Reduced order dynamics and stability of a parallel manipulator through bond-graph technique

Dynamic characteristics of complex systems are very important for control system design. This paper represents the differences between full and reduced order dynamical models of a generalized Stewart Platform Mechanism. Full model includes all the dynamics, gravity effects, viscous friction at the joints and the linear motor dynamics. Reduced order dynamics includes all the dynamics of full system model except linear motor dynamics. Both full/reduced order dynamics are modeled using bond-graph technique and nonlinear state-space representations of models are obtained. Stability of both models is investigated by observing the variations of the system matrix eigenvalues which are utilized from the state-space equations. Four different trajectories are applied to the full order and to the reduced order Bond-Graph model for validation purposes. Satisfactory match between full/reduced order models is achieved.