• The Journal of the Acoustical Society of Korea
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• v.40 no.2
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• pp.109-120
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• 2021

This paper proposes the H∞ norm based data association gate method to apply robustly the data association gate of passive sonar automatic target tracking which is on non-linear targets in dense cluttered environment. For target tracking, data association method selects the measurements within validated gate, which means validated measuring extent, as candidates for the data association. If the extent of the validated gate in the data association is not proper or the data association executes under dense cluttered environment, it is difficult to maintain the robustness of target tracking due to interference of clutter measurements. To resolve this problem, this paper proposes a novel gating method which applies H∞ norm based bisection algorithm combined with 3-σ gate method under Gaussian distribution assumption and tracking error covariance. The proposed method leads to alleviate the interference of clutters and to track the non-linear maneuvering target robustly. Through analytic method and simulation to utilize simulated data of horizontal and vertical bearing measurements, improvement of data association robustness is confirmed contrary to the conventional method.

• Journal of Drive and Control
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• v.12 no.3
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• pp.1-10
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• 2015

In this paper, the authors propose a method to easily recognize and reproduce the robot motion made by an operator. This method is targets for applications similar to painting and welding, and it is based on a process of that identifies a family of plants, by control design and by conducting an experimental evaluation. In this study, the models and controllers for all joints of 3DOF robot system are obtained individually. And a robust control system for motion control of the individual joints is designed based on $H_{\infty}$ control framework. An experimental comparison is made between the proposed control method and existing PID control method. And the results indicate that the proposed designing method is more efficient and useful than conventional method.

• Journal of Power System Engineering
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• v.7 no.3
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• pp.54-60
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• 2003

In general, the swing motion of the crane is controlled and suppressed by activating the trolley motion. In this paper, we suggest a new type of anti-sway control system of the crane. In the proposed control system, a small auxiliary mass(moving-mass) is installed on the spreader and the swing motion is controlled by moving the auxiliary mass. The actuator reaction against the auxiliary mass applies inertial control forces to the container to reduce the swing motion in the desired manner. In this paper, we apply the $H_{\infty}$ based control technique to the anti-sway control system design problem. And the experimental result shows that the proposed control system is shown to be useful and robust to disturbances like winds and initial sway motion.

• Journal of Power System Engineering
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• v.8 no.1
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• pp.55-61
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• 2004

In general, the swing motion of the crane is controlled and suppressed by activating the trolley motion. In this paper, we suggest a new type of anti-sway control system of the crane. In the proposed control system, a small auxiliary mass(moving-mass) is installed on the spreader and the swing motion is controlled by moving the auxiliary mass. The actuator reaction against the auxiliary mass applies inertial control forces to the container in order to reduce the swing motion in the desired manner. In this paper, we apply the $H_{\infty}$ based control technique to the anti-sway control system design problem. And the experimental result shows that the proposed control system is useful and robust to disturbances like winds and initial sway motion.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.3
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• pp.76-86
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• 1998

The Two-Mass Spring(TMS or Two-Inertia Resonance) system is one of the simplest models which generate a torsional vibration. In this system, it is required to design a controller achieving the control performance while suppressing the torsional vibration. In this paper, we compared and considered with the state feedback effects for the TMS system. By connecting each controller design to the state feedback control, we could predict each controller performances and decide weighting functions and parameters of LQ and $H_\infty$ controller.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.428-432
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• 2003

Quantitative Feedback Theory (QFT) is one of most effective methods of robust controller design and can be considered as a suitable method for systems with parametric uncertainties. Particularly it allows us to obtain controllers less conservative than other methods like $H_{\infty}$ and ${\mu}$-synthesis. In QFT method, we transform all the uncertainties and desired specifications to some boundaries in Nichols chart and then we have to find the nominal loop transfer function such that satisfies the boundaries and has the minimum high frequency gain. The major drawback of the QFT method is that there is no effective and useful method for finding this nominal loop transfer function. The usual approach to this problem involves loop-shaping in the Nichols chart by manipulating the poles and zeros of the nominal loop transfer function. This process now aided by recently developed computer aided design tools proceeds by trial and error and its success often depends heavily on the experience of the loop-shaper. Thus for the novice and First time QFT user, there is a genuine need for an automatic loop-shaping tool to generate a first-cut solution. In this paper, we approach the automatic QFT loop-shaping problem by using an algorithm involving Linear Programming (LP) techniques and Genetic Algorithm (GA).

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.1
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• pp.92-101
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• 2010

Recently, the magnetic bearings which have many advantages such as no noise, less mechanical friction are widely applied to the suspension of rotors on the rotary machineries. However, the magnetic bearing system is inherently unstable, nonlinear and MIMO(multi-input-multi-output) system as well. In this paper, we design a state feedback controller using linear matrix inequality(LMI) to the multi-objective synthesis, for the magnetic bearing system with integral type servo system. The design objectives include $H_{\infty}$ performance, asymptotic disturbance rejection, and time-domain constraints on the closed-loop pole location. The results of computer simulation show the validity of the designed controller.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.10
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• pp.1051-1059
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• 2013

In general, lateral ride comfort of railway vehicle is mainly influenced by a secondary suspension placed between the bogie and carbody. Higher operating speeds of train results in increased vibration of carbody, which has a negative impact related to the ride comfort. To solve this problem, researches to replace the conventional passive suspension with (semi)active technology in the secondary suspension of a railway vehicle have been carried out. The semi-active suspension using the magneto-rheological damper is relatively simpler system and has advantage in maintenance compared to the hydraulic type semi-active damper. This study was performed to reduce lateral vibration acceleration of carbody related to ride comfort of railway vehicles with a semi-active suspension system. The numerical analysis was conducted by replacing passive lateral damper with semi-active MR damper, and robust control with the MR damper was applied to the 1/5 scaled railway vehicle model.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.5
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• pp.363-372
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• 2002

In ship operation, the roll motions can seriously degrade the performance of mechanical and personnel effectiveness. So many studies for the roll stabilization system design have been performed and good results have been achieved. In many studies, the stabilizing fins are used. Recently rudders, which have been extensively modified, have been used exclusively to stabilize the roll. But, in the roll stabilization control system, the control performance is very sensitive to the ship speed. So, we can see that it is important to consider the ship speed in the rudder roll control system design. The gain-scheduling control technique is very useful in the control problem incorporating time varying parameters which can be measured in real time. Based on this fact, in this paper we examine the;$H_{\infty}$-Gain Scheduling control design technique. Therefore, we assume that a parameter, the ship speed which can be estimated in real time, is varying and apply the gain-scheduling control technique to design the course keeping and anti-rolling control system far a ship. In this control system, the controller dynamics is adjusted in real-time according to time-varying plant parameters. The simulation result shows that the proposed control strategy is shown to be useful for cases when the ship speed is varying and robust to disturbances like wind and wave.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.621-626
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• 2019

The driver's steering wheel maneuver is a typical disturbance that causes excessive body motion and traveling instability of a vehicle. Abrupt and extreme operation can cause rollover depending on the geometric and dynamic characteristics, e.g., SUV vehicles. In this study, to cope with the performance limitation of conventional cars, fundamental research on the structurization of a control system was performed as follows. Mathematical modeling of the lateral behavior induced by driver input was carried out. A controller was designed to reduce the body motion based on this model. An algorithm was applied to secure robust control performance against modeling errors due to parameter uncertainty, $H_{\infty}$. Using the decoupled 1/4 car, a dynamic load simulating model considering the body moment was suggested. The simulation result showed the validity of the load-simulating model. The framework for a lateral behavior control system is proposed, including an experimental 1/4 vehicle unit, load simulating module, suspension control module, and hardware-in-the-loop simulation technology.