A Procedure for Upgrading an Electronic Control Diesel Fuel Injection System by Considering Several Engine Operating Regimes Simultaneously

Abstract

This paper describes an optimal design procedure for improving the injection rate histories of an electronic control diesel fuel injection system (ECD-FIS) with sleeve-timing-controlled pump. The research objective was to develop an approach for upgrading an existing ECD-FIS by performing only some low-cost modifications on its design. Therefore, the design variables are related to a relative small number of geometrical and control parameters of the injection system. The geometrical parameters influence only the shape of a rational Be´zier curve, representing the cam profile of the pump. The control parameters influence the injection timing and injection quantity. These control parameters are introduced into the set of design variables in order to enable good results over the whole engine operating regime. The design problem is formulated in a form of a non-linear problem of mathematical programming. Several operating regimes are simultaneously taken into account by an appropriate objective function while some geometrical properties of the cam profile as well as some injection parameters are kept within acceptable limits by the imposed constraints. The theory is illustrated with a numerical example.