TY - JOUR AU - Beregi, Sándor AU - Avedisov, Sergei S AU - He, Chaozhe R AU - Takács, Dénes AU - Orosz, Gábor TI - Connectivity-Based Delay-Tolerant Control of Automated Vehicles: Theory and Experiments JF - IEEE TRANSACTIONS ON INTELLIGENT VEHICLES J2 - IEEE TRANS INT VEHICLES VL - 8 PY - 2023 IS - 1 SP - 275 EP - 289 PG - 15 SN - 2379-8858 DO - 10.1109/TIV.2021.3131957 UR - https://m2.mtmt.hu/api/publication/32653366 ID - 32653366 N1 - Budapest University of Technology and Economics, Department of Applied Mechanics, Budapest, H-1111, Hungary University of Bristol, Department of Engineering Mathematics, Bristol, BS8 1TW, United Kingdom University of Michigan, Department of Mechanical Engineering, Ann Arbor, MI 48109, United States Toyota Motor North America R&D - Infotech Labs, Mountain View, CA 94043, United States Plus.ai Inc., Cupertino, CA 95014, United States MTA-BME Research Group on Dynamics of Machines and Vehicles, Budapest, H-1111, Hungary University of Michigan, Department of Civil and Environmental Engineering, Ann Arbor, MI 48109, United States Correspondence Address: Takacs, D.; Budapest University of Technology and Economics, Hungary; email: takacs@mm.bme.hu AB - 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. LA - English DB - MTMT ER - TY - JOUR AU - Beregi, Sándor TI - Nonlinear analysis of the delayed tyre model with control-based continuation JF - NONLINEAR DYNAMICS J2 - NONLINEAR DYNAM VL - 110 PY - 2022 SP - 3151 EP - 3165 PG - 15 SN - 0924-090X DO - 10.1007/s11071-022-07796-7 UR - https://m2.mtmt.hu/api/publication/33169041 ID - 33169041 AB - 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. LA - English DB - MTMT ER - TY - JOUR AU - Qin, Wubing B. AU - Zhang, Yiming AU - Takács, Dénes AU - Stépán, Gábor AU - Orosz, Gábor TI - Nonholonomic dynamics and control of road vehicles: moving toward automation JF - NONLINEAR DYNAMICS J2 - NONLINEAR DYNAM VL - 110 PY - 2022 SP - 1959 EP - 2004 PG - 46 SN - 0924-090X DO - 10.1007/s11071-022-07761-4 UR - https://m2.mtmt.hu/api/publication/33115827 ID - 33115827 N1 - Funding Agency and Grant Number: National Research, Development, and Innovation Office of Hungary [NKFI-128422] Funding text: This research was partially supported by the National Research, Development, and Innovation Office of Hungary under Grant No. NKFI-128422. AB - Nonholonomic models of automobiles are developed by utilizing tools of analytical mechanics, in particular the Appellian approach that allows one to describe the vehicle dynamics with minimum number of time-dependent state variables. The models are categorized based on how they represent the wheel-ground contact, whether they incorporate the longitudinal dynamics, and whether they consider the steering dynamics. It is demonstrated that the developed models can be used to design low-complexity controllers that enable automated vehicles to execute a large variety of maneuvers with high precision. LA - English DB - MTMT ER - TY - JOUR AU - Vörös, Illés AU - Takács, Dénes TI - Lane-keeping control of automated vehicles with feedback delay: nonlinear analysis and laboratory experiments JF - EUROPEAN JOURNAL OF MECHANICS A-SOLIDS J2 - EUR J MECH A-SOLID VL - 93 PY - 2022 PG - 13 SN - 0997-7538 DO - 10.1016/j.euromechsol.2022.104509 UR - https://m2.mtmt.hu/api/publication/32574822 ID - 32574822 N1 - Funding Agency and Grant Number: National Research, Development and Innovation Office [NKFI-128422]; NRDI Fund, Hungary [TKP2020 IES, TKP2020 NC]; Ministry for Innovation and Technology Funding text: & nbsp;The research reported in this paper and carried out at BME has been supported by the National Research, Development and Innovation Office under grant no. NKFI-128422 and by the NRDI Fund, Hungary (TKP2020 IES, Grant No. BME-IE-MIFM and TKP2020 NC, Grant No. BME-NC) based on the charter of bolster issued by the NRDI Office under the auspices of the Ministry for Innovation and Technology. LA - English DB - MTMT ER - TY - CHAP AU - Avedisov, Sergei S. AU - He, Chaozhe R. AU - Takács, Dénes AU - Orosz, Gábor ED - IEEE, , TI - Machine learning-based steering control for automated vehicles utilizing V2X communication T2 - 2021 IEEE Conference on Control Technology and Applications (CCTA) PB - Institute of Electrical and Electronics Engineers (IEEE) CY - Piscataway (NJ) SN - 9781665436434 PY - 2021 SP - 253 EP - 258 PG - 6 DO - 10.1109/CCTA48906.2021.9658972 UR - https://m2.mtmt.hu/api/publication/32467015 ID - 32467015 N1 - Funding Agency and Grant Number: Mobility Transformation Center at the University of Michigan; National Research, Development, and Innovation Office of Hungary [NKFI-128422]; Rosztoczy Foundation Funding text: This research was supported by the Mobility Transformation Center at the University of Michigan and by the National Research, Development, and Innovation Office of Hungary under grant no. NKFI-128422. Denes Takacs would like to thank the Rosztoczy Foundation for their generous support. AB - A neural network-based controller is trained on data collected from connected human-driven vehicles in order to steer a connected automated vehicle on multi-lane roads. The obtained controller is evaluated using model-based simulations and its performance is compared to that of a traditional nonlinear feedback controller. The comparison of the control laws obtained by the two different approaches provides information about the naturalistic nonlinearities in human steering, and this can benefit the controller development of automated vehicles. The effects of time delay emerging from vehicle-to-everything (V2X) communication, computation, and actuation are also highlighted. LA - English DB - MTMT ER - TY - JOUR AU - Várszegi, Balázs AU - Takács, Dénes AU - Orosz, Gábor TI - On the nonlinear dynamics of automated vehicles - A nonholonomic approach JF - EUROPEAN JOURNAL OF MECHANICS A-SOLIDS J2 - EUR J MECH A-SOLID VL - 74 PY - 2019 SP - 371 EP - 380 PG - 10 SN - 0997-7538 DO - 10.1016/j.euromechsol.2018.11.015 UR - https://m2.mtmt.hu/api/publication/30454943 ID - 30454943 AB - A simple mechanical model for the lateral and yaw motion of a vehicle is presented while taking into account rolling constraints. The governing equations are derived by utilizing the Appellian framework. Analytical and numerical bifurcation analysis is performed while utilizing a PD controller. The results provide insight into the local and global stability of forward and reverse motion of automated passenger vehicles and harvesters. LA - English DB - MTMT ER - TY - JOUR AU - Bachrathy, Dániel AU - Stépán, Gábor TI - Bisection method in higher dimensions and the efficiency number JF - PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING J2 - PERIOD POLYTECH MECH ENG VL - 56 PY - 2012 IS - 2 SP - 81 EP - 86 PG - 6 SN - 0324-6051 DO - 10.3311/pp.me.2012-2.01 UR - https://m2.mtmt.hu/api/publication/2206850 ID - 2206850 AB - Several engineering applications need a robust method to find all the roots of a set of nonlinear equations automatically. The proposed method guarantees monotonous convergence, and it can determine whole submanifolds of the roots if the number of unknowns is larger than the number of equations. The critical steps of the multidimensional bisection method are described and possible solutions are proposed. An ecient computational scheme is introduced. The eciency of the method is charac-terized by the box-counting fractal dimension of the evaluated points. The multidimensional bisection method is much more ef-ficient than the brute force method. The proposed method can also be used to determine the fractal dimension of the submani-fold of the solutions with satisfactory accuracy. LA - English DB - MTMT ER - TY - BOOK AU - Insperger, Tamás AU - Stépán, Gábor TI - Semi-Discretization for Time-Delay Systems. Stability and Engineering Applications TS - Stability and Engineering Applications T3 - Applied Mathematical Sciences, ISSN 0066-5452 ; 178. ET - 0 PB - Springer London CY - New York, New York PY - 2011 SP - 174 SN - 9781461403340 DO - 10.1007/978-1-4614-0335-7 UR - https://m2.mtmt.hu/api/publication/1629264 ID - 1629264 AB - The book presents the recently introduced and already widely cited semi-discretization method for the stability analysis of delayed dynamical systems with parametric excitation. Delay-differential equations often come up in different fields of engineering, such as feedback control systems, machine tool vibrations, and balancing/stabilization with reflex delay. The behavior of such systems is often counter-intuitive and closed form analytical formulas can rarely be given even for the linear stability conditions. The same holds for parametrically excited systems. If parametric excitation is coupled with the delay effect, then the governing equation is a delay-differential equation with time-periodic coefficients, and the stability properties are even more intriguing. The semi-discretization method is a simple but efficient method that is based on the discretization with respect to the delayed term and the periodic coefficients only. This discretization results in a system of ordinary differential equations that can be solved using standard techniques, which are part of basic engineering curriculums. The method can effectively be used to construct stability charts in the space of system parameters. These charts provide a useful tool for engineers, since they present an overview on the effects of system parameters on the local dynamics of the system. The book presents the application of the method to different engineering problems, such as dynamics of turning and milling processes with constant and with varying spindle speeds, stick balancing with reflex delay, force control processes in the presence of feedback delay, and stabilization using time-periodic control gains. The book is designed for graduate and PhD students as well as researchers working in the field of delayed dynamical systems with application to mechanical, electrical and chemical engineering, control theory, biomechanics, population dynamics, neuro-physiology, and climate research. LA - English DB - MTMT ER -