Simplified kinematic calibration for a class of parallel mechanism

Calibration methods and parameter estimation analyses of a class of parallel mechanisms are discussed in order to achieve a nano-motion stage applied in the machining of high quality optical devices. The paper includes mechanical structure of Delta type parallel mechanism, its kinematics analyses for calibration, two calibration methods and their comparisons in the aspects of parameter errors, final achieved accuracy and simple procedure. Exclusion of orientation data will be also discussed for the simplicity of measurements in the calibration procedure.