Turbocharged diesel engine performance monitoring and diagnosis using system identification techniques

In the last decade demands of on board diagnosis systems have increased. Therefore condition monitoring and fault diagnosis of diesel engines has become a more prominent topic of investigation. This work, will present the use of system identification techniques to extract models representing the relationship between engine processes. In this case, torque demand (input) and the turbochargerspeed (output) in a medium duty, turbocharged diesel engine. The proposition set here is that the model that can be derived does not have to reflect the complexity of the physical system. Hence, if simple models can be derived, any deviation from the model of normal operation, if adhering to some principles, could indicate the existence of a fault in a system. The main focus of this approach in this work is the exhaust flow system of the aforementioned engine. Models were derived for both normal engine operating conditions, and conditions of simulated fault in an attempt to show the validity of this technique. The results and conclusions obtained from this research are presented in detail.