Fault Model Research Of Engine Control Circuit

Modeling of engine control system plays an important part in the modeling process of aircraft maintenance simulator. The accuracy of the engine control model affects the fidelity of simulator’s simulation directly. Modeling and simulation of the CFM56-5B turbofan engine’s control circuit was studied on in this paper.Firstly, the CFM56-5B turbofan engine control system working principle was discussed,functional model of engine control system and the control circuit’s external interface were defined by requirement analysis. It proposed basic modeling principle of simulation of engine control circuit. Then the conditional directed graph theory combined with assemblies modeling method was adopted to establish engine control circuit simulation model.Secondly, using engine fuel control circuit for example, assemblies model was established, which includes the description of units’ function module, the definition of mathematical model and input/output signals. It established typical fault model of engine control circuit through constructing the fault factors on the basis of normal state model. The established practical and simplified fault model not only improves the real time feature of simulation, but also realistically reproduced the fault performance, fault logic and effect, so can satisfy the requirements of the engine fault simulation of aircraft maintenance simulator.Finally, in order to be more intuitive model to express the functionality and the interface relations of units, MATLAB/Simulink was used to simulate the component model of engine control circuit. And the results show that the simulation models are accorded with the requirements of simulator engine control system by adjusting and proving.