Authors: Wesam Jasim; Dongbing Gu
Addresses: College of Computer Science and Information Technology, University of Anbar, Ramadi, Iraq ' School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester, UK
Abstract: In this work, a leader-follower formation control problem of quadrotors is investigated. The quadrotor dynamic model is represented by unit quaternion with the consideration of external disturbance. Nonlinear H∞ design approach is introduced and robust controllers for both leader and follower robots are derived by solving a Hamilton-Jacobi inequality following from a result for general nonlinear affine systems. Then some robustness conditions of the proposed controllers are obtained by selecting appropriate parametrised Lyapunov functions. The resultant state feedback controllers establish the asymptotically stability of the closed-loop nonlinear system. In addition, integral backstepping (IB) controllers are also derived for the leader-follower formation control problem. The purpose of designing IB controllers is to evaluate the robustness of H∞ controllers by comparison. The simulation results from both types of controllers are compared and robustness performance of the H∞ controllers over the IB controllers are demonstrated.
Keywords: leader-follower formation; nonlinear H∞ control; integral backstepping control; unit quaternion; external disturbances.
International Journal of Systems, Control and Communications, 2020 Vol.11 No.1, pp.25 - 51
Received: 12 Apr 2018
Accepted: 16 Feb 2019
Published online: 20 Feb 2020 *