Design and optimization of a semi-active suspension system for a two-wheeled vehicle using a full multibody model

Abstract

This paper focuses on the design and the optimization of a semi-active suspension system used in a full dynamic model of a two-wheeled vehicle. The two-wheeled vehicle is considered as a multibody system. The equations of motion are obtained by applying an approach used widely in the robotic modeling field. Two basic strategies, called the continuous skyhook and the modified skyhook, are used to control the semi-active suspension system. Using the developed model, a multi-objective optimization procedure, based on Genetic Algorithms (NSGA-II), is proposed. The objective is to optimize the parameters of the two control laws of the semi-active suspension systems, in order to improve the ride comfort and the safety. To study the effectiveness of this approach, the results of the optimization are used in different simulations and the results are compared with those obtained from a simulation of a two-wheeled vehicle equipped with a passive suspension system. The results show that both control strategies of the semi-active suspension system give an improvement compared to the passive suspension system. Moreover, the multi-objective optimization results show that the simplified law “Modified Skyhook” ensures a higher ride safety, whereas the “Continuous Skyhook” is more effective in obtaining a higher level of ride comfort.