Nonlinear control of quadrotor UAV under rotor failure for robust trajectory tracking

Area of Science:

• Robotics and Control Systems
• Aerospace Engineering
• Unmanned Aerial Vehicles (UAVs)

Background:

• Quadrotor unmanned aerial vehicles (UAVs) are susceptible to rotor failure, which can lead to loss of control.
• Existing control strategies often struggle to maintain stability and trajectory tracking after a complete rotor failure.

Purpose of the Study:

• To develop a trajectory tracking control law for quadrotors capable of handling single rotor failure.
• To enable quadrotors to maintain orientation and position control using only three rotors.

Main Methods:

• A two-stage control design approach was implemented using geometric control on the Lie group SO(3) for attitude dynamics.
• The controller was extended to SE(3) with a saturation-based feedback law for center of mass position tracking.
• The control law was designed for a reduced state space, excluding vertical axis angular velocity and orientation.

Main Results:

• The proposed control law achieves almost global exponential tracking for quadrotors with a single rotor failure.
• The controller enables the quadrotor to track orientation and position trajectories using only three rotors.
• Numerical simulations and preliminary experimental tests demonstrated the controller's effectiveness in aggressive maneuvers and post-failure scenarios.

Conclusions:

• The novel geometric control design offers a robust solution for quadrotor trajectory tracking despite complete single rotor failure.
• This approach enhances the resilience and operational capabilities of unmanned aerial vehicles in challenging conditions.
• The study validates the practical applicability of the control design through simulations and real-world experiments.