Fixed-time safety tracking control of QUAV under external disturbances using robust high-order time-varying control...

Area of Science:

• Robotics
• Control Systems
• Aerospace Engineering

Background:

• Quadrotor unmanned aerial vehicles (QUAVs) face challenges in dynamic environments with obstacles and external disturbances.
• Ensuring safety, stability, and precise trajectory tracking in such conditions is critical for QUAV operation.
• Existing control methods may struggle with unknown disturbance bounds or require specific initial conditions for convergence.

Purpose of the Study:

• To develop a robust fixed-time safety control scheme for QUAVs.
• To address dynamic obstacle avoidance and external disturbance rejection simultaneously.
• To achieve state convergence in a fixed-time, independent of initial states.

Main Methods:

• Design of a robust high-order time-varying control barrier function (R-HO-TV-CBF) for obstacle avoidance constraints.
• Development of a nonsingular fixed-time sliding mode control (NFxSMC) for guaranteed fixed-time convergence.
• Integration of R-HO-TV-CBF and NFxSMC for a comprehensive control strategy.

Main Results:

• The proposed R-HO-TV-CBF effectively handles dynamic obstacle avoidance and suppresses oscillations without prior disturbance bound assumptions.
• The NFxSMC ensures fixed-time convergence, irrespective of the QUAV's initial state.
• Simulation results validate superior performance in obstacle avoidance, disturbance rejection, and rapid error convergence.

Conclusions:

• The robust fixed-time safety control scheme significantly enhances QUAV performance in complex environments.
• The integrated approach provides a reliable solution for safety-critical autonomous flight applications.
• This control strategy offers improved robustness and convergence properties compared to existing methods.