Fault tolerant cooperative control of multiple UAVs-UGVs under actuator faults

Abstract

A fault tolerant cooperative control (FTCC) strategy for a team of an unmanned aerial vehicle (UAV) and unmanned ground vehicles (UGVs) in the presence of actuator faults are investigated in this paper. A combination of a linear model predictive control (MPC) and input-output feedback linearization is implemented on each UGV, while a combination of a sliding mode control and linear quadratic regulator (LQR) are applied to the UAV. When a severe actuator fault occurs in one of the robots, it becomes unable to complete its assigned task, and it has to get out from the formation mission. FTCC strategy is designed with the robots' tasks are re-assigned to the remaining healthy robots to complete the mission with graceful degradation. The FTCC problem is solved as an optimal assignment problem, while a Hungarian algorithm which applied to each robot will solve the assignment problem. Formation operation of the robot team is based on a leader-follower approach, and the control algorithm is implemented in a decentralized manner. Finally, simulation results are presented in order to demonstrate the performance of the team in both fault-free case and faulty case.