Patent ID: 6510691
Filing Date: 2003-01-28
Classification: F02D,Y02T

Abstract:
A method for a closed-loop or an open-loop control of a forced-induction combustion engine including an exhaust turbo charger with an exhaust turbine having variable turbine geometry for the variable adjustment of the effective turbine cross-section and having a boost-air compressor with different operating states of the engine being assigned different characteristic maps with at least one of engine-operating and engine-state variables and wherein the turbine geometry is adjusted as a function of the characteristic maps between an open position and a pressure buildup position and when there is a change in a significant engine parameter, the systems switching between two characteristic maps, said method comprising the steps of:defining two load/engine-speed ranges with one of said speed ranges being above and one being below a predetermined limiting value and wherein each of said two load-engine speed ranges is assigned an associated characteristic map; identifying the current load/engine-speed range by means of an engine parameter; performing adjustment of the variable turbine geometry where said current load/engine speed range is below said predetermined limiting value by the open-loop control as a function of the associated characteristic map of the load/engine-speed range below said predetermined limiting value; and adjusting of the variable turbine geometry when said current load/engine speed range is above said predetermined limiting value by the closed-loop control as a function of the associated characteristic map of the load/engine-speed range above said predetermined limiting value.