Diesel Engine Injector Waveform Monitoring in Real-Time for Fuel Efficiency

Abstract

This paper presents the development, experimentation and validation of a reliable and robust system, which can be easily calibrated for different engine platforms, to monitor the injector pulse generated by an Engine Control Module (ECM) and feedback the corresponding fueling quantity to the real-time computer in a closed-loop Controller in the loop (CIL) bench in order to achieve optimal fueling. This research utilized Field Programmable Gate Arrays (FPGA) and Direct Memory Access (DMA) transfer capability to achieve high speed data acquisition and delivery. The research is conducted in two stages, first stage was to study the variability involved in the injected fueling quantity from pulse to pulse, from injector to injector, between real injector stators and inductor load cells, over different operating conditions. Different thresholds were experimented to find out the best start of injection (SOI) threshold and the end of injection (EOI) threshold that captured the injector “on-time” with best reliability and accuracy. Second stage involved development of a system that interprets the injector pulse into fueling quantity; the system can be easily calibrated to be used over various platforms. Finally, the use of resulting correction table was found to capture the fueling quantity with best accuracy.