Robust active guidance control using the μ-synthesis method for a tramcar with independently rotating wheelsets

This paper presents a robust active guidance controller that uses the mu-synthesis method to improve the ability of guidance and to reduce the wheel-rail wear under the consideration of system nonlinearity, parameter uncertainty, and measurement noise in tramcars with independently rotating wheelsets (IRWs). Each wheel of the tramcar is connected to a sider motor, and the active yaw moment is generated by the torque differences between the left and right wheels in the same axle. To achieve local control, the wheel-rail force and the primary suspension force are considered as external disturbances, and the IRW state-space model is modeled independent of the tramcar system. The effectiveness of the controller is mainly verified by the cosimulation method: the dynamic model of the tramcar is established in SIMPACK, and the controller model is established in MATLAB. The simulation results show that compared with the passive case, for the actual tramcar, the control method can improve the vehicle's running performance and can significantly reduce the wheel-rail wear in both straight and curved tracks. A 1:5 scaled tramcar model is used for the active guidance experiment to further verify the effectiveness of the algorithm.