Kinematics accuracy and reliability analysis for 3PTT-2R series-parallel mechanism

In order to solve the problems of kinematics accuracy and reliability of parallel or series-parallel, a type of 3 parallel U 2 series mechanism was used for analysis. Posture and kinematics decoupling method is adopted and got the working space. Through the analysis of the kinematics characteristics of connecting rods and hooker, the sensitive parameters and model is determined. On basis of this, it was predicted and assessed of mechanism kinematics accuracy by reliability analysis method. The simulation analysis of surface parts processing as an example. The simulation results show that it had small error and the reliability probability. The experiment show that it was improved accuracy, got the reliability index and anywhere of working space by optimized parameters.