Control of the Combustion Process Parameters in ICE by the Ion Current Signals

Abstract

This paper is devoted to control of the combustion processes in the internal combustion engines (ICE). It presents a method for estimation of the position of the peak pressure, the maximal pressure of the cycle and the air-fuel ratio based on the analysis of the integral characteristics of the ion current signals. The advantages of the proposed method are stability of the final result of the calculation to the influence from the cycle-to-cycle combustion parameter variations, stability to the changes in the parameters of the measuring probe during a long operation time and absence of restrictions on the wave form of the ion current. It also presents the results of the experimental testing of the developed method and its comparison with the conventional methods of analysis of the ion current and control of the combustion process parameters. The authors compared the efficiency and accuracy of the method using a combustion pressure sensor, based on the piezoelectric ceramics; the methods of the ion current analysis, based on detection of the thermal-ionization ion current peak; the method of the ion current analysis based on the integral characteristic of the ion current signal. The results of the experimental studies indicate a possibility of the use of the integral characteristic of the ion current signal for estimation of the combustion process parameters with the accuracy of the combustion pressure sensor based on the piezoelectric ceramics. The ion current measurement technology is cheaper than the piezoelectric ceramic sensors and can be widely applied in the serial engines.