Variable Valve Actuation for Timing Control of a Homogeneous Charge Compression Ignition Engine

Autoignition of a homogeneous mixture is very sensitiveto operating conditions. Therefore fast combustion phasingcontrol is necessary for reliable operation. There areseveral means to control the combustion phasing of a Homogeneous Charge Compression Ignition (HCCI) engine.This paper presents cycle-to-cycle cylinder individual controlresults from a six-cylinder HCCI engine using a VariableValve Actuation (VVA) system. As feedback signal,the crank angle for 50% burned, based on cylinder pressure,is used. Three control structures are evaluated,Model Predictive Control (MPC), Linear Quadratic Gaussiancontrol (LQG) and PID control. In the control designof the MPC and LQG controller, dynamic models obtainedby system identication were used. Successful experimentswere performed on a port-injected six-cylinderheavy-duty Diesel engine operating in HCCI mode.