Future railway vehicles are going to be designed lighter in order to achieve higher speed. Suppressing the flexible modes becomes a crucial issue for
improving the ride quality of the light-weight high speed railway vehicles. The concept of smart structure brings structural damping to flexible structures by integrating smart actuators and sensors onto the structure. Smart structure eliminates the need for extensive heavy mechanical actuation systems and achieves higher performance levels through their functionality for suppressing the flexible modes. Active secondary suspension is the
effective conventional approach for vibration control of the railway vehicle to improve the ride quality. But its ability in suppressing the flexible
modes is limited. So it is motivated to combine active structural damping
for suppressing the flexible modes and the vibration control through active secondary suspension which has an effect on both rigid and flexible modes.
The side-view model of the
flexible-bodied railway vehicle integrated with piezoelectric actuators and sensors is derived. The procedure for selection
of placement configurations of the piezoelectric actuators and sensors using structural norms is presented. Initial control studies show that the flexibility
of the vehicle body will cause a considerable degradation in ride quality if it is neglected in the design model. Centralized and decentralized control strategies with various control approaches (e.g. modal control with skyhook damping, LQG/H2 control, H_infinity control and model predictive control (MPC))are applied for the combined control of active structural damping
and active suspension control. The active structural damping effectively suppresses the flexible modes as a complement to the work of the active suspension control.
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.