Fuel-Efficient Platooning of Heavy Duty Vehicles through Road Topography Preview Information

Sammanfattning: Road freight transport is a growing business and serves as a centerpiece of modern economics. Traffic congestions due to the increasing amount of vehicles, growing environmental problems due to CO2 emissions and rising fuel prizes create a vast demand for solutions to these global issues. Look ahead cruise control and vehicle platooning can be part of a future transport concept. By using GPS localization and considering road topography data (map data), a Look Ahead Cruise Controller LAC optimizes the velocity profile of a single vehicle when facing steep up- or downhills in order to save fuel. Platooning describes the concept of driving vehicles in a convoy with short intermediate distance to reduce the aerodynamic drag and achieve considerable fuel consumption reductions for all vehicles in the platoon. However, research on platooning with road topography preview information is a novel topic. In this thesis, look ahead cruise control and platooning are analyzed and results are combined in order to develop a platoon look ahead controller (PLAC). The PLAC features low computational complexity due to a simple parametric optimization method and reaches simulated energy consumption reductions of up to 20% for a vehicle in the platoon compared to its single drive on the same road. When velocity limits are considered, the fuel saving potential is even higher. It can be shown that the reached energy consumption with a PLAC lies slightly (1.3%-1.9%) over a minimum energy consumption needed to traverse the road section. Results reveal that in practical situations, a platoon should be maintained whenever possible. Errors in parameters of the vehicle, road parameters and localization errors are analyzed in terms of their influence on the energy consumption. Strategies are presented to reduce the influence of parameter errors on the fuel consumption and especially reduce the chance of a separate of the platoon.