A Flatness Based Speed Control Approach For Merge Behind Operations

Abstract

International audience; Over the last few years, several concepts dealing the delegation to the flight crew of some tasks currently performed by the air traffic controllers have emerged. Among these new ideas, relative guidance has appeared to be capable to contribute to the enhancement of air traffic capacity though it raises difficult technical challenges. Indeed, this kind of maneuver appears difficult to perform manually, and may induce an excessive increase in flight crew workload, thus requiring new on-board automated functions. Some linear and nonlinear techniques have already been studied to design a feedback loop which performs automatically merging maneuvers and maintains station keeping behind a designated aircraft. The main contribution of this paper consists in the design of a feedback control loop using flatness control: this technique takes advantage of feedback linearization through a reference error between the ghost position of the leading aircraft and the current position of the trailing aircraft to provide a commanded speed to the autothrottle speed control system of the trailing aircraft. The robustness of the proposed design with respect to uncertainties in the dynamics of the leading aircraft and in the dynamics of the autothrottle speed control system of the trailing aircraft is achieved by the periodic update of the reference error. The reference error generation is detailed and simulation results are presented.