Development Of Electronic Control System And Experimental Study For A Common Rail Diesel Engine Using Gasoline

Electronic control unit (ECU) can optimally control parameters, such as injectiontiming, injection pressure, fuel injection quantity, VVT and EGR, during all theworking conditions of diesel engines. Accordingly, people are paying more and moreattention to the development of ECU of diesel engines. However, ECU has itsdrawbacks: complex hardware structure, long period of software development andparameters’ calibration, high costs. A featured electronic controlled system canimprove the efficiency of whole developing process. This thesis, based on previouswork, does the development and maintenance work of PC-based electronic controlleddeveloping system for a common rail diesel engine.Electronic controlled developing system is based on PC rich software andhardware resources, including timer counter card and acquisition card, using DOSoperating system platform and C language, introducing hierarchical programmingmethod. It achieves a good human-computer interaction and flexible engine control.To achieve closed loop control on the common rail pressure through PID algorithm;To control the injection timing, injection pressure and fuel injection quantity throughthe combination of software and hardware. It can fulfill different injection mode andhas the advantages of simple structure, low cost and easy to use. In this thesis,research is done on the influences of different parameters of injector’s driving signal(main pulse width, zero width, duty cycle and frequency of PWM maintain wave) onthe injector current in the part of CPLD synthesis injector’s drive signal module.The ignition and combustion of HCCI engines is mainly affected by the chemicalreaction kinetics and the ignition timing is determined by the process of fuel-airmixture composition, temperature and pressure change. Compared to diesel fuel,gasoline has lower Cetane Number, higher auto-ignition temperature and bettervolatility. Then if gasoline is compressed to auto-ignition in diesel engine, the ignitiondelay will be enlarged and the combustion characteristics and emission performancesof HCCI engines will be influenced. This thesis investigates the combustioncharacteristics and emission performances using single early injection of gasoline strategy in the low load condition and comparison with diesel fuel and the resultshows very low PM and NOx emissions using gasoline; Taking single and twoinjections strategy in the high load, and the result is that directly compressing gasolinein the diesel engine has the potential to extend the engine load with the assurance ofachieving low NOx and PM emissions.