Control of a flexible manipulator using shaped inputs

This paper presents an investigation into the development of open-loop control strategies using shaped command inputs for vibration suppression in flexible manipulator systems. The method requires, at the first stage, that the natural vibration frequencies of the system be determined very precisely. A non-linear AutoRegressive process with eXogenous inputs (NARX) model is used with multilayered perception (MLP) neural networks for this purpose. Shaped command inputs including low-pass and band-stop (elliptic type) filtered torque input functions are then developed based on the identified modes of vibration and applied to a single-link manipulator in an open-loop configuration to suppress the structural vibrations. Finally, the performance of the control strategy in suppressing vibrations in the system is discussed in comparison to a bang-bang toque input.