Kinematics Analysis and Optimization Design of Semi-active Suspension for a Light Bus 2011-01-0090

In this paper, a Magneto-Rheological (MR) fluid semi-active suspension system was tested on a commercial vehicle, a domestic light bus, to determine the performance improvements compared to passive suspensions. MR fluid is a material that responds to an applied magnetic field with a significant change in its rheological behavior. When the magnetic field is applied, the properties of such a fluid can change from a free-flowing, low viscosity fluid to a near solid, and this change in properties takes place in a few milliseconds and is fully reversible. A quarter suspension test rig was built out to test the nonlinear performance of MR damper. Based on a large number of experimental data, a phenomenological model of MR damper based on the Bouc-Wen hysteresis model was adopted to predict both the force-displacement behavior and the complex nonlinear force-velocity response. Comparison with experimental results indicated that the mathematical model could effectively portray the behavior of typical MR damper and was adequate for control design and analysis. In order to accurately simulate the performance of the commercial vehicle, a detailed multi-body dynamic model of the light bus with four semi-active suspensions were established, and an actual vehicle handling and stability test was carried out to verify the correctness of the multi-body dynamic model. For the purpose of developing semi-active controller, the theory of neural network control is adopted here to identify and control the semi-active suspension systems. The primary goal of this paper is to create an effective, reliable and safe semi-active suspension that improves the ride comfort as well as handing stability of the commercial vehicle.