Vehicle steering assist by estimated self aligning torque in skid condition

In the recent aging society, traffic systems require to be safer. As treating this back ground with intellectualizing vehicle, it is useful to estimate accurate Self Aligning Torque (SAT) charged on tire. It is because we could improve some unstable movements of vehicle or operationality of steering by this technique. In this paper, the control algorithm to detect SAT by using the Reaction Torque Observer and not using sort of side slip angle sensor is proposed. It could be also realized only by changing the control algorithm of existing Electric Power Steering system and it is given a try to be applied to improve operationality in lateral skid condition of vehicle. The steering assist torque was controlled to be generated to direction reducing slip angle of front tire. The simulation and experiment was carried out in order to verify the proposed controllability.