任务/资源图模型的任务调度与资源访问仿真分析(Ⅱ)-"爱国者"拦截作战目标过程实例分析

任务/资源图仿真建模方法由于包含丰富的时间属性而非常有利于分析复杂离散实时系统，通过一个仿真实例来分析任务/资源图模型的任务调度和资源访问。首先利用任务资源图模型对“爱国者”防空导弹拦截作战目标过程进行了仿真建模，然后利用RM任务调度方法和PCP资源访问控制协议对该系统进行了可调度性分析，包括单节点调度、多节点调度和端对端调度分析。复杂系统任务执行过程中会出现各种抢占、挂起、资源冲突情况，尤其是对于最坏情况下的任务调度和资源使用情况，通过仿真分析验证了对这些复杂情况的时间序列属性。可调度性分析和仿真分析结果表明任务/资源图模型是一种强有力的复杂离散实时系统分析仿真方法。

Simulation Analysis for Tasks Schedulability and Resources Access of Task/Resource Graph (Ⅱ)-A Case Analysis for Procedure of "Patriot" Heading off Warring Targets

The simulation modeling method by Task/Resource Graph is very advantageous to analyzing complicated discrete real-time systems due to its abundant time attributes, correspondingly, effect on schedulability by its tasks schedule algorithms and resource access control protocols will be very complicated. It is analyzed the tasks schedulability and resource access by a simulation case study. At first, simulation model of Patriot missile heading off warring targets is built using Task/Resource Graph. Then the systems schedulability is analyzed by RM algorithm combining PCP protocol, including single-node analysis, multi-node analysis and end-to-end analysis. While tasks of complicated system executing, preempting, suspending, and resource conflicting always emerge, especially, for the task schedule and resource utilization in the worst instance, the time sequences of complicated cases is validated by simulation analysis. Results of schedulability and simulation analysis exhibit that Task/Resource Graph model is a powerful simulation method for analyzing complicated discrete real-time systems.