Pulse input sequences for residual vibration reduction

Preshaping of the input is a well known technique to reduce the vibration in a flexible structure. In this paper, inputs in the form of pulse sequences that are able to reduce the residual vibration in overhead crane are presented. If the exact natural frequency and damping ratio of the system are known, then the residual vibration can be eliminated completely. However, additional constraints can be imposed to incorporate some robustness in the system to variations in the natural frequency and damping ratio for practical implementation. Simulation results and experimental tests show that the inputs developed here are effective in moving the system with no or little residual vibration. In addition, the suggested inputs with robustness incorporated show marked insensitivity to errors in natural frequency and damping ratio estimates. (C) 1998 Academic Press Limited.