一种带自诊断功能的CAN总线模块设计

Designed of CAN bus module with self-diagnostic function

控制器局域网络(CAN)现场总线技术在目前的雷达系统中有着较多应用,直接关系到雷达的正常运行及任务的顺利执行,因此雷达系统中的CAN总线故障亟需做到快速准确定位。采用基于告诉运放的峰值保持方法实现对CAN总线输出电压的在线测量,并通过通讯压力测试以及数据帧丢包率指标量化了CAN总线通讯质量。通过CAN总线输出电压以及通讯质量这两个重要指标,结合常见CAN总线的故障特征,实现雷达系统中CAN总线的自诊断。以带自诊断功能的CAN总线模块以及5个CAN节点组成CAN总线网络,模拟了线路短路、线路开路以及线路干扰等常见故障类型,故障诊断结果与模拟故障类型基本一致,可以快速、准确定位CAN总线在雷达系统应用过程中出现的常见故障。

CAN bus technology is widely used in phased array radar system.CAN bus faults should be located and solved quickly,because it is directly related to the normal operation of radar and smooth completion of the task.In this text,one CAN bus module with self-diagnostic function is designed,through the test of the differential level based on high-speed op-amp and peak holding.And this module also quantifies CAN communication quality using stress testing with the index of packet loss probability.Because of these two important indicators above,this module can realize the function of fault diagnostic for CAN bus in radar system.The short circuit fault,open circuit fault and bus interferences have been setted in experiment platform which includes the module with self-diagnostic function and other five CAN nodes.The experimental results are consistent with the set faults,and the conclusion is that CAN bus faults can be located quickly and accurately using the module with self-diagnostic function.