Rotor displacement measurement device and method for planar motor

Abstract

A planar motor rotor displacement measuring device and its measuring method are provided. The motor is a moving-coil type planar motor. The device comprises probes, two sets of sine sensors, two sets of cosine sensors, a signal lead wire and a signal processing circuit. The method is arranging two sets of magnetic flux density sensors within a magnetic field pitch τ along two vertical movement directions in the rotor located in the sine magnetic field area. Sampled signals of the four sets of sensors are respectively processed with a frequency multiplication operation, four subdivision signals are obtained, the zero-crossing points of the four subdivision signals are detected, and then two sets of orthogonal pulse signals are generated. The pulse number of the orthogonal pulse signals is counted, and phase difference of the two sets of orthogonal pulse signals is respectively detected.

Description

technical field [0001] The invention relates to a mover displacement measuring device and method of a planar motor with a sinusoidal magnetic field model, in particular to a subdivision displacement measuring device and an algorithm with a large stroke and high resolution. Background technique [0002] In two-dimensional positioning processing devices, especially modern semiconductor micro-processing equipment and other ultra-precision processing equipment, high-precision motion is usually realized by planar motors. Due to the advantages of fast response, high sensitivity and simple structure, planar motors have attracted extensive attention in both academia and industry. Patent 201110045692.8, patent 200910029368.X, and patent 200910088894.3 describe several planar motors with different structures in detail. [0003] At present, optical measurement methods such as gratings and laser interferometers are often used to detect the position of the mover of planar motors. In pa...

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Problems solved by technology

In patent 200880111964.6, two-dimensional gratings are used to measure the motion of planar motors. It is necessary to install a larger area of ​​planar gratings on the planar motors to generate optical signals with displacement information for communication with optical sensors. The scale surface is polluted; patent 201110040403.5 uses a grating sensor to detect the movement position in two directions, and each movement direction needs to install a main scale that meets the range requirements and a corresponding reading head to generate moiré fringe signals or other types with displacement information The optical signal has high requirements for the use environment; the patent 200910029828.9 uses a laser position sensor to realize the motion measurement of the planar motor through the principle of laser triangulation or echo analysis. The measurement accuracy is greatly affected by the environment. Handling is difficult while keeping it simple and fast

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