A prototype of an autonomous controller for a quadrotor UAV

The paper proposes a complete real-time control algorithm for autonomous collision-free operations of the quadrotor UAV. As opposed to fixed wing vehicles the quadrotor is a small agile vehicle which might be more suitable for the variety of specific applications including search and rescue, surveillance and remote inspection. The developed control system incorporates both trajectory planning and path following. Using a differential flatness property the trajectory planning is posed as a constrained optimization problem in the output space (as opposed to the control space), which simplifies the problem. The trajectory and speed profile are parameterized to reduce the problem to a finite dimensional problem. To optimize the speed profile independently of the trajectory a virtual argument is used as opposed to time. A path following portion of the proposed algorithm uses a standard linear multi-variable control technique. The paper presents the results of simulations to demonstrate the suitability of the proposed control algorithm.

I. Introduction

Recently unmanned air vehicles (UAV's) have attracted considerable interest for a wide variety of different applications. While fixed wing vehicles have had extensive applications for military and meteorological purposes due to their range, speed and flight duration, rotorcraft vehicles are considered to be more preferable for surveillance, precise delivery and some other missions requiring agility and accuracy.