A Differential Reflective Absolute Time Grating Angular Displacement Sensor Based on Alternating Electric Field

Abstract

The invention discloses an alternating electric field-based differential electrode reflection type absolute time grating angular displacement sensor, which comprises a rotor substrate and a stator substrate, wherein an induction electrode I, a reflecting electrode I, a reflecting electrode II and an induction electrode II are arranged on the lower surface of the rotor substrate, and the inductionelectrodes I and II are connected with the reflecting electrodes I and II respectively; and an excitation electrode I, a receiving electrode I, a receiving electrode II and an excitation electrode IIare arranged on the upper surface of the stator substrate, four paths of excitation signals are applied by four excitation phases of the excitation electrode II at first respectively, in such case, the excitation electrode I does not work, a first path of differential sinusoidal traveling wave signal is output by the receiving electrode II, then the four paths of excitation signals are switched tofour excitation phases of the excitation electrode I, in such case, the excitation electrode II does not work, and a second path of differential sinusoidal traveling wave signal is output by the receiving electrode I. According to the sensor, high-precision absolute angular displacement measurement can be implemented in a relatively simple time sharing processing manner, no wires are required bya rotor, and higher industrial adaptability is achieved.

Description

technical field [0001] The invention relates to a precision angular displacement sensor, in particular to a differential reflective absolute time grating angular displacement sensor based on an alternating electric field. Background technique [0002] There are two types of angular displacement sensors: incremental and absolute. Compared with the incremental type, the absolute angular displacement sensor has the advantages of no need to reset when starting up, immediate access to absolute angle information and no cumulative error, which improves work efficiency and reliability, and thus gradually becomes the development trend of angular displacement sensors. Absolute photoelectric encoders are widely used at present, which mainly realize absolute positioning through encoding, but the encoding and decoding process is complicated. In addition, a precise reticle needs to be used as a spatial reference to achieve precise measurements, but the width of the reticle is limited by ...

AI Technical Summary

Problems solved by technology

Absolute photoelectric encoders are widely used at present, which mainly realize absolute positioning through encoding, but the encoding and decoding process is complicated

In addition, a precise reticle needs to be used as a spatial reference to achieve precise measurements, but the width of the reticle is limited by the optical diffraction limit

In recent years, a time grating sensor with clock pulse as the reference for displacement measurement has been developed, and on this basis, an electric field type time grating angular displacement sensor (public number CN103968750A) has been developed. This sensor uses high frequency clock pulse As a measurement reference, parallel capacitor plates are used to construct an alternating electric field for precise displacement measurement. Although precise measurement can be achieved, there are still the following problems: (1) the incremental counting method is used, and there is a cumulative error; (2) the excitation signal is transmitted from the sensor The excitation electrode on the stator base is connected, and the induction signal is output from the rotor electrode on the rotor base. The rotor base needs a lead signal output line, which cannot be used in some occasions and has a narrow application range.

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