Finite-Time LPV Analysis of a Vision Based Landing System with Anti-Windup Augmentation

In contrast to standard ILS-based landing control systems, vision-based strategies rely on specific measures that introduce non-linearities into the control laws. Moreover, during the landing phase high gains are often used to improve performances at the expense of stability which is then degraded. This is not much an issue since both final approach and flare segments are short-time maneuvers. However, high gains induce saturations which in turn lead to performances degradation. For these reasons, vision-based landing systems design and tuning require a specific attention which generally involves a time-consuming trial-and-error process. The latter could certainly be fasten and improved with the help of adapted analysis tools providing a reliable estimate of the finite-time performance level of the aforementioned saturated nonlinear closed-loop system. As observed in Biannic and Burlion (2017), it can be rewritten as a saturated Linear Parameter Varying (LPV) system for which many tools exist or can be extended. In this contribution, original discrete-time extensions are then proposed to characterize finite-time performance indexes for a vision-based landing system including an anti-windup device.