• Journal of the Korea Society of Computer and Information
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• v.26 no.5
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• pp.9-16
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• 2021

In this paper, we propose a building exploration drone that can be used for a digital twin-based building control system. The existing building control system using a fixed position sensor box has a problem that a management blind spot occurs. And because people patrol themselves, it takes a lot of human resources. In this paper, a drone equipped with a temperature and humidity sensor and a gas leak detection sensor is used to search the internal path of the building centering on the control blind spot. It also aims to solve the problem of the building control system by transmitting information in real time along with the video. In addition, it has a stable hovering function using an optical floor sensor and can be applied to an existing digital twin-based building control system. The results of this study are believed to be of great help in improving the quality of digital twin control systems using drones.

• The Journal of Korea Robotics Society
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• v.9 no.3
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• pp.154-159
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• 2014

The Global Positioning System (GPS) is widely used to aid the navigation of aerial vehicles. However, the GPS cannot be used indoors, so alternative navigation methods are needed to be developed for micro aerial vehicles (MAVs) flying in GPS-denied environments. In this paper, a real-time three-dimensional (3-D) indoor navigation system and closed-loop control of a quad-rotor aerial vehicle equipped with an inertial measurement unit (IMU) and a low-cost light detection and ranging (LIDAR) is presented. In order to estimate the pose of the vehicle equipped with the two-dimensional LIDAR, an octree-based grid map and Monte-Carlo Localization (MCL) are adopted. The navigation results using the MCL are then evaluated by making a comparison with a motion capture system. Finally, the results are used for closed-loop control in order to validate its positioning accuracy during procedures for stable hovering and waypoint-following.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.1
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• pp.21-27
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• 2015

A conventional fire detection has been developed based on images captured from a fixed camera. However, It is difficult to apply current algorithms to a flying Quad-rotor to detect fire. To solve this problem, we propose that the fire detection algorithm can be modified for Quad-rotor using Ego-motion compensation. The proposed fire detection algorithm consists of color detection, motion detection, and fire determination using a randomness test. Color detection and randomness test are adapted similarly from an existing algorithm. However, Ego-motion compensation is adapted on motion detection for compensating the degree of Quad-rotor's motion using Planar Projective Transformation based on Optical Flow, RANSAC Algorithm, and Homography. By adapting Ego-motion compensation on the motion detection step, it has been proven that the proposed algorithm has been able to detect fires 83% of the time in hovering mode.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.343-352
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• 2016

A multi-rotor vehicle is an unmanned vehicle consisting of multiple rotors. A multi-rotor vehicle can be categorized as tri-, quad-, hexa-, and octo-rotor depending on the number of the rotors. Multi-rotor vehicles have many advantages due to their agile flight capabilities such as the ability for vertical take-off, landing and hovering. Thus, they can be widely used for various applications including surveillance and monitoring in urban areas. Since multi-rotors are subject to uncertain environments and disturbances, it is required to implement robust attitude stabilization and flight control techniques to compensate for this uncertainty. In this research, an advanced nonlinear control algorithm, i.e. sliding mode control, was implemented. Flight experiments were carried out using an onboard flight control computer and various real-time autonomous attitude adjustments. The feasibility and robustness for flying in uncertain environments were also verified through real-time tests based on disturbances to the multi-rotor vehicle.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.9
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• pp.81-90
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• 2016

Recently drones have become popular enough to be one of the hobby. The drone refers to an unmanned aerial vehicle which can fly and be steered by a radio wave without a pilot and it has a airplane or helicopter shape. The drone was first started to be used from military purpose, but its usage has been expanded to the private such as construction site, crop-dusting, field discovery, freight shipping and drones to prevent cheating. However the drone that we can see often in the market is expansive, hard to be repaired when it broken down and has a discomfort of the short flight time. In this paper, to solve an uncomfortable talk on the cheap 8-bits microcontrollers ATmega128 Using drone for implementation. Axes gyroscope and accelerometers mcu between posture an attitude control, communications through drone control, pid. Receiver input them into transmitter signals of movements to control drone c the programming was implemented in on the basis of language. drone using ATmega128 microcontroller is possible hovering, By utilizing a pin that are not required for control it can be used as a drone for a variety of uses.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.47-59
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• 2014

This paper deals with a vision-based trajectory tracking control system for a quadrotor-type UAV for entertainment purpose in indoor environment. In contrast to outdoor flights that emphasize the autonomy to complete special missions such as aerial photographs and reconnaissance, indoor flights for entertainment require trajectory following and hovering skills especially in precision and stability of performance. This paper proposes a trajectory tracking control system consisting of a motion generation module, a pose estimation module, and a trajectory tracking module. The motion generation module generates a sequence of motions that are specified by 3-D locations at each sampling time. In the pose estimation module, 3-D position and orientation information of a quadrotor is estimated by recognizing a circular ring pattern installed on the vehicle. The trajectory tracking module controls the 3-D position of a quadrotor in real time using the information from the motion generation module and pose estimation module. The proposed system is tested through several experiments in view of one-point, multi-points, and trajectory tracking control.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.9
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• pp.88-93
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• 2003

This Paper described the simulation program development for helicopter. In the design of flight control system to accomplish some special missions like UAV, it is important to minimize the execution time obtaining a linear model from nonlinear model that is used for design of controller. The first step for this kind of purpose is to complete a nonlinear model that contains full dynamic characteristics. The second step is to get the trim values that are obtained from the nonlinear model by solving an algebraic equation. And then stability and control derivatives are derived through hovering to forward flight by numerical perturbation that will be used for linear model for a specified flight condition. The software program(HeliSim) is developed by using MATLAB GUI and will provide easy modeling procedure. The suggested method in this paper is much more simpler than any other method like a fully scale helicopter model. The advantage of our suggested method will reduce the computational time due to simple formula to extract a linear model from nonlinear model that will be beneficially used for flight control system of unmanned helicopter by some reduction of computational load.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1561-1567
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• 2013

This paper is regarding the helicopter flight control law design for the handling quality performance. MIL-F-83300 and ADS-33E specification is used of the helicopter flight handling quality and to meet these requirements, ACAH type controller is required. This paper described the ACAH type controller design and performance evaluations. Helicopter dynamics first developed as nonlinear dynamics including rotor dynamics and then linear model was extracted from hovering to forward flight mode using trim condition. Control law used the model following to meet the handling qualities, the simple inverse model as feed forward gain, decoupling logic and phase model to decouple the axes, and linear model to calculate the coefficients. Handling quality evaluation used the matlab based Conduit tool and verified that Level 1 requirement is satisfied.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.329-334
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• 2021

Korean Air has set the goal of the first stage of the development of unmanned helicopters to perform in hovering flight by remote control. In order to achieve the development goal, Korean Air carried out system integration, ground test, and safety wire test in sequence after carrying out programmed depot maintenance and aircraft modification of manned aircraft, and verified the controllability and flight safety of the unmanned helicopter system step by step. In particular, it was confirmed that the safety wire test technique used in the final stage of verification was an effective method to verify flight safety and controllability for a fully unmanned helicopter system.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.171-178
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• 2017

In this paper, in order to verify the performance of a localization algorithm using GPS as an auxiliary sensor, the algorithm was applied to a hovering-type autonomous underwater vehicle (AUV) to perform a field test. The applied algorithm is an algorithm to improve the accumulated positional error of dead reckoning using doppler velocity logger(DVL) and tilt-compensated compass module (TCM) mounted on the AUV. GPS when surfaced helps the algorithm to estimate the position and the heading bias error of TCM for geodetic north, which makes it possible to perform dead reckoning on north-east-down (NED) coordinates. As a result of field test performing heading control, it was judged that the algorithm could improve the positional error, enhance the operational capability of AUV and contribute to the research of underwater navigation depending on a magnetic compass.