Applying quadrotor aircraft to dynamic encirclement

A combination of decentralized Linear Model Predictive Control (LMPC) and Feedback Linearization (FL) is implemented on a team of quadrotor aircraft in order to accomplish dynamic encirclement around a stationary target in real-time. Dynamic encirclement is defined as the situation in which a target is isolated and surrounded by an Unmanned-Aerial-Vehicle (UAV) team in order to maintain awareness and containment of it. In this paper, the problem of maintaining a desired radius of encirclement, individual angular velocities and angular separation between team members is considered. The nonlinear plant, representing each vehicle's autonomous behaviour, is obtained through system identification and then linearized using an FL technique. Due to complex flight variables and multi-vehicle cooperation, LMPC is the most suited controller for solving the problem of dynamic encirclement on real-world platforms. The contribution of this paper lay in the application of decentralized LMPC and FL to the problem of encirclement using an autonomous team of Qball-X4 quadrotors in real-time.