Dynamic modeling and performance analysis of a lower-mobility parallel robot with a rotatable platform

Abstract

Recently, applications of high-speed, lightweight parallel robots have been gaining increasing interest. Studies have shown that their elastic that their elastic deformation during operation often affects the robot's dynamic performance. In this paper, we designed and studied a 3 DOF parallel robot with a rotatable working platform. We developed a rigid-flexible coupled dynamics model consisting of a fully flexible rod and a rigid platform by combining the Assumed Mode Method with the Augmented Lagrange Method. The driving moments under three different modes were used as feedforward in the model's numerical simulation and analysis. We conducted a comparative analysis demonstrating that the flexible rod's elastic deformation under a redundant drive is significantly smaller than that of a non-redundant one, leading to a better suppression effect on vibration. The system's dynamic performance under the redundant drive was significantly superior compared to that of the non-redundant one. Additionally, the motion accuracy was higher and the driving mode b was better than that of the driving mode c. Finally, the proposed dynamics model's correctness was verified by modeling it in Adams.