Transient control of variable geometry turbine on heavy duty diesel engines

In this paper a closed loop controller for variable geometry turbine (VGT) control during transient boost pressure build-up is presented. The controller is a state feedback controller with boost pressure, exhaust pressure and turbo speed as inputs. Boost pressure and turbo speed are measured states while the exhaust pressure is estimated using an observer. A constant feedforward term is added to the output signal for optimal working point selection. The controller has less parameters than the current open loop solution, but still shows comparable performance results. By using a model based approach the tuning is simplified and made more intuitive