Abstract:

For the limitation of traditional type-1 Smith fuzzy control in terms of inadequate time delay compensation and insufficient robustness under varying parameter driving conditions， an interval type-2 Smith fuzzy time delay compensation control method is introduced for magnetorheological （MR） semi-active suspension systems. This approach incorporates the vehicle's vertical acceleration， suspension deflection， and tire dynamic displacement as the state input of the control system， enabling a comprehensive capture and response to dynamic vehicle changes. By introducing in upper and lower membership functions， the method defines clear membership intervals for fuzzy variables， which are then leveraged to calculate activation intervals under various fuzzy rules， significantly enhancing the system's anti-interference capability. Additionally， the Center-of-sets algorithm is innovatively introduced into the fuzzy reduction process， avoiding redundant normalization calculation during the type reduction of type-2 fuzzy sets， thereby improving the system's execution speed and real-time performance. Simulation results demonstrate that the proposed interval type-2 Smith fuzzy delay compensation control strategy achieves improvement in both control effectiveness and robustness for MR semi-active suspension systems， effectively tackling complex and varied driving environment.

Key words: semi-active suspension, magnetorheological （MR） damper, time delay compensation, Smith, interval type2 fuzzy control