Tracking Differentiator-Based Active Disturbance Rejection Pressure Control in Altitude Test Facility

The altitude test facility plays a crucial role in the development of modern aeroengines, enabling the simulation of a wide range of flight conditions. Therein, the exhaust pressure system is responsible for creating the aeroengine flight altitude and speed by simulating the rear chamber ambient pressure, where accurate and effective real-time signal processing and feedback control are essential. Nevertheless, the stringent requirements for flight environment simulations, combined with inevitable measurement disturbances, often lead to signal corruption, posing challenges for signal processing and feedback control. To address these issues, a new discrete-time optimal control algorithm-based tracking differentiator (TD) is proposed by constructing isochronous region boundary curves. Also, zero-order hold discretization is employed to improve signal processing precision. Meanwhile, phase compensation is introduced to mitigate phase lag in both filtering and differential extraction. The convergence analysis via Lyapunov functions is conducted to theoretically validate the stability of the proposed TD. Numerical simulations demonstrate that the proposed TD exhibits outstanding filtering and differential extraction performance. Furthermore, integrating the proposed TD into exhaust pressure control simulations significantly improves the disturbance estimation capability of the extended state observer, thereby enhancing the overall quality of exhaust pressure control.