Abstract
The paper presents a digital gasoline engine simulator for the testing of the procedures related to generating of the fuel injections and the quality of the injection control. The essence of the presented method of simulation is to compare in each engine cycle the set injection timing with the actual duration, generated by the investigated controller. The quality measure of the control system is the difference of these two times converted into a relative error. The basis of the simulator are the three voltage signals of three quantities recorded from the engine: engine speed, intake manifold pressure and mass air expenditure. These quantities in the developed controller are for determining and generating of the gasoline injections. A modern measure&control card DS1104 by dSpace has been used in the simulator as a signal generator from the measuring sensors used in the process of fuel injection control. It is a continuous type generator, which means that the impulse from the last recorded cycle initiates the generation of the impulse of the first cycle. The method of simulation has been used in the design and testing of a unique control of an indirect fuel injection. Its characteristic is that it generates a required mixture composition in each cylinder filling cycle. The basic principle in this type of control is a continuous, real time determining of the cylinder filling. In the presented investigations a constant temperature thermoanemometer HFM-5 by Bosch has been used, measuring the air flow expenditure filling the cylinder. The here presented results confirm a high usability of the presented simulator in the assessment of the accuracy of the injection duration and timing.
Keywords: gasoline engine, injection control, engine simulation, cylinder filling