【作者】 朱笔辉；

【导师】 朱宏辉；

【作者基本信息】 武汉理工大学 ， 机械电子工程， 2008， 硕士

【摘要】 根据交通部公布的数据,交通事故呈逐年上升趋势,交通事故不仅给公民的财产造成了损失,而且给公民的人身安全也会造成威胁。因此如何更好地避免交通事故成为一个焦点课题,汽车安全系统更是成为汽车生产商和研究机构的研究热点。当前汽车安全系统有两大种类:一是被动式安全系统。例如:安全带,安全气囊等。二是主动式安全系统。主动安全系统又分为主动被动式和主动自动式。前者有ABS等。后者有汽车自动防撞系统和倒车雷达等。本文采用激光测距系统,开发一种汽车在高速公路上行驶的主动式防撞系统,本文的重点是开发测距预警系统,采用专门的激光测距芯片和接收芯片,并采用FPGA(Filed Programmable Gate Array)作为主控芯片,对前车进行有效的监控,根据检测得到的数据,实时提出建议和报警,提醒驾驶员减速或者采取制动措施,从而达到预防追尾碰撞的目的。本文工作主要有以下几个方面:1)在比较分析激光、雷达和毫米波等测距方法的基础上,根据市场需求及潜在用户分析,确定采用激光脉冲测距方式。针对激光脉冲测距存在的技术难题,提出以FPGA作为系统核心控制模块的测距系统设计方案。2)根据对车载动态测距系统测量精度、测量频率和测量范围的基本要求,结合脉冲激光测距的特点,提出采用多头脉冲激光测距和多周期脉冲测量的技术方案。该方案可有效提高系统测距精度和测量范围,降低系统成本。3)基于上述方案,完成了基于FPGA的多头脉冲激光测距系统的各功能模块的详细设计、功能仿真、综合优化及板级测试实验。实验表明,各主要功能模块基本达到预期设计要求,为测距系统的后期开发奠定了基础。4)完成了激光测距传感器外围光电转换电路、电源转换电路及通讯接口的设计、制作、安装及实验室调试。5)最后对论文研究工作进行了总结,提出了系统的不足之处和进一步研究工作的方向。更多还原

【Abstract】 According to the statistics by ministry of communications, traffice accidents increase annually, which leads to not only property loss but also safety danger. As a result, it becomes a focal point to avoid traffice accident, among which automobile safety system is a keystone for both automobile manufacturers and research organizations.The current automobile safety system can be categorised as two kinds. 1, passive system, e.g.safety belt, ballonet, etc. 2, initiative system. It can be devided into initiative passiveness and initiative automatism. And ABS and anticollision system can be taken as example for each.Based on LASER ranging system, Initiative Anticollision System when automobile is speeding on highway is going to be developed. The emphasis of this paper is to develop early warning system for ranging. By using LASER ranging chip and incept chip and taking FPGA as main chip, early warning system for ranging will monitor front automobile effectively and suggest or warn driver to decelerate or brake based on monitoring data, so as to avoid collision.The major tasks include:1) Based on the analysis of laser ranging, radar ranging and millimeterwave ranging measurments and market needs plus potential customer, laser pulse ranging measurement is determined. Targeted at the technical problems, FPGA is proposed as critical control module of this ranging system project.2) According to the basic requirements of precision, frequency,and range of dynamic ranging system, and combined with the feature of laser pulse ranging measurement, multiple pulse and cycle ranging program is proposed which can improve the precision and range, and decrease the cost.3) Based on above program, detailed design of functional modules, experiments of simulation, comprehensive optimization and board test are finished. Those experiments show that major functional modules meet the expected desigh requirements and establish the fundation for further development. 4) Finished the design, making, equip and debugging of photoelectric transformation circuit,power supply circuit and communication port of sensor for laser ranging system.5) Last but not least, this paper sμmmrizes the research work and puts forward the weakpoint of this system as well as the direction of further research work.更多还原