Demonstration Method for PHM-Oriented Testability Design

The development of PHM propels the combination of design for testability and relevant PHM technology, which leads a need for the demonstration of PHM-oriented testability design. The paper mainly introduces the evaluation and demonstration method ranging from the design phase to the demonstration phase. Firstly, the index set to be evaluated is established according to the feature of the PHM-oriented testability design and its difference between the traditional testability. Then, an indexes estimation method for the design phase which is based on the testability model is proposed. In this method, a testability design and modeling software TADS is introduced and applied. Thirdly, demonstration test based on physical fault injection is introduced. The test plan covers the sample size determination, sample distribution and fault mode selection from the mode set. Two sample size determination methods based on classical binomial distribution and Bayesian posterior risk criterion are introduced. Finally, an example of flying control system is given to verify the proposed methods.