Adaptive NMPC-based active stability comprehensive control for aero-engine compressors

This study proposes an active stability comprehensive control scheme based on adaptive Nonlinear Model Predictive Control (NMPC) to address active stability control limitations in aero-engine compressors, focusing on unclear control objectives, imperfect compressor models, and impractical control algorithms. The analysis begins by rigorously defining comprehensive control objectives based on typical flight mission aerodynamic stability requirements. The compressor model is expanded to include full-speed and full-flow characteristics, air injection effects, and uncertainties/disturbances, forming the Expanded Variable Speed Moore-Greitzer (EVSMG) model. The core of the approach is the design of an adaptive NMPC controller, which includes an adaptive prediction model using the Nonlinear Disturbance Observer (NDO), formulation of a nonlinear programming problem, and implementation of an alternating optimization strategy. Simulations confirm the EVSMG model's effectiveness in simulating various compressor instability modes across different rotor speeds. Results show that the adaptive NMPC controller achieves rapid and precise tracking of compressor pressure ratio and speed, simultaneous surge and stall suppression, and adherence to preset constraints. The NDO accurately estimates unknown compressor characteristics, uncertainties, and disturbances with an estimation error of approximately ±0.01. The alternating optimization strategy reduces computation time by about 40 %, maintaining control accuracy.