Robust cooperative control in the presence of obstacles

In this paper, a coordination of two types of heterogeneous robots, namely unmanned aerial vehicle (UAV) and unmanned ground vehicle (UGV) is considered. The UAV plays the role of a leader for the UGV. While UAV tracks a predefined geometric path, the UGV is supposed to track the planar position of UAV and avoid obstacles. Obstacle avoidance may lead to increase in the distance among agents. In order to compensate it, a sliding mode based unknown input observer is used to estimate the UGV inputs. In the next step, by utilizing feedback linearization method, the UAV adjusts its motion to keep the required distance. The simulation results validate the performance of the proposed algorithm.