List of English Publication

@article{KimShimSeo19,

title = {State Estimation and Tracking Control for Hybrid Systems by Gluing the Domains},

author = {Jisu Kim and Hyungbo Shim and Jin Heon Seo},

url = {https://arxiv.org/abs/1810.04404},

doi = {10.1109/TAC.2018.2876784},

year  = {2019},

date = {2019-07-01},

journal = {IEEE Transactions on Automatic Control},

abstract = {We study the design problems of state observers and tracking controllers for a class of hybrid systems whose state jumps. The idea is to utilize the well-known method of gluing the jump set (a part of domain where the jumps take place) onto its image, which converts the hybrid system into a continuous-time system whose state does not jump. Sufficient conditions for this idea to be implemented are listed and discussed with a few concrete examples. In particular, we present a structural condition for an observer design, and, for tracking control, we introduce a feedback to compensate residual discontinuity in the vector field after gluing. The benefits of the proposed approach include that the observer design does not require detection of the state jumps, and that the tracking control does not require the plant state jumps when the reference jumps.},

keywords = {Hybrid system, Observer, Tracking},

pubstate = {published},

tppubtype = {article}

}

@article{JoJeonShim17,

title = {Noise Reduction Disturbance Observer for Disturbance Attenuation and Noise Suppression},

author = {Nam Hoon Jo and Chanyoung Jeon and Hyungbo Shim},

doi = {10.1109/TIE.2016.2618858},

year  = {2017},

date = {2017-02-01},

journal = {IEEE Transactions on Industrial Electronics },

volume = {64},

number = {2},

pages = {1381 - 1391},

abstract = {In most research works on the disturbance observer (DOB)-based controller, stability conditions are only sufficient and not effective for handling large uncertainties. To deal with large uncertainties, a necessary and sufficient condition for robust stability has been recently provided by utilizing a novel design technique for the Q -filter. Although this design method can deal with large uncertainties, it is not capable of suppressing the effect of sensor noise. To achieve noise suppression as well as disturbance attenuation, this paper proposes a robust controller by utilizing a modified DOB structure. In contrast to the conventional DOB structure, noise suppression ability of the proposed controller can be adjusted by an appropriate choice of the Q-filter. Moreover, a necessary and sufficient condition for the modified DOB system to be robustly stable is newly presented. To show the effectiveness of the proposed controller, the performance is compared with other disturbance attenuation methods through simulation studies. Finally, in order to verify the validity of the proposed method, laboratory experiments are also conducted with brushless dc motor drives, which confirms that the proposed controller is quite useful for attenuating both input disturbance and sensor noise, while DOB controller is not capable of suppressing sensor noise.},

keywords = {Motor drive, Observer},

pubstate = {published},

tppubtype = {article}

}

@article{JooParkBackShim16,

title = {Embedding Internal Model in Disturbance Observer with Robust Stability},

author = {Youngjun Joo and Gyunghoon Park and Juhoon Back and Hyungbo Shim },

doi = {10.1109/TAC.2015.2503559},

year  = {2016},

date = {2016-10-01},

journal = {IEEE Transactions on Automatic Control},

volume = {61},

number = {10},

pages = {3128-3133},

abstract = {Abstract:

The disturbance observer has been widely employed in applications due to its powerful ability for disturbance rejection and robustness under plant uncertainties. However, it rejects the disturbance approximately rather than exactly since it is usually designed without considering structural properties of disturbance. In order to improve the disturbance rejection performance, we propose a design method to embed the internal model of disturbance into the disturbance observer structure. Furthermore, a systematic design procedure is proposed so that one can always design the disturbance observer to guarantee robust stability of the closed-loop system even though uncertain parameters of the plant belong to an arbitrarily large (but bounded) set.},

keywords = {Control system synthesis, Observer, Robustness},

pubstate = {published},

tppubtype = {article}

}