Planar two-dimensional displacement sensor based on eddy current effect

Abstract

The invention discloses a planar two-dimensional displacement sensor based on an eddy current effect. The sensor comprises a movable ruler and a fixed ruler, the fixed ruler comprises a fixed ruler base body and m conductive metal plates arranged according to a matrix, and the length and the width of each conductive metal plate are that the center distance between two adjacent conductive metal plates in an X direction and a Y direction is W; the movable ruler comprises a movable ruler base body and four planar rectangular spiral coils, and the four planar rectangular spiral coils are arranged according to a 2*2 matrix; according to the length and the width of each planar rectangular spiral coil, the four planar rectangular spiral coils are connected with alternating current excitation electric signals with the same phase, and when the movable ruler moves in parallel in an XY plane relative to the fixed ruler, the impedance of each planar rectangular spiral coil is converted into an electric signal through an alternating current bridge; and linear displacement of the movable ruler relative to the fixed ruler in the X and Y directions is acquired through processing. The structure can be simplified, the applicability is improved, and the influence of a machining process on a measurement result is reduced.

Description

technical field [0001] The invention belongs to the field of precision measurement of plane two-dimensional displacement, in particular to a plane two-dimensional displacement sensor based on eddy current effect. Background technique [0002] Existing planar two-dimensional precision displacement sensors can be divided into three types according to different principles: the first is optical two-dimensional displacement sensors, such as two-dimensional laser encoders, Heidenhain PP281 planar gratings and KGM series encoders, etc.; The second is a capacitive two-dimensional displacement sensor, such as the two-dimensional capacitance sensor developed by Bonse, the two-dimensional precision capacitive micro-displacement sensor developed by Wang Bibo, etc.; the third is an inductive two-dimensional displacement sensor, such as the two-dimensional displacement sensor developed by Feng Bin. Translational displacement sensor, which places a U-shaped iron core and a coil in two dire...

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Problems solved by technology

But it still has the following problems: (1) Both the exciting coil matrix on the fixed array and the induction coil on the moving The matrix of excitation coils forms a loop through parallel and series connection, and the AC excitation signal is passed through. If a certain excitation coil is damaged, the sensor cannot be measured; (3) In order to reduce the difference in the magnetic field generated by different coils on the fixed array surface, To make the measurement results more accurate, it requires high processing technology; (4) The induction coil on the dynamic array surface is composed of three induction coils with the same size and number of turns, and the corresponding signal processing process determines that if the dynamic array surface is relatively The fixed front is not completely parallel or there is deflection, which will cause measurement errors, resulting in inaccurate measurement results

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