Adaptive Control of Systems with Quantization and Time Delays
Doctoral thesis
Published version
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https://hdl.handle.net/11250/3069038Utgivelsesdato
2023Metadata
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Originalversjon
Schlanbusch, S. M. (2023). Adaptive Control of Systems with Quantization and Time Delays [Doctoral dissertation]. University of Agder.Sammendrag
This thesis addresses problems relating to tracking control of nonlinear systems in the presence of quantization and time delays. Motivated by the importance in areas such as networked control systems (NCSs) and digital systems, where the use of a communication network in NCS introduces several constraints to the control system, such as the occurrence of quantization and time delays. Quantization and time delays are of both practical and theoretical importance, and the study of systems where these issues arises is thus of great importance. If the system also has parameters that vary or are uncertain, this will make the control problem more complicated. Adaptive control is one tool to handle such system uncertainty. In this thesis, adaptive backstepping control schemes are proposed to handle uncertainties in the system, and to reduce the effects of quantization. Different control problems are considered where quantization is introduced in the control loop, either at the input, the state or both the input and the state. The quantization introduces difficulties in the controller design and stability analysis due to the limited information and nonlinear characteristics, such as discontinuous phenomena. In the thesis, it is analytically shown how the choice of quantization level affects the tracking performance, and how the stability of the closed-loop system equilibrium can be achieved by choosing proper design parameters. In addition, a predictor feedback control scheme is proposed to compensate for a time delay in the system, where the inputs are quantized at the same time. Experiments on a 2-degrees of freedom (DOF) helicopter system demonstrate the different developed control schemes.
Består av
Paper I: Schlanbusch, S. M. & Zhou, J. (2020). Adaptive Backstepping Control of a 2-DOF Helicopter System with Uniform Quantized Inputs. In Proceedings of the 46th Annual Conference of the IEEE Industrial Electronics Society (pp. 88–94). https://doi.org/10.1109/IECON43393.2020.9254497. Accepted version. Full-text is available in AURA as a separate file: https://hdl.handle.net/11250/3048055.Paper II: Schlanbusch, S. M., Zhou, J. & Schlanbusch, R. (2021). Adaptive Backstepping Attitude Control of a Rigid Body with State Quantization. In Proceedings of the 60th IEEE Conference on Decision and Control (pp. 372–377). https://doi.org/10.1109/CDC45484.2021.9683579. Accepted version. Full-text is available in AURA as a separate file: https://hdl.handle.net/11250/3068976.
Paper III: Schlanbusch, S. M., Zhou, J. & Schlanbusch, R. (2021). Adaptive Attitude Control of a Rigid Body with Input and Output Quantization. IEEE Transactions on Industrial Electronics, 69(8), 8296–8305. https://doi.org/10.1109/TIE.2021.3105999. Accepted version. Full-text is available in AURA as a separate file: https://hdl.handle.net/11250/2836210.
Paper IV: Schlanbusch, S. M. & Zhou, J. (2021). Adaptive Backstepping Control of a 2-DOF Helicopter System in the Presence of Quantization. In Proceedings of the 9th International Conference on Control, Mechatronics and Automation (pp. 110–115). https://doi.org/10.1109/ICCMA54375.2021.9646184. Accepted version. Full-text is available in AURA as a separate file: https://hdl.handle.net/11250/3069017.
Paper V: Schlanbusch, S. M., Aamo, O. M. & Zhou, J. (2022). Attitude Control of a 2-DOF Helicopter System with Input Quantization and Delay. In Proceedings of the 48th Annual Conference of the IEEE Industrial Electronics Society. https://doi.org/10.1109/IECON49645.2022.9968994. Accepted version. Full-text is available in AURA as a separate file: https://hdl.handle.net/11250/3058798.
Paper VI: Schlanbusch, S. M. & Zhou, J. (2023). Adaptive quantized control of uncertain nonlinear rigid body systems. Systems & Control Letters, 175: 105513. https://doi.org/10.1016/j.sysconle.2023.105513. Accepted version. Full-text is available in AURA as a separate file: https://hdl.handle.net/11250/3067270.