The Validation Of BIT For Engine Digital Control System And The Study Of Advanced BIT Testing Method

The application of BIT technique is an effective approach to improve the reliability and maintainability of the aero-engine digital control system. With the typical circuit fault model and conventional BIT testing method, this paper researches into the validation technique of BIT and smart fault detection which enhance the test effect of BIT.In this paper, on the basis of typical circuit fault model and conventional BIT testing arithmetic, the verification platform for BIT technique is founded, which is composed of a fault injector and a manage computer. There are two functions in the fault injector, one is the realization of digital controller's work environment by simulating the electrical characteristics of sensors and actuators, another function is the control of the fault injection which is realized by the voltage-controlled constant voltages source and relay switch circuit etc. The manage compuer is in charge of the fault mode setting, fault injection process controlling and result data retrieving. With the verification platform, the experiments of fault injection and fault detected algorithm validation are carried out in the prototype of electric controller. Analytic results indicate that, the verification platform can do well in fault injection and result data treatment, and the electric controller BIT attains the expected capability. Smart BIT has been studied in this paper considering the false alarm of conventional BIT. The fault diagnosis technique of the Markov model and information fusion technique based on the artificial neural network have been discussed. The fault detection tests of LVDT sensor are assessed applying the neural network of BP and ART-II, and the validity is proved by the simulated result.