Predefined-Time Composite Adaptive Fuzzy Nonsingular Attitude Control for Multi-UAVs

Abstract

This article considers the predefined-time composite adaptive attitude control problem for nonlinear multiple six-rotor unmanned aerial vehicles (UAVs) with external disturbance. The multiple six-rotor UAVs considered are regarded as nonlinear multiagent systems, and each subsystem has multiple inputs. Via the backstepping recursive algorithm, a valid adaptive predefined-time control method is proposed by combining fuzzy logic systems (FLSs) and predefined-time theory. FLSs are utilized to handle unknown nonlinearity and unmodeled parts in attitude systems. By constructing a serial-parallel estimation model, the accuracy of approximating the unknown functions is ameliorated. Moreover, taking into account the prediction error of the serial-parallel estimation model, a novel composite adaptive fuzzy control scheme is developed. Unlike some existing control schemes for multi-UAVs, the developed control scheme allows one to shun the chattering phenomenon and ameliorate the approximation performance. The developed controller assures that all signals of the multiple six-rotor UAV attitude systems are bounded and the tracking errors converge to a small neighborhood of the origin within an expected settling time. Eventually, with the help of simulation results, the effectiveness of the proposed control scheme was illustrated.