This paper studies the trajectory-tracking strategy for unmanned aerial vehicles where the autopilot is involved in the feedback control. The trajectory-tracking controller is derived based on a generalized design model using Lyapunov based backstepping. The augmentations of the design model and trajectory-tracking controller are conducted to involve the autopilot in the closed-loop system. Lya...

In this paper a full order observer has been designed using generalized matrix inverse. The design method resolves the state vector into two unique components, of which one is known and the other is unknown. This method does not assume any structure of the observer and imposes no restriction on the output distribution matrix. Condition of existence of such observer is presented with proof. An i...

This paper presents a novel formulation of the flight dynamic equations that permits a rapid solution for the design of trajectory following autopilots for nonlinear aircraft dynamic models. A robust autopilot control structure is developed based on the combination of the good features the Nonlinear Dynamic Inversion (NDI) method, Integrator Backstepping method, Time Scale separation and Contro...

This chapter describes a continuing research on design and verification of the autopilot system for an unmanned aerial vehicle (UAV) through hardware-in-the-loop (HIL) simulation. UAVs have the characteristics of small volume, light weight, low cost in manufacture, high agility and high maneuverability without the restriction of human body physical loading. Equipped with the on-board autopilot ...

This paper presents a simple unknown input estimation technique using generalized matrix inverse. The full order observer constructed by g-inverse is extended and implemented for this purpose. The necessary and sufficient condition has been introduced for existence of such an estimator. The proposed method is illustrated by numerical example (Two loop autopilot in pitch plane) and the MATLAB si...

This paper considers application of L1 adaptive output feedback controller to a missile longitudinal autopilot design. The proposed adaptive controller has satisfactory performance in the presence of parametric uncertainties and time-varying disturbances. Simulations demonstrate the benefits of the control method and compare the results to Linear Quadratic Regulator (LQR) and Linear Quadratic G...

Some level of uncertainty is unavoidable in acquiring the mass, geometry parameters and stability derivatives of an aerial vehicle. In certain instances tiny perturbations of these could potentially cause considerable variations in flight characteristics. This research considers the impact of varying these parameters altogether. This is a generalization of examining the effects of particular pa...

We have developed a visually based autopilot which is able to make an air vehicle automatically take off, cruise and land, while reacting appropriately to wind disturbances (head wind and tail wind). This autopilot consists of a visual control system that adjusts the thrust so as to keep the downward optic flow (OF) at a constant value. This autopilot is therefore based on an optic flow regulat...