The Analysis Of Time Delay And Controller Design Of Aero-engines Distributed System

With the improvement of aero-engine control requirements,the traditional centralized control architecture has been difficult to meet the complex control requirements.In order to further improve engine performance and reduce engine weight,aero-engine control system is gradually transitioning from centralized control architecture to distributed control architecture.However,the network characteristics of distributed control system inevitably lead to the complexity of the control system,which is mainly manifested in network delay,data packet loss and other problems.Among them,the influence of network delay on system stability and various control performance indexes is particularly significant,which makes the design difficulty of the controller greatly increased.In this paper,the distributed delay control algorithm design and simulation test are carried out for the distributed control system of aero-engine with time delay.The specific contents are as follows:(1)The research on network-induced delay in distributed system is carried out,and the inducing factors of delay and the influencing factors of delay size in aero-engine distributed control system are analyzed in detail,combining with bus bandwidth and trigger mechanism.(2)Aiming at the distributed control system of aero-engine with time delay and considering the multivariable control requirements of aero-engine,a delay control method of double augmented linear quadratic regulator(DALQR)based on the optimal control theory of augmented linear quadratic regulator(ALQR)is proposed.Combined with undisturbed switching control and actuator control,the aero-engine DALQR time delay control system is designed to reduce the influence of time delay on engine system performance.(3)Aiming at the uncertainty of actual system network delay,the internal model control(IMC)method based on neural network delay prediction is proposed,and the engine internal model delay control system is designed.The digital simulation verification and analysis show that the proposed control method has better control effect on time-varying network delay.(4)The simulation platform of aero-engine distributed control system is established by using Truetime toolbox to simulate the network transmission of the actual system.Three typical topologies of distributed control system are simulated and analyzed on this platform,and the proposed controller design method is verified.(5)Hardware-in-the-loop simulation test of aero-engine distributed control system is carried out.The test results show that the designed DALQR and internal model controllers can ensure the stability of the system under distributed architecture,and can ensure the desired control performance of aero-engine under long time delay,and have good anti-interference performance.