Integral control of smart structures with collocated sensors and actuators

This paper introduces a novel way of implementing simple first- and second-order feedback controllers, for vibration control in smart structures with collocated sensors and actuators. As these controllers are motivated by the simple integrator, the scheme is called Integral Resonant Control (IRC). In this approach a direct feed-though is added to a collocated system and the transfer function is modified such that it contains zeros followed by interlaced poles. This modification permits the application of the IRC scheme which results in good performance and stability margins. Problems due to unnecessarily high controller gain below the first mode are alleviated by slightly increasing the complexity from a first to a second order controller. Experiments carried out on a piezoelectric laminate cantilever beam demonstrate up to 24 dB modal amplitude reduction over the first eight modes.