| In motor condition monitoring applications, traditional human expert approach for sensor exploitation is not cost-effective. The training requirements for human experts are extensive, and the overall training process is a very time-consuming task. In addition, the performance of human experts has limitations. For human experts, it is difficult to examine all the input-output data from the motor system under varying noise and motor load conditions. With a motor condition monitoring system that can automatically generate rules in the form of interpretable linguistic fuzzy if-then rules and membership functions, it would be easier for experts to understand and modify the rule base and also to track the motor condition for maintenance and replacement requirements. In this research, a methodology for fuzzy rule and membership function generation for broken rotor bar detection of squirrel-cage induction motors was developed. The methodology consists of a set of steps that an expert might do for fuzzy rule and membership function design. The methodology is named "H-ROC", since it utilizes histogram analysis with overlapping bins and a weighted cost function based on ROC (Receiver Operating Characteristics) curve analysis. As a second method, an existing fuzzy rule extraction method was extended to broken rotor bar detection problem. The performance and sensitivity analyses of the two methods were conducted. |
