Abstract: The error model of a novel virtual center mechanism with parallel kinematics is established based on the modeling method of spatial error-vector chains. Thereafter, the mapping functions between the geometric error parameters and the output error parameters are generated. On the basis of the error model, the local sensitivity coefficient index and the global sensitivity coefficient index of each geometric error parameter are derived and graphically presented in atlases. Based on these atlases, the geometric error parameters’ influence on the output accuracy of the virtual center mechanism is identified numerically. The results contribute a lot to the determination of the parts’ tolerance and the output error of the control system.

Key words: Error model, Error sensitivity, Virtual center mechanism