Mobility and Vehicle Mechanics

29-53

Authors: Dušan Gruden

For people from ancient times, the world consisted of four elements: air, water, earth and fire. And, although a modern man knows more than 110 chemical elements, his activities in the field of environmental protection are concentrated precisely on these four elements. Further human survival on this planet depends more and more on how much humans care about these elements and their existing reserves. In the early 1970s, after nearly a hundred years of vehicle development, the vehicle’s “eco-development” had started in order to reduce or completely eliminate the negative impact of vehicles on environment. Environmental protection and efficient use of the existing reserves of energy sources and raw materials are in the spotlight of the modern car development for decades and are deeply instilled in overall development of cars. Life cycle assessment, which is carried out with increasing precision, will contribute with new knowledge on possibility for further improvement of the car’s environmental characteristics on its whole journey, from obtaining raw materials for its construction to recycling of end of life vehicles, “from the cradle to the grave”.

69-84

Authors: Marko Kitanović Predrag Mrđa Slobodan Popović Nenad Miljić

Due to Internal Combustion Engines’ (ICE) significant share in global energy demand, primarily through the transportation sector, great efforts are invested in research for solutions that will increase the fuel economy of ICE-powered vehicles. The main objective of the study presented in this paper has been to perform a comparative study of a conventional and a parallel hybrid electric transit bus employing an ultracapacitors-based energy accumulator. A high-fidelity simulation model of the vehicle has been designed in the AMESim multi-domain system analysis software. The conventional powertrain model has been calibrated using data obtained during an acquisition experiment conducted in real-world traffic conditions on a transit bus. This data also served as the basis for defining the driving cycle on which the numerical analyses will be conducted. A simple, sub-optimal control law has been implemented in the hybrid powertrain simulation model. Also, an advanced energy management law based on Dynamic Programming has been derived to assess the ultimate fuel economy improvement potential of the hybrid solution and to make design decisions. Initial study shows that considerable fuel consumption reduction in excess of 30% could be achieved by implementing a regenerative hybrid system employing an ultracapacitor-based accumulator.