A stability-guaranteed smooth-scheduled MIMO robust emergency autopilot for a lateral surface jammed UAV

Abstract

This paper investigates a methodology for autopilot design for an unmanned air vehicle where one of the lateral control surfaces, i.e. the aileron or rudder, becomes jammed and unusable. The autopilot handles the automatic recovery, autonomous guidance and landing of the disabled unmanned aerial vehicle. An accurate nonlinear aircraft model is used to build local flight control laws using loop-shaping to decouple longitudinal and lateral channels. The design is carried out in a way to allow smooth scheduling over the local controllers without losing stability and performance, culminating in a robust emergency autopilot over the full flight envelope. The autopilot is tested on an example distress scenario involving aileron surface jam. It is confirmed through simulations that the autopilot design is capable of resuming safe flight and autonomous navigation under the fault scenario and is able to safely land the unmanned aerial vehicle to a target runway.

Control of a small helicopter with linear matrix inequality-based design assuring stability and performance

“…15–17 In this work, we carry out pointwise local control design with multiple or common Lyapunov functions and present the conditions that are required for guaranteed stability and performance bounds across the design envelope. This work complements 20 by reworking the principles in mixed sensitivity design configuration to a different type of aircraft. Studies handling large-scale helicopters typically utilize a 2-degree of freedom (DOF) reference tracking controller and an attitude tracking inner loop. 14 A simpler 1-DOF structure is proposed here and the attitude tracking loop is eliminated in favor of directly controlling the velocity.…”

“…15–17 In this work, we carry out pointwise local control design with multiple or common Lyapunov functions and present the conditions that are required for guaranteed stability and performance bounds across the design envelope. This work complements 20 by reworking the principles in mixed sensitivity design configuration to a different type of aircraft.…”