Linear displacement sensor

Abstract

The invention provides a linear displacement sensor, and belongs to the field of accurate displacement measurement. The sensor consists of two substrates, namely a long ruler and a short ruler, wherein an excitation coil and an induction coil are simultaneously wound on one ruler substrate; a row of magnetizers are arranged on the other ruler substrate at equal intervals and are unwound; the excitation coil is connected with an excitation power supply; an induction signal is generated on the induction coil; when the short ruler and the long ruler do relative motion, the amplitude of the induction signal is changed due to the change of magnetic flux; and electric signals output by the excitation coil and the induction coil are connected to a conditioning circuit to be processed, the processed signals are sent to a signal processing circuit to be subjected to amplitude and phase discrimination, an amplitude difference or a phase difference of the signals is expressed by the number of interpolated clock pulses and is converted into a linear displacement value, and the linear displacement value is directly used as linear displacement data to be displayed or output or is subjected to error correction and the like by a microprocessor and a memory and used as the linear displacement data to be displayed or output.

Description

technical field [0001] The invention belongs to the field of displacement precision measurement. Background technique [0002] Linear and angular displacement measurements are the most basic and common measurements. In order to take into account the measurement resolution and range, many displacement sensors adopt a grid structure that is precisely engraved on the substrate, such as a grating, a magnetic grid, etc., and the pulse signals sent by it during the movement are accumulated and counted, that is, the displacement measurement is realized. High-precision and high-density engraved lines cause many problems. On the one hand, the denser the engraved lines, the easier it is to be polluted. No matter how it is sealed and protected, under the harsh working conditions of the production site, its tiny dust and water vapor may contaminate the grid line, making it invalid for counting. On the other hand, the reticle cannot be infinitely dense, and the existing density is far ...

AI Technical Summary

Problems solved by technology

To sum up, the disadvantages of existing grid displacement sensors are: complex structure, high price, poor anti-interference ability

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