Dynamic powertrain system modeling and simulation with applications for diagnostics, design and control

This thesis describes various approaches to powertrain system dynamical modeling, with examples of their application to diagnostics, design, and control. A vehicular powertrain system is defined in this thesis as an assembly of engine, transmission, driveline, and control systems by which the power is generated, transmitted and managed. Dynamic powertrain system modeling and simulation are at the heart of this research, whether they are for diagnostics, design, or control. Several different models and sub-systems are included in the thesis as application examples.; Modeling methodology and philosophy is introduced and detailed models are described for various components in a systematic way, which can be used for the development of many powertrain systems. As one of the applications, an M915 semi-trailer powertrain is used to show simulation results of transient system responses and dynamic coupling effects, and how these system models are helpful in understanding these dynamics.; An application of dynamic engine diagnostics is presented to show how the models can be used to identify and isolate faults or unusual operation with the engine. Two crankshaft dynamics models at different levels of fidelity are combined for engine combustion quality diagnostics and special powertrain consideration is given to small or medium size engines to monitor combustion quality. A new concept of using “synthetic” engine variables for diagnostics is discussed. A Mercury Marine 2-stroke, 2-cylinder engine is tested at different speeds of operation to validate the theory and methodology.; A case of transmission optimization design is shown using a dynamic HMMWV powertrain model with a GM Hydra-matic 4L80-E transmission. This example combines optimization of both hardware (clutch capacity) and control (shift strategy) for performance, shift quality, and clutch life. This design demonstrates how powertrain system models can be used for optimization of individual components, module sets, or overall system performance.; The M2A2 Bradley Infantry Fighting Vehicle (IFV) powertrain, which includes a Cummins VTA-903T engine and unique GE HMPT-500-3 hydromechanical steering transmission, is modeled. The model is based on the fundamentals and methodologies discussed in Chapter 2. The model is developed and used for powertrain integrated control.