Design And Validation Of Fault Tolerant Control System For A Turbofan Engine

From the perspective of improving aeroengine control system reliability, studiesof fault diagnosis and fault-tolerant control for sensor failure, as well assemi-physical simulation test verification,arecarried out. The paper involves the establishment of anaeroengine state variable model and a simplified real-time model, the design of fault diagnosis based on Kalman filter, the design of a feed-forward PID controller based on neural network,the design offault-tolerant aeroengine controlfor sensor,the design ofrapid prototyping controller and the test of semi-physical simulation.Firstly,the aeroengine state variable modeland the simplified real-time model are built based on a turbofan engine component-level model. With the built models, the aeroengine sensor diagnostic system is set up by using a bank of Kalman filter, which can realize the sensor fault detection and isolation.Secondly,a feed-forward PID controller based on RBF neural network is designed for the speed control loop. The algorithm combines the advantages of the neural network’s nonlinear self-learning ability and the PID controller’s robustness. In particular, the amount of the feedforward control can be achieved automatically by the use of RBF neural network’s self-learning ability,which is easy to realize in practical engineering.When the sensor is fault and diagnosed, the simplified real-time model is used to reconstruct the signal, which can achieve the fault-tolerant control with the control algorithm.In order to realize the semi-physical simulation test of theaeroengine fault-tolerant control system, a rapid prototyping controller is developed with Lab VIEW development environment and Compact RIO hardware platform. The rapid prototyping controller has a dual-channel control ability for the fuel metrering needle position and the engine speed,as well as the ability of data acquisition for the engine pressure and temperature. Besides, it has a strong computing power.Finally, combining rapid prototyping controller, fault diagnosis and fault-tolerant control system and fuel regulator physical conditions,the semi-physical simulation test for the aeroengine is carried out. The test results show that,the fault diagnosis and fault-tolerant control system can realize sensor fault detection, isolation and signal reconstruction quickly and accurately,to improve the control system reliability.