@article{MTMT:33432672,
	title = {Using scientific machine learning for experimental bifurcation analysis of dynamic systems},
	url = {https://m2.mtmt.hu/api/publication/33432672},
	author = {Beregi, Sándor and Barton, David A. W. and Rezgui, Djamel and Neild, Simon},
	doi = {10.1016/j.ymssp.2022.109649},
	journal-iso = {MECH SYST SIGNAL PR},
	journal = {MECHANICAL SYSTEMS AND SIGNAL PROCESSING},
	volume = {184},
	unique-id = {33432672},
	issn = {0888-3270},
	abstract = {Augmenting mechanistic ordinary differential equation (ODE) models with machine-learnable structures is a novel approach to create highly accurate, low-dimensional models of engineering systems incorporating both expert knowledge and reality through measurement data. Our exploratory study focuses on training universal differential equation (UDE) models for physical nonlinear dynamical systems with limit cycles: an aerofoil undergoing flutter oscillations and an electrodynamic nonlinear oscillator. We consider examples where training data is generated by numerical simulations, whereas we also employ the proposed modelling concept to physical experiments allowing us to investigate problems with a wide range of complexity. To collect the training data, the method of control-based continuation is used as it captures not just the stable but also the unstable limit cycles of the observed system. This feature makes it possible to extract more information about the observed system than the open-loop approach (surveying the steady state response by parameter sweeps without using control) would allow. We use both neural networks and Gaussian processes as universal approximators alongside the mechanistic models to give a critical assessment of the accuracy and robustness of the UDE modelling approach. We also highlight the potential issues one may run into during the training procedure indicating the limits of the current modelling framework.},
	keywords = {NONLINEAR DYNAMICS; machine learning; Bifurcation analysis; Universal differential equations},
	year = {2023},
	eissn = {1096-1216},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250}
}

@article{MTMT:32653366,
	title = {Connectivity-Based Delay-Tolerant Control of Automated Vehicles: Theory and Experiments},
	url = {https://m2.mtmt.hu/api/publication/32653366},
	author = {Beregi, Sándor and Avedisov, Sergei S and He, Chaozhe R and Takács, Dénes and Orosz, Gábor},
	doi = {10.1109/TIV.2021.3131957},
	journal-iso = {IEEE Transactions on Intelligent Vehicles},
	journal = {IEEE Transactions on Intelligent Vehicles},
	volume = {8},
	unique-id = {32653366},
	issn = {2379-8858},
	abstract = {The concept of utilizing vehicle-to-everything (V2X) connectivity to improve the resilience of automated vehicles in an environment where optical sensors may not provide reliable data is investigated. Longitudinal and lateral controllers are designed to enable a connected automated vehicle (CAV) to utilize V2X information from nearby connected human-driven vehicles (CHVs). The linear stability of the controllers are investigated theoretically while taking into account the time delays in the feedback loops. Novel performance measures are introduced to quantify the plant and string stability properties of the longitudinal controller from experimental data. The stability of the lateral controller is also evaluated in lane-keeping experiments. The robustness of the designed controllers against latency is demonstrated and the performance of the overall systems is showcased experimentally using real vehicles on a test track.},
	keywords = {global positioning system; DELAY; delay effects; latency; delays; Trajectory; RESILIENCE; Roads; Engineering, Electrical & Electronic; Computer Science, Artificial Intelligence; Vehicle-to-everything; Vehicle automation; V2X connectivity},
	year = {2023},
	eissn = {2379-8904},
	pages = {275-289},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250; Takács, Dénes/0000-0003-1226-8613}
}

@article{MTMT:33169041,
	title = {Nonlinear analysis of the delayed tyre model with control-based continuation},
	url = {https://m2.mtmt.hu/api/publication/33169041},
	author = {Beregi, Sándor},
	doi = {10.1007/s11071-022-07796-7},
	journal-iso = {NONLINEAR DYNAM},
	journal = {NONLINEAR DYNAMICS},
	volume = {110},
	unique-id = {33169041},
	issn = {0924-090X},
	abstract = {In this study, the numerical bifurcation analysis of a shimmying wheel is performed with a non-smooth, time-delayed model of the tyre-ground contact. This model is capable of reproducing the bistable behaviour often observed in experiments: a stable equilibrium and a stable periodic orbit coexisting for the same set of system parameters, that the simpler quasi-steady tyre models fail to capture. In the bistable parameter domain, there also exists an unstable periodic orbit within the separatrix between the domains of attractions of the two stable steady-state solutions. Although this solution never appears in a real-life system, one may still gain valuable information from tracing it as it gives an indication about the level of perturbation that would drive the system from one stable solution to the other. However, the complexity of the laws governing partial sticking and sliding in the tyre-ground contact makes the numerical bifurcation analysis with the traditional, collocation-based techniques infeasible. Instead, this study is based on numerical simulations and the technique of control-based continuation (CBC) to track the stable and unstable periodic solutions of the system allowing for the assessment of the accuracy of the non-smooth, delayed tyre model in replicating the dynamics observed in experiments. In the meantime, the physics-based model provides an insight into the relationship between the sticking and sliding regions appearing in the tyre-ground contact and the global dynamics of the system.},
	keywords = {Time delay; Bifurcation analysis; Control-based continuation; Stretched-string model; Sticking-sliding contact},
	year = {2022},
	eissn = {1573-269X},
	pages = {3151-3165},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250}
}

@article{MTMT:32653362,
	title = {Development of a digital twin operational platform using Python Flask},
	url = {https://m2.mtmt.hu/api/publication/32653362},
	author = {Bonney, Matthew S. and de Angelis, Marco and Dal Borgo, Mattia and Andrade, Luis and Beregi, Sándor and Jamia, Nidhal and Wagg, David J.},
	doi = {10.1017/dce.2022.1},
	journal-iso = {DCE},
	journal = {Data-Centric Engineering},
	volume = {3},
	unique-id = {32653362},
	year = {2022},
	eissn = {2632-6736},
	orcid-numbers = {Bonney, Matthew S./0000-0002-1499-0848; de Angelis, Marco/0000-0001-8851-023X; Dal Borgo, Mattia/0000-0003-4263-0513; Andrade, Luis/0000-0003-0679-9354; Beregi, Sándor/0000-0002-3167-9250; Jamia, Nidhal/0000-0003-0643-7812; Wagg, David J./0000-0002-7266-2105}
}

@article{MTMT:32653456,
	title = {Robustness of nonlinear parameter identification in the presence of process noise using control-based continuation},
	url = {https://m2.mtmt.hu/api/publication/32653456},
	author = {Beregi, Sándor and Barton, David A. W. and Rezgui, Djamel and Neild, Simon A.},
	doi = {10.1007/s11071-021-06347-w},
	journal-iso = {NONLINEAR DYNAM},
	journal = {NONLINEAR DYNAMICS},
	volume = {104},
	unique-id = {32653456},
	issn = {0924-090X},
	year = {2021},
	eissn = {1573-269X},
	pages = {885-900},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250}
}

@mastersthesis{MTMT:31262490,
	title = {Delay effects and non-smoothness in the dynamic tyre-road contact and vehicle steering [Időkésés és nem-sima hatások a dinamikus kerék-talaj kontaktban és a járművek kormányzásában]},
	url = {https://m2.mtmt.hu/api/publication/31262490},
	author = {Beregi, Sándor},
	publisher = {Budapest University of Technology and Economics},
	unique-id = {31262490},
	year = {2019},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250}
}

@article{MTMT:31087126,
	title = {Correction to:Bifurcation analysis of wheel shimmy with non-smooth effects and time delay in the tyre-ground contact (vol 98, pg 841, 2019)},
	url = {https://m2.mtmt.hu/api/publication/31087126},
	author = {Beregi, Sándor and Takács, Dénes and Stépán, Gábor},
	doi = {10.1007/s11071-019-05207-y},
	journal-iso = {NONLINEAR DYNAM},
	journal = {NONLINEAR DYNAMICS},
	volume = {98},
	unique-id = {31087126},
	issn = {0924-090X},
	year = {2019},
	eissn = {1573-269X},
	pages = {859-859},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250; Takács, Dénes/0000-0003-1226-8613; Stépán, Gábor/0000-0003-0309-2409}
}

@article{MTMT:30893747,
	title = {Theoretical and experimental study on the nonlinear dynamics of wheel-shimmy},
	url = {https://m2.mtmt.hu/api/publication/30893747},
	author = {Beregi, Sándor and Takács, Dénes and Gyebrószki, Gergely and Stépán, Gábor},
	doi = {10.1007/s11071-019-05225-w},
	journal-iso = {NONLINEAR DYNAM},
	journal = {NONLINEAR DYNAMICS},
	volume = {4},
	unique-id = {30893747},
	issn = {0924-090X},
	year = {2019},
	eissn = {1573-269X},
	pages = {2581-2593},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250; Takács, Dénes/0000-0003-1226-8613; Gyebrószki, Gergely/0000-0002-0263-7510; Stépán, Gábor/0000-0003-0309-2409}
}

@article{MTMT:30840377,
	title = {Bifurcation analysis of wheel shimmy with non-smooth effects and time delay in the tyre–ground contact},
	url = {https://m2.mtmt.hu/api/publication/30840377},
	author = {Beregi, Sándor and Takács, Dénes and Stépán, Gábor},
	doi = {10.1007/s11071-019-05123-1},
	journal-iso = {NONLINEAR DYNAM},
	journal = {NONLINEAR DYNAMICS},
	volume = {98},
	unique-id = {30840377},
	issn = {0924-090X},
	year = {2019},
	eissn = {1573-269X},
	pages = {841-858},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250; Takács, Dénes/0000-0003-1226-8613; Stépán, Gábor/0000-0003-0309-2409}
}

@{MTMT:30624168,
	title = {Theoretical and experimental study on the nonlinear dynamics of wheel-shimmy},
	url = {https://m2.mtmt.hu/api/publication/30624168},
	author = {Beregi, Sándor and Takács, Dénes and Stépán, Gábor},
	booktitle = {NODYCON Book of abstracts},
	unique-id = {30624168},
	year = {2019},
	pages = {477-478},
	orcid-numbers = {Beregi, Sándor/0000-0002-3167-9250; Takács, Dénes/0000-0003-1226-8613; Stépán, Gábor/0000-0003-0309-2409}
}