Abstract: Multibody system dynamics provides a strong tool for the estimation of dynamic performances and the optimization of multisystem robot design. It can be described with differential algebraic equations (DAEs). In this paper, a particle swarm optimization (PSO) method is introduced to solve and control a symplectic multibody system for the first time. It is first combined with the symplectic method to solve problems in uncontrolled and controlled robotic arm systems. It is shown that the results conserve the energy and keep the constraints of the chaotic motion, which demonstrates the efficiency, accuracy, and time-saving ability of the method. To make the system move along the pre-planned path, which is a functional extremum problem, a double-PSO-based instantaneous optimal control is introduced. Examples are performed to test the effectiveness of the double-PSO-based instantaneous optimal control. The results show that the method has high accuracy, a fast convergence speed, and a wide range of applications. All the above verify the immense potential applications of the PSO method in multibody system dynamics.

Key words: crack, cylinder, benduig, singular integral, multibody system, instantaneous optimal control, robotic dynamics, symplectic method, particle swarm optimization(PSO)algorithm