Conception of Cylinder Pressure Based Diesel Injection Control System

Control of diesel fuel injection is very important and has influence not only at engine operating conditions but also at emission of toxic gases as NOx, HC, and Particulate Matter (PM) are effect of combustion process. Directly observing of combustion process is very difficult, but implementation to injection control algorithm procedures based on additional sensors as knock sensor, cylinder pressure sensor and observing of rotational speed course could give enough information to optimize control algorithm. In traditional diffusion-burn diesel combustion start of combustion occurs a cetane-number based time delay after the start of the fuel injection. To fulfill of new emission standards is need to observing not only start of combustion but also whole combustion process. In the paper conception of injection control system applied with combustion process observer based on additional sensors. Closed-loop feedback control of cylinder pressure sensor and advanced control algorithm with high-resolution rotational speed sensor offers the potential to improve controllability of combustion process. Advanced control system based on heat release estimated from cylinder pressure and rotational speed fluctuations enabling improving engine exhaust emissions, engine performance and reduced noise emission. Introducing into control system a low cost glow plug integrated cylinder pressure sensor allow to achieve complete injection control system with advanced functions which could be very effective also in aspect of fuel consumption reduction.