【作者】 杨朝龙；

【导师】 须文波；

【作者基本信息】 江南大学 ， 计算机应用， 2006， 硕士

【摘要】 船舶结构安全监测系统用于实现航运中的船舶结构应变的实时监测报警和船舶结构安全的评估。在比较分析了RS-485总线技术与CAN总线技术各自的优缺点、通用操作系统和嵌入式操作系统各自特点的基础上,本文给出了一种CAN总线与Windows CE嵌入式操作系统相结合的船舶结构监测系统实现方案。该方案的实现包括三部分内容。第一部分是基于CAN总线的数据采集模块的设计,负责应变数据的采集和上传。该部分涉及数据采集模块软硬件设计。在硬件设计方面,本文选用单片机SST89C54、独立的CAN控制器SJA1000、AD转换器AD679组建数据采集模块的核心部分,并对主要芯片间的接口电路、硬件抗干扰处理进行了详细阐述;在模块的软件设计方面,详细描述了数据采集模块的初始化、数据收发主要功能模块的程序流程。此外,本文讨论了影响应变测量精度的几个因素,分别采用针对应变测量非线性问题的软件修正方法、应变电阻的三线连接技术和电桥激励的四线检测技术来提高测量精度;第二部分是基于嵌入式操作系统Windows CE.NET的主机系统设计,该部分实现分为嵌入式系统内核的定制、流接口的CAN适配卡驱动程序的设计、应用系统的设计。在嵌入式系统内核的定制方面,根据硬件资源和应用需求实现了Windows CE.NET系统功能裁剪、定制;在流接口CAN适配卡的驱动设计方面,分析了Windows CE.NET的中断处理过程,阐述了CAN中断服务线程(IST)、报文收发的程序流程,本文讨论了CAN驱动对接收报文响应能力的影响,并给出了一种具有实时响应能力的解决办法,该办法根据实时响应要求和传输率设置接收缓冲队列大小和接收缓冲队列中接收报文的临界个数,从而满足对接收报文的实时要求;在应用系统的设计方面,以模块化的设计思想,阐述了应用系统主流程、系统自检、参数设定与修改、零点平衡、数据测量功能模块的程序流程设计。第三部分是通讯协议的定制。根据本系统主从式的控制特点,本文建立了主机与采集模块之间主从式的通讯机制。实现了主机对采集模块和通道的参数设置与查询、采样和数据传输控制。更多还原

【Abstract】 Vessel structure safety monitoring system can be used to implement real-time monitoring for strain and evaluation of vessel structure. safety By the comparison and analysis of RS-485 bus technology and CAN bus technology, characters of general operation system and embedded operation system, vessel structure safety monitoring system integrating CAN bus technique with embedded system technique was demonstrated, which can be described from two parts in the structure: data collection module based on CAN bus and the host system based embedded operating system Windows CE.NET.The first part is data collection module,which takes charge of collecting strain data and transferring them to the host over CAN bus. This part involves design of Software and hardware of the module. In designing of hardware, singlechip SST89C54, stand-alone CAN controller SJA1000 and AD converter AD679 were selected to establish the kernel controlling part of data collection module, and interface connection of main chips and hardware anti-jamming technology were described in detail. In the implement of software, procedural flows of main functional modules such as initialization, data receipt and transmission were particularly described. In addition, Considering factors of influencing measurement precision of strain, corresponding technology, including software correction method of non linear of strain measurement, three wires connection technology for strain resistance and four wires detecting technology for measurement bridge power, were adopted to improve measurement precision of strain.The second part is the host system based on Windows CE.NET. The system is composed of customization of the kernel of embedded operating system, design of CAN adapter driver and application system. At first, according to difference of resources of hardware and requirements of application, functional modules in Windows CE.NET were tailored , customized. Secondly, in the design of stream interface CAN adapter driver, process of interrupt disposal in Windows CE.NET was analyzed, and CAN interrupt serve thread(IST), receipt and transmission of message was described in detail. In addition, the thesis discussed CAN driver’s influence on response ability of received message, and gave a method with a real-time response on received message, which set the size of receiving buffer queue and the critical number of received messages in it according to requirement of real-time response time and transmission rate of CAN bus. Thirdly, for application system, the thesis specified program flow of important functional modules such as main flow ,self check and initialization, parameter setting and modifying, calibration of strain benchmark at a sampling position and measurement controlling of strain.The third part is customization of communication protocol. According to the feature of the monitoring system, Master-slave communication mechnism was set up. Setting and querying of parameter and controlling of sampling and transfers of sampling modules and channels were implemented.更多还原