Structural vibration control using PZT patches and non-linear phenomena

We investigate non-linear saturation control, non-linear internal resonance control, and linear position-feedback control of steady-state and transient vibrations of a cantilever beam by using PZT (lead zirconate titanate) patches as actuators and sensors. The. saturation control method uses the saturation phenomenon to suppress steady-state vibrations of a dynamical system with quadratic nonlinearities and 2:1 internal resonances. The internal resonance control method uses the energy exchange phenomenon due to internal resonances and added dampings to suppress transient vibrations. To test these control techniques in an efficient and systematic way, we built a digital control system that consists of SIMULINK modelling software and a dSPACE DS1 102 controller in a pentium computer. Both numerical and experimental results show that the saturation control method is robust and efficient in suppression steady-state resonant vibrations. The linear position-feedback control is more robust, efficient, and convenient than the internal resonance control in suppressing transient vibrations, but it is not as robust as the saturation control in suppressing steady-state vibrations. A hybrid controller consisting of a saturation controller and a position-feedback controller is shown to be robust and efficient in controlling both transient and steady-state vibrations. (C) 1998 Academic Press.