Image Based Visual Servoing for Multi Aerial Robots Formation

There are numerous advantages of flying in group over using single robot in mission execution. However this implies solving a crucial issue: the coordination between drones. Moreover, according to the targeted application, it may be necessary or desirable that drones fly following a given geometric shape (line, diamond, etc.), a problem known as formation control. Building and maintaining a spatial geometric shape while evolving within the environment usually requires extensive communications between the robots for coordinating their movements. In this work we focus on the use of an Image-Based Visual Servoing (IBVS) technique for building and maintaining a Leader-Follower (LF) configuration of multi aerial vehicles (UAVs) without communication. While most IBVS techniques either require rigor camera calibration or can not regulate the error according to the three robot axes, our approach avoids the calibration phase by relying on image moments features to provide a vision-based predictive compensation method. The follower robot's solution works in GNSS-denied conditions and can run using only on-board sensors. The method is validated through simulations for a group of three quadrotors.