Active disturbance rejection control for flight test chamber system subject to multi-source disturbances: An extended state observer with dynamic compensation approach

The flight test chamber system for high-altitude environment simulation is subject to complex multi-source of disturbances, such as strong airflow fluctuations, large model uncertainties and high-intensity measurement noises. Although active disturbance rejection control (ADRC) has become a practical anti-disturbance method, its performance is severely limited by the disturbance estimation capability of extended state observer (ESO), which serves as the core of the ADRC framework. Toward this end, this paper proposes a novel ESO design approach with a dynamic compensation term, which augments the conventional pure error-feedback estimation mechanism via state-driven compensation, to achieve smoother, small-lag and high-precision disturbance estimation for enhanced disturbance rejection performance. The proposed approach is applied to the fal function-based nonlinear ESO ( fal ( · )-NESO), which features the characteristic of “large gain for small errors and small gain for large errors”, and is denoted as CF ( · )-NESO. The boundedness properties of the proposed observer are rigorously analyzed, and its superiority is validated through numerical simulation comparisons. Finally, the proposed CF ( · )-NESO-based ADRC (CF-NESO-ADRC) is implemented to the pressure control of the flight test chamber system, the results demonstrate that the proposed approach effectively improves steady-state tracking performance and enhances disturbance rejection capability than ADRC based on fal ( · )-NESO (fal-NESO-ADRC).