A Preview Type-2 Fuzzy Controller Design for the Semi-active Suspension to Improve Adhesion Characteristics during Braking and Handling

A full vehicle of a preview control semi-active suspension system based on an interval type-2 fuzzy controller design using a magnetorheological (MR) damper to improve ride comfort is investigated in this paper. It is integrated with the force distribution system to obtain the optimal rate of road adhesion during braking and handling. The nonlinear suspension model is derived by considering vertical, pitch, and roll motions. The preview interval type-2 fuzzy technique is designed as a system controller, and it is attached with a Signum function method as a damper controller to turn on the voltage for the MR damper. This voltage is adjusted for each wheel based on the external excitation generated by road roughness in order to enhance ride comfort. To describe the effectiveness and adaptable responses of the preview controlled semi-active system, the performance is compared with both the passive and MR passive suspension systems during time and frequency domains. The mathematical models of full-vehicle suspension systems are solved using MATLAB/Simulink software. The Magic Formula tire model is used to evaluate both longitudinal and lateral forces based on normal load estimated by a suspension system. These forces are adjusted for each wheel based on the distribution control used in the braking system. Simulation results show that the novel semi-active controlled system integrated with the force distribution system used for the braking system can achieve ride comfort with the supporting contact patch significantly according to the investigated factors including tire workload, stopping braking distance, weight transfer, and cornering force.