Active Vibration Control of Smart Beam under Random Vibrations

Thepresent paper discusses active vibration control of a cantilever beam subjected to random base excitation. The smart materials used are piezoelectric patches for both as sensor and actuator, and actuation based on the surface strains. Finite element model of the smart beam is obtained using Euler-Bernoulli formulation. Positive Position Feedback (PPF) controller is proposed for active damping to control the vibrations at all the resonant modes using piezoelectric sensor voltage feedback.Experiments are carried out on a smart cantilever beam and the closed loop responsesare studied using three collocated sensor-actuator pairsat different locations and with different controller gains. It is observed that the selection of the sensor-actuator pair helps in controlling the modes significantly.Generally,larger gains are required for controlling the higher modes. For a particular chosen collocated sensor-actuator pair, higher damping ratios are achieved for lower modes; lower damping ratios are obtained for higher modes even with higher gains. Key wordsSmart Beam, Active Vibration Control, PZT patch, PPF controller