Research On Relevant Technology In Analysis And Decision At The Testability Aid Design For Mechatronics Equipments

With the development of mechatronics system, reliability, testability and maintainability of it becomes more and more important. Design For Testability (DFT) extends the capability of fault diagnosis technique by arranging the test and diagnostic resources in the system design phase. However, because of the lack of the aid tools in DFT, little progress was made in DFT. To solve this problem, the relevant technology in the aid tools in DFT for mechatronics equipments is studied in this paper. The main contents are described in brief as follows.1. Testability Information Description Model (TIDM) is the information bridge between system design process and DFT process. To outline such information, the TIDM is constructed by utilizing the EXPRESSE-G language, on which testability DBMS are constructed as the base of DFT.2. Aiming at the problem of test selection, a mathematical model for optimal test selection is established. After the analysis on the test combination sets, some punished functions on testability are proposed. A genetic-algorithm-based algorithm is constructed to solve such problem. The design experiments show such algorithm is very effective and efficient.3. The test sequence is another important problem of DFT. A cost evaluating function of test sequence is constructed by utilizing the test-fault information matrix. In order to get the minimization of the cost of test sequence, an AO*-based test sequence algorithm is implemented, whose heuristic evaluation function (HFE) is Entropy or Huffman code function. The experiments show that the optimal sequence can be reached by utilizing such an algorithm.4. A prototype computer aid design tool for testability is implemented by integrating testability information description module, optimal test selection module and optimal test sequence module. Based on the system, the scheme of optimal testability design of a mechatronics platform is achieved.