• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.839-843
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• 2001

For robotic endoscope, some researchers suggest pneumatic actuators based on inchworm motion. But, the existing endoscopes are not seemed to be replaced completely because human intestine is very sensitive and susceptible to damage. We design and test a new locomotion of robotic endoscope able to maneuver safely in the human intestine. The actuating mechanism is composed of two solenoids at each side and a single permanent magnet. When the current direction is reversed, repulsive force and attractive at the opposition side propels permanent magnet. Impact force against robotic endoscope transfer momentum from moving magnet to endoscope capsule. The direction and moving speed of the actuator can be controlled by adjusting impact force. Modeling and simulation experiments are carried out to predict the performance of the actuator. Simulation experiments show that force profile of permanent magnet is the dominant factor for the characteristic of the actuator. The results of simulations are verified by comparing with the experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.743-747
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• 2000

The coordinated mechanism of terrestrial vertebrates enables them to maneuver over all of the terrain conditions since they have a distinct ability to adapt to varying conditions. Their locomotions remain infinitely more advanced and elegant than that of present-day existing mechanical walking robots. However, the principles of existing walking robots are based more on technical rather than on biological concepts, yielding unstable locomotion with low speed. In order to apply these advanced biological phenomena to the mechanical design of 4-legged walking robot, modeling methods are introduced and mathematical equations are also introduced.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.6
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• pp.743-754
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• 2015

FASCAM is a newly introduced mean against enemy fire power and supposed to be scattered on base areas in front of a tunnel so as to deter maneuver and shooting of enemy artilleries. However, for its characteristics different from conventional munitions, only a few studies have been undertaken on operations system using this new measure. In this research, we propose a procedure to describe and analyze mathematically an operation system for suppression of enemy fire power using FASCAM. Two suggested simulation methods, impact point generation and density integration, both can describe the actual operation rationally and each has advantages of its own respectively. Further, we demonstrated an example analysis to derive an optimal suppression plan based on the proposed procedure.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.7-17
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• 2006

Depth and heading control of an AUV are considered to follow the predetermined depth and heading angle. The proposed control algorithm is designed. based on a sliding mode control using estimated hydrodynamic coefficients. The hydrodynamic coefficients are estimated with conventional nonlinear observer techniques, such as sliding mode observer and extended Kalman filter. By using the estimated coefficients, a sliding mode controller is constructed for the combined diving and steering maneuver. The simulation results of the proposed control system are compared with those of control system with true coefficients. This paper demonstrates the proposed control system, discusses the mechanisms that make the system stable and follows the desired depth and heading angle, accurately, in the presence of parameter uncertainty.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.141.6-141
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• 2001

This paper presents the attitude algorithm using Fuzzy technique to mix gyro information with accelerometer. The attitude angle calculated by the low-cost gyros only increases its error with time rapidly because of the integration process of the algorithm and large sensor error. It is known that the accelerometer output includes the attitude information of a vehicle and its information is more effective during low dynamic maneuver. Therefore it is needed to combine two information appropriately for obtaining the attitude information from low-cost MEMS inertial sensors. Because Fuzzy logic is very effective to make a decision of maneuvering state, it is applied to the mixed algorithm. It is shown by experiment ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.90-90
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• 2001

This paper deals with the development of a practical control system or an algorithm for optimal aerobatic maneuvers and aerial combat maneuvers. First, a nonlinear flight trajectory tracking control system is synthesized and used to realize the optimal aerobatic maneuver. Some simulation results show that the trajectory achieved with the proposed tracking system is close to the optimal one. This means that the tracking system presented is the practical and effective method to realize the optimal aerobatic maneuvers. Second, the algorithm for a fighter in air combat is presented. This is a simple algorithm that uses a proportional navigation, some dynamic rules based on the conservation of specific energy and some experiential rules in air combat. However ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.156.1-156
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• 2001

It is observed that if the 2-gimballed seeker is stabilized using rate gyros mounted along its primary axis, line of sight change measured in the seeker is induced by the rolling due to the bank-to-turn(BTT) steering as well as the actual change. This body-coupling within BTT homing includes the spurious target maneuver effect and the coupling loop due to the rate gyro misalignment. In this paper we formulates the linear BTT homing loop model with a 2-gimballed seeker including those body-coupling effects. With the model, we analyze the effects of the couplings, and show that the roll rate coupling to the rate gyro for the stabilztion of gimbal could seriously deteriorate the homing loop stability. And we propose a direct linear compensator for the coupling to recover the stability.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.973-980
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• 1988

This two-part paper presents a control method that allows for stable interaction of a robot manipulator with the environment. In part 1, we focus on the input ouput relationships (unstructured modeling) of the robot and environment dynamics. This analysis leads to a general condition for stability of the robot and environment taken as a whole. This stability condition, for stable maneuver, prescribes a finite sensitivity for robot and environment where sensitivity of the robot(or the environment) is defined as a mapping forces into displacement. According to this stability condition, smaller sensitivity either in robot or in environment leads to narrower stability range. In the limit, when both systems have zero sensitivity, stability cannot be guaranteed. These models do not have any particular structure, yet they can model a wide variety of industrial and research robot manipulators and environment dynamic behavior. Although this approach of modeling may not lead to any design procedure, it will allow us to understand the fundamental issues in stability when a robot interacts with an environment.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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• pp.346-352
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• 2010

This paper presents an intuitive interface scheme for controlling a hydraulic backhoe, which is a piece of excavating equipment consisting of a digging bucket on the end of a two-part articulated arm, and typically mounted and rotated on the back of a tractor or front loader. The passive levers/joysticks for actuator operations of a hydraulic backhoe are replaced into electric joysticks with a robotic controller, which will generate the end-effecter command trajectories of the backhoe through joystick rate control in cylindrical coordinate. The developed backhoe with the hydraulic control system showed the maxim position error of 3 cm with intuitive coordinate operations, which would be helpful for conveniently performing various excavating tasks with natural and effective ways.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.1
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• pp.105-114
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• 2007

This article presents the details of a designed control moment gyroscope (CMG) with a constant speed momentum wheel and one-axis-gimbal, and its experimental results performed at Korea Aerospace Research Institute. The CMG which is able to produce a torque of lOO mNm per each, is mounted in a pyramid configuration with four SGCMGs. Each CMG test and a single axis maneuver test with four-CMG cluster configuration are performed to confirm their performance on a ground-test facilities consisted of three major parts: a vibration isolation system, a dynamic force plate (Kistler sensor), and a DSP board. These facilities provide the accurate data of three axial and torques from the control moment gyro. Details of the CMG experimental results are presented with discussion of the experimental errors. The experimental data are compared with theoretical results and both results are used to verify their performance specifications.