Collision-Free Trajectory Generation and Tracking for UAVs Using Markov Decision Process in a Cluttered Environment

A collision-free trajectory generation and tracking method capable of re-planning unmanned aerial vehicle (UAV) trajectories can increase flight safety and decrease the possibility of mission failures. In this paper, a Markov decision process (MDP) based algorithm combined with backtracking method is presented to create a safe trajectory in the case of hostile environments. Subsequently, a differential flatness method is adopted to smooth the profile of the rerouted trajectory for satisfying the UAV physical constraints. Lastly, a flight controller based on passivity-based control (PBC) is designed to maintain UAV's stability and trajectory tracking performance. Simulation results demonstrate that the UAV with the proposed strategy is capable of avoiding obstacles in a hostile environment.