Active Steering of Railway Vehicles Via DOBC Techniques

A novel control scheme for the active steering of railway vehicles is presented in the paper using disturbance observer based control (DOBC) techniques. in contrast to existing DOBC schemes which are mainly for single-input-single-output (SISO) systems and designed by trial and error, a new DOBC technique for multi-input-multi-output (MIMO) systems is developed. This is achieved by reforming the DOBC into the parameterisation of all stabilising controllers and then the disturbance observer is designed to minimise the influence of disturbances. in this scheme, the disturbance observer does not have influence on tracking/regulation performance and stability. The developed DOBC scheme is then applied to the control of railway vehicles, where an LQG controller is designed as the primal controller for the vehicle running on straight tracks and the disturbance observer is employed to improve the curving performance. This overcomes the difficulty in compromising the performance and wheelset stability on straight tracks and the curving performance when a single controller is used. The simulation reveals that the curving performance of railway vehicles is improved while the straight track performance/wheelset stability remains the same.