Improved Smith Predictive Control Design of Aeroengine Based on H∞ algorithm

Aiming at the network delay problem that exists in the aeroengine distributed control, system stability of the original H" controller under different time delays is investigated, and an improved Smith predictive structure is proposed to reduce the influence of delays. Firstly, according to the control requirements of aeroengine under some typical operating conditions, the appropriate parameters of performance index weighting function are selected to obtain corresponding H∞ output feedback controller. Then, Lyapunov function is constructed to analyze the stability of the original designed system under delays, and the allowable maximum delay that ensures the system stability is determined accordingly. In order to reduce the impact of delays and enhance the system robustness, an improved Smith compensator is designed to form a composite controller on the basis of H∞ law. Finally, taking a turbofan engine control as an example, some numerical simulation cases considering varying-time delay and disturbance are conducted to verify the effectiveness and robustness of the proposed method.