A Simplified Backstepping Design for 3D Time-based Aircraft Relative Guidance

Abstract : The delegation to the flight crew of some tasks currently performed by air traffic controllers provides new perspectives to potentially increase air traffic control capacity. The objective of this communication is to provide technical insight into the airborne devices and algorithms which may be used to automatically perform merging and station keeping operations. Indeed, these maneuvers in the field of civil aviation seem difficult to be performed manually and may result in this case in an increase of the flight crew workload. Nevertheless new automated functions onboard aircraft could help to overcome this limitation. This paper investigates the design of a new autopilot mode dedicated to merging and station keeping maneuvers behind a leading aircraft. The proposed relative guidance law considers a 3-D relative motion, including constant wind and lateral, longitudinal and vertical control. It is based on vectorial backstepping and takes advantage of the skewsymmetric matrix which appears in the relative motion equations. An alternative "simplified" design based on a matrix form of the Young's inequality is also presented in order to simplify the computation of the guidance law. Then, an illustrative example is discussed and conclusions are raised.