Robust Design of Passive Suspension System of Half Railway Vehicles via Control Theory

This study deals with the robust design in designing passive suspension system of half railway vehicles via feedback control theory. This design with robustness performance is examined in the change of body weight corresponding to full and empty load of vehicle. These two states of system can be described by two sets of equations of motion that can be extended as one control object, and the controller designed by feedback control theory will control this extended model. By applying feedback control theory, parameter selection and optimization of a huge class of passive suspension system becomes a structural control problem. Since minimizing ℋ_∞ norm of the system implies suppressing the peak of the magnitude of frequency response of the extended system, parameters selection of passive suspension systems becomes an ℋ_∞ static output feedback problem, which turns into Bilinear Matrix Inequality (BMI) problem. One of simple methods to solve BMI problem is alternative algorithm which is derived from iterative schemes of alternation between analysis and synthesis via Linear Matrix Inequalities (LMIs). The effectiveness of vibration reduction is simulated by MATLAB software.