Jerk-Limited Trajectory Planning and Robust Control for Time-Optimal Flight of Quadrotors Through Narrow Gaps

This paper investigates the time-optimal flight traversing narrow gaps of quadrotors in cluttered environments that exploits a time-optimal trajectory planner and a tracking controller. Specifically, after the collision-free path is generated by the RRT* method, a jerk-limited trajectory is designed considering the optimality of time which satisfies the position and attitude constraints to fly through gaps. Then, a robust hierarchical controller is utilized for trajectory tracking consisting of a saturated control force and an attitude constraint control torque, where a dynamic estimator is introduced to counteract the disturbances. In addition, a switching algorithm is designed to improve the accuracy of traversing gaps. Finally, simulation results validate the proposed strategies.