Affine Formation Tracking Control of Multi-UAVs Based on Sliding Mode Technique

This paper investigates an affine formation tracking control approach for multiple quadrotor unmanned aerial vehicles (UAVs). The control scheme can make those quadrotors not only achieve the desired formation pattern, but also track any time-varying affine formation, for example, a rotation, scaling, shearing of a nominal configuration. The leader-follower strategy is adopted to solve the affine formation problem, in which the target formation is only known by the leader quadrotors, and the follower quadrotors are solely required to track the leaders. The nonlinear model of each quadrotor is considered, and a sliding mode control law is developed to achieve various affine formation patterns. The proposed control law is proven to be globally stable by Lyapunov stability theory. Finally, the effectiveness of the proposed control law for tracking affine formations is corroborated by the simulation results.