A Survey on Control Design Approaches for Remotely Operated UAVs

Quadrotors find their roles in various sectors ranging from remote surveillance to autonomous delivery due to their capabilities of hovering, Vertical Take Off and Landing (VTOL) and rapid manoeuvring. They are a viable asset to humans in safety-critical and hazardous operations such as remote inspection and manipulation of tunnels and windmills. These applications induce external disturbances and noises along with the modelling uncertainties in the dynamics. Applications such as aerial manipulation require control from a ground station autonomously or semi-autonomously, which leads to unpredictable delays and lags. In this context, the quadrotor has to perform its goals of following the desired trajectory with minimal deviation and holding its position without any deviation while operating in the environment. So, this article analyses the existing control techniques for the quadrotor tracking problem, which also tackle parametric uncertainties, unknown time-varying delays and ensure safety.