A GPC-based auto-throttle with robust fuel-efficient operation in 4D flights

This paper introduces a novel auto-throttle controller designed for robust and fuel-efficient operation under changing flight conditions in four-dimensional (4D) flight trajectories (3D + time). Following typical receding horizon techniques, the throttle values are obtained by optimizing the predicted response of the system over future time intervals. The novelty is two-fold: First, the controller is designed to achieve a user-defined, realistic reference value for the aircraft Specific Fuel Consumption (SFC), while maintaining the nominal safety margins during the 4D flights. Second, the throttle commands result from a closed-form expression with minimal computational effort, thus simplifying the proposed auto-throttleʹs on-board implementation. Tests against a conventional PID-based auto-throttle illustrate the current controllerʹs superior robustness under challenging flight conditions (turbulence).