Collocated independent modal control with self-sensing orthogonal piezoelectric actuators (theory and experiment)

Distributed self-sensing piezoelectric actuators provide perfect collocations of sensors and actuators in closed-loop structural controls. To achieve independent control of various natural modes, spatially distributed self-sensing orthogonal piezoelectric actuators are proposed. A generic spatially shaped orthogonal sensor/actuator theory is derived first, followed by an application to a Bernoulli-Euler beam. Spatially distributed orthogonal sensors/actuators are designed based on the modal strain functions and they are fabricated using a 40 mu m piezoelectric polymer. A cantilever beam laminated with these self-sensing orthogonal piezoelectric actuators combined with a self-sensing feedback control circuit is tested. Collocated independent modal control of the cantilever beam with spatially distributed self-sensing orthogonal actuators is demonstrated and control effectiveness studied.