Non-Linear Analysis of the Combustion Process in Compression-Ignition Direct Injection Engines of Non-Road Vehicles with the Use of Vibroacoustic Processes in the Point of View of the OBD III Engine Diagnostics

The paper presents a new method for assessment of combustion process correctness taking place in CI engines, based on the expanded vibroacoustic signal analysis. The method uses chosen non-linear, spectrum and time-frequency analyses of the signal. Diagnostics of the correctness of the above main engine process and misfire detection for engines at exploitation conditions with the use of the various methods of the accompanying processes analysis was the aim of the presented analyses. Possibility of the method application to combustion process assessment of the CI engines was verified, algorithms of misfire detection for the each method are described, quantity point estimators of processes and conditions of the OBD diagnostics realization were obtained, methodology of the measurement process, limits of the methods use and their diagnostic accuracy in the point of view of the combustion OBD III engine monitor design are also presented.