Papers by Andrzej Puchalski
W artykule przedstawiono wyniki prac naukowych ukierunkowanych na rozwiązanie zadania automatyczn... more W artykule przedstawiono wyniki prac naukowych ukierunkowanych na rozwiązanie zadania automatycznej detekcji zużycia i uszkodzeń mechanicznych silnika spalinowego. Bazując na metodach analizy fraktalnej zaproponowano technikę detekcji uszkodzeń mechanicznych układu napędowego pojazdu na podstawie sygnałów przyspieszenia drgań obudowy przekładni głównej. Analizowano cechy diagnostyczne zależne od skali czasowej obserwacji. Badania prowadzono metodami analizy fluktuacji detrendowanych. Wyznaczono widma osobliwości zarejestrowanych sygnałów wibracyjnych. Jako miarę uszkodzeń przekładni głównej zweryfikowano poziom multifraktalności sygnału.
System diagnostics based on vibroacoustics signals, carried out by means of stochastic subspace m... more System diagnostics based on vibroacoustics signals, carried out by means of stochastic subspace methods was undertaken in the hereby paper. Subspace methods are the ones based on numerical linear algebra tools. The considered solutions belong to diagnostic methods according to data, leading to the generation of residuals allowing failure recognition of elements and assemblies in machines and devices. The algorithm of diagnostics according to the subspace observation method was applied – in the paper – for the estimation of the valve system of the spark ignition engine. Keyworda: system diagnostic, subspace method, vibroacoustic.
System diagnostics based on vibroacoustics signals, carried out by means of stochas-tic subspace ... more System diagnostics based on vibroacoustics signals, carried out by means of stochas-tic subspace methods was undertaken in the hereby paper. Subspace methods are the ones based on numerical linear algebra tools. The considered solutions belong to diag-nostic methods according to data, leading to the generation of residuals allowing fail-ure recognition of elements and assemblies in machines and devices. The algorithm of diagnostics according to the subspace observation method was applied – in the paper – for the estimation of the valve system of the spark ignition engine. Keyworda: system diagnostic, subspace method, vibroacoustic.
Journal of KONES, 2008
Hardware/software hybrid technologies used in the vehicles required computer aided simulation and... more Hardware/software hybrid technologies used in the vehicles required computer aided simulation and experimental testing during the designing process to make sure about reliability and quality. The growth of the number of mechatronic systems in the typical automobile, increasing legislative safety and environmental mandates, global standarization started virtual vehicle creation process. In the paper the mechatronic design of automotive EE systems is discussed. The modeling, simulation and system integration environment SystemVision that supports various engineering disciplines (electrical, mechanical, thermal, hydraulic and pneumatic) and multiple levels of systems abstraction is presented. Simulation and analysis includes domains: time, frequency and DC with the parametric and statistical design processes. This paper provides some models available in VHDL-AMS (IEEE 1076.1) open-source hardware description language for automotive electrical system design and analysis. The significanc...
Energies
A driving cycle is a time series of a vehicle’s speed, reflecting its movement in real road condi... more A driving cycle is a time series of a vehicle’s speed, reflecting its movement in real road conditions. In addition to certification and comparative research, driving cycles are used in the virtual design of drive systems and embedded control algorithms, traffic management and intelligent road transport (traffic engineering). This study aimed to develop an adaptive driving cycle for a known route to optimize the energy consumption of an electric vehicle and improve the driving range. A novel distance-based adaptive driving cycle method was developed. The proposed algorithm uses the segmentation and iterative synthesis procedures of Markov chains. Energy consumption during driving is monitored on an ongoing basis using Gaussian process regression, and speed and acceleration are corrected adaptively to maintain the planned energy consumption. This paper presents the results of studies of simulated driving cycles and the performance of the algorithm when applied to the real recorded dr...
Journal of Vibroengineering, 2015
The results of the research directed towards solving the task of automatic detection of wear and ... more The results of the research directed towards solving the task of automatic detection of wear and mechanical defects of internal combustion engines, are presented in the paper. The fractal geometry assumptions were applied in defining diagnostic features depended on the time scale of observations. Investigations were performed by means of the detrended fluctuation analysis. The scaling curves for the fluctuation function and singularity spectra of vibration signals obtained in monitoring a valve system of a spark ignition engine, were determined. The Hurst exponent, multifractality level and singularity exponent of a signal were tested as defects measures.
Journal of Vibroengineering, 2013
The parametric model proposition of modelling vibrations signal of the vehicle drive system is pr... more The parametric model proposition of modelling vibrations signal of the vehicle drive system is presented in the paper. The reference model is established for the new drive system to which the control measurements, performed at definite time intervals of automobile running, are compared. This base model must be actualized after each drive system overhaul and as the casual wear progresses. The recursive identification method of the model is performed. The method allows the on-board diagnostics of a gearbox, main gearbox, differential gear and triple joints. The diagnostic method was verified on the example of the vibrations signal recorded for the drive system of the Fiat Punto automobile.
In the era of embedded systems the qualifications of engines, machines and on-board vehicle devic... more In the era of embedded systems the qualifications of engines, machines and on-board vehicle devices into no-fault and fault categories on the basis of vibration signals is the process in conformity with the paradigm of pattern recognitions. The most popular way of looking for vibrodiagnostic features is based on frequency analysis and spectral properties of the observed signals. There is no doubt that the ‘a priori’ knowledge concerning objects being diagnosed is important in gathering information on technical states of mechatronic systems of vehicles. The diagnostic task of vehicle systems solved in the article was considered as the process realised according to properties of statistical signals originated from sensors of vibrations accelerations and not as searching for filtration algorithms of selective time-frequency properties. The data set originated from the observation of time series after angular resampling, without any transformations encompassing a frequency domain, was u...
Vibroacoustic diagnostics of combustion engines might be a complementary tool to OBD systems espe... more Vibroacoustic diagnostics of combustion engines might be a complementary tool to OBD systems especially in mechanical defects detection. The presented method allows preliminary diagnosing of the mechanical defects on-line during driving without resampling the signal. The diagnosis is based on statistical features of the vibration signal. Principal components analysis (PCA) offers an approach for linear transformation of the problem variables so that the redundant information is reduced and the diagnostic model is more easily extracted. The product chosen for the investigation presented in this paper is a spark ignition engine. Performing analytical model, which is time consuming and costly, can supplement described method only in chosen cases. It is possible to diagnose of engine from the objective parameters of the specially prepared vibration signal without performing simulation models.
The paper proposes the WLMF (Wavelet Leaders Multifractal Formalism) method enabling the adoption... more The paper proposes the WLMF (Wavelet Leaders Multifractal Formalism) method enabling the adoption of multifractal parameters mapped by vibration signal log-cumulants as diagnostic features, in the procedure of automatic classification of assembly errors and wear of demonstration gearbox. In the analysis of vibration time signals, initially, a multifractal formalism was used based on the study of time series local regularity, which is measured by Holder exponents. The presented test results relate to time-frequency multifractal analysis, the starting point of which was a continuous wavelet transform. Discrete wavelet transform allowed for much better grounded multifractal formalism and more accurate estimation of multifractal parameters using wavelet leaders, which are determined based on wavelet coefficients and are representatives of Holder exponents.
A vibration signal of an internal combustion engine contains several diagnostic information, whic... more A vibration signal of an internal combustion engine contains several diagnostic information, which are for the most part not utilised since they require complex processing methods in order to separate useful data and noise elimination. The method of diagnostics of leakages in a system: exhaust valve – cylinder, on the basis of reference model of the vibration signal is presented in the paper. It is proposed the statistical autoregressive model of signal with abstractive parameters. The recursive time-varing parameters estimation in the model is performed by the Kalman filtering. The model presented in the paper is illustrated with the signal of the spark ignition combustion engine Fiat Punto. The results of the analysis of the engine vibration signal under conditions of a defected exhaust valve and an increased valve clearance are presented. During road tests the vibrations acceleration signal was recorded as well as certain auxiliary signals used for a synchronisation and identific...
Internal combustion engine is a complex system consisting of a large number of elements interacti... more Internal combustion engine is a complex system consisting of a large number of elements interacting in non-linear way, subjected to external excitations of various characters. In spite of more and more advanced investigation methods, assuming linearity as well as non-linearity, deterministic dynamics with stochastic excitations and the random dynamics, the engine model description is not complete. The successive step for better understanding of dynamic processes, necessary at the development and optimisation of control and on-board diagnostic algorithms of vehicles, seems to be the analysis performed by means of unified measure in various observation scales. The application of the scale-dependent Lyapunov exponent for the segmentation of vibrations signals and for the qualitative analysis of SI engines dynamics was discussed in the hereby paper.
The paper proposes the Detrended Fluctuation Analysis (DFA) of the vibration signal for diagnosin... more The paper proposes the Detrended Fluctuation Analysis (DFA) of the vibration signal for diagnosing of mechanical defects of the vehicle powertrain. The DFA allows investigations of the observed signals with regard to their multifractality. The results of vibration signal analysis of the engine with the damaged exhaust valve and with the unsuitable exhaust valve clearance are presented. During road test the acceleration vibration signal was recorded with additional signals for synchronization and engine timing. The vibration data are analysed by DFA and the resultant scaling-law curve with crossover points are obtained. The estimated Hurst exponents are used in the selection procedure of diagnostic features.
Sensors
Diagnosing the condition of rotating machines by non-invasive methods is based on the analysis of... more Diagnosing the condition of rotating machines by non-invasive methods is based on the analysis of dynamic signals from sensors mounted on the machine—such as vibration, velocity, or acceleration sensors; torque meters; force sensors; pressure sensors; etc. The article presents a new method combining the empirical mode decomposition algorithm with wavelet leader multifractal formalism applied to diagnosing damages of rotating machines in non-stationary conditions. The development of damage causes an increase in the level of multifractality of the signal. The multifractal spectrum obtained as a result of the algorithm changes its shape. Diagnosis is based on the classification of the features of this spectrum. The method is effective in relation to faults causing impulse responses in the dynamic signal registered by the sensors. The method has been illustrated with examples of vibration signals of rotating machines recorded on a laboratory stand, as well as on real objects.
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Papers by Andrzej Puchalski