Air Vehicle System Research Articles

Air vehicle system health and asset management: modeling, simulation, and decision support

AbstractEffective Asset Management (AM) is essential to achieve operational excellence in the context of large complex Cyber-Physical Systems (CPSs). It involves coordinated activities across all life-cycle stages, including information and service exchange within and between adjacent air operations domains, for effective air operations and collaboration. For enterprises and military air operations, AM presuppose information and service exchange between the adjacent domains of air operations. Important aspects of aviation AM are that CPSs include Integrated Vehicle Health Management (IVHM), CPS models, and Digital Twin (DT), as central concepts used to predict and optimize asset performance. This article provides an overview of the aviation AM phenomenology, environment, and challenges, and how they may impact envisioned realisations of effective AM solutions for support to enterprise air vehicle operations. The article serves as an extension of the paper Cyber-physical Asset Management of Air Vehicle Systems presented at the International Congress and Workshop of Industrial AI and Maintenance (Candell et al., in Proceedings of the IAI2023–7th international congress and workshop on industrial AI and eMaintenance, Luleå, Sweden, 2023). A comprehensive approach is presented, comprising interdependent dimensions of the problem domain, and how they may be integrated into a framework and a platform concept addressing aviation AM needs.

Modular reconfigurable rotorcraft for autonomous cargo delivery

Traditional air mobility capability development consists of defining a set of requirements and subsequently designing an aircraft that satisfies these requirements. Once designed, the overall structure or topology of the aircraft is fixed. That is, the aircraft has certain fixed physical dimensions, number and sizes of rotors, engines, etc. The topology cannot be changed to accomplish missions outside of its original design envelope, and if designed for a robust mission spectrum, the aircraft may be inefficient during routine missions that do not require peak performance. The work reported here takes a different approach where a core set of components (fuselage, rotor, power plant, etc) defines the fundamental modules of the air mobility system. The modules were developed using mature and readily available technologies and designed to be quickly connected to other modules to assemble different aircraft configurations with widely varying performance characteristics. The aircraft can be reconfigured between missions to best satisfy mission requirements. Thus, the envelope of achievable performance characteristics is significantly expanded compared to a single aircraft. This concept is explored for autonomous air cargo delivery missions targeted for nominal payloads and ranges around 500 pounds and 500 nautical miles with maximum payloads up to 3500 pounds across shorter distances. Results indicate that for mission spectrums with large differences between nominal and maximum payloads and skewed towards smaller payloads, the operational cost per lb-km is significantly reduced using a modular and reconfigurable air mobility system since cargo delivery requirements can be better matched to an air vehicle system.

Design, Simulation and Implementation of an Unmanned Aerial Vehicle System

Teknolojide elde edilen gelişmelerle birlikte İnsansız Hava Aracı (İHA) sistemlerinin kullanım alanları yaygınlaşmakta ve çeşitlenmektedir. Günümüzde İHA’lar uzaktan algılama, fotogrametri, trafik denetimi ve büyük tesislerin gözetimi gibi birçok farklı amaçla kullanılmaktadırlar. Bu çalışmada, İHA olarak bir dörtuçar gerçekleştirilmiştir. Bu dörtuçarın teorik çalışmaları ve performans özelliklerini çıkarmak için “eCalc” programı kullanılmıştır. eCalc’te tasarım süreci ve benzetim işlemleri etkileşimli olup, mümkün olduğunca gerçek elemanların özelliklerinin kullanıldığı gerçeğe çok yakın ortamlar oluşturulabilmektedir. eCalc ile elde edilen sonuçlar MATLAB uygulamalarından elde edilen sonuçlarla karşılaştırılarak, bir İHA genel sistemi ve alt sistemleri için gerekli olan donanım ve yazılım mimarileri tasarlanarak uygulamada kullanılacak dörtuçar gerçekleştirilmiştir. Yer kontrol istasyonu, olarak Mission Planner kullanılmıştır.

Efficient large multibody flight dynamic simulation through improved nonlinear control constraint stabilization

Some air vehicles are configured such that major components exhibit relative motion with respect to one another where this relative motion significantly affects vehicle motion. In these cases, multibody flight dynamics is needed to adequately model system dynamics. This paper reports on a numerically efficient and versatile method for multibody flight dynamic simulation where the air vehicle is idealized as a collection of rigid bodies connected together by a set of joints. The method uses constrained coordinates with a constraint stabilization method based on a nonlinear control framework. The key innovation lies in relating the connections of the rigid bodies to an undirected graph and its adjacency matrix. By reordering connections, the bandwidth of the adjacency matrix can be minimized leading to substantial computational improvements. These improvements are applied to several air vehicle systems to highlight the computational benefits of the proposed technique.

UAV Platforms for Data Acquisition and Intervention Practices in Forestry: Towards More Intelligent Applications

Unmanned air vehicle (UAV) systems for performing forestry applications have expanded in recent decades and have great economic benefits. They are validated to be more appealing than traditional platforms in various aspects, such as repeat rate, spatial resolution, and accuracy. This paper consolidates the state-of-the-art unmanned systems in the forestry field with a major focus on UAV systems and heterogeneous platforms, which are applied in a variety of forestry applications, such as wood production, tree quantification, disease control, wildfire management, wildlife conservation, species classification, etc. This review also studies practical applications under multiple forestry environments, including wild and managed forests, grassland, urban green parks, and stockyards. Special forest environments and terrains present customized demands for unmanned systems. The challenges of unmanned systems deployment are analyzed from environmental characterization, maneuverability and mobility improvement, and global regulatory interpretation. To better apply UAV systems into forestry, future directions are analyzed in terms of mobility enhancement and customized sensory adaption, which need to be further developed for synchronizing all possible agents into automatic functioning systems for forestry exploration.

Modeling and adaptive control of air vehicles with partial nonlinear parametrization

This paper studies the control of a generic longitudinal air vehicle dynamic model during the cruise phase with nonlinearly parametrized uncertain aerodynamic functions. Verified by the improved coefficient precision of the aerodynamic forces and moments, using a curve fitting technique on available flight data, it is demonstrated that a nonlinearly parametrized model can more accurately capture the vehicle dynamics than a linearly parametrized model. For control design, the air vehicle model is decomposed into a flight-path angle subsystem with rotational dynamics and a speed subsystem with engine actuation dynamics. An adaptive control scheme is developed using the combination of a function bounding technique and a modified backstepping control method for two interconnected subsystems. The designed adaptive control laws ensure both global stabilization and adaptive non-zero equilibrium point regulation of the closed-loop control system. A thorough simulation study is presented to show the effectiveness of the developed adaptive control scheme for a nonlinearly parametrized air vehicle system model.

An Investigation of Scale-Resolving Turbulence Models for Supersonic Retropropulsion Flows

Characterization of unsteady loads is critical for the development of control systems for next-generation air vehicles. Both Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) methods are prohibitively expensive, and existing Reynolds-Averaged Navier-Stokes (RANS) approaches have been shown to be inadequate in predicting both mean and unsteady loads. In recent years, scale-resolving methods, such as Partially Averaged Navier-Stokes (PANS) and Detached Eddy Simulation (DES), have been gaining acceptance and filling the gap between RANS and LES. In this study, we focus on a new variant of the PANS method, namely blended PANS or BPANS, which was shown to perform well in the incompressible regime for both wall-bounded and free shear flows. In this paper, we extend BPANS to compressible supersonic flows by adding a compressibility correction, leading to a new model called BPANS CC. The new model is tested using a well-known supersonic mixing layer case, and the results show good agreement with experimental data. The model is then used on a complex supersonic retropropulsion case and the results are in good agreement with experimental data.

Dynamic Event-Triggered Control of Networked Stochastic Systems With Scheduling Protocols

In the present article, we consider network-based control of linear systems with state multiplicative noise. For the sensor-controller network, round-robin, try-once-discard, and independent and identically distributed protocols are proposed to orchestrate the measurement transmission from multiple sensor nodes. By using the time-delay approach to networked control systems, sufficient conditions for the exponential mean-square stability are obtained in terms of linear matrix inequalities. Moreover, a discrete-time dynamic event-trigger is suggested to reduce the number of sent control signals from controller to actuator. An air vehicle system from the literature illustrates the efficiency of the presented approach.

Practical output tracking control for nonlinearly parameterized longitudinal dynamics of air vehicles

This paper studies a practical output tracking control problem of the nonlinearly parametrized longitudinal dynamics of air vehicles. To make output tracking errors within an arbitrarily prescribed bound, a practical output control scheme is developed, employing a new integrated framework of a functional bounding technique for handling nonlinearly parametrized dynamics and a nonlinear state-feedback controller structure for regulating the multi-output tracking errors. A coordinate transformation and a control input domination design are used to decouple the air vehicle system into the attitude subsystem and velocity subsystem. The proposed control scheme achieves the closed-loop signals global boundedness and practical output tracking properties, despite the unknown parameters appearing in aerodynamic forces and moments nonlinearly. An air vehicle under additional disturbances is also studied for enhancing the robustness of the proposed controllers. Simulation results on a vehicle model that is affected by the structural flexibility illustrate the effectiveness and robustness of the practical output tracking control scheme.

Energy and performance optimization of an adaptive cycle engine for next generation combat aircraft

For next generation aircraft, Adaptive Cycle Engine (ACE) is a candidate to fulfill the multi-mission requirements of flight. This new concept is promising to complete deficiencies of conventional low by-pass mixed turbofan engines because the ACE model incorporates different thermodynamic cycles (turbojet and turbofan) on the same air vehicle system. Firstly, performance and design results of the ACE model are compared with those of fixed cycle low by-pass turbofan engine by using specific fuel consumption (SFC), specific thrust (ST), power and efficiency parameters. Moreover, verification of the newly developed ACE model is performed. Secondly, considering some design parameters, ST and SFC values of the ACE model are analyzed for double by-pass mode (DBM) and single by-pass mode (SBM). Considering performance analysis of the ACE, SFC value is determined as 17.85 g/kN.s at DBM and 42.18 g/kN.s at SBM. According to results of energy analysis, overall efficiency of the ACE is calculated as 23% for DBM and 9% for SBM whereas fixed cycle engine has 18% for military mode and 7% for afterburner mode. Finally, minimization of (SFC) is obtained with genetic algorithm approach. Based on the design variables such as by-pass ratio and turbine inlet temperature, minimum SFC value for the ACE model is calculated as 17.41 g/kN.s at DBM and 40.45 g/kN.s at SBM.

Robust adaptive control of nonlinearly parametrized multivariable systems with unmatched disturbances

SummaryA new robust adaptive control scheme is developed for nonlinearly parametrized multivariable systems in the presence of parameter uncertainties and unmatched disturbances. The developed control scheme employs a new integrated framework of a functional bounding technique for handling nonlinearly parametrized system dynamics, an adaptive parameter estimation algorithm for dealing with parameter uncertainties, a nonlinear feedback controller structure for stabilization of interconnected system states, and a robust adaptive control design for accommodating unmatched disturbances. It is proved that such a new robust adaptive control scheme is capable of ensuring the global boundedness and mean convergence of all closed‐loop system signals. A complete simulation study on an air vehicle system with nonlinear parametrization in the presence of an unmatched wind disturbance is conducted, and its results verify the effectiveness of the proposed robust adaptive control scheme.

Design and flight testing of closed-loop simple adaptive control for a biplane micro air vehicle

This article presents the implementation of closed-loop simple adaptive control on fixed-wing micro air vehicle dynamics to improve flight performance characteristics. It is known that to retain the micro air vehicle system performance during the entire flight regime is difficult due to model uncertainties, large parameter variation and wind disturbances compared to flight velocity. An adaptive controller can adapt to the uncertainties but the complexity involved in their implementation is high due to unavailability of required sensor information and computational resources on a micro air vehicle platform. Lack of flight test results in the open literature incorporating adaptive control so far can be partially attributed to this complexity. In this case, adaptive control architecture is implemented in such a way that only the uncertainties in the system dynamics are taken care of by the adaptive control and desired nominal plant performance is achieved by the basic controller. The proposed adaptive controller architecture is implemented in real flight test, and improvement of tracking performance over a proportional–integral–derivative controller is demonstrated which illustrates superior performance to conventional architectures. The proposed design approach can be implemented easily to an existing system, and system performance can be enhanced in the presence of unmodelled and uncertain system dynamics.

Guest Editorial Pushing for Higher Autonomy and Cooperative Behaviors in Maritime Robotics

The papers in this special section examine the technology of maritime robotics. These papers are the result of a collaborative effort between the IEEE Oceanic Engineering Society, the U.S. Office of Naval Research (ONR), and RoboNation, a nonprofit robotics organization formerly known as AUVSI foundation. The field of maritime robotics is swiftly moving toward integration of air, surface, and subsurface autonomous systems. For example, where autonomous maritime systems (AMS) are composed of heterogeneous assets, surface vehicles are now often capable of transporting aerial and underwater vehicles, leveraging the benefits of each to increase mission endurance and capabilities. In seeking to integrate land, sea, and air vehicle systems, it is natural to look toward leveraging advances made separately in each domain. For example, substantial similarities exist between the desired behavioral capabilities of autonomous land vehicles and those of autonomous marine systems. Recent advances in the field of driverless cars may therefore be applicable to autonomous surface vessels, underwater vehicles, and even aerial vehicles.

Toward Dynamic Monitoring and Suppressing Uncertainty in Wildfire by Multiple Unmanned Air Vehicle System

Containing a wildfire requires an efficient response and persistent monitoring. A crucial aspect is the ability to search for the boundaries of the wildfire by exploring a wide area. However, even as wildfires are increasing today, the number of available monitoring systems that can provide support is decreasing, creating an operational gap and slow response in such urgent situations. The objective of this work is to estimate a propagating boundary and create an autonomous system that works in real time. It proposes a coordination strategy with a new methodology for estimating the periphery of a propagating phenomenon using limited observations. The complete system design, tested on the high-fidelity simulation, demonstrates that steering the vehicles toward the highest perpendicular uncertainty generates the effective predictions. The results indicate that the new coordination scheme has a large beneficial impact on uncertainty suppression. This study thus suggests that an efficient solution for suppressing uncertainty in monitoring a wildfire is to use a fleet of low-cost unmanned aerial vehicles that can be deployed quickly. Further research is needed on other deployment schemes that work in different natural disaster case studies.

Flight Phases With Tests of a Projectile-Drone Hybrid System

A fully functional prototype of a gun-launched micro air vehicle system (GLMAV) is developed for long-distance observation capabilities. A subsonic projectile is launched from an ad hoc tube and transforms into a micro air vehicle (MAV) once arrived over the site to be observed. The ballistic, transient, and operational flight phases of the GLMAV are studied theoretically and experimentally in this paper. Ballistic flight tests prove the stability of the platform in projectile mode and the availability of the inertial measurement unit and GPS measurements for the autopilot. Based on wind-tunnel measurements, a model of the transient phase is built, allowing the design and simulation of control laws for this phase. Indoor and outdoor tests of the system are successfully achieved highlighting the hovering and maneuvering flight capabilities of the GLMAV.

Dynamic output feedback control for stochastic networked control systems based on a periodic event-triggered mechanism

In this paper, the event-triggered dynamic output feedback control for stochastic networked control systems is investigated. The measurement output signal is periodically sampled but aperiodically transmitted. The time-delay system method is utilized to model the stochastic networked control system under the periodic event-triggered mechanism, then the corresponding stability criteria are obtained. Based on the stability criteria, the suitable output-based controller and event-triggered parameters are co-designed. Two air vehicle systems are presented to illustrate the efficiency of the proposed control method.

Event-triggered dissipative control for networked stochastic systems under non-uniform sampling

This paper is concerned with dissipative control for networked stochastic systems with an event-triggered transmission mechanism. Different from some existing results, signals from a physical plant are sampled non-uniformly. In order to save precious communication resources, a data-packet processor is introduced to choose necessary data-packets based on a flexible event-triggered condition. By establishing an integral inequality in stochastic setting, which is regarded as a counterpart of Wirtinger-based inequality, a criterion is derived such that the resultant closed-loop system is mean-square stable and dissipative. This criterion is then used to calculate suitable event-triggered controllers in terms of solutions to linear matrix inequalities. An air vehicle system is finally taken to substantiate the validity of the proposed method.

GENERATION AND ASSESSMENT OF HIGH RESOLUTION DIGITAL SURFACE MODEL BY USING UNMANNED AIR VEHICLE BASED MULTICOPTER

Abstract. Unmanned air vehicle systems (UAVSs), which are presently defined as effective measuring instruments, can be used for measurements and evaluation studies in fields. Furthermore, UAVs are effective tools that can produce high-precision and resolution data for use in geographic information system-based work. This study examined a multicopter (hexacopter) as an air platform to seek opportunity in generating DSM with high resolution. Flights were performed in Kahramanmaras Sutcu Imam University Campus area in Turkey. Pre-assessment of field works, mission, tests and installation were prepared by using a Laptop with an adaptive ground control station. Hand remote controller unit was also linked and activated during flight to interfere with emergency situations. Canon model IXSUS 160 was preferred as sensor. As a result of this study, as mentioned previous studies, .The orthophotos can be produced by RGB (Red-green-blue) images obtained with UAV, herewith information on terrain topography, land cover and soil erosion can be evaluated.

무인비행체 탑재 단일 카메라용 가변 필터 자동 회전장치 개발에 관한 연구

학술 연구는 물론 국방 분야의 연구용 장비로써의 무인비행체(이하 드론)의 역할은 날로 증가하고 있는 추세이며, 드론을 활용한 광학 장비의 성능실험 등에 있어서 그 효율을 극대화하기 위해서는 체공 시간 내에 데이터수집을 위한 최적화된 메커니즘과 이를 운용하기 위한 컨트롤 시스템이 필수라 할 수 있다. 본 논문에서는 탑재하중의 한계로 인해 동시에 여러 다른 대역의 영상 촬영이 필요한 경우 다수의 카메라를 탑재할 수 없는 드론의 특성을 고려한 단일 카메라용 가변 필터 자동 회전 장치를 제작하는데 있어서 고려된 설계의 착안점들과 이러한 메커니즘의 제어방법에 대해 다루고 있으며, 효율적 영상획득을 위하여 카메라, 드론, 3D프린터, 코딩기술과 같은 융복합 차원의 다양한 기술을 적용함으로서 기존의 동일시간 대비 다량의 영상자료를 확보할 수 있는 방법론을 제시하고 있다. 연구의 결과는 다음과 같다. 첫째, 자동화된 데이터 획득 절차에 의하여 정밀한 영상의 획득이 가능하였고, 둘째, 여러 대의 카메라 또는 여러 번의 촬영을 해야만 획득할 수 있었던 영상을 단일작업을 통하여 획득할 수 있었으며, 셋째, 3D프린터와 마이크로 프로세서를 활용하는 융복합화 된 작업을 통하여 효율화된 영상획득 작업의 새로운 가능성들을 제시하였다.

Sustainable alternative fuels in aviation

Abstract In recent years, renewable energy resources have become more important due to the limited number of regions for production of petroleum-based fuels, which are continuously depleting. The aviation sector in terms of commercial and cargo transportation has an increasing need for conventional, as well as, alternative fuels. Derivatives of petroleum fuels used in aviation have negative impacts on air quality. Factors causing greenhouse gas emissions (GHG) in the aviation sector must be reduced. However, such fuels used in the aviation sector are not sustainable. Biofuels which have the potential to replace petroleum fuels and help with emissions are heavily investigated in developed countries for independency, creating a better environment and sustainability. Biofuels which are already used for ground vehicles could also be implemented in the aviation sector to reduce fuel cost and emissions. Overall, aviation fuels made of sustainable resources would also support social and economic development. Numerous industrial initiatives have emerged to find alternative ways to attain bio-aviation fuels. Therefore, there is an increasing level of research with regards to alternative aviation fuels made of biomass in recent years. It is important to obtain basic feedstocks and to develop biofuel production processes in a cost-effective way. This study examines the necessity and the types of biofuels in the aviation sector. By designing unique fuel systems for air vehicles, it is possible to formulate biofuels which can be used for both air and ground vehicle applications. This type of consensus would help with sustainability and a better environment.