The Study Of Optimization Calibration For Gas-Fuel Engines Electronically Controlled System

Recently, environmental improvement and energy issues have become more and more important as worldwide concerns. Natural gas is a good alternative fuel to improve these problems because of its plentiful resources and clean burning characteristics. As the development of the technology of gas engine, the content that controlled by the electronic controlling unit becomes more and more and the function is enhanced gradually. To develop the electronic controlling calibration system of CNG engine, it becomes an important trend of updating the technology that to pursuit the better performance of power and economy though matching, calibrating and improving the characteristic of electronic controlling system. Therefore, it' s full of engineering value and academic significance to conduct the research and the development of gas optimization calibration system.This report fixed the designing train of thought of electronically CNG controlled calibration system and the whole frame, after which it compiled the serial interface communication program of upper and nether machine. And it realized the mutual communication function between ECU for engine and the main calibrating system computer. In addition, it developed a CNG engine's calibration software which possesses multitudinous module functions, including calibrating on line, the calibration of the data piece, failure checking and so on. On the basis of the above, it applied calibration system to test-bed of electro jet CNG engine of WT615 type and conducted tentative matching. Combining both the part and the whole's optimization is the choice method to conduct the optimization calibration over the control variable, which is reached by the study and research on the optimization arithmetic. It also developed optimization calibration software which is used for searching the whole optimization with the help of genetic algorithm. On the basis of above arithmetic, the calibration test of two control variable, the pulse width of CNG engine and spark timing has been accomplished. In addition, the basic jet map of CNG engine and the basic spark timing map are both chalked out.