Multidimensional digital control system for mechanical damping of suspended mass

In this paper we describe the architecture and the performances of a digital control system designed to damp the mechanical motion of a suspended mass. The position of the mass with respect to fixed reference points is acquired in real-time using classical optical levers, while the actuation is obtained through standard coil-magnet actuators. The number and the position of these devices allows the control of all the degrees of freedom of the mass. The algorithm developed to generate the control signals from the computed mass position error signals is based both on classical linear and non linear filtering techniques. The latter are necessary to manage the control of the mechanical system mainly in the first phase of control, when generally the position of the mass is far from the one chosen as reference and, therefore, nonlinearities may play a relevant role in the control.