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.