• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.153-160
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• 1998

A master-slave system for tele-operation had been developed and tested for several decades. In this paper the master robot is composed of several wires and provides position information of the handle which is driven by a operator within the master robot work space. A PC is used for the command calculation for a slave robot. This paper deals with the relation between the number of strings and D.O.F of the master robot, control method of the slave robot during the operation and the monitoring method over the working area by the computer graphics simulation. The D.O.F of the master robot can be modified by adding or subtracting some strings. The controller of the slave robot uses the advanced PD control method to keep the performance against varying working load.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.1-7
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• 2000

In this paper, an adaptive control law for nonlinear systems represented by input-output models are proposed under the assumption that unknown system parameters are in a known compact and convex set. Contrary to the previous results, the compact and convex set is not restricted to a ball whose center is at the origin or convex hypercube. It is proven that the proposed parameter update rule produces a sequence of parameters which reside in the set and guarantees that the position, velocity, and acceleration error converges to zero as time goes to infinity. This theoretical result was justified through simulations.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.41.4-41
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• 2002

In this paper we deal with visual servoing that can control a robot arm with a camera using information of images only, without estimating 3D position and rotation of the robot arm. Here it is assumed that the robot arm is calibrated and the camera is uncalibrated. Here we consider two coordinate systems, the world coordinate system and the camera coordinate one and we use a pinhole camera model as the camera one. First of all, the essential notion can be show, that is, epipolar geometry, epipole, epipolar equation, and epipolar constrain. And these plays an important role in designing visual servoing in the later chapters. Statement of the problem is giver. Provided two a priori...

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.100.1-100
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• 2002

In this paper, we present autonomous mobile robot system, which has an image recognition module and perform tasks by itself with manipulator. Autonomous mobile robot can push each individual button on an elevator panel from a person's command. After the robot receives its command, it analyzes the image information of the elevator button that is acquired by CCD camera in an indoor environment with an elevator. In order to recognize the numbers on the button, the robot separates the number area in button and recognizes the segment through a neural network algorithm. We use the bar code form on the manipulator to find the position of the end of manipulator. The validity of the proposed method i...

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.406-409
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• 1997

An economical 4-axis CNC controller employing step motors is designed and implemented in this paper. By using the inherent ability of holding position of the motor, the CNC controller uses open-loop control for removing trajectory error and for a simple hardware. Each drive of axis has an 8-bit microprocessor 89C52 and a PC controls the axes and pendant by means of RS232C serial communication. Backlash is also compensated at the axis controller. While compensating the backlash, the feed rate becomes zero in order to minimize trajectory error. The trajectories of 16ms interval are computed on PC and are sent to motor drives. In the drives, the trajectories are linearly interpolated for 2ms interval. The developed CNC does not require add-on specific motion card on PC. From the experimental results, the validity of the CNC controller based on step motor is proved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.150-153
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• 1997

In this paper, a control and data analysis S/W of a dedicated measuring machine for cams is developed. A rotary encoder is employed to measure the angular displacement of the motor, and a linear scale does the linear displacement of the prove. The design and measuring data are interpolated by cubic spline curves respectively to compute the error which is defined by the maximum distance between two curves. Further, optimization module to find the exact error is also developed to remove the error occurred due initial measuring position. The developed system takes only 6 minutes to measure the cam and to analyze the measuring data while the CMM takes about 1 hours even with a skilled operator.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.524-532
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• 2002

This paper presents a new in-flight alignment method for an SDINS under large initial heading error. To handle large heading error, a new attitude error model is introduced. The attitude errors are divided into heading error and leveling errors using a newly defined horizontal frame. Some navigation error dynamic models are derived from the attitude error model for indirect feedback filtering of the in-flight alignment system. A Kalman filter with Position measurement is designed to estimate navigation errors as the indirect feedback filter Simulation results show that the proposed in-flight alignment method reduces the heading error very quickly from more than 40deg to about 5deg so as to apply a refined navigation filter. The total alignment process including leveling mode and navigation mode in addition to the proposed one allows large initial values not only in heading error but also in leveling errors.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.9
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• pp.898-903
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• 2008

In most cases, the trajectory of a ballistic missile is well explained by the Kepler's laws. It implies that the remaining trajectory of the ballistic missile including its final destination can be easily predicted if the position and velocity vector of the ballistic missile at any point on its path can be exactly known. Hence, an effective tracking algorithm based on an exact radar measurement model is very important for developing Ballistic Missile Defense(BMD) system. In this paper, we address to design a nonlinear filter, Unscented Kalman Filter(UKF), to track the ballistic missile.

• International Journal of Control, Automation, and Systems
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• v.6 no.3
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• pp.434-443
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• 2008

This paper develops a novel automatic parking algorithm based on a fuzzy logic controller with the vehicle pose for the input and the steering rate for the output. It localizes the vehicle by using only external sensors - a vision sensor and ultrasonic sensors. Then it automatically learns an optimal fuzzy if-then rule set from the training data, using an evolutionary fuzzy system. Furthermore, it also finds the green zone for the ready-to-reverse position in which parking is possible just by reversing. It has been tested on a 4-wheeled Pioneer mobile robot which emulates the real vehicle.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.974-978
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• 2013

AVI (Automatic Vision Inspection) systems automatically detect defect features and measure their sizes via camera vision. AVI systems usually report different measurements on the same defect with some variations on position or rotation mainly because different images are provided. This is caused by possible variations from the image acquisition process including optical factors, nonuniform illumination, random noises, and so on. For this reason, conventional area based defect measuring methods have problems of robustness and consistency. In this paper, we propose a new defect size measuring method to overcome this problem, utilizing volume information that is completely ignored in the area based defect measuring method. The results show that our proposed method dramatically improves the robustness and consistency of defect size measurement.