Fault diagnosis expert system for hydraulic system of missile launcher

The hydraulic system is a power source of a missile launcher, and its reliability decides the working performance of the launcher. Based on the characteristics of the knowledge of the hydraulic system's failures, a new way to express the expert's knowledge in this field which is to divide the knowledge into failure phenomena, failure causes and failure rules is put forward. A method to acquire knowledge of failures is also designed. In this method, the before and after components of a failure rule are constituted respectively by failure phenomena and causes, and the effective organization and maintenance of the failure-knowledge's databases are actualized. As for the structure of the fault-diagnosis flow chart, a new concept, which converts the flow chart to a fault-diagnosis binary tree, is presented. According to this idea, the fault inference engine and the interpretation machine with preorder traversal algorithm of the binary tree are achieved. The results show that these methods and principles to design the expert system have practicability and universality, and can be used as references for designing other expert systems.