Torsional vibration suppression by wave absorption controller

We discuss vibration suppression in a lumped torsional system using a wave-absorption filter. The controlled system is that treated previously [M. Saigo, et al., Torsional vibration suppression by wave-absorption control with imaginary system, Journal of Sound and Vibration 270 (2004) 657–672] in which an imaginary wave-propagation system similar to the real controlled system is computed online. Here, we introduce a new control algorithm we developed, using a modified impedance-matching wave-absorption filter taking the boundary condition into consideration, and that requires no online computation of an imaginary system with initialization. Our new wave filter provides much better control performance than the imaginary system computed online. The filter's basic concept enables the dynamics of the end element to which a control actuator is connected to meet the wave solution by control force. Experiments for 2 and 3 dof systems confirm that the wave-absorption control filter realizes traveling wave characteristics accurately without reflecting and shows very high control performance in vibration suppression.