Trajectory Optimization of Electric Vehicles for Eco-Driving Applications
Résumé
Due to environmental concerns and scarcity on non-renewable fossil fuels researchers are currently looking for new, more fuel efficient solutions in the transportation sector. With its ability to regenerate kinetic energy while braking the electric vehicle is an attractive solution. In addition the electrification gives flexibility for the source of energy chosen to generate the electricity. One way to improve energy efficiency of road vehicles is to adapt their utilization to the system operation. The concept of eco-driving refers to a driver behavior that minimizes energy consumption. While the efficient operation of a conventional vehicle might be intuitive, the general driver does not know how to optimally operate an electric vehicle. With this work we are trying to identify potential gains in energy consumption as well as to detect factorsthat are important for eco-driving. The paper presents a system model of a small electric vehicle. In order to compute the energetically optimal velocity trajectory the dynamic programming optimization method is applied. For comparison, normal driving is defined using stored real-life drive cycles. Given the drive cycle optimization constraints are defined in time, distance and speed. The calculated optimal velocity trajectories are analyzed in order to identify important eco-driving factors. To verify the potential eco-driving gains the trajectories were tested in an experimental setting on a chassis test bench.