Crank Event Based Fuel Injection and Spark Ignition Timing Control Strategy for SI Engines

Abstract

For the controlled gasoline engine MR479Q, the crank speed, camshaft position, fuel injection, spark ignition timing signals and their relationships under control mode of group ignition and fuel sequential injection were deeply analyzed, then an electronic control unit (ECU) hardware platform solution based on Freescale 16-bit microcontroller MC9S12XEP100 was given out. Taking advantages of the hardware platform itself, a crank event based fuel injection and spark ignition timing control strategy was proposed to enhance traditional fuel injection and ignition reliability. Fuel pulse width, ignition coil dwell time and spark advance control under different engine operating conditions were then designed in detail respectively. The bench test results show that, the fuel injection and spark ignition timing control signals of ECU are accurate and stable enough under steady operating conditions, even under transient operating conditions when step disturbance exists in throttle opening, the fuel pulse width, dwell time and spark advance are also delivered correctly and reliably. The strategy is feasible enough to accomplish precise control of fuel injection and spark ignition.

Development of a New-Concept Supercharged Single-Cylinder Engine for Race Car

“…After supercharged modification, the stock fuel injector may not have the capacity to provide the larger fuel flow rate. Once a large injector is installed, the injection pulse width at idle or light load will be quite low (even less than 1.5 ms); thus, the injection control accuracy will deteriorate [18,19]. Therefore, this study used dual-stage fuel injection to compromise the fuel flow rate at high load and the control accuracy at low load.…”