The Application Of Fault Dictionary And M-FastICA In Analog Circuit Fault Diagnosis

Fault means lead to product unable to complete the function or performance degradation leads to a state that can not meet the requirements specified. Analog circuit fault diagnosis in the design and production of electronic systems play an important role, but the fault circuit can not be avoided in use, many people proposed different methods for fault diagnosis. Since the sixties of the last century to the present, the circuit fault diagnosis has become a hot research field. With the development of electronic technology, especially the development of large-scale circuits for analog circuit fault diagnosis presents new challenges, the need to explore new theories and methods.1. This thesis elaborates the development of the present situation of the circuit fault diagnosis method and theory,for the results of analog circuit fault diagnosis technology in recent years give a brief overview. Paper describes the basic concepts and classification of analog circuit fault, features of analog circuit fault, the diagnostic method, and analog circuit fault diagnosis dictionary method of general process, describing the DC fault dictionary method, AC fault dictionary method and some new fault diagnostic methods. The innovation of this article is as follows.2. Further study of the negative entropy maximization FastICA algorithm. The objective function based on FastICA algorithm becomes smaller with successive iterations until convergence is updated each iteration, affect the speed of calculation, a signal separation method based on analog circuit fault diagnosis method based on M-FastICA and establish a test circuit for testing the validity of the method. In computing speed reflects the M-FastICA quickly. For more overlapping fault types encountered in fault dictionary method, a new method proposed for integrating fault type or split, for lower complexity analog circuits, proposed to increase the diagnostic data dimension approach to troubleshooting overlap problem.Studied the application of fault dictionary method in analog circuit fault diagnosis, and established an instance of the method for testing circuit verification. Firstly,described the application of fault dictionary method and diagnostic process, after that established a two-stage RC coupled amplifier circuit, through the fault dictionary method to diagnose faults in the circuit, proposed solutions for the problem of overlapping in the fault diagnosis. Described the example circuit fault diagnosis based on M-FastICA algorithm, first of all. create an instance of the circuit, for the original type in the circuit give a categorization process, at the excitation signal, extract the source signal. Create a test circuit with these circuits original, implant failure, and then extract mixed-signal, extract the source signals from the mixed signals with M-FastICA method to identify the fault diagnosis.