Wheel Slide Protection System by the Use of the Tangential Force in the Macro Slip Area

Abstract

Almost all railway vehicles have brake systems which use the tangential force between rails and wheels. It is difficult to stabilize braking performance and to prevent wheel damage because the tangential force is influenced by various conditions, such as weather, the contact surfaces of the rails and the wheels, etc. Wheel slide protection systems (WSP) are one solution adopted on many vehicles. However, in existing WSP systems, braking force is controlled using limited information from the rotational speed of the wheel. Therefore, they do not always offer optimal control when the tangential force varies frequently. This study proposes a new WSP system which can determine the quality of the tangential force from the brake cylinder pressure when wheel slips occur. The performance of the new WSP was verified through bench tests. As a result, application of the new WSP method reduced braking performance loss.