List of English Publication

@article{noneb,

title = {Asymptotic output tracking in a class of non-minimum phase nonlinear systems via learning-based inversion},

author = {Namguk Kim and Hyungbo Shim},

doi = {https://doi.org/10.1002/rnc.6969},

issn = {1049-8923},

year  = {2024},

date = {2024-01-10},

urldate = {2024-01-10},

journal = {International Journal of Robust and Nonlinear Control},

volume = {34},

issue = {1},

pages = {240-269},

abstract = {Asymptotic output tracking of non-minimum phase (NMP) nonlinear systems has been a popular topic in control theory and applications. Many approaches have focused on finding solutions under minimal assumptions either in the target system or desired trajectories, as there is no general solution available. In this article, we propose a practical and simple solution for cases where the reference trajectory is periodic in time. Our approach employs a learning-based scheme to iteratively determine the desired feedforward input. Unlike previous learning-based frameworks, our method only requires the output tracking error to update the feedforward input iteratively and can be applicable to NMP systems. Our method retains the key advantages of the learning-based framework, including robustness to parameter uncertainties and periodic disturbances. We evaluate the effectiveness of our algorithm using simulation results with an inverted pendulum on a cart, a typical NMP nonlinear system.},

keywords = {asymptotic output tracking, iterative learning, Non-minimum phase, stable inversion},

pubstate = {published},

tppubtype = {article}

}

@article{KimKimBackShimSeo16,

title = {Design of Stable Parallel Feedforward Compensator and its Application to Synchronization Problem},

author = {Hongkeun Kim and Seongjun Kim and Juhoon Back and Hyungbo Shim and Jin Heon Seo},

doi = {10.1016/j.automatica.2015.11.020},

year  = {2016},

date = {2016-02-01},

journal = {Automatica},

volume = {64},

pages = {208-216},

abstract = {This paper addresses the design problem of a stable parallel feedforward compensator V for a given SISO LTI plant P (possibly being of non-minimum phase and/or having relative degree greater than one). The objective of the problem is that their parallel interconnection P+V becomes minimum phase having relative degree one. Based on the classical results of simultaneous stabilization, a necessary and sufficient condition for solving the problem is presented as well as a design procedure for constructing such a compensator. The proposed feedforward compensator allows the control system to have the three useful features: (1) the ability that assigns the zeros of P+V to a region of complex numbers having arbitrary negative real parts, (2) infinite gain margin property of P+V controlled by a static output feedback, and (3) block diagonal structure of P+V. These features are extensively exploited in the synchronization problem of multi-agent systems to achieve arbitrary fast convergence rate and to have the synchronized trajectory independent of the initial conditions and parameters of the involved dynamic controllers.},

keywords = {Multi-agent system, Non-minimum phase, Parallel feedforward compensator, Synchronization},

pubstate = {published},

tppubtype = {article}

}