Modelling and control for simultaneous laser beam alignment of a dual-PSD industrial robot calibration system

Calibration plays a critically important role for improving the accuracy of industrial robots. Recently, position sensitive device (PSD) based calibration methods provide a more efficient way to perform joint offset calibration than the conventionally used methods. We have proposed a dual-PSD based method to accurately calibrate the joint offsets of industrial robots. However, the required alignment of laser beam to shoot at the two PSD centers was performed separately, which required to pre-know some parameters for the alignment task. This paper proposes a simultaneous laser beam alignment method without knowing these parameters to perform the laser beam alignment task. The modeling and control for the alignment system are derived and simulation results illustrate the effectiveness of the proposed methods.