Software System Development Of High Pressure Common Rail Diesel Engine Management System And Experimental Study

How to achieve the high efficiency and clean combustion of the diesel enginehas been paid more and more attention for the shortage of energy and deterioration ofenvironment. High efficiency and clean burning depends on the advanced combustiontechnology, however, it has been proved that the single combustion strategy couldn’tmake the diesel engine realize the high efficiency and clean burning in the entire load,the Combined combustion strategy of low temperature combustion and high densitylow temperature combustion, which is Proposed by the author’s team, is a effectiveway to achieve the high efficiency and clean burning of the diesel engine in the entireload.The combined combustion of low temperature combustion and high density lowtemperature combustion couldn’t been realized without the supportive of the powerfulengine management system. The engine management system, namely electroniccontrol unit, includes software and hardware, and the software is the compass of theentire management system and determines the running route of the whole system. Theintegrity, reliability and stability of the EMS is the key factor to realize the combinedcombustion strategy and make it be more reliable and steady.As the goal of improving the function, reliability and the stability of the EMS,and achieving the combined combustion strategy, the author has finished a lot ofresearch work based on the author’s group preliminary work. The author proposed thehierarchical design method of the EMS software, designed the CAN buscommunication system, realized the function of direct memory access which savingthe CPU overhead, and transplanted the Multi-task real time operation system for theEMS, The RTOS(real time operation system) improves the reliability and stability ofthe ECU and saves its resources.In order to meet the needs from the low temperature and high density lowtemperature combustion strategy, the author developed the electronic EGR system,designed the Turbocharger electronic control system and IVCA(Intake Valve ClosingActuator) electronic control system. The author also developed the adjustable fuelinjection strategy for the engine, and the switching of fuel injection mode is flexible.In order to meet the harsh needs for the diesel engine transient emissions from theemission legislation, the author designed the dynamic control strategy based on theresearch of ELR and ETC test cycle, obtained the preliminary results based on thecontrol strategy. In order to prove the validity and reliability of the EMS control strategy, a lot ofresearch which is based on the experiment have been done. The result showed that theelectronic EGR system which was used to realize the low temperature combustionstrategy was reliable and effective, the effect rule of the fuel injection timing and EGRrate to the engine exhaust emissions and thermal efficiency has been analyzed. Theexperimental result also showed that the turbocharger electronic control system couldimprove the engine performance, the affect rule to the engine performance from thedifference valves and valve opening has been argued. Two times fuel injection didwell in ameliorating the emission performance in the high speed and high load of thediesel engine, the different effect rules of the fuel ration and post injection timinghave been displayed. Based on the comparative analysis, it showed that the IVCAsystem had a remarkable effect in improving the engine emissions fuel economy.