Entire Vehicle Simulation in the Product Development with BMW and Tesis Dynaware Model

A brief account is given of an entire vehicle simulation model developed by BMW in co-operation with Tesis Dynaware for use in considering different design options. The model has a modular structure which enables the easy implementation of subsystems with different levels of detail and the omission of elements not required. The subsystems represented in the complete model include the internal combustion engine, transmission, axles, driving resistances, electrical power supply, hybrid components, controls and a driver module with driving cycles. The model focuses on the flow of electrical, thermal, mechanical and chemical energy through the vehicle, considering longitudinal dynamics only. The software used is 'Dymola' based on the programming language 'Modelica'. The use of the model in developing BMW's first full hybrid system is noted. The effects on fuel consumption and the durability of the battery were tested in different driving cycles and a number of conflicts resolved.