• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.404-414
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• 2016

Autonomy of unmanned systems is important because the unmanned system with high level of autonomy is able to perform desired tasks in unstructured environments without continuous human guidance. Evaluation of their autonomy is vital to realize the autonomous operation ability of unmanned system. Compared to the methods of evaluating the level of autonomy(LOA) for an unmanned ground vehicle(UGV) and unmanned aerial vehicle(UAV), the method of expressing the LOA of unmanned maritime system(UMS) is not established yet. Since UMS has a unique characteristics in terms of operational area, mission complexity and required technologies, compared to the UGV and UAV, it is required to establish for expressing the LOA for UMS. This paper reviews the current approaches to assess the LOA of unmanned system and proposes potential metrics for UMS in order to determine the autonomy levels of UMS.

• Advances in aircraft and spacecraft science
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• v.6 no.5
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• pp.371-389
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• 2019

The implementation of a robust $H_{\infty}$ Control, which is numerically efficient for uncertain nonlinear dynamics, on longitudinal and lateral autopilots is realised for a quarter scale Piper J3-Cub model accepted as an unmanned aerial vehicle (UAV) under the condition of sensor noise and disturbance effects. The stability and control coefficients of the UAV are evaluated through XFLR5 software, which utilises a vortex lattice method at a predefined flight condition. After that, the longitudinal trim point is computed, and the linearization process is performed at this trim point. The "${\mu}$-Synthesis"-based robust $H_{\infty}$ control algorithm for roll, pitch and yaw displacement autopilots are developed for both longitudinal and lateral linearised nonlinear dynamics. Controller performances, closed-loop frequency responses, nominal and perturbed system responses are obtained under the conditions of disturbance and sensor noise. The simulation results indicate that the proposed control scheme achieves robust performance and guarantees stability under exogenous disturbance and measurement noise effects and model uncertainty.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.269-276
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• 2015

Unmanned Aerial Vehicle (UAV) has several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly. And with a comparatively lower flight altitude, they can obtain good quality images even in cloudy weather. In this paper, we discussed the state-of-the-art of the domestic and international use of UAV in agricultural sector as well as assessed its utilization and applicability for agricultural environment in Korea. Association of robotic, computer vision and geomatic technologies have established a new paradigm of low-altitude aerial remote sensing that has now been receiving attention from researchers all over the world. In a field study, it has been found that use of UAV imagery in an agricultural subsidy program can reduce the farmers' complain and provide objective evidence. UAV high resolution photography can also be helpful in monitoring the disposal zone for animal carcasses. Due to its expeditiousness and accuracy, UAV imagery can be a very useful tool to evaluate the damage in case of an agricultural disaster for both parties insurance companies and the farmers. Also high spatial and temporal resolution in UAV system can increase the prediction accuracy which in turn help to maintain the agricultural supply and demand chain.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.50-55
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• 2017

The objective of this study was to use the Lanchester equation to predict the outcome of our engagement between our unmanned aerial vehicle (UAV) (Blue Group) and enemy UAV (Red Group). Lanchester's law states that the power of corps is proportional to the number of combatants. A second law states that the power of corps is proportional to the square of the number of combatants. The first law is a suitable law for guerrilla warfare while the second law is known as the law suitable for all-out war. Therefore, the second law is commonly used. The second law of Lanchester's was used in this study to predict engagement results. We estimated the battle loss rate value to win the battle as well as the required power number. We also predicted power number to make the damage of our group less than one. The battle loss rate to reliably receive victory when the enemy's UAV and the ally's UAV are equal in number of combat units must be 1: 1.5 or more.

• The Journal of Korea Robotics Society
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• v.11 no.4
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• pp.262-269
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• 2016

Flight of an autonomous unmanned aerial vehicle (UAV) generally consists of four steps; take-off, ascent, descent, and finally landing. Among them, autonomous landing is a challenging task due to high risks and reliability problem. In case the landing site where the UAV is supposed to land is moving or oscillating, the situation becomes more unpredictable and it is far more difficult than landing on a stationary site. For these reasons, the accurate and precise control is required for an autonomous landing system of a UAV on top of a moving vehicle which is rolling or oscillating while moving. In this paper, a vision-only based landing algorithm using dynamic gimbal control is proposed. The conventional camera systems which are applied to the previous studies are fixed as downward facing or forward facing. The main disadvantage of these system is a narrow field of view (FOV). By controlling the gimbal to track the target dynamically, this problem can be ameliorated. Furthermore, the system helps the UAV follow the target faster than using only a fixed camera. With the artificial tag on a landing pad, the relative position and orientation of the UAV are acquired, and those estimated poses are used for gimbal control and UAV control for safe and stable landing on a moving vehicle. The outdoor experimental results show that this vision-based algorithm performs fairly well and can be applied to real situations.

• Journal of Korea Multimedia Society
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• v.24 no.10
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• pp.1346-1357
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• 2021

The drone technology, which is receiving a lot of attention due to the 4th industrial revolution, requires an Unmanned Aerial Vehicles'(UAVs) flight path search algorithm for automatic operation and driver assistance. Various studies related to flight path prediction and recommendation algorithms are being actively conducted, and many studies using the A-Star algorithm are typically performed. In this paper, we propose an Optimal 3D Flight Path Recommendation System for unmanned aerial vehicles. The proposed system was implemented and simulated in Unity 3D, and by indicating the meaning of the route using three different colors, such as planned route, the recommended route, and the current route were compared each other. And obstacle response experiments were conducted to cope with bad weather. It is expected that the proposed system will provide an improved user experience compared to the existing system through accurate and real-time adaptive path prediction in a 3D mixed reality environment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.9
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• pp.800-806
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• 2012

This paper proposes design and development of the Integrated Ground Support System (IGSS) for the flight test of the Unmanned Aerial Vehicle (UAV), which combines ground support and ground control. The integrated flight test of the UAV is a necessary procedure to validate the functionality of the Unmanned Aerial System (UAS). In order to execute cost-effective and systematic flight tests, the IGSS is regarded as an inevitable infrastructure of UAS for small laboratories. The proposed IGSS has functions of ground control, radio communication, power generation, transportation and the maintenance of the UAV.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.47.6-47
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• 2002

UAV(Unmanned Aerial Vehicle) has become one of the most popular military/commercial aerial robots in the new millenium. In spite of all the advantages that UAVs inherently have, it is not an easy job to develop a UAV because it requires very systematic and complete approaches in full development envelop. The ground test & evaluation phase has the utmost importance in the sense that a well developed system can be best verified on the ground. In addition, many of the aircraft crashes in the flight tests were resulted from the incomplete development procedure. In this research, a verification procedure of the whole airborne integrated system was conducted including the flight management sys...

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.675-683
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• 2018

In this paper, we have proposed a design and verification methods of electrical system and power loads for unmaned aeriel vehicles(UAVs) through electrical load analysis. In order to meet a UAV system requirement and electrical system specifications, we have designed an electrical power system for efficient power supply and distribution and have theoretically analyzed the power loads according to the power consumption and power bus design of UAV. Using electrical system rig, the designed electrical power system has been experimentally verified. Also, we have performed several flight tests to verify the UAV electrical system and power loads. It is concluded that the proposed design and verification method of electrical system for UAV system.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.331-337
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• 2024

Mission autonomy system should be embedded on UAV (unmanned aerial vehicle) for mosaic warfare where UAVs autonomously assign tasks to themselves. UxAS (unmanned x-systems autonomy service) proposed by Air force research laboratory is mission autonomy system for unmanned platforms. UxAS has extensible structure composed of numerous module services. We have developed mission autonomy system based on UxAS that performs mission allocation and path planning. In this paper, We present a method of analyzing and evaluating the mission autonomy software according to the performance evaluation index.