Comparative Analysis Between iCam/i and iCam-less/i Valve Actuating for Automotive System

摘要

A promising alternative of the conventional camshaft in iinternal combustion/i engines is one that replaces the camshaft with electromagnetic actuators. This so-called icamless/i system provides great opportunities for the automotive industry. To investigate the advantage of the system against the cam system firstly, we modelled the lift profiles of both systems with novel mathematical expressions. For the icamless/i system we modelled an Electromagnetic Valve Actuating (EMVA) system that captures a plant transfer function and a PID controller with a set-point tracking scheme. Simulation result in MATLAB/Simulink of the theoretical icamless/i lift profile was imported into Curve Fitting (CF) Toolbox of MATLAB and the novel mathematical model was realized. Experimentally measured data for the icamless/i lift profile were then fitted with this model and a ituned/i experimental model was realized. While for the cam system, the mathematical model was developed directly from experimental data via Curve Fitting Toolbox of MATLAB. Secondly, we computed volumetric efficiencies of both systems using the novel mathematical lift profiles at different engine speeds. The icamless/i system was observed to outperform the cam system.