Determination of the Fuel-optimal Trajectory for a Vehicle along a Known Route

Integration of topology data of the entire road ahead into the pow ertrain con trol unitin combination with hybrid electric pow ertrains o ers a huge potential for optimising the control strategy. The intension of the present paper is to show a methodology for computing the maximum potential of fuel saving over a speci ed route. For this o ine calculation a non-linear state-space model of the longitudinal dynamics is used to nd the fuel optimal trajectory using Bellman's Dynamic Programming (DP). As the model is of third order with three con trol inputs and DP can only be applied to systems with a maximum sum of inputs and states of four, the iterative varian t of DP is used. This special method described in this paper allows the solution of optimisation problems with a number of states and inputs up to six, without leading to insu erable computing times.