Experimental performance analysis of a model-based gain-scheduling controller of the common rail pressure in GDI engines

Nowadays, the Common Rail (CR) injection system plays a fundament role for improving engine performance in terms of fuel economy and pollutant emission reduction. To this aim the precise control of the mean value pressure in the common manifold is fundamental for achieving the benefits promised by the CR technology. In this report the closed loop performance of a model-based gain scheduling control algorithm for controlling CR mean value pressure for Gasoline Direct Injection (GDI) engines are widely evaluated via experiments. The controller manly consists of a model-based feedforward and integral feedback actions. Both control actions are adapted on the basis of two fundamental plant paraments, i.e. pump speed (or equivalently engine speed) and battery voltage. The experimental investigation shows that in a wide range of operating conditions typical control specifications are achieved hence confirming the effectiveness of the control strategy. The simple control structure makes the control strategy particularly suitable for its implementation in commercial Electronic Control Units (ECUs).