Geometry-Based Adaptive Tracking Control for an Underactuated Small-Size Unmanned Helicopter
Xun Gu, Bin Xian, Yinxin Wang
Abstract
This article focuses on the position and attitude tracking control design for an underactuated small-size unmanned helicopter. Considering the modelling uncertainties and the unknown external disturbances associated with the small-size unmanned helicopter, a new geometry-based adaptive tracking controller on special orthogonal group (SO(3)) is developed. To overcome the singularity and ambiguous issue inherented in the Euler angle expression and quaternion expression, the small-size unmanned helicopter’s dynamics is established on SO(3). Then, by using the sliding observer and radial basis function-based neural networks (RBFNNs), the helicopter’s dynamic modelling uncertainties and the unknown external disturbances are compensated. The stability of the closed-loop system is proved via the Lyapunov-based stability analysis. Moreover, the effectiveness of the proposed control strategy is verified on the self-made hardware-in-loop (HIL) testbed, and the experimental results show high position and attitude tracking accuracy of helicopter and the strong robustness to the unknown external disturbances.