UNIST · 공학
Ngo Phong Nguyen 교수의 연구실은 비선형 시스템의 고성능 제어를 목표로 하며, 주로 외란에 강한 저항성을 갖는 고속 수렴 제어 기법을 연구하고 있습니다. 특히 슈퍼트위스트 알고리즘, 유한시간 관측기, 비특이 종단 슬라이딩 모드 제어를 기반으로 한 연속적이고 안정적인 제어 구조를 개발하고 있습니다. 해양 플랫폼, 드론, 회전형 역경량 펜던텀 시스템 등 실제 응용 분야에 적용 가능한 제어 전략을 중심으로 연구가 진행되고 있습니다. 특히 외부 외란과 불확실성을 효과적으로 보상하는 실시간 정밀 제어 기술에 초점이 맞춰져 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
This article proposes a continuous nonsingular terminal sliding-mode control with integral-type sliding surface (CNTSMC-ISS) framework for disturbed systems, in which we consider two types of finite-time controllers: the state feedback CNTSMC-ISS and the disturbance-observer-based CNTSMC-ISS. Compared with the existing sliding-mode controllers, the noteworthy contributions of two finite-time controllers in the proposed CNTSMC-ISS framework are the alleviation of the chattering phenomenon, the fa
This paper considers the stabilization problem for under-actuated rotary inverted pendulum systems (RotIPS) via a fuzzy-based continuous sliding mode control approach. Various sliding mode control (SMC) methods have been proposed for stabilizing the under-actuated RotIPS. However, there are two main drawbacks of these SMC approaches. First, the existing SMCs have a discontinuous structure; therefore, their control systems suffer from the chattering problem. Second, a complete proof of closed-loo
Abstract This article proposes a finite‐time disturbance observer‐based modified super‐twisting algorithm (FDO‐STA) for disturbed high‐order integrator‐chain systems under matched and mismatched disturbances. We first design a finite‐time observer for disturbance estimation, in which we show the finite‐time convergence of disturbance estimation errors to zero. Second, by employing the estimates of disturbances and their derivatives, a new dynamic sliding surface is derived, which ensures the fin
In this letter, we propose a multivariable disturbance observer-based finite-time sliding mode attitude control (MDOB-FT-SM-AC) for fixed-wing UAVs in the presence of both matched and mismatched disturbances. Compared with existing sliding mode attitude controllers, the significant improvements of the proposed MDOB-FT-SM-AC are the multivariable control structure, strong robustness, and high precision performance with continuous control input signal. In the proposed MDOB-FT-SM-AC, we first devel
Open sea loading/unloading cargos provides a potential solution to tack the problem related with port construction, expansion and congestion. This process involves a crane attached to a mobile harbor (MH) which can dynamically handle container from a large container anchored in deep water. The control objective during the operation is to maintain the payload in the desired position in the presence of ocean waves. This paper presents a robust control strategy for trajectory tracking and sway supp
In this paper, we propose the disturbance observer-based continuous finite-time sliding mode controller (DOBCSMC) for input-affine nonlinear systems in which additive matched and mismatched disturbances exist. The objective is to show the robustness and disturbance attenuation performance of the closed-loop system with the proposed DOBCSMC subjected to general classes of matched and mismatched disturbances. The proposed DOBCSMC consists of three main features: (i) the nonlinear finite-time distu
This article proposes finite-time continuous nonsingular terminal modified adaptive-gain super-twisting control (FT-CNT-MAG-STC) for the second-order disturbed systems. Compared with existing sliding-mode controllers, the noteworthy improvements of the proposed framework are the fast finite-time convergence, continuous control signal, ease-of-implementation feature, and relaxation of the assumption related to the information on the bounds of the disturbance and its derivative. In the proposed fr
A Fuzzy-PD control strategy for an offshore container crane is investigated in this study. The offshore crane is used to handle containers between a mega container ship (called the "mother ship") and a smaller ship (called the "mobile harbor"), which is equipped with container crane. The concept of the mobile harbor is a floating form that has the capability of transferring cargo to the local harbor from a large ship that is anchored in a nearby sea, thereby minimizing the port congestion and al
In this paper, we propose an observer-based super-twisting sliding mode control with fuzzy variable gains (OST-FVG) for general second-order nonlinear systems. First, the super-twisting observer with fuzzy variable gains is designed for state estimation, for which we show finite-time convergence of the estimation error to zero under the bounded disturbance. Then, together with the proposed observer, the sliding mode control with fuzzy variable gains is designed to ensure precise tracking control
We propose the neural-network based control (NNC) approach for rotary inverted pendulum (RIP). The control structure for RIP consists of two phases: (i) swing-up phase, which drives the pendulum up towards the desired upright position; and (ii) stabilization phase, which enables the pendulum to keep the desired upright position. In our paper, the swing-up controller is designed based on energy control approach with feedback linearization technique, where the corresponding control gain Kec is det
An adaptive sliding mode control scheme using radial basis function network (RBFN) for container cranes is investigated in this study. Here, a sliding surface is designed in such a way that sway motion of the payload is incorporated into the trolley dynamics. In addition, to relax the requirement of mathematical model in the design of a traditional sliding mode control (SMC) system, a neural network compensator, obtained by a radial basis function network and an adaption law, which approximates