• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2926-2934
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• 2000

This study presents a direct adaptive controller which is derived by using Lyapunovs direct methods for trajectory tracking control of a pneumatic cylinder. The structure of the controller is very simple and computationally efficient because it does not use either the dynamic model or the parameter values of the pneumatic system. The bounded stability of the system is shown in the presence of the bounded unmodeled dynamics. The bounded size of tracking errors can be made arbitrarily small without giving andy influences on either input or output variables. The trajectory tracking performance and the stability of the control system is verified experimentally. The results of the experiments show that the proposed controller tracks the given trajectories, sine function and cycloidal function trajectories, more accurately than PD controller does, and it stabilizes the system and adaptive variables.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1281-1286
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• 2014

This paper presents an iterative learning control (ILC) approach for tracking problems with specified data points that are desired points at certain time instants. To design ILC systems for such problems, unlike traditional ILC approaches, an algorithm which updates not only the control signal but also the reference trajectory at each trial will be developed. The relationship between the reference trajectory and ILC control in tracking problems where there are specified data points through which the system should pass is investigated as the rate of convergence. In traditional ILC, the desired data is stored in a tracking profile file. Due to the huge size of the data file containing the target points, it is important to reduce the computational cost. Finally, simulation results of the presented technique are mentioned and compared to other related works to confirm the effectiveness of proposed scheme.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1205-1207
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• 1996

The computed-torque method (CTM) shows good trajectory tracking performance in controlling robot manipulator if there is no disturbance or modelling errors. But with the increase of a payload or the disturbance of a manipulator, the tracking errors become large. So there have been many researchs to reduce the tracking error. In this paper, we propose a new control algorithm based on the CTM that decreases a tracking error by generating new reference trajectory to the controller. In this algorithm we used a fuzzy system based on the rule bases. For the numerical simulation, we used a 2-link robot manipulator. To simulate the disturbance due to a modelling uncertainty, we added errors to each elements of the inertia matrix and the nonlinear terms and assumed a payload to the end-effector. In the simulations of several cases, our method showed better trajectory tracking performance compared with the CTM.

• The Journal of Korea Robotics Society
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• v.18 no.2
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• pp.155-163
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• 2023

Auto Guided Vehicle (AGV) equipped with mecanum wheels can move in all directions, unlike ordinary wheeled AGVs. In this paper, we propose a robust trejectory tracking control method for the mecanum wheeled AGVs in the presence of disturbances. It is constructed by combining impedance control with Integral Sliding Mode Control (ISMC), which shows robust performance against disturbances, and adding a disturbance observer (DOB) that estimates and removes disturbances. Simulation result using MATLAB/SIMULINK shows that the proposed control method has robust performance in tracking the reference trajectory under the circumstance with disturbance. The control performance is further improved when the disturbance observer is additionally used. In addition, the performance of the proposed control method was verified through experiment. It shows the result of tracking the set trajectory well.

• Smart Media Journal
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• v.13 no.2
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• pp.23-31
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• 2024

In precision cattle farm, reliably tracking the identity of each cattle is necessary. Effective tracking of cattle within farm environments presents a unique challenge, particularly with the need to minimize the occurrence of excessive tracking trajectories. To address this, we introduce a trajectory playback decision tree algorithm that reevaluates and cleans tracking results based on spatio-temporal relationships among trajectories. This approach considers trajectory as metadata, resulting in more realistic and accurate tracking outcomes. This algorithm showcases its robustness and capability through extensive comparisons with popular tracking models, consistently demonstrating the promotion of performance across various evaluation metrics that is HOTA, AssA, and IDF1 achieve 68.81%, 79.31%, and 84.81%.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.6
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• pp.53-61
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• 2014

For monitoring the flight trajectory and the status of a launch vehicle, the mission control system in NARO space center process data acquired from the ground tracking system, which consists of two tracking radars, four telemetry stations, and one electro-optical tracking system. Each tracking unit exhibits its own tracking error mainly due to multi-path, clutter and radio refraction, and by utilizing only one among transmitted informations, it is not possible to determine the actual vehicle trajectory. This paper presents a way of generating flight trajectory via post-processing the data received from the ground tracking system. The post-processing algorithm is divided into two parts: compensation for atmosphere radio refraction and multi-sensor fusion, for which a decentralized Kalman filter was adopted and implemented based on constant acceleration model. Applications of the present scheme to real data resulted in the flight trajectory where the tracking errors were minimized than done by any one sensor.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.20-23
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• 1996

This paper deals with the flexible manipulator with rotational and translational degrees of freedom, which has an arm of time-varying length with the prismatic joint. The tracking control problem of the flexible manipulator is considered. First we design the controller of the 2-type robust servo system based on the finite horizon optimal control theory for the trajectory planned as a discontinuous velocity. Next, to reduce the tracking error, we use the method of the dynamic programming and of modifying the reference trajectory in time coordinate. The simulation results show that the dynamic modeling is adequate and that the asymptotic stabilization of the flexible manipulator is preserved in spite of nonlinear terms. The PTP control error has been reduced to zero completely, and the trajectory tracking errors are reduced sufficiently by the proposed control method.

• Journal of Mechanical Science and Technology
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• v.19 no.5
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• pp.1107-1115
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• 2005

In this study, a position and force simultaneous trajectory tracking control algorithm is proposed for a driving apparatus that consists of two pneumatic cylinders connected in series. The controller applied to the driving apparatus is composed of a non-interaction controller to compensate for interaction between cylinders and a disturbance observer aimed to reduce the effect of model discrepancy that cannot be compensated by the non-interaction controller. The effectiveness of the proposed control algorithm is proved by experimental results.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2390-2392
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• 2003

ILC(Iterative Learning Control: 이하 ILC)는 현재 기계, 전기, 화학 등 많은 분야에 널리 적용되고 있다. ILC는 특히 반복적인 trajectory tracking Control 문제에 아주 효과적인 방법 중의 하나이다. 하지만 ILC는 메모리 기반의 scheme로서 trajectory tracking을 위해서는 많은 메모리를 요구하게 된다. 한편, 자세한 관찰에 의하면 인간의 팔, 다리 등의 관절의 움직임은 아주 정확하지가 않다. 이러한 사실로 미루어 인간이 정화한 모션을 취하는데 드는 비용을 줄이고자 모션 명령을 간단히 한다는 가정을 추론 해 낼 수 있다. 이러한 가정에 기초하여 우리는 ILC 명령을 간단히 하기 위해서 약간의 trajectory tracking의 정확성을 회생하는 메커니즘을 제안한다. 간단해진 ILC 명령은 적은 메모리 공간에 저장될 것이다. 또한, 로봇의 trajectory tracking을 위한 기존의 방법들은 아주 복잡할 뿐만 아니라 하나의 task의 수행만이 가능할 뿐 어떤 일반화의 방법도 제시하지 못하고 있다. 그래서 본 논문에서는 ILC 명령의 scaling에 대한 메커니즘을 제공하여 하나의 trajectory에 대해서 비슷한 모양이지만 다른 크기와 속도를 가지는 trajectory를 구현 할 수 있도록 하였다.

• Journal of Power System Engineering
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• v.10 no.3
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• pp.97-103
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• 2006

In this study, a position trajectory tracking control algorithm is proposed for a pneumatic artificial muscle driving apparatus composed of a actuator which imitates the muscle of human, a position sensor and a control valve. The controller applied to the driving apparatus is composed of a state feedback controller and disturbance observer. The feedback controller which feeds back position, velocity and acceleration is derived from the linear model of pneumatic artificial muscle driving apparatus. The disturbance observer is designed to improve trajectory tracking performance and to reduce the effect of model discrepancy. The effectiveness of the designed controller is proved by experiments and the experimental results show that the pneumatic artificial muscle driving apparatus with the proposed control algorithm tracks given position reference inputs accurately.