Three dimensional stabilization controller based on improved quaternion transformation for fixed-wing UAVs.

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Robotics

Background:

• Fixed-wing unmanned aerial vehicles (UAVs) require advanced control for stable three-dimensional flight.
• Traditional Euler angle representations of attitude can lead to singularities and complex dynamics.
• Understanding nonholonomic characteristics is crucial for UAV stabilization.

Purpose of the Study:

• To develop a robust control strategy for achieving three-dimensional stabilization of fixed-wing UAVs.
• To simplify the UAV's dynamic model and overcome attitude representation singularities.
• To design and validate a novel continuous periodic time-varying controller (CPTVC).

Main Methods:

• Analysis of nonholonomic characteristics, constraint non-integrability, and controllability.
• Application of quaternion theory to transform UAV dynamics, simplifying trigonometric terms.
• Design of a continuous periodic time-varying controller (CPTVC).
• Validation using the homogeneous method and hardware-in-the-loop simulation.

Main Results:

• Quaternion transformation effectively simplifies the UAV dynamic matrix and avoids Euler angle singularities.
• The designed CPTVC demonstrates effectiveness in stabilizing UAV dynamics.
• Hardware-in-the-loop simulations confirm the controller's ability to achieve exponential stability.
• The controller successfully stabilizes UAVs from any initial position.

Conclusions:

• The proposed quaternion-based approach and CPTVC provide an effective solution for three-dimensional UAV stabilization.
• The method enhances control system conciseness and robustness.
• The validated controller ensures reliable performance for fixed-wing UAVs in diverse flight conditions.