Active vibration control of beams using filtered-velocity feedback controllers with moment pair actuators: Fid-Bau Portal

Active vibration control of beams using filtered-velocity feedback controllers with moment pair actuators

Shin, Changjoo / Hong, Chinsuk / Jeong, Weui Bong

This study investigates the active vibration control of clamped beams using FVF (filtered-velocity feedback) controllers with a non-collocated sensor/ moment pair actuator configuration. A moment pair actuator is used for the control actuator and a velocity sensor is used for the feedback sensor, located at the opposite center of the moment pair actuator. This non-collocated configuration is the main source of instability problems in control systems. In order to overcome such instability problems, the FVF controller is proposed. To obtain the characteristics of the FVF controller, a parametric study followed by stability and performance analysis is conducted for a proposed design of the FVF controller. The following conclusions are highlighted: The parametric study on the design parameters of the FVF controller is conducted to characterize their effects on the stability and performance of the controller. It is found that, as any conditionally stable system, the gain does not affect the absolute stability, but does affect the relative stability. As the damping ratio of the FVF controller is increased, the magnitude of the open loop transfer function decreases around the cut-off frequency, and the phase of the open loop transfer function is affected over a wider range near the cut-off frequency. This means that the control system can be stabilized with the increase in the damping ratio of the FVF controller. FVF controllers are numerically and experimentally implemented based on the results of the parametric study. Comparisons are made to verify the performance of the controller, and the qualitative features agree well. Using an FVF controller, the source of instability at high frequencies is reduced, and therefore, the FVF controller can reduce the responses below the cut-off frequency, including more than 10 dB reductions of the second and third modes. Consequently, the FVF controller proposed in this study can be applied for multimode control while can alleviate the high frequency instability.