Control of Smoothness of Engine Operation: a Possibility for Reducing Pollutant Emissions in Otto Engines With Gasoline Injection

The goal of a control system for the smoothness of an engine's operation is to hold engine agitation at partial loading to an imperceptible level. This may be easily done in an engine with a high air/fuel ratio by means of a system that reduces this ratio if a given engine agitation factor~defined in terms of variations of the crankshaft's average time of rotation~exceeds a specified value. The paper develops the formulation of this agitation factor. Gasoline injection simplifies the incorporation of such a system, permitting smooth operation of Otto engines at very high air/fuel ratios. Consequently, favorable pollutant emission and fuel consumption characteristics can be achieved.

The engine agitation value can be determined relatively easily by electronic means. Its mean value can be used as a standard for comparison of an engine's smoothness of operation. Preliminary tests indicate that the electrical signal can be used to control exhaust recirculation mechanisms as well as ignition angles; it can also activate warning and diagnostic devices