Distributed Formation Control for Multiple Quadrotor UAVs Based on Distributed Estimator and Singular Perturbation System

In this paper, the leader-follower distributed formation control of quadrotor unmanned aerial vehicles (UAVs) with communication constraints is studied, in which the leader’s information can only be obtained by one follower quadrotor UAV. To make every follower quadrotor UAV get the leader’s information, a distributed estimator was designed for each follower to estimate the leader’s information. Therefore, the requirements of communication topology can be reduced, and the accuracy and speed of formation control can be improved under the condition of reducing the communication of quadrotor UAVs. An improved integral sliding mode control protocol is provided by introducing a multi-time scale singularly perturbed system to ensure that follower quadrotor UAVs can keep a predetermined formation while tracking the desired trajectory. Then, the stability analysis of the proposed controller is conducted using singularly perturbed and Lyapunov theory. Simulation results of different formations show that multiple quadrotor UAVs can complete formation tasks efficiently and accurately.