Design of passive suspension system to mimic fuzzy logic control active suspension system

Background: This paper proposes a method for designing a passive suspension system that determines the optimal suspension settings while offering feasible performance near an active suspension system. A mathematical model of a nonlinear quarter car is developed and simulated for control and optimization in MATLAB/Simulink (R) environment. The input road condition is a Class C Road, and the vehicle moves at 80 kmph. Fuzzy logic control (FLC) action is used to accomplish active suspension system control. An approach for investigating optimal suspension settings based on the FLC control force is described here. The optimized passive suspension system is supposed to have the same suspension travel and velocity as an active suspension system. The least square technique is implemented to optimize the suspension parameters of the passive suspension system. Results: The initial passive suspension system, FLC active system, and optimized suspension system are simulated in MATLAB/Simulink (R) environment. It is observed that RMS acceleration for the FLC system is 0.5057 m/s(2), which is reduced by 46% (passive suspension system has RMS acceleration of 0.9322 m/s(2), which is uncomfortable). For optimized system, RMS acceleration is 0.6990 m/s(2). It is observed that the optimized passive suspension system almost mimics the initial FLC active suspension system. For the optimized system, sprung mass acceleration and VDV are improved by 30% and 27%, respectively, compared to the initial passive system. Conclusion: It is observed that the optimized passive suspension system mimics the initial FLC system. Also, an optimized FLC system has improved health criterion-based results compared to other suspension systems.