UCAV Research Articles

Design Rule Extraction Using Multi-Fidelity Surrogate Model for Unmanned Combat Aerial Vehicles

Due to the instability of the pitching moment induced by the strong vortical flow at moderate to high angles of attack in the unmanned combat aerial vehicle (UCAV) configuration, previous design studies focused primarily on low-speed flight conditions where the longitudinal stability is a serious issue. Furthermore, because of the limitation of computational cost, univariate analyses based on low-fidelity flow solvers are performed to investigate the relationships between design variables and quantities of interest. In this study, since the high-speed condition may occupy a high proportion in the UCAV mission, it was additionally considered through multi-objective optimization. A high-fidelity flow solver is used for both low-speed and high-speed conditions to accurately capture the vortical flow structure, and corresponding computational costs are relieved by multi-fidelity surrogate modeling. Based on this surrogate model, design rules are extracted, and the effects of design variables are investigated through univariate and multivariate data mining techniques. At last, universal design rules that can be referenced regardless of the parameterization method are visualized in an airfoil shape using proper orthogonal decomposition. The time-efficient design rule extraction framework and the approach to analyzing extracted design rules presented in this study can be extended to any engineering field.

Crashworthiness study of UCAV’s main landing gear using explicit dynamics

In the aircraft industry, the ultimate goal in any component’s design is to minimize its weight, maximize its durability, and increasing its life while keeping its overall life cycle costs low. As technology is progressing, UCAVs are gaining more and more prominence as jet powered UCAVs are already taking to skies presenting a myriad of challenges. This is especially true in the case of Landing gears as greater crashworthiness is required in high-speed high payload UCAVs. As jet powered UCAVs have a higher touchdown velocity and thus a higher chance of failure. In this research, a category of unmanned combat aerial vehicles was picked. In that category, a number of reference unmanned combat aerial vehicles were selected to extract the required parameters and dimensions of their main landing gears from literature review and analysis. The main landing gear was then modeled in CAD. Simultaneously loading conditions were defined and loads were determined. The equivalent von mises and maximum principal stresses were obtained from finite element analysis for multiple materials using the finite element package ANSYS. These results were then in turn used to calculate the factor of safety. Furthermore, an impact analysis was carried out in this crashworthiness study using Explicit Dynamics in LS DYNA for the same material. The stress formulations and deformations in impact were highly non-linear and more realistic and accurate than in static structural. The results were then validated.

An Approach to Air-to-Surface Mission Planner on 3D Environments for an Unmanned Combat Aerial Vehicle

Recently, interest in mission autonomy related to Unmanned Combat Aerial Vehicles(UCAVs) for performing highly dangerous Air-to-Surface Missions(ASMs) has been increasing. Regarding autonomous mission planners, studies currently being conducted in this field have been mainly focused on creating a path from a macroscopic 2D environment to a dense target area or proposing a route for intercepting a target. For further improvement, this paper treats a mission planning algorithm on an ASM which can plan the path to the target dense area in consideration of threats spread in a 3D terrain environment while planning the shortest path to intercept multiple targets. To do so, ASMs are considered three sequential mission elements: ingress, intercept, and egress. The ingress and egress elements require a terrain flight path to penetrate deep into the enemy territory. Thus, the proposed terrain flight path planner generates a nap-of-the-earth path to avoid detection by enemy radar while avoiding enemy air defense threats. In the intercept element, the shortest intercept path planner based on the Dubins path concept combined with nonlinear programming is developed to minimize exposure time for survivability. Finally, the integrated ASM planner is applied to several mission scenarios and validated by simulations using a rotorcraft model.

TECHNOLOGY OF PROPULSION SYSTEM FOR UNMANNED COMBAT AERIAL VEHICLE (UCAV) – A REVIEW

Unmanned Combat Aerial Vehicle (UCAV) is an unmanned aerial vehicle (UAV) that is used for intelligence, surveillance, target acquisition, and reconnaissance and carries aircraft ordnance such as missiles, ATGMs, and/or bombs in hardpoints for drone strikes. These drones are usually under realtime human control, with varying levels of autonomy. Unlike unmanned surveillance and reconnaissance aerial vehicles, UCAVs are used for both drone strikes and battlefield intelligence. Unmanned Combat Aerial Vehicle (UCAV) propulsion technology is significantly related to the flight performance of UCAVs, which has become one of the most important development directions of aviation. It should be noted that UCAVs have three types of propulsion systems, namely the fuel, hybrid fuel-electric, and pure electric, respectively. This paper presents and discusses the classification, working principles, characteristics, and critical technologies of these three types of propulsion systems. It is helpful to establish the development framework of the UCAV propulsion system and provide the essential information on electric propulsion UCAVs. Additionally, future technologies and development, including the high-power density motors, converters, power supplies, are discussed for the electric propulsion UCAVs. In the near future, the electric propulsion system would be widely used in UCAVs. The high-power density system would become the development trend of electric UCAVs. Thus, this review article provides comprehensive views and multiple comparisons of propulsion systems for UCAVs.

Drone affective politics against state impunity: The case of 43 disappeared students in Ayotzinapa, Mexico

This article analyzes some implications of new drone aesthetics involved in affective politics against state impunity in social conflicts. Whereas the literature on media, war and conflict has been centered around the war aesthetics of military drones, the author argues that civilian drones can mobilize affective politics – expressed, for example, in the aestheticization of shame, rage and the subversion of fear – as a means of political communication with and against the state. Further, she proposes that the present focus on drone aesthetics should be expanded to also account for the political affects that aesthetic sensory perceptions mobilize. Drawing on actor-network theory and new materialism, the article takes the disappearance of 43 students in Ayotzinapa (Mexico) as an exemplary case of state impunity in the context of the war against drugs and social conflict. By means of a digital ethnography of the social collective project Rexiste, the author analyzes its public interventions deploying a civil drone named ‘Droncita’, which sought to generate an aesthetics of affect against state impunity. The article contributes toward expanding investigation of (civilian) drone aesthetics and the mobilization of affective politics in the literature on war and social conflicts and collective action.

FTLE and Surface-Pressure Signature of Dynamic Flow Reattachment During Delta-Wing Axial Acceleration

An experimental investigation was conducted on the aerodynamics of an NACA0012 airfoil wing with triangular planform geometry undergoing steady and axial accelerations at as a model of an unmanned combat air vehicles encountering unsteady environments at pre- and poststall angles of attack (Marzanek, M., and Rival, D., “Separation Mechanics of Non-Slender Delta Wings During Streamwise Gusts,” Journal of Fluids and Structures, Vol. 90, Oct. 2019, pp. 286–296.). Ensemble-averaged flowfields, forces, moments, and surface-pressure distributions were measured in the Optical Towing Tank for Energetics Research facility at Queen’s University. To characterize the evolution of the flowfield coherent structures around a wing under axial gusts or accelerations, a Lagrangian flowfield analysis including the finite-time Lyapunov exponent (FTLE) was conducted. Results indicate that axial acceleration can induce a dynamic flow reattachment at the poststall angle of attack, and clear FTLE ridges extend from the wing surface and travel down the chord as reattachment progresses. A distinct signature in the surface-pressure distribution tracks closely with the location where the FTLE ridges meet the wing. The timing of how this surface-pressure distribution moves aft is shown to correlate with the relatively large-scale fluctuation in the pitching moment. The current work reveals the correlation between FTLE and surface pressure, which further hints at a potential approach of dynamic estimation by using Lagrangian coherent structures.

Derivation of structural weight estimation for Unmanned Combat Aerial Vehicle (UCAV)

AbstractEstimation of the structural weight of an Unmanned Combat Aerial Vehicle (UCAV) during conceptual design has proven to be a significant challenge mainly due to its unconventional configuration. We investigate development of a customised approach for structural weight estimation of UCAV based on statistical weight of the manned fighter’s components by applying minor modifications on weight formulations of fuselage, wing, empennage, power plant and landing gear. The modifications are applied by considering the corresponding differences between manned fighters and UCAVs such as manned requirements and mission variances. Some new empirical formulas for estimating the weight of UCAV’s components are proposed. Results for the empty weight estimation are validated against actual values of some well-known UCAVs. Moreover, the structural weight is validated against the benchmark UCAV case studies. The results show that the ratio of structural to takeoff weight for UCAVs is approximately between 20% to 10%. Finally, a generalised equation is developed for estimating the structural weight of UCAVs in conceptual design phase.

Airfoil Analysis and Effect of Wing Shape Optimization on Aerodynamic Parameters in a Steady Flight

The work in this paper deals with reconstructing and optimizing the wing geometry of an Unmanned Combat Aerial Vehicle for improved performance and reviewing the impact of the modification on flight parameters in a steady flight. The behavior of airfoils at planned flight conditions under I.S.A. is checked in XFLR5 software. Following up by 2-D CFD and boundary layer analysis of former and new airfoil, dimensions of the wing are re-developed, keeping the fuselage and tail structure same. The existing wing and the optimized wing design is analyzed by Vortex Lattice Method and Triangular Panel Method, with an objective to make the shape of the wing aerodynamically suitable for an increased Lift to Drag ratio and thereby minimizing drag coefficients.

Autonomous maneuver decision-making for a UCAV in short-range aerial combat based on an MS-DDQN algorithm

To solve the problem of realizing autonomous aerial combat decision-making for unmanned combat aerial vehicles (UCAVs) rapidly and accurately in an uncertain environment, this paper proposes a decision-making method based on an improved deep reinforcement learning (DRL) algorithm: the multi-step double deep Q-network (MS-DDQN) algorithm. First, a six-degree-of-freedom UCAV model based on an aircraft control system is established on a simulation platform, and the situation assessment functions of the UCAV and its target are established by considering their angles, altitudes, environments, missile attack performances, and UCAV performance. By controlling the flight path angle, roll angle, and flight velocity, 27 common basic actions are designed. On this basis, aiming to overcome the defects of traditional DRL in terms of training speed and convergence speed, the improved MS-DDQN method is introduced to incorporate the final return value into the previous steps. Finally, the pre-training learning model is used as the starting point for the second learning model to simulate the UCAV aerial combat decision-making process based on the basic training method, which helps to shorten the training time and improve the learning efficiency. The improved DRL algorithm significantly accelerates the training speed and estimates the target value more accurately during training, and it can be applied to aerial combat decision-making.

The future of unmanned combat aerial vehicles: An analysis using the Three Horizons framework

This article examines the future of unmanned combat aerial vehicles (UCAVs). As a foresight tool it uses the Three Horizons framework, which helps understand the process of change underway at present in combat aviation as a result of the advances in technology associated with the fourth industrial revolution. According to this framework, the first horizon corresponds to manned combat aviation, the strategic effectiveness of which is beginning to be called into question. The second horizon comprises different strategic innovations currently in progress which can be viewed as support for the first horizon but also as disruptive innovations that may bring about a change in the dominant model. The article then explores a third hypothetical horizon in which UCAVs take centre stage in combat missions and identifies potential drivers of this alternative and disruptive future.

The Development of the Lithuanian Armed Forces and Its Response to the Russian Conventional Threats in 2015‒2020

In a period of 2015-2020, Lithuanian Armed Forces (LAF) military spending increased twice, thus it enabled to initiate and to arrange significant critical projects that eventually allowed armed forces to upgrade military equipment and tactics. New artillery units, armoured personnel vehicles, air defence systems, anti-tank weapons, radars, anti-drone systems boosted military power of LAF. Tactics switched from anti green men to conventional tactics, where fire and manoeuvre dominates again. Meanwhile, in the same period of time in Kaliningrad the Russian armed forces boosted the number of military personnel, upgraded equipment (most of it to offensive one) and increased military exercises. In order to be prepared, LAF must look for the most efficient ways of defence towards a potential foe. In a near future LAF must decentralize a central military storage thus critical assets could be secured and used by battalions at any time. Moreover, LAF capabilities could be improved by cyber conscripts and non-conventional tactics which could bring extra dividends when a small state fights against technologically advanced adversary. Eventually, with an additional military spending LAF could obtain MLRS artillery, the coastal defence systems and unmanned combat aerial vehicles that could deal with enemy from a safer distance.

Visual Range Maneuver Decision of Unmanned Combat Aerial Vehicle Based on Fuzzy Reasoning

Visual Range Maneuver Decision of Unmanned Combat Aerial Vehicle Based on Fuzzy Reasoning

The Military-Civilian Symbiosis: Evidence of Civil Innovation from the Global Drone Industry

Private parties operating in the civil domain are not always capable of engendering innovation and new industry creation because of lacking complementary assets, short-term horizons, underinvestment in fundamental research, and limited ‘translational’ capacity. In this study, we theorize and demonstrate that important innovations often have their roots in an institutional realm that can compensate for these shortcomings: the military. We hypothesize that the military is capable of fostering private sector innovation through technological and human-capital spillover, investments in high-risk innovation projects, and building vital innovation infrastructure. We test our hypotheses in the context of the global drone industry, using a unique longitudinal database tracking the emergence of the industry between 2006 and 2016. Our sample consists of 1341 civil drone systems created by 473 producers situated in 52 countries. We employ survival analysis to test the influence of national-level military drone production, overall military expenditure and arms imports on civil drone market-readiness. Our results show that the military plays an integral role in civil innovation and new industry creation in this setting. As one of the first studies in management to provide systematic, non-anecdotal evidence on the civil innovation role of the military, our work contributions to the institutions-for-innovation and innovation policy literatures.

Cooperative Planning for an Unmanned Combat Aerial Vehicle Fleet Using Reinforcement Learning

In this study, reinforcement learning (RL)-based centralized path planning is performed for an unmanned combat aerial vehicle (UCAV) fleet in a human-made hostile environment. The proposed method provides a novel approach in which closing speed and approximate time-to-go terms are used in the reward function to obtain cooperative motion while ensuring no-fly-zones (NFZs) and time-of-arrival constraints. Proximal policy optimization (PPO) algorithm is used in the training phase of the RL agent. System performance is evaluated in two different cases. In case 1, the warfare environment contains only the target area, and simultaneous arrival is desired to obtain the saturated attack effect. In case 2, the warfare environment contains NFZs in addition to the target area and the standard saturated attack and collision avoidance requirements. Particle swarm optimization (PSO)-based cooperative path planning algorithm is implemented as the baseline method, and it is compared with the proposed algorithm in terms of execution time and developed performance metrics. Monte Carlo simulation studies are performed to evaluate the system performance. According to the simulation results, the proposed system is able to generate feasible flight paths in real-time while considering the physical and operational constraints such as acceleration limits, NFZ restrictions, simultaneous arrival, and collision avoidance requirements. In that respect, the approach provides a novel and computationally efficient method for solving the large-scale cooperative path planning for UCAV fleets.

Multi-UAVs task assignment method considering expected destruction probability of target

To solve the combat task assignment of reconnaissance unmanned aerial vehicle (RUAV)/unmanned combat aerial vehicle(UCAV), this paper proposed an efficient task assignment method that takes into account the expected destruction probability of target. This method improves the utility function and constraint of the model that based on the goal of destroying the total sum of the target value. The adjustment factor is added to the model to achieve a balanced distribution of RUAVs/UCAVs resources; the expected destruction probability of target is introduced as a constraint to prevent the excessive distribution of RUAVs/UCAVs resources. Subsequently, a greedy algorithm based on maximizing marginal-return is designed to solve the proposed model. The simulation results show that the improved algorithm not only meets the combat effectiveness but also improves the economic performance on the basis of real-time task allocation.

Trapped in the System

In the interview, Mark Curran and Rune Peitersen talk about topics of the artist’s visual explorations, which in his past projects (which concern the usage of military drones), revolve around physical distance and the powerlessness of drone operators and their targets, while considering whether the visua lrepresentations of drone warfare has any power to elicit empathy. On the other hand, in another system of control, the same distance and its relationship to the viewer is stressed in the interplay between human interest and interference with nature in Peitersen’s latest ongoing project, in which he questions systematization again, this time not due to artificial algorithmic intelligence, but as a human-made system of attempted ownership of nature.

Factors Determining a Drone Swarm Employment in Military Operations

The aim of this study is to identify a drone swarm’s capabilities and the key factors influencing its employment in military operations. The research takes the quantitative analysis of scientific literature related to the technical and operational utilization of drones. The use of drones for military purposes in contemporary world is widespread. They conduct dull, dirty, dangerous and deep military operations replacing manned aviation in many areas. Progressive technological development including artificial intelligence and machine learning allows for the use of military drones in the form of a swarm. It is a quite new technology at the beginning of development. The study indicates that the capabilities of a drone swarm based on communication within the group and autonomy differentiate it from the typical use of unmanned aircraft. Size, diversity, self-configurability and self-perfection amongst the others indicated in literature are attributes of a drone swarm which may give advantage in military operation comparing to the classic use of unmanned aircraft. Emergent coordination as a command and control model of a drone swarm is a future way of utilizing that technology in military operations. In the future, a drone swarm will be a cheaper equivalent of advanced and much more expensive weapon systems conducting combat operations.

Fuzzy logic based air-to-air combat algorithm for unmanned air vehicles

Unmanned combat air vehicles (UCAV) are finding increasing use in military applications due to their autonomy, processing capabilities and low cost with respect to manned flights. In order to use the UCAVs in the air to air combat, required algorithms must be carefully designed to enhance them with aerial combat competence. There are challanges for the design of this kind of an algorithm such as real-time operability and the case with inadequate number of sensors on the UAVs. In this paper a novel attack algorithm is introduced for UCAVs, with the assumption that in order to launch an effective attack the pursuer aircraft must be able to follow the target aircraft from behind with a predetermined distance. The attack algorithm consists of navigation and reference velocity calculation steps. In navigation part the reference values for bank, heading and flight path angles are computed. In velocity generation part, a PID based method and a fuzzy inference based method are employed to compute the reference velocity of the pursuer and the results obtained with these two approaches are compared. The performance of this algorithm is assessed with simulations performed in three different scenarios with different initial conditions for the pursuer and the target. Simulation results show that the effectiveness of the proposed fuzzy inference based air to air attack algorithm is better in action with respect to PID based algorithm since various effects that cause the change in velocity, can be incorporated into the fuzzy inference mechanism.

DÜNYA BASININDA TÜRKİ YE’Nİ N S/İ HA GÜCÜ VE KÜRESEL Sİ YASETE YANSIMALARI

Technological innovations in the 􀏐ield of informatics, rapid developments in subjects such as arti􀏐icial intelligence and robotic engineering have put Unmanned Aerial Vehicles (UAV) and Armed Unmanned Aerial Vehicles (UCAV) into the battle􀏐ield of the 21st century. At this point, states whose common concerns are security have taken the path of both obtaining intelligence and developing unmanned aerial systems, whose use is rapidly increasing in the 􀏐ield of war-defense. It is known that many countries are currently working on developing and producing UAVs, beside United States of America (USA) and Israel which both have advanced unmanned aerial systems. Because states that are developing and manufacturing their own unmanned aerial systems are aware that this situation will provide a strategic advantage in terms of their military, political and economic interests. In this context, Turkey didn’t stay indifferent to the developments of unmanned aerial systems emerging in each passing day, it has made considerable momentum towards the last 􀏐ifteen years to develop national and indigenous UAV systems. Especially since mid-2010, these systems have been used ef􀏐iciently in both intra border operations and crossborder operations The main question of this article is how Turkey’s UAV/UCAV power is re􀏐lected in global politics and in this direction, world press will be scanned. In this context, this study will primarily explained by Turkey’s domestic and national development of unmanned aerial systems adventure in general terms; then Turkey’s use of these vehicles in where and for what purpose will be evaluated. Afterward it will be evaluated that how Turkey’s power of UAV/UCAV is perceived by other states in economic and military-political aspects by examining the relevant state press and publishing organizations Keywords: Turkey, Unmanned Aerial Vehicles, Unmanned Combat Aerial Vehicles, Press- Publishing Organizations.

4차 산업혁명시대 군사드론 위협에 관한 연구

본 연구의 목적은 4차 산업혁명시대 군사드론의 위협에 대한 국·내외 사례를 다각적으로 분석하여 군사 드론의 위협에 대해 분석하는 것이다. 즉, 4차 산업혁명시대 초연결성(Hyper-Connectivity), 초지능성(Hyper Intelligence), 사물인터넷(Internet of Things) 기술이 진보화될수록 군사 드론의 위협은 증가 될 것이며 특히, 군 사작전 분야에 목적으로 활용되어야 하는 군사 드론이 민간인 대상 위협 및 테러로 전개될 경우 그 치명적인 여 파의 영향은 상상할 수 없을 것이다. 따라서 본 연구에서는 군사 드론의 개념 및 군사분야 활용사례를 고찰함으로 써 군사드론의 위협에 대해 다양한 사례를 분석하고 군사 드론의 위협에 대한 시사점을 도출하여 정책적 방향을 제시하고자 한다.