High Precision Multi-Frame Motion Detection for PMSLM' Mover Based on Extended Upsampling Normalized Cross-Correlation

A sub-pixel detection algorithm by means of extended upsampling normalized cross-correlation is studied to realize fast and accurate position detection of permanent magnet synchronous linear motor (PMSLM). First, a linear motor mover positioning system composed of a line scan camera and an aperiodic fence stripe image is designed to realize realtime signal acquisition during the motion of the mover. Second, a normalized cross-correlation (NCC) algorithm is utilized to obtain the initial estimation of displacement parameters between adjacent frames. Finally, a matrix multiplication discrete Fourier transform (DFT) is used to realize the local upsampling of the cross-correlation function, and the precise displacement parameters are obtained. Simulation results show that the proposed method can achieve 0.01 pixels accuracy. And the reliability and practicability of the proposed method are verified by setting up an experimental platform.