Support Hydraulic Valve Test System Fault Diagnosis And Software Reliability Study

When the Support hydraulic valve test system failures, it is difficult to remove the obstacles since the complex and comprehensive incentive. In order to solve the problems, we developed an expert system of online condition monitoring of hydraulic system and fault diagnosis based on the LabVIEW. This system combined with data acquisition, system bus, theory of intelligent control and technology of virtual instruments, which can find out the location and the cause of fault quickly, and then provide some corresponding troubleshooting suggestions to the user. with the diagnosis expert system, user would avoided with blind searching for the cause, which then saved the time and the cost and then improved the efficiency and economic benefits of the system.The fault diagnosis expert system was developed with LabVIEW. Firstly, we developed a online condition monitoring module based on the platform of NI hardware platform. The data acquisition card of NI collect all the monitoring parameters, such as pressure, temperature and flow, which were detected and sent back by the sensors. Then the data would be send to the computer for analysis and processing, and then extract the features fault signal. Secondly, the fault diagnosis module was developed. With the principle of parameter measurement, the feature signal which were extracted in the condition monitoring module, would be compared with the normal equipment parameters to judge whether there is an error. If so, There would be an system alerts and then fault handling. Otherwise, the tendency of parameters change would be predicted. The principle of production-rules representation to express domain expert's knowledge and the development methods of expert system knowledge base on Microsoft Access were described in detail. Finally, a reasonable mechanism to explain the location and cause of fault, and the solutions were offered to the users with an easy understandable way.The fault diagnosis expert system implements a visualization of operating parameters of the hydraulic system and a high efficiency of fault diagnosis. At the same time, the system could meet the needs of different users since it's capability to do more post-processing for the data collected with powerful data processing toolkit in LabVIEW.