With the increasing demand of the drive safety and ride comfort of vehicles, various new technologies are being applied in vehicle suspension system. In this case, the magnetorheological damper can adjust the damping dynamically, and fuzzy logic controller development to track the desired damping force is possible. The combination of two will effectively improve the suspension performance. Thereafter, a model built in Simulink is composed by road model, quarter vehicle model, Magneto Rheological damper model based on Bouc Wen model, damper coil current controller model and Fuzzy logical controller to track the desired damping force. The results obtained from road models have been used in combined simulation model. Finally, the comparative simulation experiments of passive suspension and semi-active suspension with magneto rheological damper was performed. The results show that, the ride comfort of quarter car model has been improved 10% compared to passive suspension; and vehicle stability 30% respectively.

The slipping of railway vehicle wheels during curve negotiation has been always a major problem in railway transportation. One of the causes of these slippages is predicted to be the lack of proper curve radius which incites high creepages. The creepages cause improper wheel rail interaction during curve negotiation. Most of the light rail transit system, with condensed population, there is a huge demand which increases the railway vehicles' weight to the maximum. However, this weight is again expected to have additional effects on the wheelset slipping when negotiating the curve or braking on a gradient curvature. Therefore, the aim of this paper is to model the anti-skid control of a railway vehicle in curved track operating in two instances: when the train is braking on a gradient curve and when the train is negotiating a curved track. To achieve this objective, the lateral dynamics equations of motion of the wheelset have been solved to predict the yaw angle and lateral displacements as well as their velocities. These quantities are used to calculate the creepages and creep forces. In return, they are input to the control model to limit the skidding. Computer simulations using MATLAB/ Simulink have been carried out to assess the feasibility of the control method. The results have used to design proper control systems that the rail network in congested environment are able to use. Antiskid control offers other benefits such as increasing the lateral comfort by reducing lateral forces and limiting noises generated by skidding in curvatures.