Dynamics of Non-Ideal Topology Transitions in Multibody Mechanical Systems

Mechanical systems with time-varying topology appear frequently in various applications. In this paper, topology changes that can be modeled by means of bilateral impulsive constraints are analyzed. We present a concept to project kinematic and kinetic quantities to two mutually orthogonal subspaces of the tangent space of the mechanical system. This can be used to obtain decoupled formulations of the kinetic energy and the dynamic equations at topology transition. It will be shown that the configuration of the multibody system at topology change significantly influences the projection of non-ideal forces to both subspaces. Experimental analysis, using a dual-pantograph robotic prototype interacting with a stiff environment, is presented to illustrate the material.