19 Engine Gas Exchange Controlled by Digital Hydraulics

In this study, a novel digital hydraulic Electro-Hydraulic Valve Actuation (EHVA) system is introduced. A Model-Based DigiController is included in system, and function of the controller is explained. The controller/gas exchange valve tracking performance is investigated by means of co-simulation between Matlab/Simulink and AMESim simulation environments. The environmental parameters of the EHVA are changed, and the tracking error should maintain inside the ±0.5mm range. Control parameters and valve sizes are tuned in order to achieve this goal. Effect of the on/off valve number is then investigated. The study shows that total 6 on/off valves is the minimum demand to fulfill the tracking error requirement in this particular application.