Modeling and Control of Automotive Systems
Scientific project supported by the Ministry of Science and Technology of the Republic of Croatia (2002-2006)
Project number: 0120-053
Period: June 2002 - Summary:
The application of various control systems of ground vehicles results in significant improvement of drivability, safety, comfort, fuel economy, and emissions. The development of automotive control systems is based on the knowledge of mathematical models of automotive elements and systems. Since a control system often requires knowledge of power train quantities which cannot be measured conveniently, it is necessary to develop on-line estimators of these quantities.
In the known models of automotive elements and systems, some important dynamics effects are often neglected (e.g. dynamics of friction in clutches, servo-system gears, and tires), or the models are too complex from the standpoint of control system development (e.g. finite-element-based models). Development of simple, physical, control-oriented, and experimentally validated dynamic models of automotive power trains is proposed in this project. Alternatively, the application of black-box models based on the neural nets is to be considered. The emphasis is given on modeling of engine, electronic throttle body, wet clutch of an automatic transmission, and tire. A detailed analysis of the dynamic behavior of these elements and the overall power train with automatic transmission is carried out, in order to facilitate model parameterization and control system design.
Estimation of engine torque, vehicle traction force, and other quantities of an automotive power train is usually conducted in the open loop. Design and experimental examination of closed-loop nonlinear estimators are proposed in this project, in order to increase static and dynamic accuracy of estimation in the presence of emphasized process parameters variations. A special attention is given to the choice of estimator structure which would provide estimator robustness
Based on the developed models and estimators, various high-performance automotive control systems are designed and experimentally verified. An emphasis is on idle speed control, active compensation of combustion pulses in hybrid vehicles, servo-control of electronic throttle, and vehicle dynamics control systems including ABS and traction control.