Optimal gain scheduling controller for a diesel engine

A generalized gain scheduling control mechanism based on off-line optimization techniques has been developed for a 2-cylinder, water cooled diesel engine. First, a set of linearized models is obtained for the engine operating at three different speeds and a total of 15 load conditions. From the experimental data analysis, it is concluded that the behavior of the engine can best be characterized by a set of fifth order difference equations with appropriate time delays. Optimal controllers with a PID structure are then synthesized by off-line numerical optimization using these mathematical models to minimize the integral squared error of the engine speed deviation subject to a step speed change command. The designed control system has been implemented and tested on a Petter diesel engine (Model PH2W). Experimental results indicated that the designed optimal control strategy has greatly improved the performance of the original engine in terms of both speed regulation and disturbance rejection. Attempts have also been made to evaluate the fuel efficiency of the engine with respect to controller parameter variations. It is concluded that there exists a strong correlation between controller parameter settings and the engine fuel consumption rate.<>