基于CAN通信的DNC系统智能转换模块设计

发布时间：2018-06-12 01:38

本文选题：网络化制造 + 数控机床　；参考：《兰州交通大学》2017年硕士论文

【摘要】：制造业是整个国家的工业基础,其发展水平直接体现了一个国家的综合国力。随着“互联网+制造业”的到来,将计算机网络技术和制造业两者紧密结合起来组成新的网络化制造模式可以提高企业的经济效益。数控机床是现代制造业的重要设备,其产量和技术水平体现了国家在制造业的国际竞争力。目前,我国仍存在大量的不具备联网功能的中低档经济型数控机床,限制了我国制造业发展水平的提升。数控机床网络化利用不同网络组建分布式数字控制(DNC)系统可实现计算机对多台数控机床的实时控制,提高了设备利用率,降低生产成本。CAN总线构建的DNC系统,上位机对多台数控机床控制过程中即使在可调度范围内,由于调度不当仍会发生通信冲突。本文设计的智能协议转换模块增加了先进先出(FIFO)存储子模块,模块的智能性体现在构建了双层通信网络,可以对FIFO存储器的存储状态进行判断,模块向上位机发送状态信号,满状态时上位机转而服务其它模块,空状态时上位机转而服务该模块,保证数控机床正常工作的同时提高了设备的使用效率。接收数控机床的状态信号,保证数据的正常传输。以通信冲突为研究点,CAN总线速率、程序消耗率、数据传输效率等参数建模计算FIFO存储器的上下限及分析具体环境参数变化对上下限的影响,通过设置合理的门限值可以有效完成上位机对数控机床控制的调度,避免通信冲突的发生。大多数中低档经济型数控机床接口为RS232C,RS485两种,一般的协议转换模块只能实现对其中一种接口数据的转换。设计的协议转换模块具有两种接口可完成CAN-RS232C,CAN-RS485功能的转换,用户可根据需要选择适当的转换接口。最后,针对设计要求进行了相应的硬件和软件设计,根据使用环境的设计要求对可靠性进行了研究。本文所设计协议转换模块在DNC系统中对不同总线间的数据进行格式转换,通过对各模块的仿真和现场运行验证了设计的合理性。
[Abstract]:Manufacturing industry is the industrial foundation of the whole country, and its development level directly reflects the comprehensive national strength of a country. With the advent of "Internet manufacturing industry", the combination of computer network technology and manufacturing industry to form a new networked manufacturing model can improve the economic benefits of enterprises. CNC machine tool is an important equipment in modern manufacturing industry. Its output and technical level reflect the national international competitiveness in manufacturing industry. At present, there are still a large number of medium and low grade economic NC machine tools without networking function in China, which limits the development level of manufacturing industry in China. The distributed digital control (DNCC) system based on different networks can be used to realize the real time control of many NC machine tools, which can improve the utilization rate of the equipment and reduce the production cost. Can bus is used to construct the DNC system. In the process of controlling several NC machine tools, communication conflicts still occur due to improper scheduling, even in the range of scheduling. The intelligent protocol conversion module designed in this paper adds the first-in-first-out FIFO (FIFO) storage sub-module. The intelligence of the module is reflected in the construction of a two-layer communication network, which can judge the storage status of FIFO memory and send the state signal to the host computer. The upper computer serves other modules when it is in full state, and the upper computer serves this module when it is in space, which ensures the normal operation of NC machine tools and improves the efficiency of the equipment at the same time. Receive the status signal of NC machine tool to ensure the normal transmission of data. With the communication conflict as the research point, can bus rate, program consumption rate, data transmission efficiency and other parameters are modeled to calculate the upper and lower limits of FIFO memory and to analyze the influence of the change of specific environmental parameters on the upper and lower limits. By setting reasonable threshold values, the scheduling of NC machine tools can be accomplished effectively and communication conflicts can be avoided. There are two kinds of interface for most middle and low grade economical NC machine tools: RS232CU RS485, and the general protocol conversion module can only realize the conversion of one kind of interface data. The designed protocol conversion module has two interfaces to complete the conversion of CAN-RS232CU CAN-RS485 function. The user can choose the appropriate conversion interface according to the need. Finally, the corresponding hardware and software are designed according to the design requirements, and the reliability is studied according to the design requirements of the operating environment. In this paper, the protocol conversion module is designed to convert the format of data between different buses in DNC system, and the rationality of the design is verified by simulation and field operation of each module.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP273

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