Wing UAV Research Articles

Flight control of a rotary wing UAV using backstepping

This paper presents a novel application of backstepping controller for autonomous landing of a rotary wing UAV (RUAV). This application, which holds good for the full flight envelope control, is an extension of a backstepping algorithm for general rigid body velocity control. The nonlinear RUAV model used in this paper includes the flapping and servo dynamics. The backstepping-based controller takes advantage of the ‘decoupling’ of the translation and rotation dynamics of the rigid body, resulting in a two-step procedure to obtain the RUAV control inputs. The first step is to compute desired thrusts and flapping angles to achieve the commanded position and the second step is to compute control inputs, which achieve the desired thrusts and flapping angles. This paper presents a detailed analysis of the inclusion of a flapping angle correction term in control. The performance of the proposed algorithm is tested using a high-fidelity RUAV simulation model. The RUAV simulation model is based on miniature rotorcraft parameters. The closed-loop response of the rotorcraft indicates that the desired position is achieved after a short transient. The Eagle RUAV control inputs, obtained using high-fidelity simulation results, clearly demonstrate that this algorithm can be implemented on practical RUAVs. Copyright © 2009 John Wiley & Sons, Ltd.

A3 翼展開型無人自律飛行機の収納・展開機構に関する研究

A3 翼展開型無人自律飛行機の収納・展開機構に関する研究

Evolutionary methods for multidisciplinary optimization applied to the design of UAV systems†

The implementation and use of a framework in which engineering optimization problems can be analysed are described. In the first part, the foundations of the framework and the hierarchical asynchronous parallel multi-objective evolutionary algorithms (HAPMOEAs) are presented. These are based upon evolution strategies and incorporate the concepts of multi-objective optimization, hierarchical topology, asynchronous evaluation of candidate solutions, and parallel computing. The methodology is presented first and the potential of HAPMOEAs for solving multi-criteria optimization problems is demonstrated on test case problems of increasing difficulty. In the second part of the article several recent applications of multi-objective and multidisciplinary optimization (MO) are described. These illustrate the capabilities of the framework and methodology for the design of UAV and UCAV systems. The application presented deals with a two-objective (drag and weight) UAV wing plan-form optimization. The basic concepts are refined and more sophisticated software and design tools with low- and high-fidelity CFD and FEA models are introduced. Various features described in the text are used to meet the challenge in optimization presented by these test cases.

Health Monitoring of UAV Wing Skin-to-spar Joints using Guided Waves and Macro Fiber Composite Transducers

This article deals with the monitoring of the composite wing skin-to-spar joint in unmanned aerial vehicles using ultrasonic guided waves. The study investigates simulated wing skin-to-spar joints with two different types of bond defects, namely poorly cured adhesive and disbonded interfaces. The bond-sensitive feature considered is the ultrasonic strength of transmission through the joints. The dispersive wave propagation problem is studied numerically by a semi-analytical finite element method that accounts for viscoelastic damping, and experimentally by ultrasonic testing that uses highly durable, flexible macro fiber composite transducers. The discrete wavelet transform is also employed to de-noise and compress the ultrasonic measurements. Both numerical and experimental tests confirm that the ultrasonic strength of transmission increases across the defected bonds.

Detecting impact damage in experimental composite structures: an information-theoreticapproach

This work describes a procedure for detecting the presence of damage-inducednonlinearities in composite structures using only the structure’s vibrational response.Damage is assumed to change the coupling between different locations on the structurefrom linear to nonlinear. Utilizing concepts from the field of information theory, we are ableto deduce the form of the underlying structural model (linear/nonlinear), and hence detectthe presence of the damage. Because information theoretics are model independent theymay be used to capture both linear and nonlinear dynamical relationships. We describe twosuch metrics, the time delayed mutual information and time delayed transfer entropy, andshow how they may be computed from time series data. We make use of surrogate datatechniques in order to place the question of damage in a hypothesis testing framework.Specifically, we construct surrogate data sets from the original that preserve only the linearrelationships among the data. We then compute the mutual information andthe transfer entropy on both the original and surrogate data and quantify thediscrepancy in the results as a measure of nonlinearity in the structure. Thus, wedo not require the explicit measurement of a baseline data set. The approach isdemonstrated to be effective in diagnosing the presence of impact damage in athick composite sandwich plate. We also show how the approach can be used todetect impact damage in a composite UAV wing subject to ambient gust loading.

일본의 민간 회전익 무인항공기 (UAV) 현황

일본의 민간 회전익 무인항공기 (UAV) 현황

Rotary wing UAV potential applications: an analytical study through a matrix method

Industrial designers often need decision‐making methods to develop innovative solutions combining specified customer's requirements with project technical constraints. This paper describes a matrix approach as a technique to support system designer since the early stages of development, when many and important decisions must be taken. In this work, the matrix method has been used to analyze the civil unmanned aerial vehicle potential market and particularly for selecting the most promising applications of a multi‐role rotary wing unmanned aerial vehicle. According to the matrix results, two rotary wing multi‐role missions have been chosen as most promising customer attractive applications. This matrix method can also be improved for subsequent decision‐making in preliminary‐configuration analysis since it can be easily tailored to different specific engineering applications.

Parachute recovery for UAV systems

Parachute recovery systems are described from a systems perspective. Parachute recovery is particularly suited to tactical fixed wing UAV systems that require a high degree of mobility by allowing air vehicle recovery onto unprepared terrain. The descent environment is described, and the impact of wind on recovery is considered. The relative merits of cruciform, round and parafoil canopies are assessed, taking three real‐world systems as design examples. Throughout, design considerations are approached from a systems perspective, with a view to producing safe, autonomous and accurate recovery systems.

Impact blasting with glass beads

A variable sweep wing UAV is developed utilising off the shelf components with a custom mechanism for the wing box. The movement of the wing sweep in flight enables large pitching moments suitable for performing perching manoeuvres. Wind tunnel data is presented that confirms the favourable characteristics expected from sweeping the wing and achieving high pitch rates. Whilst only small sweep changes are required during flight, the design allows up to 30∘ forward sweep for significant pitching moments during the flare.A new collection of controllers is developed based on observations from similar landing techniques performed by birds and hang-gliders onto flat ground. The three-stage landing process takes the aircraft along an approach path, through a roundout procedure during which airspeed decays and concludes with rapid pitch up. Flight test results are presented during which it is found that the airspeed can be reduced to, on average, under 3 m/s in the final moments before landing – well below the stall speed of 9 m/s.