Error analysis of binocular active hand-eye visual system on parallel mechanisms

Binocular active hand-eye visual system on parallel mechanisms is a novel workspace monitoring mechanism, which fixed on the moving platform of a parallel mechanism with a circular orbit. Considering kinematic coupling between the parallel mechanism and the visual system, a general scheme based on the 3D reconstruct model of a binocular stereo vision is proposed to evaluate the control errors of the robot and the visual mechanism using the image coordinates of two kinds of target points. First, the optimal estimation of the perspective transformation matrix (PPM) relative to the base frame and the moving platform frame are calibrated respectively. Then the actual kinematic parameters of the parallel mechanism and the visual system are estimated by decomposing PPM. The tracking experiment on a 6-PUS parallel engraving machine is presented to show effectiveness of the method.