Adaptive trajectory tracking control of quadrotors based on trigonometric parameter estimation law

This paper proposes a trigonometric adaptive control (TAC) approach for quadrotors in order to obtain remarkable trajectory tracking performance in the presence of time-varying parameters. The stability of proposed controller is guaranteed by using Lyapunov stability theory. A square trajectory for way-point tracking and a 6-DoF under-actuated nonlinear quadrotor model with time-varying parameters have been used for numerical analysis. To better assess the performance of proposed adaptive controller on trajectory tracking, the results have been compared with those of a similar previous adaptive controller. The effectiveness of proposed adaptive controller has been provided highlighting that the lateral x and y position errors have been reduced by 75.18% and 71.86%, respectively, while the attitude (pitch, roll and yaw) errors have been reduced by 75.87%, 74.72% and 98.32%, respectively. Additionally, the altitude (z) error has been minimised by 37.89%. The most remarkable result to emerge from this study is that better trajectory tracking performance has been obtained by proposed adaptive controller without causing chattering phenomenon. Furthermore, the results demonstrate that the attenuation of disturbance inputs on the responses has been achieved.