LQG control based lateral active secondary and primary suspensions of high‐speed train for ride quality and hunting stability

This study focuses on the ride quality and hunting stability of high‐speed train by employing the lateral active secondary and primary suspensions. First, the full‐scale railway vehicle dynamics with 17‐degree‐of‐freedom are introduced, where the actuator saturation, suspension deflection, and random and periodic track irregularities are considered. The system characteristic and control ability are discussed by analysing the spectrum of the open‐loop system. Here, it is found that improving ride quality and hunting stability simultaneously is difficult by only using the secondary suspension. In consequence, both the active secondary and primary suspensions are employed to improve the ride quality and hunting stability simultaneously by utilising the linear‐quadratic‐Gaussian (LQG) control theory. Finally, the random and periodic track irregularities are given to illustrate the efficiency of the proposed LQG‐based active secondary and primary suspensions.