Hierarchical Formation Control With Applications to Multi-Quadrotor Systems

A hierarchical formation control framework is proposed to study the formation control problem for the leader-follower multi-quadrotor systems. The proposed framework includes a coordinating control level and a tracking control level. On the coordinating control level, the virtual position and the virtual velocity are obtained based on the finite-time consensus theory such that the virtual shape is formed and virtual velocity consensus is reached. On the tracking control level, the real position and the real velocity track the virtual position and the virtual velocity, respectively, such that a number of quadrotors can reach the desired formation shape and the velocity consensus. Consequently, a coordinating control algorithm and a tracking control algorithm are designed, respectively. The results of simulations and experiments employing three quadrotors and a leader demonstrate that the quadrotors can quickly complete the formation shape and the corresponding velocity consensus is arrived.