The article presents the results of approximating of ion current signal of the most appropriate parametrical models in Matlab software. It is shown that in spite of the high accuracy of approximation, parametrical model Gaussian, which chosen early in Matlab, have significant drawbacks. In order to eliminate the identified deficiencies authors was developed parametric model in which the discrete Fourier transform was used to approximate of the ion current signal.

Keywords: ion current, the internal combustion engine, a parametric model, a discrete Fourier transform, the Gaussian model, the approximation of a signal

The article presents the results of an analytical review of the major conventional approaches to processing and analysis of the ion current signal of contemporary domestic and foreign authors. Analysis of works made in terms of assessing the possibility of calculating the parameters of the combustion of the fuel-air mixture. It is shown that strong susceptibility of ion current to influence of intercyclic variations limits application of methods in practice, despite considerable theoretical opportunities of such methods.

Keywords: ion current, internal combustion engine, burning, combustion chamber, fuel and air mixture

In article the comparative analysis of various versions of circuitry solutions of realization of devices of registration of ionic current, is made, theoretical justification of almost known advantages and shortcomings of the considered devices. In article are given the experimental data obtained at registration of a signal of ionic current by various devices. Is made processing of oscillograms and shown qualitative advantage of the device of registration of ionic current with the stabilized boost converter for the solution of problems of registration of a signal of ionic current with increased requirements to quality of a signal.

Keywords: internal combustion engine, signal of ionic current, energy, spark discharge, device of registration