• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.12
• /
• pp.981-988
• /
• 2021

This paper presents a decentralized guidance algorithm for swarm flight of fixed-wing UAVs (Unmanned Aerial Vehicles). Considering swarm flight missions, we assume four representative swarm tasks: gathering, loitering, waypoint/path following, and individual task. Those tasks require several distinct maneuvers such as path following, flocking, and collision avoidance. In order to deal with the required maneuvers, this paper proposes an integrated guidance algorithm based on vector field, augmented Cucker-Smale model, and potential field methods. Integrated guidance command is synthesized with heuristic weights designed for each guidance method. The proposed algorithm is verified through flight tests using up to 19 small fixed-wing UAVs.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.12
• /
• pp.971-980
• /
• 2021

Recently popularized drone technologies have revealed that low-cost small unmanned aerial vehicles(UAVs) can be a significant threat to prevailing power by operating in group or in swarms. Researchers in many countries have tried to utilize integrated swarm unmanned aerial system(SUAS) in the battlefield. Agency for Defense Development also identified four core technologies in developing SUAS: swarm control, swarm network, swarm information, and swarm collaboration, and the authors started researches on swarm control and network technologies in order to be able to operate vehicle platforms as the first stage. This paper introduces design and integration of SUAS consisting of small fixed-wing UAVs, swarm control and network algorithms, a ground control system, and a launcher, with which swarm control and network technologies have been verified by flight tests. 19 fixed-wing UAVs succeeded in swarm flight in the final flight test for the first time as a domestic research.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.5
• /
• pp.433-438
• /
• 2012

In this paper, a operation network system equipped with onboard wireless communication systems and ground-based mission control systems is proposed for swarm flight of small UAVs. This operating system can be divided into two networks, UAV communication network and ground control system. The UAV communication network is intend to exchange the informations of navigation, mission and flight status with minimum time delay. The ground control system consisted of mission control systems and UDP network. Proposed operation network system can make a swarm flight of various UAVs, execute complex missions decentralizing mission to several UAVs and cooperte several missions. Finally, PILS environments are developed based on the total operating system.

• Aerospace Engineering and Technology
• /
• v.13 no.1
• /
• pp.153-165
• /
• 2014

Multi-rotor UAVs are utilized in various fields because of the advantages such that a hovering capability such as helicopters, a simple structure and a relatively high thrust. Recently, AR.Drone manufactured by Parrot is easily operated by beginner due to its internal stabilization loop in the on-board computer and it can be easily applied on various researches for the multi-rotor UAVs by providing an SDK(Software Development Kit). Further this platform can be suitably used for application to swarm flight since it is low cost and relatively small. Therefore, in this paper, we introduce the development process of the controller for indoor swarm flight by using the AR.Drone.

• Aerospace Engineering and Technology
• /
• v.13 no.1
• /
• pp.166-173
• /
• 2014

Recently, small quadcopters have been widely used in various areas ranging from military to entertainment applications because interest in the quadcopter increases. Especially, the research on swarm flight which control quadcopters simultaneously without any collision can increase success probability of a important mission. In addition the swarm flight can be applied for demonstrating choreographed aerial maneuvers such as dancing and playing musical instruments. In this paper, we introduce multiple AR.Drone control system based on motion capture for indoor environment in which quadcopters can recognize current position each other and perform scenario based mission.

• Advances in aircraft and spacecraft science
• /
• v.6 no.5
• /
• pp.349-369
• /
• 2019

In the design of flight control systems there are issues that deserve special consideration and attention such as external perturbations or systems failures. A Simple Adaptive Controller (SAC) that does not require a-priori knowledge of the faults is proposed in this paper with the aim of realizing a fault tolerant flight control system capable of leading the pitch motion of an aircraft. The main condition for obtaining a stable adaptive controller is the passivity of the plant; however, since real systems generally do not satisfy such requirement, a properly defined Parallel Feedforward Compensator (PFC) is used to let the augmented system meet the passivity condition. The design approach used in this paper to synthesize the PFC and to tune the invariant gains of the SAC is the Population Decline Swarm Optimization ($P_DSO$). It is a modification of the Particle Swarm Optimization (PSO) technique that takes into account a decline demographic model to speed up the optimization procedure. Tuning and flight mechanics results are presented to show both the effectiveness of the proposed $P_DSO$ and the fault tolerant capability of the proposed scheme to control the aircraft pitch motion even in presence of elevator failures.

• Convergence Security Journal
• /
• v.18 no.2
• /
• pp.133-139
• /
• 2018

The 5 Game changer means the concepts of the army's operation against the enemy's asymmetric threats so that minimize damage to the public and leads to victory in war in the shortest time. A study of network architecture of Dronebot operation is a key study to carry out integrated operation with integrated C4I system by organically linking several drones battle groups through ICT. The NBC reconnaissance drones can be used instead of vehicles and humans to detect NBC materials and share situations quickly. However, there is still a lack of research on the swarm flight of the NBC reconnaissance drones and the weaknesses of cyber electronic warfare. In this study, we present weaknesses and countermeasures of CBRNs in swarm flight operations and provide a basis for future research.

• Journal of Digital Convergence
• /
• v.15 no.8
• /
• pp.195-202
• /
• 2017

Unmanned Aerial Vehicles (UAV) have mostly been used for military purposes but with the progress in ICT and reduced manufacturing costs, they are increasingly used for various private services. UAVs are expected to carry out autonomous flying in the future. In order to carry out complex tasks, swarm flights are essential. Although the swarm flights has been researched a lot due to its different network and infrastructure from the existing UAV system, There are still not enough study on security threats and requirements for the secure swarm flights. In this paper, to solve these problems, UAV autonomous flight technology is defined based on US Army Corps of Engineers (USACE) and Air Force Research Laboratory (AFRL), and swarm flights and security threat about it are classified. And then we defined and compared security requirements according to security threats of each swarm flights so as to contribute to the development of secure UAC swarm flights in the future.

• Journal of KIISE
• /
• v.43 no.12
• /
• pp.1315-1324
• /
• 2016

Recently, the increasing interest in drones has resulted in development of new related technologies. Attention has been focused toward research on swarm flight which controls drones simultaneously without collision. Thus, complicated missions can be completed rapidly through collaboration between drones. Due to low position accuracy, GPS is not appropriate for the outdoor mission involving accurate flight. In addition, the inaccurate position estimation of GPS gives rise to the serious problem of collision, since many drones are controlled in a narrow space. In this study, we increased the accuracy of position estimation through various sensors with Real-Time Kinematic-GPS (RTK-GPS). The mode switching algorithm was proposed to minimize the problem of sensor error. In addition, we introduced the outdoor swarm flight system based on the proposed position estimation.

• Electrical & Electronic Materials
• /
• v.9 no.7
• /
• pp.660-667
• /
• 1996

The electron transport characteristics in $SF_6$ gas is calculated for range of E/N values from 150 -800(Td) by the Monte Carlo simulation using a set of electron collision cross sections determined by the authors. The results suggest that the value of an electron swarm parameter such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients in nearly agreement with the respective experimental and theoretical for a range of E/N. The electron energy distributions function were analysed in sulphur hexaflouride at E/N:500 and 800(Td) for a case of the equilibrium region in the mean electron energy. The validity of the results obtained has been confirmed by a Time of Flight method also investigated as a set of electron collision cross section for sulphur Hexaflouride.