Wide-Range High-Confidence Surge Margin Estimation Method for Aircraft Engine

The confidence of the onboard adaptive model in estimating surge margin significantly affects the operating stability in an aircraft engine’s active surge margin control process. Unfortunately, the existing onboard adaptive models lack high confidence, although wide-ranging in estimation, due to the unknown surge boundaries in component characteristics. Therefore, this paper first accurately estimates the actual surge margin during the engine operating near-surge boundary using a pressure correlation measurement technology. Then, innovatively, the estimated surge margin is used to correct the surge boundary of the nonlinear onboard model of the engine to obtain the actual surge boundary, thereby guaranteeing confidence. Finally, a nonlinear onboard adaptive model based on an improved spherical unscented Kalman filter is employed to achieve wide-range high-confidence surge margin estimation throughout the engine’s life cycle. Simulation results demonstrate that the proposed method is effective and has a high-confidence level in surge margin estimation, ensuring estimation accuracy of over 95% for both standard and degraded engines, far surpassing existing techniques. The proposed method provides a technical means for sensing surge margin in future high-stability engine active control.