Formation control of quadrotor UAVs without linear velocity measurements

The problem of formation control of a group of quadrotors without linear velocity measurements is addressed in this paper. A distributed controller is developed directly on the orthogonal group SE(3) to avoid the singularities associated with Euler-angles and the ambiguity of quaternions. The control design procedure can be divided into two main steps. First, an intermediary control input is designed to achieve the formation objective, where some auxiliary systems are introduced to obviate the need for linear-velocity measurements. After decoding the intermediary control input into the trust force and reference angular velocity, then the torque input for each quadrotor is designed to drive the actual angular velocity to the desired ones. The asymptotic stability analysis is presented with Lyapunov-like tools. Simulation results on three quadrotors show the effectiveness of the proposed strategy.