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Purpose – The purpose of this paper is to design a new standard instrument arrival called the point merge system (PMS) for converging runways. The PMS enables controllers to handle traffic with no heading instruction, as well as aiming to reduce a controller's frequency occupancy time. Design/methodology/approach – The point merge model was designed for converging runways. Istanbul International Ataturk Airport, which has converging runways, was chosen as an application area for this model. The same 50 traffic arrivals per hour were used both for point merge and vectoring. Implementation was compared using a real time simulation. Findings – The simulation results show that the total average number of instructions is about 33 per cent less and the frequency occupancy is about 37 per cent less for point merge than for vectoring. In addition, in terms of trajectory dispersion, in point merge, traffic is within a narrower triangular area, while in vectoring large traffic dispersion occurs. Practical implications – The point merge model for converging runways proposed in this paper can be applied by airspace designers and air navigation service providers to perform efficient standard instrument arrival routes. Originality/value – The PMS has been developed for single and parallel runways; however, in this study, the point merge model is designed for converging runways at Istanbul International Ataturk Airport. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to develop a directional and roll control system for unmanned combat air vehicle (UCAV) automatic takeoff roll, with the objective of keeping the UCAV along the runway centerline and keeping the wings level, especially when there is a crosswind. Design/methodology/approach – The nonlinear model of the UCAV during takeoff roll is established. The model is linearized about the lateral-directional equilibrium point at different forward speeds. The approximate directional model and roll model are extracted using time-scale decomposition technique. Then the directional control law and roll control law are developed using gain scheduling approach. Nose wheel steering, differential brake and rudder are used as the primary directional control device at low, medium and high speeds, respectively, according to both the qualitative and quantitative analysis of their control effectiveness at different speeds. A priority matrix is developed to determine the secondary control device which is used if the primary control device fails, thus the directional control system can have a certain degree of fault tolerance. Findings – This work developed the directional control law and roll control law by using gain scheduling approach. Experimental results verified that the developed directional and roll control system has high robustness and satisfactory fault tolerance: it can guarantee a safe takeoff under a 50 ft/sec crosswind, even if one directional control device fails, which satisfies the relevant criteria in MIL-HDBK-1797. Practical implications – The directional and roll control system developed can be easily applied to practice and can steer the UCAV during takeoff roll safely, which will considerably increase the autonomy of the UCAV. Originality/value – The paper shows how time-scale decomposition technique is employed to extract the approximate directional model and roll model, which simplifies model analysis and control law design. A fault-tolerant directional control system is designed to improve safety during takeoff. [ABSTRACT FROM AUTHOR]

Purpose |!|#8211; The purpose of this paper is to develop an integrity monitoring method using ERAIM (Extended Receiver Autonomous Integrity Monitoring) for the integrated GNSS/Inertial (Global Navigation Satellite System and inertial navigation system) of general aviation aircraft. Design/methodology/approach |!|#8211; First the tightly integrated GNSS with Strapdown Inertial Navigation System (GNSS/SINS) and the Kalman filter is designed. Then the processing of ERAIM is presented, in which the least-squares theory is used to calculate the best estimators by integrating the predicted states with measurement states of Kalman filter. Based on the new measurement model, the integrity monitoring for GNSS/inertial system is carried out, including the fault detection, identification, reliability and separability. Lastly, the simulation and analysis for ERAIM vs RAIM are performed to validate the proposed method. Findings |!|#8211; Simulation results show that the ERAIM method is able to detect and identify effectively any type of failure including step failure and ramp failure. Compared to the RAIM method for only GNSS, the ERAIM increases the redundant information and reduces the correlation of test statistics, as well as enhancing the reliability and thus can significantly improve the performance of integrity monitoring. Practical implications |!|#8211; In safety critical sectors such as aviation, stringent integrity performance requirements must be met. The ERAIM method cannot only be used in integrity monitoring for the integrated GNSS/Inertial system, but also can be applied to only GNSS or other integrated navigation systems for general aviation aircraft. Originality/value |!|#8211; The paper presents a new integrity monitoring method of ERAIM, which is able to improve the fault detection and identification capabilities significantly by extending GNSS-used RAIM method into the GNSS/Inertial integrated system. [ABSTRACT FROM AUTHOR]

Purpose |!|#8211; The purpose of this paper is to present an adaptive controller of nonlinear path following for a fix-wing micro-aerial-vehicle (MAV) in flight. The adaptive controller discussed in this work was able to successfully complete the flight tasks in complicated terrain, with improved trajectory tracking precision and flight quality. Design/methodology/approach |!|#8211; The nonlinear desired trajectory was fitted by the method of fifth-order B-splines with a sequence of waypoints which are created and sent by the ground station. According to the relationship between the nonlinear desired trajectory and aircraft|!|#39;s flight path, the authors have built the relevant error equations of position and course under wind disturbances, based on the Serret-Frenet frame. The Lyapunov function can be constructed in virtue of the error equations and desired course function applying the vector field theory. On the basis of Lyapunov stability arguments, the authors have also constituted the course adaptive control law, which is converged asymptotically and stably. Findings |!|#8211; According to the nonlinear desired trajectory fitted by the proposed adaptive control methods, the authors have carried out the flight tests experiments with various positions, courses and airspeeds of aircraft. The experimental results show a good path following, as well as under wind disturbances. Practical implications |!|#8211; A new methodology for the nonlinear path following has been proposed, which is also proven to be promising for other special applications such as the path following in straight-line segment and orbit, etc. Originality/value |!|#8211; The paper provides a novel realization method for accurate path following for MAVs. This method can also be carried out in many applications by a simple hardware. [ABSTRACT FROM AUTHOR]

Purpose – To study the application of three-dimensional differential geometric (DG) guidance commands to a realistic missile defense engagement, and the application of the Newton's iterative algorithm to DG guidance problems. Design/methodology/approach – The classical differential geometry theory is introduced firstly to transform all the variables in DG guidance commands from an arc length system to the time domain. Then, an algorithm for the angle-of-attack and the sideslip angle is developed by assuming the guidance curvature command and guidance torsion command equal to its corresponding value of current trajectory. Furthermore, Newton's iteration is utilized to develop iterative solution of the stated algorithm and the two-dimensional DG guidance system so as to facilitate easy computation of the angle-of-attack and the sideslip angle, which are formulated to satisfy the DG guidance law. Findings – DG guidance law is viable and effective in the realistic missile defense engagement, and it is shown to be a generalization of gain-varying proportional navigation (PN) guidance law and performs better than the classical PN guidance law in the case of intercepting a maneuvering target. Moreover, Newton's iterative algorithm has sufficient accuracy for DG guidance problem. Originality/value – Provides further study on DG guidance problem associated with its iterative solution. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to propose a supervisory command-to-line-of-sight guidance law with lead angle which keeps the missile flight within the tracking beam. Design/methodology/approach – A nonlinear supervisory controller is designed and coupled with the main sliding mode controller in the form of an additional control signal. The supervisory control signal is activated when the beam angle constraint goes to be violated. Initially a supervisory controller is designed using nonlinear control theory. Subsequently the main tracking controller is designed using sliding mode approach which forces the missile to fly along the desired line-of-sight. The stability of the supervisory controller coupled with the main controller is proved in the Lyapunov sense. Findings – There exists a major drawback with the lead angle method of guidance, which is a high probability of flying out of the beam. The proposed supervisory controller has successfully overcome this deficiency. Thus, a better performance has been achieved. Practical implications – The proposed guidance scheme can be applied to tactical surface to air missiles. Additionally the idea of supervisory controller can be applied to any similar control problem where there are some constrains over the states of the system. Originality/value – The idea of supervisory controller has not been applied to the problem of command-to-line-of-sight guidance law. This paper utilizes and extends the idea of supervisory controller design to cases when a special state is to be supervised while considering the effect of external disturbances. [ABSTRACT FROM AUTHOR]

Purpose – To demonstrate that different approaches to commercialisation can determine the nature of intangible resources that managers can develop. Design/methodology/approach – A framework linking political strategy, financial capitalisation and business strategy is developed to analyse the management of intellectual capital in the commercialisation of air navigation services in New Zealand and Fiji. Case study evidence is organised as an intellectual capital portfolio and links are drawn to subsequent business outcomes for each organisation. Findings – Explains how key decisions about financial capitalisation and business strategy at the time of commercialisation influence the subsequent management and development of intangible resources in the organisation. Identifies how political assumptions about commercialisation can constrain or enhance subsequent management success in developing intellectual capital to pursue business growth. Research limitations/implications – The interpretations offered, although plausible in the context of the case studies, may not generalise to other situations. Practical implications – Key decision makers need to design commercialisation arrangements that will resource the desired intellectual capital portfolio of the commercialised organisation. Originality/value – The paper provides a framework for establishing a linkage between strategic management decisions and the development of an intellectual capital portfolio in the context of commercialisation. The paper develops the theoretical extent of intellectual capital concepts and provides practical analysis to decision makers contemplating commercialisation issues. [ABSTRACT FROM AUTHOR]

Purpose – To demonstrate that different approaches to commercialisation can determine the nature of intangible resources that managers can develop. Design/methodology/approach – A framework linking political strategy, financial capitalisation and business strategy is developed to analyse the management of intellectual capital in the commercialisation of air navigation services in New Zealand and Fiji. Case study evidence is organised as an intellectual capital portfolio and links are drawn to subsequent business outcomes for each organisation. Findings – Explains how key decisions about financial capitalisation and business strategy at the time of commercialisation influence the subsequent management and development of intangible resources in the organisation. Identifies how political assumptions about commercialisation can constrain or enhance subsequent management success in developing intellectual capital to pursue business growth. Research limitations/implications – The interpretations offered, although plausible in the context of the case studies, may not generalise to other situations. Practical implications – Key decision makers need to design commercialisation arrangements that will resource the desired intellectual capital portfolio of the commercialised organisation. Originality/value – The paper provides a framework for establishing a linkage between strategic management decisions and the development of an intellectual capital portfolio in the context of commercialisation. The paper develops the theoretical extent of intellectual capital concepts and provides practical analysis to decision makers contemplating commercialisation issues. [ABSTRACT FROM AUTHOR]