Modeling and Design of an Electro-hydraulic Camless Valve Actuation System

摘要

The improvement of internal combustion engine is largely accomplished though the introduction of innovative actuators that allows optimization and control of the flow mixing,and combustion processes.This paper presents the electro-hydraulic valve actuation modeling and control design of a new fully flexible engine valve actuation system which is an enabler for camless marine diesel engine.Unlike existing electromechanical valve actuation systems,precise valve motion control is achieved with a valve lift displacement feedback.The servo actuated model reveals issues associated with uncertainties,nonlinearities,and limitation of different subsystems.The nonlinear control scheme is designed to achieve cylinder-to-cylinder balancing,fast cycle-to-cycle response,and minimization of pumping losses.The effectiveness of the designed model is verified with AMESim (Advanced Modeling Environment for Simulation of engineering systems) simulations.