Development of research engine control unit using FPGA - based embedded control system

Though the Electronic Control Unit (ECU) systems are wide use in modern vehicles, they are manufactured by a few companies and supplied to engine manufacturers. Automotives with factory made ECUs designed to maximize the performance while minimize cost. However, factory made ECUs (FECU) have closed software and hardware. The control gain, lookup tables, and constants used in the algorithms are also calibrated for a particular engine design. Unlike the carburettor, these systems cannot be opened and studied under different operating conditions to determine their characteristics and how they influence the performance of an engine. They can be used as black boxes and work only at specified modes as determined by their electronic control unit (ECU) and more over the algorithms and their implementation are maintained as trade secret by the developers. In the research work, it often becomes necessary to study parameters like injection duration, injection timing, sensor responses etc. to ascertain their effects. Thus in such cases the factory made ECU supplied with the injection system cannot be used. The required need is fulfilled by developing a customized electronic controller that would be suitable for studying the variations at engine operating points. The project involved the development of a research ECU (RECU) using reconfigurable field programmable gate arrays (FPGA) based embedded control system for a four-stroke port fuel injected gasoline engine. A calibrated fuel map is generated for various operating points of the engine using virtual instrumentation (VI) based software while simulating functions of sensors. From the mapping, the fuel injection time and fuel delivery quantity is estimated for the required running conditions of the engine. The developed Research Electronic Control Unit (RECU) could reveal gasoline engine performance in particular for research-based applications as it involves frequent programme development and control implementations.