Accurate High-Maneuvering Trajectory Tracking for Quadrotors: A Drag Utilization Method

The balanceness between the tracking performance and the aerodynamic drag treatment is of paramount importance especially in the presence of the quadrotor aggressive maneuvers. Different from standard approaches that achieve precise tracking by feedforward compensating the estimated drag, this work presents a scheme to appropriately utilize drag. By means of the proposed drag-utilization scheme, the disturbance absorption can be achieved. In addition to eliminate the adverse effect, the control gains are subtly enlarged with less noise. Moreover, an adaptive law for estimating the drag coefficients onboard is provided. Subsequently, the wind disturbance is explicitly considered at the control design stage. A wind speed observer (WSO) is designed to improve the tracking performance, based on current velocity and attitude. Compared with the traditional disturbance observer (DO), the proposed WSO can not only fully utilize the disturbance characteristic but also contribute to reduce the control conservativeness. In experiments, two types of quadrotors with different thrust-to-weight ratios (TWRs) are employed to evaluate the applicability of the presented scheme. Comparative results show that the proposed scheme outperforms several popular methods.