Emerald | Aircraft Engineering and Aerospace Technology | Table of Contents http://www.emeraldinsight.com/0002-2667.htm Table of contents from the most recently published issue of Aircraft Engineering and Aerospace Technology Journal en-gb Tue, 26 Aug 2014 00:00:00 +0100 2013 Emerald Group Publishing Limited editorial@emeraldinsight.com support@emeraldinsight.com 60 Emerald | Aircraft Engineering and Aerospace Technology | Table of Contents http://www.emeraldinsight.com/common_assets/img/covers_journal/aeatcover.gif http://www.emeraldinsight.com/0002-2667.htm 120 157 Performance of Minimum Energy Controllers on Tiltrotor Aircraft http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116063&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - The purpose of this article is to evaluate performance of minimum energy controllers thoroughly on tiltrotor aircrafts.<B>Design/methodology/approach</B> - Minimum energy controllers are designed for tiltrotor aircraft models for helicopter and airplane modes. Performance of minimum energy controllers are evaluated with respect to several criteria. <B>Findings</B> - Minimum energy controllers can be used for tiltrotor aircraft flight control system design. These controllers show satisfactory performance when noise intensities and variance bounds vary.<B>Research limitations/implications</B> - None<B>Practical implications</B> - Minimum energy controllers can be implemented for tiltrotor aircraft flight control system design.<B>Originality/value</B> - Applying minimum energy controllers for tiltrotor aircraft flight control system design and evaluating performance of minimum energy controllers deeply on a complex physical system (i.e. tiltrotor aircraft). Article literatinetwork@emeraldinsight.com (TUGRUL OKTAY) Tue, 26 Aug 2014 00:00:00 +0100 Development of an improved framework for the preliminary design of a rotorcraft http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116061&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - The purpose of the present paper is to obtain the capability of designing modern rotorcrafts with enhanced accuracy and reliability.<B>Design/methodology/approach</B> - Among the existing rotorcraft design programs, an appropriate program was selected as a baseline for improvement. It was based on a database comprised of conventional fleets of rotorcrafts. The baseline program was not robust because it contained a simple iteration loop, which only monitored the gross weight of the aircraft. Therefore, it is not accurate enough to fulfil the quality and sophistication of a preliminary design framework useful for present and future generations of rotorcrafts. In this paper, the estimation formulas for the sizing and weight of the rotorcraft subsystem were updated by referring to modern aircraft data. In addition, a database of various turboshaft engines available these days was established. Instead of using the power estimation algorithm based on the momentum theory with empirical corrections, blade element rotor aerodynamics and trim analysis were developed and incorporated into the present framework. Moreover, the simple iteration loop for the aircraft gross weight was reinforced by adding a mathematical optimization algorithm, such as a genetic algorithm.<B>Findings</B> - The improved optimization framework for rotorcraft preliminary design which has the capability of designing modern rotorcrafts with enhanced accuracy and reliability was constructed by using MATLAB optimization toolbox. <B>Practical implications</B> - The optimization framework can be used by the rotorcraft industries at an early stage of the rotorcraft design.<B>Originality/value</B> - It was verified that the improved optimization framework for rotorcraft preliminary design has the capability of designing modern rotorcrafts with enhanced accuracy and reliability. Article literatinetwork@emeraldinsight.com (Jaehoon Lim, SangJoon Shin, Vaitla Laxman, Junmo Kim, JinSeok Jang) Tue, 26 Aug 2014 00:00:00 +0100 Hybrid DE-PEM Algorithm for Identification of UAV Helicopter http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116016&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - – to develop a hybrid algorithm using DE and PEM for identification of small scale autonomous helicopter state-space model<B>Design/methodology/approach</B> - flight data collection and analysis; development of MATLAB-based system identification algorithm using DE and PEM; estimation of parameterized state-space model parameters using the developed algorithm, model dynamic analysis <B>Findings</B> - the proposed hybrid algorithm improves the performance of PEM algorithm in the identification of autonomous helicopter model. It gives better results when compared with conventional PEM algorithm inside MATLAB toolboxes.<B>Research limitations/implications</B> - only applicable to linearized state-space model.<B>Practical implications</B> - the identification algorithm is expected to facilitate the required model development for model-based control design for autonomous helicopter development.<B>Originality/value</B> - – a novel hybrid algorithm for system identification of autonomous helicopter model. Article literatinetwork@emeraldinsight.com (Ismaila Bayo Tijani, Rini Akmeliawati, Ari Legowo, Agus Budiyono, Asan Gani) Tue, 26 Aug 2014 00:00:00 +0100 Direct maintenance cost prediction of civil aircraft http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116051&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - Reducing direct maintenance cost of civil aircraft is one of important ways to improve economy. Direct maintenance cost (DMC) prediction can provide decision support for the optimization of the design parameters optimization to realize the objection in decreasing the maintenance cost, it also can improve the aircraft competitiveness.<B>Design/methodology/approach</B> - The paper analyzes some parameters comprehensively, which influence DMC in the civil aircraft's operational phase. Based on the analysis of the influential parameters and the characteristics of data in the period of civil aircraft’s designing period, the paper presents prediction support method based on fuzzy support vector machine and realizes quantitative forecast of DMC in the aircraft design phase. <B>Findings</B> - The paper presents the process of DMC analysis and model in the aircraft design phase, the DMC prediction model is used to newly developed aircraft.<B>Practical implications</B> - The numerical examples using B737NP fleet data in the paper have proved the effectiveness of the proposed method. <B>Originality/value</B> - The paper establishes the prediction model of civil aircraft DMC based on fuzzy support vector machine. The model can handle fuzzy data and small sample data which contain noise. The results prove that the method can satisfy the demand of the real data in civil aircraft designing. Article literatinetwork@emeraldinsight.com (huawei wang, Jun Gao, Haiqiao Wu) Tue, 26 Aug 2014 00:00:00 +0100 Research on fuzzy logic control methods for Mars airplane http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116036&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - The purpose of this paper is to present the flight control law based on the fuzzy logic control methods for Mars airplane, and the research emphasis is placed on the attitude hold and the command track using the fuzzy control.<B>Design/methodology/approach</B> - The aircraft model is established with the combination of atmospheric environment, aerodynamic force and propulsive action. Then, the dynamic characteristics are analyzed in response to the different flight points for Mars airplane. Afterwards, the flight control law is designed by applying the fuzzy logic theory to realize the attitude hold and the command track for Mars airplane.<B>Findings</B> - The simulation results demonstrate that the proposed control law based on the fuzzy logic control methods is effective to guarantee system stability and relieve coupling dynamics. Also, this control system can provide strong robustness and good tracking performance for Mars airplane.<B>Practical implications</B> - The current work offers a new approach for the control law design of Mars airplane. The presented fuzzy control system can be applied to the other unconventional airplanes which will fly under unknown and uncertain environment in order to implement the complicated tasks such as deep space exploration.<B>Originality/value</B> - This paper provides the new methods for Mars airplane to design the fuzzy control system which consists of three implementation steps: the fuzzy quantization control step, the fuzzy decoupling control step and the fuzzy attitude control step. Through the progressive design, this presented control system of Mars airplane has strongly nonlinear and robust control ability due to the application of the fuzzy expert concepts. Article literatinetwork@emeraldinsight.com (Yanbin Liu, Keming Yao, Yuping Lu) Tue, 26 Aug 2014 00:00:00 +0100 Robust LPV autopilot design for hypersonic reentry vehicle http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116070&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - Since the aerodynamic coefficients of the hypersonic vehicle vary quickly during the reentry phase, a robust Angle-of-attack (AOA) tracking control system is designed for the Hypersonic Reentry Vehicle (HRV) based on the Linear Parameter Varying (LPV) theory.<B>Design/methodology/approach</B> - Firstly, longitudinal moment trim is done along the desired flight trajectory. The linearized system at each trim point is built and the dynamic characteristics analysis is made. Then the LPV control law with Parameter Dependent Quadratic Lyapunov Function (PDQLF-LPV) is applied to design the AOA tracking autopilot at each trim point. Frequency performance of the autopilot is assessed and the step response simulation is conducted to validate the effectiveness of the control system. Finally, actual AOA command tracking simulations based on the time-varying nonlinear model are carried out to test the correctness and robustness of the PDQLF-LPV autopilot.<B>Findings</B> - Analysis results demonstrates that the PDQLF-LPV control system can track the AOA command perfectly during the whole flight envelop with dynamics parameter variation or disturbances, which indicates that it is effective to integrate the PDQLF-LPV control theory with a parameter-varying reference model for control system design of HRV.<B>Originality/value</B> - A reference model with varying parameters is utilized to guarantee the transient performance of the autopilot, and induced L2-norm analysis is introduced to describe and guarantee the robust stability of the autopilot. Article literatinetwork@emeraldinsight.com (Gaohua Cai, Jianmei Song, Xianxiang Chen) Tue, 26 Aug 2014 00:00:00 +0100 Decentralised spacecraft manoeuvre planning http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116037&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - This paper aims to investigate the decentralised strategy to coordinate the reconfiguration of multiple spacecraft.<B>Design/methodology/approach</B> - The system of interest consists of multiple spacecraft with independent subsystem dynamics and local constraints, but is linked through their coupling constraints. The proposed method decomposes the centralised problem into smaller subproblems. It minimizes the fuel consumption of multiple spacecraft performing a reconfiguration manoeuvre through an iterative computation. In particular, each agent optimises its individual cost function using the most recently available local solution for the other agents.<B>Findings</B> - The simulation scenarios include spacecraft formation reconfiguration and close proximity manoeuvres around obstacles were conducted. The simulation results showed the fast convergence of the proposed algorithm, while local and inter-vehicles constraints were maintained.<B>Originality/value</B> - The main advantage of this approach is that it adopts a linear form of the objective function. This allows the local optimisation problem to be formulated as mixed-integer, linear programming problem, most of which can be quickly solved with resort to commercial software. Article literatinetwork@emeraldinsight.com (Haoyang Cheng, John Page, John Olsen, Nathan Kinkaid) Tue, 26 Aug 2014 00:00:00 +0100 Roll control problem for the long-range maneuverable warhead http://www.emeraldinsight.com/journals.htm?issn=0002-2667&volume=86&issue=5&articleid=17116045&show=abstract <strong>Abstract</strong><br /><br /><B>Purpose</B> - The purpose of this paper is to propose a combination BTT (Bank-to-turn) control mode with the single moving mass and reaction jet and design the roll control law for the long-range reentry maneuverable warhead.<B>Design/methodology/approach</B> - Based on the dynamics model of this new control mode, the control model of roll channel is converted into a perturbed double-integral system. The on-off optimal feedback control law is designed on the phase plane formed by Euler angle error and angular velocity error. In order to weaken the "on-off chattering" that is generated near the origin of the phase-plane and effectively reduce the jet fuel consumption for stability control, an on-off control outer ring and an inner ring are introduced into the phase plane.<B>Findings</B> - This control mode can not only avoid the aerodynamic rudder ablation to improve the efficiency of attitude control, but also reduce the fuel consumption of jet control by using moving mass control. The simulation results indicate that the designed control law can meet the speediness and robustness requirements of the long-range maneuverable warhead controlled by the single moving mass and reaction jet. This measure can also weaken the on-off chattering effectively.<B>Practical implications</B> - The new control mode solves some engineering problems of long-range reentry maneuverable warhead controlled by only one actuator. The control mode has a promising prospect in engineering practice.<B>Originality/value</B> - The paper provides a new control mode and a combination control strategy, and designs an effective control law. Article literatinetwork@emeraldinsight.com (Pengxin Wei, Wuxing Jing, Changsheng Gao) Tue, 26 Aug 2014 00:00:00 +0100