Automatic control system for ic engine fuel injection

Abstract

An automatic control method and system for internal combustion (IC) engines fuel injection systems are described. This automatic control method is a nonlinear and global method, that applies directly to automotive engines whose dynamics are highly nonlinear and complex, in the global sense to all internally and externally changing operating and environmental conditions for all transients and quasi-steady-state operations. Furthermore, the automatic control method is robust to unmodeled dynamics and disturbances. The automatic control method consists of estimating or measuring the mass rate of air entering the combustion chambers of an engine, estimating or calculating its time rate of change, and applying prescribed closed loop feedback correction term. In this fuel injection control method, the current mass rate of fuel command is the sum of the previously commanded fueling rate, plus the dynamic correction term according to the change in the mass rate of air entering combustion chambers multiplied by the elapsed time duration between the two injection commands and divided by a desired air to fuel ratio, plus the sensor based feedback correction term specially structured to automatically adjust in accordance with the amount of mass rate of air entering combustion chambers and its time rate of change, and to automatically adapt to the changes in both external and internal conditions. The resulting system can provide stability robustness properties and optimal regulation of desired air to fuel ratio globally for the entire operating range of IC engines.