Robust Control of Manifold Air Injection in a Marine Diesel Engine

In diesel engines, during a load increase, due to poor combustion from the fuel/air mismatch, excessive exhaust smoke may be caused. One possible measure to reduce smoke emissions is the use of compressed air injection into the manifold downstream of the turbocharger compressor and before the cylinders. This work addresses feedback of pressure in the intake manifold for the control of air injection. The novel robust control strategy considers uncertainty in the modeling representation and allows acceptable engine performance over an operating envelope around a nominal point. Experimental results on a marine diesel engine validated the controller approach.