The optimal design of braking system for heavy haul trains

Abstract

The train brake system is a complex pneumatic device whose performance and reliability are relatively important. When the train is beging braked, the coupler force caused by the inherent delays in pneumatic airbrakes, commonly used in freight trains, becomes relatively large. The problem is even severe for long freight trains where the delayed response involves heavy longitudinal forces between vehicles. It is clear that proper design of of braking system can reduce the damage between vehicles. In this paper, firstly, according to the character of variational curve of braking pressure, we adopt a simple function to simulate the brake force. Secondly, we introduce an optimal control model to minimize the brake stopping distance under safe coupler forces, and prove the existence of optimal solution to the model. Finally, we change the model to one without continuous state inequality constraints by introducing penalty function.