Stability Investigation of Hydraulic Interconnected Suspension System of a Vehicle with a Quaternion Neural Network Controller

Using hydraulic interconnected suspension (HIS) system to improve the stability of the vehicles is a matter of recent interest of many scholars. In this paper, application of this kind of suspension system and its impact on the stability of the vehicle are studied. The governing dynamic relations of the system are presented, using free body diagram, Newton-Euler motion equations, and relations related to the mass flow rate of fluid. By completing the design of the passive suspension system and the hydraulic interconnected suspension system and employing the half car model in the transverse direction with four degree of freedom, MATLAB® (V.8.1) /Simulink (MATLAB® is a software package produced by The Math Works, Inc.) software is used to investigate and compare the body and wheel responses of the vehicle in exposure to road surface roughness. In the end, quaternion neural network controller has been used due to the obtained nonlinear equations in interaction of suspension system as well as the coupled differential equations. Using quaternion neural network controller, the results indicated that the stability of vehicle and ride comfort are increased and also more smooth responses are generated.