The vehicles evolution, the emission limits reduction and the on board diagnosis will require more sophisticated LPG systems. To obtain the best results in terms of driveability, performances, fuel consumption and emissions, taking the maximum advantages by LPG fuel characteristics, not only an accurate fuel metering but also the optimum injection phase and spark advance should be achieved. Indeed LPG has different requirements in terms of fuel management, injection phase and spark advance compared with the gasoline. An engine control system, called Metafuel, has been developed by Fiat Research Center and Metatron with the aim to fulfill the most stringent emissions standards, and, at the same time, to ensure on board diagnosis compatibility and the optimization of fuel consumption and driveability. The system is based on an innovative system where the gas is injected in liquid phase, thus allowing the highest level of accuracy on engine control. Metafuel, could be used on stand alone basis for fully dedicated vehicles or integrated in a bi-fuel vehicle using link" with gasoline ECM through standard communication protocol (i.e. CAN). The LPG engine control system is discussed by showing its peculiarities in terms of hydraulic components, hardware platform and software strategies. Some experimental results are reported in order to show the necessity to manage fuel, closed loop parameters, injection phase and spark advance independently by gasoline calibration.
展开▼
