Error modeling of a 3-RPS parallel mechanism based on screw theory

Abstract Due to the highly nonlinear nature of the kinematic equations of parallel mechanisms, this paper conducts an error modeling study of the 3-RPS parallel mechanism based on the efficiency and unification advantages of screw theory in handling nonlinear systems. First, the geometric structure and kinematic characteristics of the mechanism are analyzed; in addition, redundant error elimination is performed. Then, an error model is established using the screw theory. The impact of structural parameter errors on the end-effector’s position and orientation is analyzed through simulations. The conclusions indicate that the model can accurately predict the error distribution patterns of the parallel mechanism, providing important theoretical support for the precision optimization design of parallel mechanisms.