自主作业氢燃料电池拖拉机通信网络设计与试验

Research and Experiment on Communication Network Design for Autonomous Operation Hydrogen Fuel Cell Tractor

摘要:

针对传统通信网络布线方式难以满足自主作业氢燃料电池拖拉机对信息传输高效性、稳定性及功能扩展需求的问题，本文基于SAE J1939协议和ISO 11783标准提出一种多速率控制器局域网（Control area network, CAN）总线架构。首先，结合田间自主作业流程，对传感、定位与驱动控制等数据流进行需求分析。其次，依据图论最小复杂度原则，对比多种拓扑结构，确定网关加三总线结构，并根据自主作业氢燃料电池拖拉机结构及其作业工况特点，划分 CAN 通信网络节点并定义各节点的功能。进而，基于图论建立网络拓扑的数学模型，对不同结构的每秒总信息量N和每秒节点信息量Z进行分析和比较。在此基础上，设计高速（500kb/s）与低速（250kb/s）双速率总线结构，通信报文格式与系统软件开发严格遵循 SAE J1939 协议和 ISO 11783 标准。最后，利用CANoe 软件对通信系统的硬件功能和通信效果进行测试，并在整车上开展实车验证。测试结果表明，各总线的负载率分别为28.22%、19.20%、22.85%，均低于50%的要求，研究结果可为自主作业氢燃料电池拖拉机通信网络设计提供理论依据和参考。

Abstract:

In response to the issue that traditional communication network cabling methods are unable to meet the requirements of high efficiency, stability and functional expansion for information transmission in autonomous hydrogen fuel cell tractors, a multi-rate control area network (CAN) bus architecture was proposed based on the SAE J1939 protocol and ISO 11783 standard. Firstly, the data flow requirements for sensing, positioning, drive control, etc. were analyzed in combination with the autonomous operation process in the field. Then, using the principle of minimum complexity in graph theory, multiple topologies were compared and a gateway plus three-bus structure was determined. The CAN communication network nodes were divided based on the structure of the autonomous operation hydrogen fuel cell tractor and its working conditions, and the functions of each node were defined. For common network topologies, a mathematical model was established based on graph theory, and the total information volume per second N and the node information volume per second Z of each structure were analyzed and compared. A high-speed and low-speed dual-bus structure was adopted to design the communication network of the autonomous operation hydrogen fuel cell tractor, with bus rates selected as 500kb/s and 250kb/s. The communication message and system software design were developed based on the SAE J1939 protocol and ISO 11783 standard. The hardware functions and communication effects of the communication system were tested by using CANoe software and verified on the whole vehicle. The test results of the bus load rate were 28.22%, 19.20% and 22.85%, all below the 50% requirement. These results verified the feasibility and provided a feasible solution for the design of the communication network of autonomous operation hydrogen fuel cell tractors.