Nonsingular Hierarchical Trajectory Tracking Control for Miniature Helicopter Considering Perturbation Caused by Attitude Error and Nonlinear Coupling

This work proposes a nonsingular trajectory tracking controller for a miniature helicopter based on hierarchical inner-outer loop strategy. Compared to traditional hierarchical control strategy based on timescale separation assumption, this work design the controller considering the perturbation caused by attitude error and nonlinear coupling, and provide rigorous stability for the closed loop system. Besides, an explicitly bounded intermediary control for the position loop is designed to ensure that no singularity occurs in generation of reference attitude signal. As for the attitude control, a pair of virtual angles extracted from rotation matrix is adopted to derive the attitude kinematics, by which the reference attitude is simplified. Also, a barrier Lyapunov function based attitude control is designed to determine the initial attitude constraint ensuring the roll and the pitch won’t reach ±
^π
/
2
to avoid singularity.