Zsolt Tabakov

57223330433

Publications - 4

Wear Scar Classification with Convolutional Neural Network

András Lajos Nagy Zsolt Tabakov

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1345 LNNS

Issue: Unknown

Page Range: 13-20

Description:

This article categorizes the wear features of ball-on-disc type specimens into two classes using a Tensorflow Convolutional Neural Network network. The convolutional neural network is employed for image classification, specifically in the field of tribology, involving surface analysis and wear characterization.

Open Access: Yes

DOI: 10.1007/978-3-031-87620-2_2

Oil Degradation Patterns in Diesel and Petrol Engines Observed in the Field—An Approach Applying Mass Spectrometry

Charlotte Besser Péter Raffai Marcella Frauscher András Lajos Nagy Adam Agocs Andjelka Ristic Zsolt Tabakov

Publication Name: Lubricants

Publication Date: 2023-09-01

Volume: 11

Issue: 9

Page Range: Unknown

Description:

Engine oil degradation and tribological properties are strongly interrelated. Hence, understanding the chemical processes resulting in additive depletion and degradation products is necessary. In this study, in-service engine oils from petrol and diesel vehicles were analyzed with conventional and advanced methods (mass spectrometry). Additionally, the effect of the utilization profile (short- vs. long-range) was studied. Petrol engine oils generally showed accelerated antioxidant and antiwear degradation and higher oxidation, especially in the case of a short-range utilization profile, which can be attributed to the higher air-to-fuel ratio (more rich combustion) compared to diesel engines. A detailed overview of oxidation and nitration products, as well as degradation products resulting from zinc dialkyl dithiophosphate and boron ester antiwear additives, diphenylamine antioxidants and salicylate detergents is given. A side reaction between oxidation products (aromatic carboxylic acids) and the boron ester antiwear is highlighted. This reaction was only detected in the petrol engine oils, where the oxidation products were measured in a high abundance. However, no side reaction was found in the samples from the diesel vehicles, since there the aromatic carboxylic acids were largely absent due to lower oxidation.

Open Access: Yes

DOI: 10.3390/lubricants11090404

Comprehensive assessment of oil degradation patterns in petrol and diesel engines observed in a field test with passenger cars – Conventional oil analysis and fuel dilution

Charlotte Besser András Lajos Nagy Adam Agocs Jan Rohde-Brandenburger József Perger Michael Schandl Zsolt Tabakov Nicole Dörr

Publication Name: Tribology International

Publication Date: 2021-09-01

Volume: 161

Issue: Unknown

Page Range: Unknown

Description:

Requirements for modern internal combustion engines are lower emissions, higher power density and longer maintenance intervals. These trends increase the demands on engine components, including lubricants. In a field study of petrol and diesel vehicles, oil condition of 47 engine oils from 12 vehicles are correlated with fresh oil properties and operating conditions, i.e., trip length and speed. Long-range petrol vehicles displayed accelerated chemical oil degradation compared to diesel vehicles. An explanation for this behaviour is assumed to be the difference air-to-fuel ratio. Short-range petrol vehicles showed an even faster oil degradation and significant changes in oil viscosity due to fuel dilution. Diesel vehicles exhibited higher soot loading and more pronounced engine wear indicated by iron content in the oils.

Open Access: Yes

DOI: 10.1016/j.triboint.2021.107079

Processing FT-IR data for facilitated oil condition monitoring

András Lajos Nagy Adam Agocs Zsolt Tabakov

Publication Name: 2022 IEEE 1st International Conference on Cognitive Mobility Cogmob 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 47-50

Description:

The physical and chemical condition of a lubricant plays a vital role in the long-term operability of engineering systems. Hence, oil condition monitoring of high-value and heavy-duty equipment is a common practice across numerous industries. However, this practice is not utilized on a regular basis for passenger cars, and car fleets. For general automotive purposes, a simpler time and mileage-based approach is favored. This approach employs fixed oil change intervals, that are based on average usage, with more recently produced vehicles only slightly modifying these intervals by monitoring oil temperatures over time. With rising environmental concerns and increasing focus on systemic approaches, reducing waste production is gaining importance. Being aware of lubricant condition opens up the opportunity to optimized, condition-based oil changes, that can help reduce waste by elongating the service life of engine oils. This study presents a methodology of processing FT-IR data that allows for a simplified decision making regarding the prolonged applicability of used engine oil. The presented method can be implemented as a step of planned maintenance during scheduled service at a repair shop, as well as a regular investigation by fleet operators.

Open Access: Yes

DOI: 10.1109/CogMob55547.2022.10117798