中文摘要：

针对水下平台工作环境复杂、通信实时性和可靠性要求高的特点，设计了一套分布式冗余通信系统。该通信系统以西门子PLC S7-400H和工控机为主控制器，基于波分复用技术建立了冗余的光纤传输通路；同时提出了一种新型的扩展单调速率算法，对水下平台的任务进行了优先级分配，并基于此算法进行了通信系统软件设计。经过可靠性分析和半实物仿真试验验证，该通信系统的实时性、可靠性及冗余机制符合设计要求，可以成功应用于水下平台，效果良好。

英文摘要：

A distributed communication system is designed to apply in an underwater platform, considering the complexity of its actual working environment and the high real-time and reliability requirements. A redundant fiber optic transmission path is established based on WDM （Wave Division Multiplexing）, using Siemens PLC S7-400H and IPC as the main controllers. A new ERM （Extend Rate Monotonic） algorithm is proposed to assign the task priority according to the practical communication requirements, based on which the software design is finished. After reliability analysis and semi-physical simulation, it is confirmed that the real-time, reliability and redundancy of the communication system can meet the design requirements, which can be successfully applied in the underwater platform with good effects.