Image based PZT control calibration for 3D measurement

Abstract

Creep drift of piezoelectric actuators in solder paste 3D inspection was difficult to be accurate calibrated. Connected with actuated projecting grating, this paper proposed a new calibration method that a quarter-cycle sinusoidal grating was used for projection to substitute normal cycle grating and two phase-shift sinusoidal gray images were matched to calculate displacements. As calibration conditions including image capturing time delay were the same as in 3D measuring working, the creep drift and non-linear of PZT were all considered. Experimental results show that the PZT was delicate calibrated and 3D reconstructed accuracy was effectively improved. © 2011 Published by Elsevier Ltd.