular displacement sensor has been improved greatly after applying this method.