A survey of autonomous landing techniques for UAVs

Landing an aerial vehicle is a very challenging problem. Pilots spend numerous hours practicing touchdowns because of the risk involved during landing phase. Developing autonomous landing technologies have been an active area of research over the past decade. This paper presents a review of landing techniques ranging from GPS based landing to vision based landing techniques; from basic nonlinear to intelligent, hybrid and robust control. It is aimed at providing a broad perspective on the status of the landing control problem and controller design. The paper provides a comparison based on parameters such as type of the vehicle, assumptions made in the problem design, techniques used and efficacy of the algorithm in real world conditions.