Modular Design and Integration of In-Cycle Closed-Loop Combustion Controllers for a Wide-Range of Operating Conditions

This paper investigates how multiple in-cycle closed-loop combustion controllers can be integrated for a seamless operation under a wide-range of operating conditions. The stochastic cyclic variations of the combustion can be successfully compensated by the adjustment of the fuel injection pulses within the same cycle. The feedback information and controllability obtained relies on the different operating conditions, emissions regulations and fuels. Various in-cycle closed-loop combustion controllers are found in the literature to overcome the numerous challenges of the combustion control. In this paper, the modularization for the controller design and their integration is investigated, and how the transition between the available information, control actions and control strategy affects the final combustion behaviour. The approach consists in the design of a finite-state machine that supervises the transition between virtual sensors and measurements, regulators and the possibility of additional fuel injections. The proposed approach was tested in a Scania D13 engine for a wide-range of operating conditions. The results confirm the improved controllability and reduced steady-state RMSE of the controlled parameters, with a smoother transition between set-points, regardless of operating conditions and fuel.