Modeling and Control of Torsional Beam Vibrations: A Wave-Based Approach

This paper presents a wave-based modeling and control approach for suppressing torsional vibrations of an elastic shaft driven by a motor at one end and an inertial load at the other end. A two-port network model representing the dynamics of torsional displacements is obtained starting from the partial differential equations governing a shaft in torsion. By incorporating appropriate boundary conditions, the infinite dimensional transfer function of the system is obtained. Furthermore, the system is represented by delay elements that can be used for simulation purposes. An inversion-based controller that can be used to suppress vibrations while rotating the shaft according to a specific trajectory is then developed. The performance of the controller is further studied using numerical simulations.