Piloted Simulation Evaluation of a Model-Predictive Automatic Recovery System to Prevent Vehicle Loss of Control on Approach

Abstract

This paper describes a model-predictive automatic recovery system for aircraft on the verge of a loss-of-control situation. The system determines when it must intervene to prevent an imminent accident, resulting from a poor approach. It estimates the altitude loss that would result from a go-around maneuver at the current flight condition. If the loss is projected to violate a minimum altitude threshold, the maneuver is automatically triggered. The system deactivates to allow landing once several criteria are met. Piloted flight simulator evaluation showed the system to provide effective envelope protection during extremely unsafe landing attempts. The results demonstrate how flight and propulsion control can be integrated to recover control of the vehicle automatically and prevent a potential catastrophe.

An Intelligent Propulsion Control Architecture to Enable More Autonomous Vehicle Operation

“…C-MAPSS40k models a 40,000-lbf thrust class, high-bypass ratio turbofan engine with a representative commercial-type controller. There have been multiple control and diagnostic algorithms demonstrated using the combined simulation, [26][27][28] or C-MAPSS40k [29][30][31] by itself, so the initial implementation of the architecture framework was in place.…”

Validation of an Integrated Airframe and Turbofan Engine Simulation for Evaluation of Propulsion Control Modes

“…For example, an exemption may be granted for the engine response requirement (FAR §33.73(b)) on the basis of compliance with the climb performance for installed thrust requirement, FAR §25.119, 9 which states that the thrust achieved eight seconds after power application (starting from minimum flight idle) must allow a climb gradient (the ratio of the increase of altitude to horizontal distance travelled, expressed as a percentage) of not less than 3.2% for a go-around. 10 Previous testing has demonstrated go-around maneuvers from a variety of approaches, 11 both stabilized and unstabilized. 12 In all cases, the aircraft started to climb at a relatively constant rate within eight seconds (Figure 2), and much sooner in the more stabilized approaches (where the sink rate was less than 1000 ft/s at an appropriate approach speed).…”