Abstract:

The Controller Area Network （CAN） based Autonomous Underwater Vehicle （AUV） dual-machine redundant control system requires a certain degree of clock synchronization， and it lacks an Ethernet interface that implements IEEE 1588 （precision clock synchronization protocol standard for network measurement and control systems）. In view of this problem， a precision clock synchronization method based on CAN and IEEE 1588 principle was proposed. Firstly， the core code of CAN-based clock synchronization software was written on the basis of the principle of IEEE 1588. Then， the key data of interaction were encoded and compressed to 8 bytes based on the data length of CAN standard frame. Finally， the synchronization performance of the CAN-based dual-machine clock synchronization software was tested and compared with that of the Ethernet-based dual-machine clock synchronization software. Test results on actual hardware platforms show that by using the proposed method， the clock synchronization accuracy of dual-machine redundant control system can reach and maintain within 25 μs， satisfying the 1 ms synchronization accuracy requirement of dual-machine redundant control system. It can be seen that the proposed method can guarantee the clock synchronization accuracy of dual-machine redundant control system.

Key words: precision clock synchronization, Controller Area Network (CAN), dual-machine redundant control system, IEEE 1588, Autonomous Underwater Vehicle (AUV)

摘要：

针对基于控制器局域网（CAN）的自主水下航行器（AUV）双机冗余控制系统既需要达到一定程度的时钟同步，又缺乏可实施IEEE 1588（网络测量和控制系统的精密时钟同步协议标准）的以太网接口的问题，提出一种基于CAN和IEEE 1588原理的精密时钟同步方法。首先，基于IEEE 1588原理编写基于CAN的双机时钟同步软件的核心代码；其次，根据CAN标准帧的数据长度编码交互的关键数据并压缩至8字节；最后，测试基于CAN的双机时钟同步软件的同步性能，并与基于以太网的双机时钟同步软件的同步性能进行对比分析。实际硬件平台上的测试结果表明，使用所提方法的双机冗余控制系统的时钟同步精度可达到并维持在25 μs内，满足本双机冗余控制系统1 ms的同步精度要求。可见，所提方法可有效保障双机冗余控制系统的时钟同步精度。

关键词: 精密时钟同步, 控制器局域网, 双机冗余控制系统, IEEE 1588, 自主水下航行器