Improved adaptive super-twisting sliding mode controller design for trajectory tracking control of QUAV

Abstract To address the trajectory tracking control problem for quadrotor unmanned aerial vehicle (QUAV) under external disturbances, an improved adaptive super-twisting sliding mode controller (IASTSMC) is designed in this paper. Firstly, by considering the response speed in attitude channel is much faster than that in position channel, the dynamic system is decomposed into two subsystems: the position and attitude subsystem, to prevent performance degradation caused by dynamic coupling between subsystems. Secondly, in order to accelerate the system response speed, a linear function is used to replace the generic function, and then an IASTSMC is developed to achieve the fast trajectory tracking speed. Moreover, a new piecewise function is designed to replace the generic sign function to suppress the chattering of the control system. Thirdly, in order to deal with the unknown bounded disturbances, an adaptive law is constructed to optimize control gains in real time. In the end, numerical simulations demonstrate that, compared with some existing control algorithms, the methods proposed in this paper achievedsuperior trajectory tracking results.