The purpose of this paper is to describe an approach which performs data fusion on the output of multiple, spatially separate, sensors engaged in the real time tracking of obstacles in a helicopter's environment. The generated information can be used either as a flight director aid or as feedback required by an automatic collision avoidance system. Obstacle track estimation has been commonly carried out using the Kalman filter (KF) for linear estimation, or the extended Kalman filter (EKF) for use on nonlinear problems. However, certain assumptions made in the derivation of the EKF algorithms render it sub-optimal for aerial obstacle track estimation. Additionally, the EKF has problems with initialisation and divergence (stability) for many non-linear processes.

Research at the University of Southampton has highlighted a link between fuzzy networks and associative memory neural networks. This link is important as it allows new learning rules to be developed for training fuzzy rules, and learning convergence to be proved. This paper explores methods of fusion of estimates using neuro-fuzzy models, and addresses some of the weakness of the Kalman filter approximation introduced by the assumptions made in its derivation.

This paper proposes a correlation which attempts to relate an aerofoil's low speed dynamic stall onset incidence to particular parameters describing its stall behaviour in steady conditions. These parameters, which can be derived from experiment or predictive algorithm, are the incidence of steady stall and a term related to trailing-edge separation characteristics. The correlation is based on a large amount of data obtained from a number of aerofoils broadly classified into two families: the NACA four digit series of symmetrical sections and a family of four profiles with the NACA 23012 as the generic shape.

The correlation has been extended to low pitch rates outside the “deep” dynamic stall range and, whilst it pertains to stalling under ramp motions, a link has been established with oscillatory motions. The potential of the correlation is demonstrated by its application to the design of a symmetric aerofoil for use on wind turbines.

A theoretical study was undertaken to determine the effect of taper ratio on the trailing vortex structure of a high aspect ratio unswept wing. The wing was modelled using lifting line theory, and the vortex was assumed to have a Rankine distribution of circulation. The results show that reducing the taper ratio of the wing, decreases the maximum tangential velocity of the vortex as well as the vortex span while the core's diameter increases. Data is also presented showing the sensitivity of induced drag to wake vortex parameters.

This paper reviews the status of aerospace materials currently under development or moving to application and assesses the difficulties inherent in their transition from research to commercial use. The author then speculates upon future trends in aerospace structures and on the consequences for advanced materials.

ACT embodying FBW and digital computing is now implemented routinely in almost all classes of aircraft, and is often essential in achieving performance requirements. However, careful design, thorough understanding, and attention to detail are necessary if the benefits of ACT are to be realised and attention must be focused appropriately among the issues to be resolved to ensure that development proceeds efficiently and overall costs are minimised. This paper introduces structural coupling as one of the important “details” of FCS design, and shows how the “state-of-the-art” has developed at BAe Warton in order to help achieve the performance specification for a modern weapons system, while maintaining a balanced and efficient FCS design effort.