Juhani Nissilä


Doctoral Researcher, M.Sc.
Intelligent Machines and Systems (Mechatronics and Machine Diagnostics)
Faculty of Technology
University of Oulu


Research interests

Machine diagnostics:

- Fractional order of regularity of vibration signals
- Modelling and measurements of vibrations in epicyclic gearboxes
- Statistical pattern recognition of different faults states

Technical mathematics:

- Fourier and wavelet analysis
- Pointwise and uniform Hölder regularity estimation
- Numerical fractional calculus
- Cyclostationary random signals and envelope analysis

Real-time monitoring of steelmaking processes:

- Vibrations in vacuum tank degassing
- Vibrations and audio in basic oxygen steelmaking
- Mold oscillation in continuous casting



Publications

Peer reviewed scientific articles:

J. Nissilä, J. Laurila, K. Ruotsalainen, T. Liedes: Bearing Defect and Misalignment Diagnostics using Local Regularity and Sparse Frequency Analysis,
in Proceedings of The First SIMS EUROSIM Conference on Modelling and Simulation, SIMS EUROSIM 2021,
and 62nd International Conference of Scandinavian Simulation Society, SIMS 2021, 21.09. - 23.09.2021, Virtual Conference, Finland
https://doi.org/10.3384/ecp21185171

K. Karioja, E. Juuso, J. Nissilä: Some further studies about generalised spectral norms,
Insight - Non-Destructive Testing and Condition Monitoring, 63(6): pp 362-369, June 2021
https://doi.org/10.1784/insi.2021.63.6.362

M. Pylvänäinen, V.-V. Visuri, J. Nissilä, J. Laurila, K. Karioja, S. Ollila, T. Fabritius, T. Liedes:
Vibration-Based Monitoring of Gas-Stirring Intensity in Vacuum Tank Degassing,
steel research international, 91(6): 1900587, 2020
https://doi.org/10.1002/srin.201900587

J. Nissilä, J. Laurila: Diagnosing simultaneous faults using the local regularity of vibration signals,
Measurement Science and Technology, 30: 045102, 2019
http://urn.fi/urn:nbn:fi-fe202001131835
https://doi.org/10.1088/1361-6501/aaf8fa

J. Nissilä: Error analysis of numerical Weyl fractional derivatives in the case of certain Hölder continuous functions,
in Proceedings of The 14th IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications,
MESA 2018, 2. – 4.7.2018, Oulu, Finland
http://urn.fi/urn:nbn:fi-fe2018091035359
https://doi.org/10.1109/MESA.2018.8449193

J. Nissilä: Local regularity analysis with wavelet transform in gear tooth failure detection,
Management Systems in Production Engineering, 25(3): pp 176-182, 2017
https://doi.org/10.1515/mspe-2017-0026
and in Proceedings of Maintenance Performance Measurement and Management, MPMM 2016, 28.11.2016, Luleå, Sweden

J. Nissilä, E. Juuso: Extracting Vibration Severity Time Histories From Epicyclic Gearboxes,
in Proceedings of The 9th Eurosim Congress on Modelling and Simulation, EUROSIM 2016, 12. – 16.09.2016, Oulu, Finland
https://doi.org/10.3384/ecp17142422

J. Nissilä: Stress evaluation of a guillotine cutter with steels of varying yield strength and thickness using displacement and snap signals,
in Proceedings of Maintenance, Condition Monitoring and Diagnostics, Maintenance Performance Measurement and Management,
MCMD 2015 and MPMM 2015, 30.09. – 01.10.2015, Oulu, Finland
http://urn.fi/urn:nbn:fi-fe2018091835974

J. Nissilä, S. Lahdelma, J. Laurila: Condition monitoring of the front axle of a load haul dumper with real order derivatives and generalised norms,
in Proceedings of The 11th International Conference on Condition Monitoring and Machinery Failure Prevention Technologies,
CM 2014 and MFPT 2014, 10. – 12.06.2014, Manchester, UK
http://urn.fi/urn:nbn:fi-fe2018091835968
https://www.researchgate.net/publication/286767140

Preprints:

J. Nissilä: Fourier decay of absolutely and Hölder continuous functions with finitely or infinitely many oscillations,
2nd version of the preprint available
https://arxiv.org/abs/1805.02445v2