Vehicle diagnostic system of the car engine

Support of the established technical characteristics of engines is reached by its regular service and diagnostics in particular - existence of the diagnostic programs built in the onboard computer of the car which carry out constant control of the main parameters of the engine.Based on the algorithm of vibroacoustic diagnostics, a system of vibration and vibroacoustic diagnostics of the internal combustion engine (ICE) is proposed, which can be integrated into the intelligent environment of self - diagnostics of the car (Check - Engine). The algorithm takes into account the normalized parameters and criteria for assessing the vibration state: the absolute values of displacements, velocities and accelerations and their changes.For the self-diagnostic system, it is important to develop a classifier of engine states also to determine and / or predict the failure of its parts or units. Engine vibrations can be attributed to the following types: imbalance of the 1st and 2nd order of the engine; vibration associated with combustion in the engine; auxiliary units.The analysis of a vibroacoustic signal at work of the serviceable and faulty engine is carried out, influence of various elements of a design, placement of the gauge in horizontal and vertical directions is shown on it.

COMPREHENSIVE APPROACH TO VIBROACOUSTIC DIAGNOSTICS OF INTERNAL COMBUSTION ENGINE

As part of the procedure for diagnosing technical devices operating at production facilities, the specialists of the department performed vibration diagnostic control of equipment at a number of enterprises in Kharkov and the Kharkov region. Using the example of diagnostics of the technical condition of diesel power units, we consider the formation of vibroacoustic characteristics of an internal combustion engine (ICE) and the features of an extended analysis of vibration parameters, identification of typical equipment defects.

Comparative stochastic analysis of the anomalous dynamics of machines under the action of operational defects

The possibility of increasing the confidence of vibroacoustic diagnostics of the technical condition of rotor-type machinery is being investigated. The search for additional sensitive and reliable features is based on the analysis of two-dimensional probability distribution densities of vibration amplitudes. This approach allows to assess the degree and character of the nonlinearity of the machine dynamic model as an oscillatory system. An example of diagnosing the technical condition of a compressor installation is given, showing the possibility of an indirect operational assessment of the accomplished repair. Keywords vibroacoustic diagnostics, nonlinear oscillations, stochastic connection, sliding bearing, defects. [email protected]

The Use of Generalized Gaussian Distribution in Vibroacoustic Detection of Power Transformer Core Damage

Vibroacoustic diagnostics (VM—Vibroacoustic Method) is one of the methods for diagnosing the active part of power transformers. Measurement technologies have been refined over the past several years, but the methods of analyzing data obtained in VM diagnostics are still in development. In most cases, they are based on a simple frequency spectrum analysis, and the diagnostic conclusions are subjective and depend on the expert’s professional experience. The article presents an objective method for the detection of transformer unit core damage, based on the analysis of the statistical properties of the vibration signal registered on the surface of the tank of an unloaded transformer in the steady state of vibrations (VM). The algorithm for proceeding further is: FFT analysis of the vibroacoustic signal, with the determination of the relative changes in vibration power as a function of frequency P r ( f ) and, finally, the determination of the statistic properties of the dataset P r ( f ) . The Generalized Gaussian Distribution (GGD) is used to describe the P r ( f ) set. The detector output values are the λ and p parameters of the GGD distribution. These two numerical values form the basis for the classification of the technical condition of the transformer unit core. The correctness of the described solution was verified on the example of ten pieces of 16 MVA power transformers with different operating times and degrees of wear.

Comparative results of evaluating the smoothness of automatic transmission gear shifting during car operation

The authors have studied the process of gear shifting, smoothness of it and peculiarities of automatic gearbox functioning of during car operation. The article describes the urgency of the problem of jerks and vibrations when changing gears. When assessing the smoothness of gear shifting, the method of technical state vibroacoustic diagnostics is applied. The method is based on the recorded parameters of vibration velocity, vibration acceleration, vibration movement with their further conversion (fast Fourier transform) into a spectralsignal. The procedure of longitudinal vibration acceleration measurements on cars in operation is described. A comparative analysis of the smoothness of gear shifting in an automatic transmission was carried out using the example of modern passenger cars. Keywords car; car operation; automatic gearbox; technical condition; gearbox malfunction; smoothness; jerks; jolts; gear shift quality criteria; vibration acceleration