• Journal of Mechanical Science and Technology
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• v.14 no.7
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• pp.782-788
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• 2000

In this paper, we present a new approach to visual feedback control using image-based visual servoing with stereo vision. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only around a desired location but also at other locations. The suggested technique can guide a robot manipulator to the desired location without providing a priori knowledge such as the relative distance to the desired location or the model of an object even when the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by experimental results and compared with conventional control methods for an assembly robot.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.82-89
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• 2015

This study proposes a new approach to design and control for autonomous mobile robots. In this paper, we describes a fuzzy logic based visual servoing system for an autonomous mobile robot. An existing system always needs to keep a moving object in overall image. This mes difficult to move the autonomous mobile robot spontaneously. In this paper we first explain an autonomous mobile robot and fuzzy logic system. And then we design a fuzzy logic based visual servoing system. We extract some features of the object from an overall image and then design a fuzzy logic system for controlling the visual servoing system to an exact position. We here introduce a shooting robot that can track an object and hit it. It is illustrated that the proposed system presents a desirable performance by a computer simulation and some experiments.

• Journal of Power System Engineering
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• v.6 no.1
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• pp.96-101
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• 2002

In this paper, we address the problem of controlling an end-effector to track and grab a moving target using the visual servoing technique. A visual servo mechanism based on the image-based servoing principle, is proposed by using visual feedback to control an end-effector without calibrated robot and camera models. Firstly, we consider the control problem as a nonlinear least squares optimization and update the joint angles through the Taylor Series Expansion. And to track a moving target in real time, the Jacobian estimation scheme(Dynamic Broyden's Method) is used to estimate the combined robot and image Jacobian. Using this algorithm, we can drive the objective function value to a neighborhood of zero. To show the effectiveness of the proposed algorithm, simulation results for a six degree of freedom robot are presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.316-320
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• 2003

This paper introduces an autonomous underwater vehicle (AUV) model, ASUM, equipped with a visual servo control system to dock into an underwater station with a camera and motion sensors. To make a visual servoing AUV, this paper implemented the visual servo control system designed with an augmented state equation, which was composed of the optical flow model of a camera and the equation of the AUV's motion. The system design and the hardware configuration of ASUM are presented in this paper. ASUM recognizes the target position by processing the captured image for the lights, which are installed around the end of the cone-type entrance of the duct. Unfortunately, experiments are not yet conducted when we write this article. The authors will present the results for the AUV docking test.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.763-768
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• 1999

The space variant imaging system which mimics the human beings visual system has some merits such as wide field-of-view, the low computational cost and the high accuracy in matching of correspondence points of stereo images. In this presentation, a visual servoing system based on the space variant imaging technique is proposed for the control of the rehabilitation robot arm. The position information of an object obtained by space variant imaging techniques is used for the visual servoing. According to the empirical data, the degree of correlation extracted by the space variant imaging technique is more accurate than that of the space invariant imaging technique.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.1
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• pp.42-46
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• 2012

A simple and accurate depth estimation algorithm for an IBVS (Image-Based Visual Servoing) is presented. Specifically, this algorithm is useful for under-actuated systems such as visual-guided quadrotor UAVs (Unmanned Aerial Vehicles). Since the image of a marker changes with changing pitch and roll angles of quadrotor, it is difficult to estimate depth. The proposed algorithm compensates a shape of the marker, so that the system acquire more accurate depth information without complicated processes. Also, the roll and pitch channels are decoupled so that the IBVS algorithm can be used in an under-actuated quadrotor system.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2312-2314
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• 1998

To improve the visual servoing performance, several strategies were proposed in the past such as redundant feature points, using a point with different height and weighted selection of image features. The performance of these visual servoing methods depends on the configuration between the camera and object. And redundant feature points require much computation efforts. This paper proposes the visual servoing m based on the disturbance observer, which compe the upper off-diagonal component of image fe Jacobian to be null. The performance indices su sensitivity for a measure of richness, sensitiv the control to noise, and controllability are sho improved when the image feature Jacobian is giv a block diagonal matrix. Computer simulation carried out for a PUMA560 robot and show results to verify the effectiveness of the pro method.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3077-3079
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• 1999

A visual servoing method has been proposed based on disturbance observer to eliminate the effect of the off-diagonal component of image feature Jacobian, since performance indices such as measurement sensitivity of visual features, sensitivity of the control to noise and controllability could be improved when an image feature Jacobian was given as a block diagonal matrix. In this paper, experimental results of disturbance observer-based visual servoing are discussed where Samsung FARAMAN-ASl 6-axis industrial robot manipulator is employed. Also, the feature saturator is proposed to stabilized the disturbance observer loop by saturating the differential changes of the image features.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1771-1772
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• 2007

The purpose of this project is to develop the visual servoing system with 5d.o.f robot manipulator. For this, we developed robot manipulator by using 5 serial RC motors and the visual system is also developed by using low cost USB CCD camera. RISC MPU ATMEGA128 is main controller MPU for the robot manipulator. To control the manipulator Kinematics was analyzed and GUI, API for vision system also were developed.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.989-994
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• 2011

This study aims to demonstrate the feasibility of a visual servoing-based paired structured light (SL) robot for estimating structural displacement under various external loads. The former paired SL robot, which was proposed in the previous study, was composed of two screens facing with each other, each with one or two lasers and a camera. It was found that the paired SL robot could estimate the translational and rotational displacement each in 3-DOF with high accuracy and low cost. However, the measurable range is fairly limited due to the limited screen size. In this paper, therefore, a visual servoing-based 2-DOF manipulator which controls the pose of lasers is introduced. By controlling the positions of the projected laser points to be on the screen, the proposed robot can estimate the displacement regardless of the screen size. We performed various simulations and experimental tests to verify the performance of the newly proposed robot. The results show that the proposed system overcomes the range limitation of the former system and it can be utilized to accurately estimate the structural displacement.