Rapid-Precision Position Measurement of Linear Motor Mover Based on Joint Spatial Phase Method

In this article, a rapid and precise position measurement method based on joint spatial phase is studied for linear motors. First, a low-cost mover position measurement system is designed on the basis of motion characters of linear motors. The target image is an aperiodic fence stripe. The image sequences with the movement of the mover are recorded quickly by linear charge coupled device (CCD) camera. Second, spatial domain algorithm is introduced for the rough registration, and according to the registration results, the overlapping regions are extracted to form two new images, and then the improved phase difference method is used to get the accurate displacement of the two new images. The actual mover displacement is finally calculated by the calibration coefficient of the system. Simulation and experimental results show that this method proposed takes approximately 2 ms on average, and the measurement accuracy reaches 0.02 mm.