• Journal of Institute of Control, Robotics and Systems
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• v.4 no.2
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• pp.226-234
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• 1998

The concept of dynamic tracking line is proposed as the feasible tracking region for a robot in a robot-conveyor system, which takes the conveyor speed into consideration. This paper presents an effective method to identify the dynamic tracking line in a robotic workcell. The maximum line speed of a robot is derived in an analytic form using the parameterized dynamics and kinematics of the manipulator, and some of its properties are established mathematically. The identification problem of the dynamic tracking line is then formulated as a root-solving problem for a single-variable equation, and solved by using a simple numerical technique. Finally, numerical examples are presented to demonstrate the methodology and its applications in workspace specification.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.3
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• pp.349-359
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• 1998

A robot control scheme for specific application a line-tracking system is newly presented. To improve the performance of line-tracking, robot arm dynamics and torque constraints are incorporated into the control scheme. The tracking problem for the workpiece on a variable-speed conveyor is formulated as an optimal tracking problem with specific criteria. Dividing the conveyor speed into the nominal term and the perturbed term, a two-stage control strategy is employed to cope with the nonlinearity and uncertainty of the robot-conveyor system. Simulation results are given to verify good tracking performance with fast cycle time and high accuracy in a robotic workcell.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.11
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• pp.945-954
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• 1990

In this paper, we presents a robust adaptive control system design method in the work coordinate of the robot arm for conveyor tracking. In the design, if the weighting function $L_K$ is smaller than the design parameter then the transient characteristics of system becomes stable, if $L_K$ is larger than then the system becomes unstable. Proposed design method presented here is based on model referenece adaptive control and Popov stability theorem. By the utiliza/tion of an auxilary input, it is improved the transent characteristics of the system in comparison with the conventional model reference adptive control, since the rate of V and V(t) is large. The usefulness of a proposed design method has been confirmed by computer simulations.

• International Journal of Control, Automation, and Systems
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• v.3 no.3
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• pp.461-468
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• 2005

This paper proposes a wheel-assembly automation system, which assembles a wheel into a hub of a vehicle hung to a moving hanger in a car manufacturing line. A macro-micro manipulator control strategy is introduced to increase the system bandwidth and tracking accuracy to ensure insertion tolerance. A camera is equipped at the newly designed wheel gripper, which is attached at the center of the end-effector of the macro-micro manipulator and is used to measure position error of the hub of the vehicle in real time. The redundancy problem in the macro-micro manipulator is solved without complicated calculation by assigning proper functions to each part so that the macro part tracks the velocity error while the micro part regulates the fine position error. Experimental results indicate that tracking error satisfies the insertion tolerance of assembly $({\pm}1mm)$, and thus it is verified that the proposed system can be applied to the wheel assembly task on a moving hanger in the manufacturing line.

• Journal of Power System Engineering
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• v.21 no.4
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• pp.42-50
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• 2017

A velocity controller using a modified model reference adaptive controller (M-MRAC) and a projection operator for a fish sorting belt conveyor system with uncertainty parameters, input saturation and bounded disturbances is proposed in this paper. To improve the tracking performance and robustness of the proposed controller in the presence of bounded disturbances, the followings are done. Firstly, the reference model for the conventional model reference adaptive controller (CMRAC) is replaced by a modified reference model for a M-MRAC to reduce unexpected high frequency oscillation in control input signal when the adaptation rate is increased. Secondly, estimated parameters in an adaptive law are varied smoothly under bounded external disturbances and a projection operator is utilized in an adaptive law for the proposed M-MRAC controller to be robust. Thirdly, an auxiliary error vector is introduced for compensating the error dynamics of the system when the saturation input occurs. Finally, the experimental results are shown to verify the better effectiveness and performance of the proposed controller under the bounded disturbance and saturated input than that of a CMRAC.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.211-215
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• 1989

This paper describes a dynamic robotic assembly system in which an industrial robot executes peg-in-hole task in a moving state. As an effective means to synchronize the end-effector of the robot with the moving conveyor this work uses a control algorithm which is essentially a PID position control scheme combined with velocity feedforward loop. A RCC wrist is used for the inserting task and its force responses are investigated for various tracking conditions and inserting velocities through a series of experiments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.415-420
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• 2017

In this paper, an algorithm for object counting via a conveyor system using machine vision is suggested. Object counting systems using image processing have been applied in a variety of industries for such purposes as measuring floating populations and traffic volume, etc. The methods of object counting mainly used involve template matching and machine learning for detecting and tracking. However, operational time for these methods should be short for detecting objects on quickly moving conveyor belts. To provide this characteristic, this algorithm for image processing is a region-based method. In this experiment, we counted young abalone shells that are similar in shape, size and color. We applied a characteristic conveyor system that operated in one direction. It obtained information on objects in the region of interest by comparing a second frame that continuously changed according to the information obtained with reference to objects in the first region. Objects were counted if the information between the first and second images matched. This count was exact when young shells were evenly spaced without overlap and missed objects were calculated using size information when objects moved without extra space. The proposed algorithm can be applied for various object counting controls on conveyor systems.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.643-646
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• 2003

이 논문은 작업 대상물(object)을 최소 시간으로 interception 하기 위한 방법에 대하여 기술한다. 목표는 로봇이 world coordinate system을 기준으로 x축으로 이동하는 컨베이어 라인 상에서 이동되는 작업 대상물을 intercept 하는 것이다. 컨베이어 시스템이 최소의 시간으로 작업 대상물을 intercept하기 위해서는 다음의 주요 계획이 필요하다. 첫째는 최적의 object과 end effector의 meeting point 선택, 두 번째는 첫 번째 계획이 실효를 이루기 위한 로봇의 trajectory선택이다. 두 가지의 계획 중 여기서는 두 번째 계획이 최적이라고 가정하고 첫 번째 계획법 즉, 컨베이어 시스템 로봇을 이용한 작업 대상물의 gripping 동작을 행함에 있어서 최소 시간으로 작업대상물을 gripping 하기 위한 컨베이어 시스템과 minimum time gripping 알고리즘이 제시된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.653-656
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• 2002

본 논문에서는 연속된 영상 정보를 이용하여 물체를 추적하는 시스템에 대하여 기술한다. 물체를 추적하는 시스템은 물체를 구별하는 단계에서 자동으로 물체를 추적하는 단계로 구성된다. 물체를 구별 하기 위해서는 영상에서 사용자가 원하는 물체를 추출해야 한다. 이를 위해서 여러 가지 전처리 과정을 거쳐서 물체를 추출하고, 물체에 대한 정보를 추출한다. 추출된 정보와 미리 입력된 물체에 대한 정보와 비교하여 사용자가 원하는 물체인지를 구별한다. 사용자가 원하는 물체라고 판단이 될 경우 추적 시스템은 추적 알고리즘을 이용하여 물체를 추적한다. 이 시스템을 평가하기 위해서 본 논문은 conveyor belt에서 물체를 추적, 추적된 물체를 잡는 실험을 하였고 성공적인 결과를 보였다.