2024 |
Hyuntae Kim / Hamin Chang / Hyungbo Shim Evaluating MR-GPR and MR-NN: An Exploration of Data-driven Control Methods for Nonlinear Systems Journal Article In: International Journal of Control, Automation, and Systems, vol. 22, pp. 2934–2941, 2024, ISSN: 1598-6446. Abstract | Links | BibTeX | Tags: Data-driven control, Gaussian process, Neural Network, nonlinear systems, Stability, System identification @article{nokey, This paper addresses the challenge of data-driven control of nonlinear systems, focusing on the limi-tations and capabilities of model reference Gaussian process regression (MR-GPR) and its evolved counterpart,model reference neural networks (MR-NN). MR-GPR, based on Gaussian processes renowned for their adaptabil-ity to diverse data structures, encounters scalability issues especially when handling large datasets. To address theselimitations, this paper introduces MR-NN, an extension of MR-GPR, leveraging neural networks (NN) to managelarge datasets and capture complex nonlinear dynamics effectively. We present a comprehensive evaluation of bothmethods through a classical control problem of the inverted pendulum, a system well-recognized for its nonlinearbehavior. Numerical experiments are conducted to compare the methods in terms of control performance, compu-tational efficiency, and reliability. |
Yeongjun Jang / Hamin Chang / Heein Park / Hyungbo Shim Path Generating Inverse Gaussian Process Regression for Data-Driven Ultimate Boundedness Control of Nonlinear Systems Journal Article In: IEEE Control Systems Letters, vol. 8, pp. 748 - 753, 2024, ISSN: 2475-1456. Abstract | Links | BibTeX | Tags: Data-driven control, Gaussian process, nonlinear systems @article{nokey, A data-driven ultimate boundedness controller for a nonlinear system is proposed. The controller is designed based on the inverse model of the system identified by Gaussian process regression with state/input measurement data to track a reference trajectory suitable for achieving a desired ultimate bound. In particular, a suitable reference trajectory is actively generated based on the data that have been used for the identification. For this reason, the controller is named the path generating inverse Gaussian process regression (PGIGP) controller. We provide a sufficient condition on the data under which the PGIGP controller guarantees ultimate boundedness with a desired ultimate bound. It is shown that the condition can serve as a practical guideline for data acquisition and, conversely, be employed to determine the baseline of the control performance achievable from a given dataset. The effectiveness of the PGIGP controller is demonstrated through numerical simulations. |
2023 |
Hyuntae Kim / Hamin Chang / Hyungbo Shim Model Reference Gaussian Process Regression: Data-Driven Output Feedback Controller Proceedings Article In: 2023 American Control Conference (ACC), pp. 955-960, IEEE, San Diego, CA, USA, 2023, ISBN: 979-8-3503-2806-6. Abstract | Links | BibTeX | Tags: Data-driven control, Gaussian process, MR-GPR @inproceedings{nokey, Data-driven controls using Gaussian process regression have recently gained much attention. In such approaches, system identification by Gaussian process regression is mostly followed by model-based controller designs. However, the outcomes of Gaussian process regression are often too complicated to apply conventional control designs, which makes the numerical design such as model predictive control employed in many cases. To overcome the restriction, our idea is to perform Gaussian process regression to the inverse of the plant with the same input/output data for the conventional regression. With the inverse, one can design a model reference controller without resorting to numerical control methods. This paper considers single-input single-output (SISO) discrete-time nonlinear systems of minimum phase with relative degree one. It is highlighted that the model reference Gaussian process regression controller is designed directly from pre-collected input/output data without system identification. |
Yongsoon Eun / Jaeho Lee / Hyungbo Shim Data-Driven Inverse of Linear Systems and Application to Disturbance Observer Proceedings Article In: 2023 American Control Conference (ACC), pp. 2806-2811, IEEE, San Diego, CA, USA, 2023, ISBN: 979-8-3503-2806-6. Abstract | Links | BibTeX | Tags: Data-driven control, Disturbance observer, Disturbance rejection, Linear Systems @inproceedings{nokeyt, This work develops a data-based construction of inverse dynamics for LTI systems. Specifically, the problem addressed here is to find an input sequence from the corresponding output sequence based on pre-collected input and output data. The problem can be considered as a reverse of the recent use of the behavioral approach, in which the output sequence is obtained for a given input sequence by solving an equation formed by pre-collected data. The condition under which the problem gives a solution is investigated and turns out to be L-delay invertibility of the plant and a certain degree of persistent excitation of the data input. The result is applied to form a data-driven disturbance observer. The plant dynamics augmented by the data-driven disturbance observer exhibits disturbance rejection without the model knowledge of the plant. |
List of English Publication
2024 |
Evaluating MR-GPR and MR-NN: An Exploration of Data-driven Control Methods for Nonlinear Systems Journal Article In: International Journal of Control, Automation, and Systems, vol. 22, pp. 2934–2941, 2024, ISSN: 1598-6446. |
Path Generating Inverse Gaussian Process Regression for Data-Driven Ultimate Boundedness Control of Nonlinear Systems Journal Article In: IEEE Control Systems Letters, vol. 8, pp. 748 - 753, 2024, ISSN: 2475-1456. |
2023 |
Model Reference Gaussian Process Regression: Data-Driven Output Feedback Controller Proceedings Article In: 2023 American Control Conference (ACC), pp. 955-960, IEEE, San Diego, CA, USA, 2023, ISBN: 979-8-3503-2806-6. |
Data-Driven Inverse of Linear Systems and Application to Disturbance Observer Proceedings Article In: 2023 American Control Conference (ACC), pp. 2806-2811, IEEE, San Diego, CA, USA, 2023, ISBN: 979-8-3503-2806-6. |