Study on fault diagnostic strategy of intelligent magnetic detection microsystems

Intelligent Magnetic Detection Microsystems (IMDM) are complex microsystems, which are used to obtain the information of motor flux and speed in single-driveway traffic system; the microsystems have to fulfill the task in a harsh environment of field, which would infect the reliability of system. An effective method to ensure maintenance cost and reliability is to integrate efficient built-in-test and monitoring function into IMDM, so testability analysis is introduced in the design of Microsystems. The Microsystems testing-points and diagnostic strategy are reasonably identified, which are beneficial to implement the rapid detection and fault isolation. This paper presents an approach to construct a fault message matrix based on the functional block diagram and signal flow chart of the microsystems. By analyzing the contribution of the testing-points to fault detection and fault isolation, the matrix is resolved step by step, the most necessary testing-points are identified and optimal diagnostic strategy is determined. Thus, the purpose of fault detection and fault isolation is achieved by the use of the fewest testing-points and short time.