Optimal Control of the Driving of Trains (Optimale Steuerung der Fahrweise von Zügen)

The optimal control of the driving of trains has been a field of active research for many years. The optimization objective is to drive a train so that the use of energy is minimized subject to time constraints and physical limitations. Most published results are based on the analytical solution of the problem for a simple linear train model and on empirical extensions. In this paper we consider a more detailed nonlinear train model. The methods of Sequential Quadratic Programming (SQP) and Discrete Dynamic Programming (DDP) are evaluated for the numerical solution of the nonlinear optimal control problem. The advantages of the treatment as nonlinear problem and of the use of DDP in this application are discussed on practical examples. Results obtained during the on-line application in a decision support system onboard of running trains are reported.