The Research And Application Of Combat System Fault Model Based On Extension Fault Tree

With the development of computer technology, computer software has been widely used in many fields of national defense construction, such as navigation, aviation and aerospace, etc. As one of the important components of military system, combat system has become the focus of research. Combat system can control the force information and operational information in the battlefield quickly and effectively, and it is more and more important in the military battlefield. But in the war, once the combat system failure, the entire battlefield is difficult to control which resulting in significant casualties and economic losses. So it is very important to model and analyze the fault of the combat system. This paper studies the fault model based on the extended fault tree.First, the combat system as a real-time control system can deal with complex activities in the time domain, fault descriptions were related to the time between events. While the traditional fault tree hadn't the ability to describe the time factor. A time constraint fault tree generation method based on extended class diagram and activity diagram was proposed. On the basis of original definition of fault tree, time constraint fault tree of semantic description was added, designing conversion rules from the extended class diagram and activity diagram to time constraints fault tree. Based on the transformation rules and time conversion rules, designing algorithm inverse traversal activity diagram and class diagram to top-down generate fault tree with time constraints. This algorithm can solve the problem that the traditional fault tree can't fully reflect the static structure of the system and can't describe the behavior of time constraint, and it can realize the automatic generation of the extended fault tree.Secondly, aiming at the problem that the traditional fault tree can't analyze the time of fault propagation, a time constraint fault tree analysis method was put forward based on the extended semantic of the fault tree. The calculation rules of the time constraint logic gate and the event average transfer rate, the input event to the output event propagation rate and the intermediate event arrival rate are given. The propagation rate and arrival rate of the basic event and the minimum cut sets of the fault tree were designed, and the algorithm was proposed to obtain the basic event time importance and the minimum cut sets arrival rate for each node in the fault tree. The experimental results showed that the proposed timing analysis method can provide theoretical basis for fault diagnosis and prevention.Then, aiming at the problem of the comprehensive evaluation of the traditional fuzzy fault tree model, the reliability of the expert evaluation was seldom considered in the process of dealing with the expert opinion. Fuzzy number determination method based on the confidence degree of S type curve was proposed, the expert's authority coefficient and the consistency coefficient were introduced. Using the probability deviation method to get the adjustable parameters of the S type curve, the fuzzy failure probability of the basic events of the fault tree can be calibrated based on the adjustable parameters and the confidence level. Experiments were carried out in the combat system. The experimental results show that the improved fuzzy fault tree was more consistent with the objective reality.Finally, based on the proposed extended fault tree generation and analysis algorithms, the extended fault tree construction and analysis system was designed and implemented. Taking the anti-missile operation system as an example, the static composition class diagram and time constraint activity diagram of the anti-missile operation system were constructed, and the extended fault tree with time constraint was generated, then the failure time and failure probability were analyzed. The experimental results showed that the proposed method can provide a new and effective approach for fault diagnosis and prevention of anti-missile operation system.