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Data-driven Modeling and Adaptive Predictive Anti-swing Control of Overhead Cranes
Gyoung-Hahn Kim,Keum-Shik Hong,Mahnjung Yoon,Jae Young Jeon 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8
This study investigates a novel data-driven model and an adaptive predictive anti-swing control law for overhead cranes. As an alternative solution to the physics-based modeling approach, a data-driven modeling framework is formulated using the feedforward neural network and extreme learning machine, approximating the nonlinear functional mapping between the system inputs and outputs. Using the proposed data-driven modeling approach, the complete input-output behavior, including the dynamics associated with sensors and actuators, is captured from experimental data. After converting the data-driven model to a state-space form, an adaptive predictive anti-swing control law is developed using the empirical model. To compensate for the modeling discrepancy resulting from abrupt parameter variations, an online parameter adaptation law for updating the data-driven model is further developed. Thus, accurate bridge/trolley positioning and rapid swing suppression are realized in ordinary and uncertain operating conditions. The asymptotic stability of the error dynamics and the boundedness in the estimated parameters are analyzed using the Lyapunov technique. Finally, three types of experiments are performed to verify the effectiveness of the proposed modeling and control methods.
Phuong-Tung Pham,Gyoung-Hahn Kim,Keum-Shik Hong 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10
This paper develops a boundary control for an overhead crane with the input constraint, wherein the hoisting rope is considered as an axially moving string with varying length. The mathematical model of the crane consisting of a trolley, a hoisting rope, and a payload is developed by using the Hamilton principle. To deal with the input saturation, an auxiliary system is used, and a boundary control law is designed based on this system. The stability of the crane system under the proposed control law is also verified via the Lyapunov stability theory. The simulation results reveal the impressive effectiveness of the proposed control law.
박명욱(Mingxu Piao),김경한(Gyoung-Hahn Kim),Umer Hameed Shah,홍금식(Keum-Shik Hong) 제어로봇시스템학회 2016 제어·로봇·시스템학회 논문지 Vol.22 No.6
This paper discusses the dynamics and control problem of an overhead shuttle system (OSS), which is a critical part of the automated container terminal at a port. The main purpose of the OSS is efficient automated transport function of containers, which also requires high precision and safety. A major difference between the OSS and the conventional container crane is the configuration of the cables for hoisting the spreader. A mathematical model of the OSS is developed here for the first time, which results in an eight-pole system. Also, open loop control methods (trapezoidal and notch-type velocity profiles) are investigated so that the command input to the overhead shuttle produces the minimum possible sway of the payload. Simulation results show that the vibration suppression capability of the OSS is superior to the conventional overhead container crane, which is partially due to the cable configuration.
Control of a Non-uniform Flexible Beam: Identification of First Two Modes
Phuong-Tung Pham,Gyoung-Hahn Kim,Quoc Chi Nguyen,Keum-Shik Hong 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.11
This paper presents an experimental study implementing the input shaping control of the first two modes of the vibration of a non-uniform flexible cantilever beam having a translating base. Examples of a moving cantilever beam appear in many industrial systems. Vibration suppression of the beam has important implications for improving the effectiveness of such systems. The equations of motion of the cantilever beam, including the moving base, are developed using the extended Hamilton principle. The partial differential equation representing the beam’s dynamics is then transformed into a finite-dimensional model using the Galerkin method. Accordingly, the modal parameter identification procedure is established based on experimental modal analysis. Under the estimated modal parameters, including the natural frequency and damping ratio, single- and two-mode input shaping controllers of three different types (zero vibration, zero vibration derivative, and zero vibration derivative-derivative) are designed for vibration suppression of the beam. Experimental results are discussed, reporting that the two-mode shaper’s vibration suppression was superior to the single-mode shaper. In contrast, the two-mode shaper’s settling time has slightly increased compared to that of the single-mode shaper.
Vibration Control of a Timoshenko Cantilever Beam with Varying Length
Phuong-Tung Pham,Gyoung-Hahn Kim,Keum-Shik Hong 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.1
This paper addresses the vibration control of a Cartesian palletizer consisting of a trolley and a robotic arm, wherein the robotic arm is modeled as a thick cantilever beam of varying length. The Timoshenko beam theory, which describes the behavior of thick beams, is used to model the robotic arm’s dynamics. A mathematical model describing the trolley’s motion and the robotic arm’s vibration is established based on the extended Hamilton principle. According to this dynamic model, a boundary control law is proposed to suppress the undesired transverse vibration of the robotic arm. The uniform stability of the closed-loop system is proven via the Lyapunov method. The simulation results show that the proposed control law can simultaneously control the trolley’s position and the robotic arm’s vibration.
박명욱(Mingxu Piao),김경한(Gyoung-Hahn Kim),홍금식(Keum-Shik Hong) 제어로봇시스템학회 2018 제어·로봇·시스템학회 논문지 Vol.24 No.10
In this paper, a super-twisting (i.e., modified 2nd-order) sliding mode control (STSMC) is proposed for sway control of an offshore container crane system (i.e., a mobile harbor system equipped with a container crane on it). The mobile harbor is used for ship-to-ship transfer of containers, where the container ship is anchored in an open sea. To load/unload the containers in an open sea, it is necessary to suppress the position error of the load caused by the wave-induced movements of the mobile harbor. In this paper, a super-twisting sliding mode controller is developed for suppressing the position error of the payload. The sliding surface is designed in such a way that the longitudinal sway of the load is incorporated within the trolley dynamics. The chattering problem is also solved by utilizing a second order sliding surface. Lyapunov function-based stability analysis is performed to prove the uniform stability of the closed-loop system. Simulation results are provided to prove the effectiveness of the proposed control law.
Muhammad Riaz,Muhammad Ashraf,Keum-Shik Hong,Gyoung-Hahn Kim,Muhammad Rehan 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10
This article addresses the synchronization problem for two different chaotic systems with state time-delays, disturbances, and mutually Lipschitz nonlinearities. For analysis of the two different kind of chaotic oscillators, adaptive control theory, mutually Lipschitz condition and linear matrix inequalities (LMIs) based methodology are utilized to suppress the synchronization error and mismatch between the master-slave chaotic in the presence of disturbances and state delays. A novel adaptive control scheme for the synchronization of such systems is established that guarantees the convergence of the error trajectory and ensures the stability of the synchronization error system. In the end, established adaptive control law is verified by a numerical example of two different, popular in electronics, chaotic Chua’s circuit and Rossler system.
Active Vibration Control of a Flexible Rod in Water
Umer Hameed Shah,Mingxu Piao,Gyoung-Hahn Kim,Keum-Shik Hong 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10
This paper addresses the vortex-induced vibration (VIV) suppression problem of nuclear fuel rods, which are transported by a refueling machine (RM) to given reactor locations in water. First, Hamilton’s principle is used to develop the equations of coupled motions of the RM and the fuel rod. The resulting equations of the hybrid (lumped-mass RM and distributed-parameter flexible rod) system are then utilized to investigate the VIVs of the fuel rod upon the movements of the RM. Then, a boundary control scheme is developed to suppress the VIVs of the rod in the course of its transportation in water. Furthermore, Lyapunov function-based stability analyses are performed to prove the uniform ultimate boundedness of the closed-loop system, considering the influence of the nonlinear hydrodynamic force acting on the fuel rod. Finally, simulations are performed to demonstrate the effectiveness of the proposed boundary control scheme.
Vibration Control of a Nuclear Fuel Rod Maneuvering Under Water
Umer Hameed Shah,Mingxu Piao,Gyoung-Hahn Kim,Keum-Shik Hong 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10
This paper addresses the vibration control problem of a fuel transport system (FTS) in a nuclear power plant. The FTS transports the fuel rods in the nuclear reactor to desired locations within the fuel building. The fuel rods must be transported under water to avoid radiation leaks into the environment. It has been observed that a quick maneuver of the trolley can cause vibrations that can damage the structure of the fuel rods, due to the hydrodynamic force exerted by the surrounding fluid. In this study, a distributed parameter model of the FTS, using the extended Hamilton’s principle, is developed. The developed model is verified with experiments. A velocity command is designed, as an open-loop control, to transport the fuel rods in quick time to the target locations with minimal vibrations. The residual vibrations of the fuel rod are controlled while considering the effects of the hydrodynamic force imposed by the surrounding water. Simulation and experimental results show that the proposed velocity command transports the fuel rods to the target location quickly resulting in a significant decrease in the rod’s vibrations.