Formation flight of small scale unmanned aerial vehicles: A review

The use of small scale Unmanned Aerial Vehicles (UAV) and their formation flight is a field that has been greatly gaining popularity for the past decade or so. UAVs today are being integrated in various industries such as oil & gas, agriculture, security, filming, and landscaping just to name a few. However, UAVs are still not used extensively due to the various limitations imposed when using a single UAV. Such limitations include and are not limited to load tolerance, battery life, load area, failure, and speed of data acquisition. Formation flight is the coordinated flight of UAVs towards achieving a certain goal. This is achieved through the use of a formation controller which works at coupling UAV states and maintaining a certain formation structure. The use of formation flight allows for overcoming most of the limitations imposed when using single UAVs. This opens the door for enhancing the effectiveness of using UAVs to perform tasks in practical life situations. Many researchers have been nvestigating and developing the theory behind performing a uccessful and robust formation flight controller for various types of UAVs, such as rotary wings, fixed wings, flapping wings, and blimps. This chapter offers a survey of the development and applications of the various types of UAVs being used in literature today, their formation flight, and the components necessary to design a robust formation flight. The chapter also contains a review of the development and different types of formation flight schemes of small scale UAVs (virtual structure, leader-follower, behavioral). Moreover it discusses the various configurations of controllers (centralized, decentralized, hierarchal) that have been used in literature to achieve that. The other components necessary for a robust formation flight which are reviewed involve path planning, trajectory generation, collision avoidance, and fault tolerance.