A Novel Approach to Computationally Lighter GNSS-Denied UAV Navigation Using Monocular Camera

A good receptivity of GNSS signals during autonomous navigation is of prime importance. Due to this, navigation becomes close to impossible with places having low receptivity or GNSS-denied zones. In this paper, a navigational system is presented for a multi-rotor UAV in a GNSS-denied environment. The global positioning problem is solved by taking a local reference frame and estimating the UAV's position and velocity w.r.t it, using an onboard monocular camera and barometer. The navigational problem is solved by designing a required velocity function and tuning the system's response to this input by a PID controller. The results of both simulations and actual flight tests show the effectiveness and reliability of the presented work, which enables a UAV to perform full automated missions from takeoff, waypoint navigation and landing, in complete absence of any GNSS signals.