Controllers for flight in a string-type geometry and string stability in a group of UAVs with kinematic and input generator dynamic models

The paper presents a control algorithm for solving the trajectory tracking problem for an Unmanned Aerial Vehicle (UAV) in flight at a fixed altitude when control signal generators are integrated in the model. The approach presented in the article allows us to implement a control law under physical constraints and to avoid singular cases in the control process. Using the concept of virtual vehicles we apply tracking controllers for a group of UAVs flying in a string-type formation. Using the proposed algorithm we establish string stability, and with the help of the concept of L-2 string stability the controller reduces the spacing error propagations between the UAVs flying in a convoy-like formation. Numerical and simulation results are demonstrated.