LAUSR

In this brief, the estimates of the upper bound of disturbance and all physical parameters of attitude dynamics of quadrotor system are considered, respectively. By virtue of the estimation result of the upper bound, any prior information of disturbance are not required in the construction of quadrotor controller. To compensate for saturation effect, an adaptive second-order saturation auxiliary system based on the parameter estimation result is proposed. Furthermore, a robust attitude trajectory tracking controller based on sliding mode approach is presented to guarantee that the defined tracking error is stabilized asymptotically. The bound of real transient attitude tracking error in terms of $L_{2}$ norm is derived by designing an auxiliary equation. Finally, simulations are carried out to illustrate the effectiveness of the proposed controller.