List of English Publication

@article{Na2020,

title = {Disturbance observer approach for fuel-efficient heavy-duty vehicle platooning},

author = {Gyujin Na and Gyunghoon Park and Valerio Turri and Karl H. Johansson and Hyungbo Shim and Yongsoon Eun},

doi = {https://doi.org/10.1080/00423114.2019.1704803},

issn = {0042-3114},

year  = {2020},

date = {2020-05-01},

journal = {Vehicle System Dynamics},

volume = {58},

number = {5},

pages = {748-767},

abstract = {Heavy-duty vehicle platooning has received much attention as a method to reduce fuel consumption by keeping inter-vehicle distance short. When a platoon follows a fuel-optimal velocity profile calculated using preview road slope information, significant improvement in the fuel economy occurs. To calculate the optimal velocity in the existing method, however, platoon should acquire expensive road slope data in advance. As an alternative, we propose a road slope estimation method, which enables platoon to calculate the optimal velocity profile without the usage of actual road slope data. Other major challenges in platoon operation include overcoming the effect of the vehicle model uncertainties and external disturbances for ensuring the control performance. The most significant part of the disturbances arises from slopes along a route. Existing method for reducing the effect of the slope employs a feed-forward type compensation in the control loop by combining the vehicle position acquired from GPS and the slope database. However, this method exhibits limitations: the mass of the vehicles in the platoon is uncertain which lowers the accuracy of the feed-forward compensation, and the platoon requires the pre-acquired slope database. To overcome these limitations, we propose an alternative method employing disturbance observer. Simulations of various scenarios are conducted to show the efficacy of the proposed method using the actual road slope data of a Swedish highway.},

keywords = {Disturbance observer, Heavy-duty vehicle platoon, Road slope estimation, Robust control},

pubstate = {published},

tppubtype = {article}

}

@article{SeoBackShimSeo09,

title = {Robust Adaptive Control for a Class of Nonlinear Systems with Complex Uncertainties},

author = {Sang-Bo Seo and Juhoon Back and Hyungbo Shim and Jin Heon Seo},

doi = {doi.org/10.5370/JEET.2009.4.2.292},

issn = {1975-0102},

year  = {2009},

date = {2009-06-30},

journal = {Journal of Electrical Engineering and Technology},

volume = {4},

number = {2},

pages = {292-300},

abstract = {This paper considers a robust adaptive stabilization problem for a class of uncertain nonlinear systems which include an unknown virtual control coefficient, an unknown constant parameter, and a time-varying disturbance whose bound is unknown, We propose a new estimator for an un-known virtual control coefficient and present a robust adaptive backstepping design procedure which results in a smooth state feedback control law, a new two-dimensional parameter update law, and a C1 Lyapunov function which is positive definite and proper.},

keywords = {Robust control},

pubstate = {published},

tppubtype = {article}

}

@article{BackShim08,

title = {Adding Robustness to Nominal Output Feedback Controllers for Uncertain Nonlinear Systems: A Nonlinear Version of Disturbance Observer},

author = {Juhoon Back and Hyungbo Shim},

doi = {10.1016/j.automatica.2008.02.024},

issn = {0005-1098},

year  = {2008},

date = {2008-10-01},

journal = {Automatica},

volume = {44},

number = {10},

pages = {2528-2537},

abstract = {The linear disturbance observer (DOB) approach has been successfully employed as a tool for robust control and disturbance rejection in practice. In this paper, we present a nonlinear DOB which inherits all the benefits of the classical linear DOB approach. In particular, we prove that the proposed nonlinear DOB recovers not only the steady-state performance but also the transient performance of the nominal closed-loop system under plant uncertainties and input disturbances. One novel feature of the proposed controller is that it is an add-on type inner-loop output-feedback controller; thus any type of outer-loop controller can be combined to enhance the closed-loop system performance. Our result is a semi-global one and the stability proof is given when the nonlinear system has a well-defined relative degree with a stable zero dynamics.},

keywords = {Robust control},

pubstate = {published},

tppubtype = {article}

}