Boost Pressure Control of Twincharger Diesel Engines

This paper addresses the boost pressure control of twincharger equipped Diesel engines. The variable geometry turbine and the supercharger by-pass are the two control inputs of the system. A static and dynamic analysis of the system is performed, highlighting a decoupling of the dynamics between the turbocharger and the supercharger. This allows the control problem to be reduced to two SISO problems. Consequently, the focus is put on controlling the boost pressure using the supercharger by-pass, the turbocharger control strategy remaining as-is. The proposed control strategy is based on a feedback linearization, using a physical model of the engine airpath. Experimental results stress the relevance of the approach.