• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.62-65
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• 2010

Field robot represented by excavator can be applied for various working in manufacturing, construction, agriculture etc. Because of the flexibility of its multi-joint mechanism and the high power of hydraulic actuators. Since the excavator operates in the hazardous working circumstance, operators exposed in harmful environment. Therefore, automation system has been investigated to protect from the harmful environment. In this paper, the method to construct the remote control system is proposed. The remote control system is consisted of a manual and auto mode. Manual mode controls a hydraulic cylinder as open loop control. and auto mode controls the end effecter of excavator using tracking control system. The efficiency of remote control system was evaluated through the field test.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.688-696
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• 2017

This paper presents an integrated roll-pitch-yaw autopilot using an equivalent based sliding mode control for skid-to-turn nonlinear time-varying missile system with lumped disturbances in its six-equations of motion. The considered missile model are developed to integrate the model uncertainties, external disturbances, and parameters perturbation as lumped disturbances. Moreover, it considers the coupling effect between channels, the variation of missile velocity and parameters, and the aerodynamics nonlinearity. The presented approach is employed to achieve a good tracking performance with robustness in all missile channels simultaneously during the entire flight envelope without demand of accurate modeling or output derivative to avoid the noise existence in the real missile system. The proposed autopilot consisting of a two-loop structure, controls pitch and yaw accelerations, and stabilizes the roll angle simultaneously. The Closed loop stability is studied. Numerical simulation is provided to evaluate performance of the suggested autopilot and to compare it with an existing autopilot in the literature concerning the robustness against the lumped disturbances, and the aforesaid considerations. Finally, the proposed autopilot is integrated in a six degree of freedom flight simulation model to evaluate it with several target scenarios, and the results are shown.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1521-1527
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• 2013

This study proposes a wearable master device that can measure the joint stiffness and the angular displacement of a human operator to enhance the adapting capability of a slave system. A lightweight inertial sensor and the exoskeleton mechanism of the master device can make an operator feel comfortable, and artificial pneumatic muscles having a working principle similar to that of human muscles improve the performance of the slave device on emulating what a human operator does. Experimental results revealed that the proposed master/slave system based on the muscle stiffness sensor yielded uniform tracking performance compared with a conventional position-feedback controller when the payload applied to the slave system changed.

• Journal of Digital Contents Society
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• v.15 no.4
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• pp.473-480
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• 2014

As the use of computer has been popularized these days, an active research is in progress to make much more convenient and natural interface compared to the existing user interfaces such as keyboard or mouse. For this reason, there is an increasing interest toward Microsoft's motion sensing module called Kinect, which can perform hand motions and speech recognition system in order to realize communication between people. Kinect uses its built-in sensor to recognize the main joint movements and depth of the body. It can also provide a simple speech recognition through the built-in microphone. In this paper, the goal is to use Kinect's depth value data, skeleton tracking and labeling algorithm to recognize information about the extraction and movement of hand, and replace the role of existing peripherals using a virtual mouse, a virtual keyboard, and a speech recognition.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.523-525
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• 2004

Over the last few years, the control of bipedal robot has been considered a promising research field in the community of robotics. But the problems we encounter make the control of a bipedal robot a hard task. The complicated link connection of the bipedal robot makes it impossible to achieve its exact model. In addition, the joint velocity is needed to accomplish good control performance. In this paper a control method using ANFIS as an system approximator is purposed. First a model biped robot of a biped robot with switching leg influence is presented. Unlike classical method, ANFIS approximation error estimator is inserted in the system for tuning the ANFIS. In the entire system, only ANFIS is used to approximate the uncertain system. ANFIS tuning rule is given combining the observation error, control error and ANFIS approximation error. But this needs velocity information which is not available. So a practical method is newly presented. Finally, computer simulation results is presented to show this control method has good position tracking performance and robustness without need for leg switching acknowledgement.

• Journal of Welding and Joining
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• v.8 no.2
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• pp.58-69
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• 1990

In conventional arc welding, position error of the weld torch with respect to the weld seam and variation of groove dimension are induced by inaccurate fitup and fixturing. In this study, a vision system has been developed to recognize and compensate the position error and dimensional inaccuracy. The system uses a structured laser light illuminated on the weld groove and perceived by a C.C.D camera. A new algorithm to detect the edge of the reflected laser light is introduced for real time processing. The developed system was applied to arbitarary weld paths with various types of joint in arc welding process. The experimental results show that the proposed system can detect the weld groove parameters within good accuracy and yield good tracking performance.

• 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.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.1 s.307
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• pp.13-20
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• 2006

In this paper, we propose a motion control scheme of robot manipulators based on visual feedback under camera-in-hand configuration. The desired joint velocity and acceleration for motion control is made by the feature-based visual data in the outer loop. The control input for tracking feature points on the image plane uses robot kinematics dynamic. The proposed control input consists of the image feature and the joint velocity error to achieve robustness to the parametric uncertainty. The stability of the closed-loop system is proved by Lyapunov approach. Computer simulations and experiments on a two degree of freedom manipulator with 5 links are presented to illustrate the performance of proposed control system.

• Physical Therapy Korea
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• v.31 no.1
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• pp.72-78
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• 2024

Background: Limitations of shoulder range of motion (ROM), particularly shoulder internal rotation (SIR), are commonly associated with musculoskeletal disorders in both the general population and athletes. The limitation can result in connective tissue lesions such as superior labrum tears and symptoms such as rotator cuff tears and shoulder impingement syndrome. Maintaining the center of rotation of the glenohumeral joint during SIR can be challenging due to the compensatory scapulothoracic movement and anterior displacement of the humeral head. Therefore, observing the path of the instantaneous center of rotation (PICR) using the olecranon as a marker during SIR may provide valuable insights into understanding the dynamics of the shoulder joint. Objects: The aim of the study was to compare the displacement of the olecranon to measure the rotation control of the humeral head during SIR in individuals with and without restricted SIR ROM. Methods: Twenty-four participants with and without restricted SIR ROM participated in this study. The displacement of olecranon was measured during the shoulder internal rotation control test (SIRCT) using a Kinovea (ver. 0.8.15, Kinovea), the 2-dimensional marker tracking analysis system. An independent t-test was used to compare the horizontal and vertical displacement of the olecranon marker between individuals with and without restricted SIR ROM. The statistical significance was set at p < 0.05. Results: Vertical displacement of the olecranon was significantly greater in the restricted SIR group than in the control group (p < 0.05). However, no significant difference was observed in the horizontal displacement of the olecranon (p > 0.05). Conclusion: The findings of this study indicated that individuals with restricted SIR ROM had significantly greater vertical displacement of the olecranon. The results suggest that the limitation of SIR ROM may lead to difficulty in rotation control of the humeral head.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1219-1224
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• 2007

This is Presents experimental results of a force tracking controller for a quarter-car suspension system. The active suspension system was decomposed into two loops. At the main loop, the desired force signal is calculate by using a standard LQ design process. The Time Delay Control(TDC) design technique is then used to design the force controller such that the desired force signal is achieved in a robust manner when actuator or other plant uncertainties are present. The ADAMS controls module was used to realize the joint simulation of ADAMS and MATLAB, of which the results showed that the TDC strategy is reasonable and feasible.