Towards autonomous control of quadrotor unmanned aerial vehicles in a GPS-denied urban area via laser ranger finder

In this paper, the autonomous control problem of a quadrotor UAV (unmanned aerial vehicle) in GPS-denied unknown environments is addressed. The quadrotor UAV is equipped with a minature laser range finder as the main onboard sensor. A new localization methodology based on the PLICP (iterative closest/corresponding point based on point to linemetric) algorithm is proposed to provide accurate position estimation of the vehicle. The autonomous hovering and trajectory tracking control are achieved via on-board sensor and processors. Real-time flight tests are implemented under different scenarios including indoor hovering and trajectory tracking between buildings. These experiments results show that safe autonomous fight control is achieved for the quadrotor when it is flying in an unknown environment where the GPS signals are very weak or absent.