Research On Technologies And Applications Of Testability Virtual And Physical Integrated Test

Testability addresses the extent to which a system or unit supports fault detection and fault isolation in a confident, timely and cost-effective manners. Testability indices are the key performance indicators that reflect the testability level, and can be tested and measured by testability test. The testability test technology is divided into physical test and virtual test techniques which are technically excellent complementary. The integrated testability test that combines the merits of testability virtual test and physical test holds the promise of a more accurate testability assessment a less sample size of physical test.Currently, the related research is relatively few. The main problems existing in the integrated test technology include how to determine the sample sizes of virtual and physical tests simultaneously, how to model the virtual prototype, and how to use data gathered from two types of tests for testability index assessmentThe main contents of the dissertation are as follows1. The scheme design and index assessment solution for testability virtual&physical integrated testFor the scheme design problem, based on the Bayesian sample size determination method, this paper constructs an indicator to evaluate the test design effect and a equivalent model that discounts virtual samples to physical samples. Then, testability virtual&physical integrated test scheme design methods are studied with different constraints, one of which is considering the virtual test cost and the other is not. The results show that the optimal scheme should be selected between traditional physical test scheme and the virtual and physical integrated test scheme.For the index assessment problem, this paper refers to the power priors method to construct the prior distribution using the virtual test data, and then combining the physical test data, the posterior distribution of the index parameter is given. Based on the posterior distribution, the testability index is evaluated.2. Testability virtual prototype modeling framework and its implementationFor the virtual prototype modeling problem, a hierarchical modeling framework is proposed for the testability virtual test. Based on the Modelica language, this paper studies the specific implementation approach of various elements in the hierarchical framework. The hierarchical modeling framework and its Modelica implementation are validated by a certain case.3 The testability virtual&physical test technology and the application in a certain AHSTaking a certain attitude heading system(AHS) as the research object, in order to study the whole technical processes and the entire technical content of the testability virtual&physical test, the AHS virtual prototype is built using the Modelica language and Dymola software, and the credibility of the virtual test data is evaluated by combining the analytic hierarchy process and the fuzzy comprehensive evaluation method. Then, according to the scheme design approaches of the testability virtual&physical integrated test and the traditional minimum acceptable value test, different test schemes are designed and testability tests are carried out respectively. Finally, the testability index is assessed and the results are analyzed. Results show that, the proposed virtual modeling framework and its implementation approach is feasible, and the scheme design approaches of the testability virtual&physical integrated test is effective.