Karim Achaibou

Trajectory Generation for Relative Guidance of Merging Aircraft

In this chapter is considered the problem of generation of time efficient trajectories for N aircraft performing merging maneuvers behind a leading aircraft. The resulting multi trajectory generation problem is first considered as a minimum time control problem. The analysis of the resulting set of complex optimality conditions shows that the minimum time trajectories are produced by bang-bang control laws and can be characterized by few geometric parameters. Based on these considerations, a merging sequence is established for the N aircraft. Then regular minimum time convergence trajectories can be defined for each aircraft following a target generated by its own predecessor. For practical considerations it appears necessary to solve on-line this problem. An off-line exhaustive solution approach, based on reverse dynamic programming is proposed to cover a large set of initial relative positions. Then feed forward neural networks can be trained to generate on board each aircraft guidance directives to perform efficiently the overall merging maneuver.

A new flight guidance approach based on differential flatness

With the sustained increase of air traffic, the demand for new maneuvering capabilities of transport aircrafts is getting more important in order to tackle traffic saturated conditions. In this communication, a new guidance control structure is proposed to perform trajectory tracking through smooth manoeuvers. The design approach is based first on a differential flatness property of aircraft guidance dynamics which is displayed in This work and then on the use of neural networks to invert the guidance dynamics in order to generate directives to the autopilot. To compensate the effect of modeling errors and of other disturbances, an adaptive control approach is adopted to perform the maneuvers.

Design of a supervised flight control system for aircraft relative guidance

In this paper, the automation of the relative guidance is performed thanks to the recursive non-linear control technique, namely backstepping according to M. Krstic et al. (1995). This is quite new design methodology for construction of both feedback control laws and associated Lyapunov functions in a systematic manner. In order to tackle safety and passenger comfort aspects, which are crucial points for commercial aircraft, the controller is supervised: the purpose of this device is to handle on-line the gain of the controller, taking into account the current value of the state in order to satisfy some limitations in commercial aircraft maneuvering capabilities.

Aircraft Noise Exposure around Airports A Differential Flat Approach for Trajectory Assessment

The sustained growth of air transportation traffic along the last decades has induced increasing noise exposure for the areas surrounding large and medium airports. International and national regulations regarding noise exposure have been established by civil aviation authorities. So to meet the resulting noise constraints, new departure and arrival procedures have been established locally. The accuracy of the trajectory followed by a given aircraft depends on many parameters such as navigation and guidance systems and trajectory dispersion is a common phenomenon which should modify the expected performance with respect to noise exposure of airport neighbourhood. Since the guidance flight dynamics present a differential flatness property, given the 4D trajectory to be followed by the aircraft, nominal control inputs which are characteristic of the generated and diffused noise, can be established. The generation of deviations from the nominal trajectory can be used to establish more realistic noise level curves at ground level. The proposed approach is illustrated in the case of an approach trajectory at Santos Dummont domestic airport.

A Dynamic Booking Model Revenue for Airline Management

In this communication the design of a decision support system for improving the booking policy of an airline company is considered. Since the Airline Deregulation Act of 1978 in the USA, many studies on revenue (yield) management have been performed, some of them particularly towards the implementation of the dynamic programming technique for decision making. Here a step further is taken in this direction by the proposal of a new recursive model for maximum expected revenue evaluation which, contrarily to other approaches, takes into account daily booking requests arrivals.

An Adaptive Approach for Improved Airline Revenue Management

Abstract In this communication an on-line approach, based on two optimization modules, for the solution of the airline Revenue Management problem is proposed. For the demand forecasting module of the Revenue Management system, an updating process of the probability distribution of upcoming demand, which makes use of geometric programming, is presented. For the inventory control part, the obtained probability distributions are used for establishing a new dynamic programming optimization model which is designed to cope with physically confined and unconfined fare classes situations.