Dynamic modeling and trajectory tracking control of an electromagnetic direct driven spherical motion generator

As the demands for multi-degree-of-freedom actuators increase, novel mechanical-electrical integrated designs of motion generator are required for robotic applications. In this work, a spherical motion generator integrating electromagnetic actuators with a 3-RRR spherical parallel manipulator is introduced. The design allows to generate 3-DOF rotations in a compact structure. In this paper, a complete dynamic model in the task space is built for the integrated system, with consideration of uncertainties such as modeling errors and external disturbances. Addressing the uncertainties in the model, a robust adaptive switching learning control algorithm is developed, which can improve its trajectory tracking performance. The stability of the proposed method is analyzed by using Lyapunov method. A co-simulation platform by Matlab/Simulink and ADAMS was developed, with simulations conducted. The results show that the proposed control algorithm has better trajectory tracking performance and robustness to uncertainties.