Design and verification of aero-engine full envelope control system

The design and verification of full flight envelope robust control system for aero-engine is presented in this paper. Firstly the full flight envelope was divided into eight regions and eight nominal points that represent each sub-region were selected based on the temperature and pressure of the engine inlet. Then based on the linearized engine model at each nominal point, two degrees-of-freedom (2DOF) H-infinity controller solved by LMI which could improve the tracking performance meanwhile maintaining stability robustness was used to design the aero-engine´s controller. Face to the fact of finite robustness of H-infinity controller, as the original work, gain scheduling control system which could be coded by RTW was constructed for full flight envelope operation, where the controllers of different sub-regions could be switched with the change of engine altitude and Mach number. Meanwhile, in order to decrease the disturbance occurs in the switchover between any two controllers of different sub-regions, the bumpless switch logic based on the technology called `soften switching with inertia delay´ was adopted in the control system. Results of the hardware in-the-loop simulations based on the real-time simulation platform show well performance of aero-engine flight envelope robust control system, as well as the bumpless switch logic.