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车速检测开题报告

工程大学机电学院

本科毕业设计(论文)开题报告题目:基于单片机的智能车速检测系统设计

课题类型:设计□√实验研究□论文□

学生姓名:王健鹏

学号: 3082102305

专业班级:电子信息工程2083

教学单位:工程大学机电学院

指导教师:会成

开题时间: 2012.3.3

2012年3月3日

一、毕业设计容及研究意义

如今社会,应用单片机的产品已经渗透到我们生活的各个领域,几乎很难找到哪个领域没有单片机的足迹。现在,这种单片机的使用领域已十分广泛,如智能仪表、实时工控、通讯设备、导航系统、家用电器等,这些都离不开单片机。因此,单片机的学习、开发与应用将造就一批计算机应用与智能化控制的工程师和科学家。科技越发达,智能化的东西就越多。学习单片机是社会发展的必然需求,也是大学期间的必修课。自动化电力拖动系统正向着计算机控制的生产过程自动化的方向迈进,以达到高速、优质、高效率地生产。因此,在低成本自动化技术与设备的开发领域,特别对于小型企业,实现计算机控制的生产过程自动化是亟需深入研究的重要课题之一,具有长远的意义。

二、毕业设计(论文)研究现状和发展趋势

随着目前微电子技术的发展,技术工艺的不断提高,单片机技术也有了长足的进步。单片机即单片微型计算机,它是微型计算机的一个分支,它是在一块芯片上集成了CPU、RAM和ROM存储器I/O接口等而构成的微型计算机。因为它主要应用于工业测控领域故又叫做微控器或嵌入式控制器。单片机在最近几年中得到了极大的发展,目前世界围单片机发展的主要领域有4个:一是欧美,最新开发产品主要厂商:National semicundutor的cop8系列单片机,美国的Scenix 的八位单片机,荷兰PHILIPS的51系列单片机,美国AMD公司186系列16位嵌入式微机控制器,MOTOROLA的各个系列单片机;二是日本,TOSHIBA公司开发了从4位到64位多系列单片机,日本公司也有从4位到32位多系列单片机,NEC公司的75X、78X 系列微机;三是地区,主要有WINBOND的W741/W516,W78/W77,等系列产品微控制器;四是国,主要有HYUNDAI microelrctrionics的GMS800、GMS30系列微控制器。另外还有LG公司也生产单片机,可见单片机发展到今天可以说种类繁多、性能各异。但目前我国的许多单片机应用单位仍停留在采用片无ROM等低档单片机状态。

随着科技的不断进步,单片机技术也有新的发展方向。如嵌入式单片机和Internet技术。Machz单芯片PC是嵌入式单片机的进一步发展和延伸,是微电子技术发展的必然产物。“嵌入式Internet”并非一般意义上的“嵌入式循控制嚣”概念,而是后PC时代信息技术发展的必然产物。前几部分介绍的嵌入式MCU, 已经在工业的各个领域和家庭都得到了十分广泛的应用。但大多数嵌入式系统尚处于单独应用阶段。如果将这些互相独立的分散的嵌入式系统再连接到Internet 上,就可方便地、低廉地将信息传送到几乎世界的任何地方一一这就是嵌入式Internet。这种嵌入式Internet能非常容易地实现远程数据采集、远程控制、上/下载数据文件、自动发E-MAIL。在不久的将来,现代家庭中的空调、数字电视、手机、微波炉、打印机、等信息家电均可嵌入到Internet上,实现家庭环境的信息交互、自动控制、远程升级、远程维护等。这种家电网络化技术,不仅大大提高人们的生活质量,而且会带动相关产业的迅猛发展。

三、毕业设计研究方案及工作计划

1、研究方案

硬件部分设计

图1 硬件模块框图

该框图简单明的介绍整个体统的组成部分,电源模块、时钟电路、复位电路与单片构成最小系统,采集模块将电动机的实时速度转换为电信号传输到整个系统的核心单片机,单片机应用所给算法得出车速,传输给显示模块,并运算得出控制信号输入到电机驱动模块,控制电机的转速,以此来改变车速,使智能车能正常的行驶。

软件部分设计

主程序为整个数据采集系统的主体部分,它是由若干模块组成;主程序主要完成A/D转换初始化、单片机中断初始化、串口初始化等工作。

图3 主程序框图

2、工作计划:

四、主要参考文献:

[1] Curtis,Johnson.Process control Instrumentation

Technology(6th)[M].pearson Education,Inc,2002

[2] Xiao Chen.Image Acquisition Technology with AVR Single Chip

Microcomputer[M].International Conference on MultiMedia and Information Technology, 2008

[3] 俞竹青,全胜.一种光电编码器用可编程计数电路的设计[J].传感器技

术, 2002,10-14

[4] 卓晴,黄开胜,邵贝贝.学做智能车[M].:航空航天大学,2007.3

[5] 学军.如何用MCS-51单片机扩展串口进行通讯[J].机械,2003,2-3

[6] 伟.单片机C语言程序设计实训100例[M].电子工业,2009,18(2):

104-110

[7] 永湘,等.过程控制与自动化仪表[M].:机械工业,2007.5

[8] 雷贞勇,光骥.电子设计工程[J].2010第2期:91-92

[9] 毅刚.单片微机原理及应用[M].:电子科技大学,1994

[10] 滁光,徐德好.步进电机的单片机控制方法探讨[J].仪器仪表用

户,2009,4-5

[11] 周斌,荻南,黄开胜.电子产品世界[J].2006第025期:132-134

[12] 欧阳峥峥,林茂.基于TCP/IP协议通信软件的分析与实现[J].工业学院

学报,2005,8(02):8-9

[13] 王琳,商周,王学伟.数据采集的发展及应用[J].电测与仪表,2004,6

(2):45-46

[14] Harmon Ray W.Advanced Process Control[M].NY:McGraw-Hill,1981

[15] A. Neto,H.Fernandes,A.Duarte.Firesignal-Data acquisition and

control system software,FusionEngineering and Design[M].82(2007),1359-1364

外文文献

Performance Degradation and Reliability Analysis for

Redundant Actuation System

Redundant actuator is the key component of Fly-By-Wire ( FBW) system in which existst he inherent force fig hting among different r edundant channels at colligation point . This paper establishes the mathematical model of quad redundant actuator (QRA) , investigates the force equalization algorithm and carries out the performance degradation simulation and reliability analysis under the first failure and the second failure. The results indicate that the optimal equalization algorithm can solve the force fighting effectively , and the QRA can operate at degradation performance continuously under the first failure and the second failure. With the dynamic fault tree analysis, this paper calculates the reliability based on the performance of QRA and proves that the redundant actuator has very high reliability and safety.

In modern aircraft , redundant actuation system is widely used to achieve high reliability and safety . As a matter of fact , the reliability of single channel of FBW system is low , and the redundant technique is the most effective method to realize the active control with high reliability. Redundant actuator is the last component of FBW whose performance affects the control capability of whole system directly. It is known that many redundant actuation systems are used in advanced aerospace successively , whereas the corresponding performance degradation due to failure and dynamic process are less investigated in its reliability analysis. In addition, the equalization algorithm, which caneliminate the force fighting and lead to failure recovery, existed in QRA is little to be considered in system analysis.

On account of the characteristics of redundant actuator aforement ioned, this paper studies the influence of equalization algorithm, simulates the performance degradation variance under failure occurring and carries out the performance reliability analysis of QRA.

1 Mathematic Model of QRA

Single hydraulic actuator is a close-loop system,which consists of displacement sensor, amplfier, servo valve and cylinder. 1. Due to the output of cylinder is linear displacement , it can be transferred into angle through gearing to realize the real time angle control of rudder.

Fig. 1 Block diag ram of hydraulic actuator

Fig.1 show s the hydraulic actuator system in which an input of command uc is, after passing through the system, transformed into an angle θ of

a load.

2 Force Equalization of QRA

Although the consistency of separated channels should be guaranteed in actuator system design,there exist some differences among separated channels more or less. When the QRA is synthesized at colligation point , the output difference among different channels will lead to force fighting because of the manufacture error, assemble error and performance error. The force fighting will affect the output precision and operation life of actuator system and lead to the damage of actuator in the serious condition. So the effective force equalization must be considered in the design of redundant actuator so as to eliminate and restrain it s force fighting.

Because the force fighting is rooted in the difference among separated channels, the conceivable equalization is to design a close-loop control law to trace the mean value of QRA. In order to improve the dynamic performance and control precision of QRA, this paper adopts the proportion-integral law and mean vale selector to realize the force equalization.

3 Performance Degradation Analysis of QRA

In spite of the fact that the QRA can reach high fault-tolerant level when failure occurs, its performance degradation and failure reconfiguration become complex enough. In order to describe the dynamic performance variance process, this paper simulates the performance degradation of QRA under the first failure and the second failure.

Supposing the input of QRA is unit step signal,insert the first failure and the second failure on short circuit of amplifier at 0. 3 s. The system can detect the failure and cut-off the failed channel in 0.04s after failure occurring, then the dynamic performance curves can be obtained as show n in Fig. 5, in which θ is the pitch angle and t is operational time.

In Fig. 5, curve 1 and curve 2 express the system step responses under the first failure and the second failure on short circuit of servo amplif ier separately. It indicates that the variance of system performance is not too big between one failure and two failures occurrences, so QRA can

operate when failure occurs. In addition, curve 3 shows the normal system response of QRA. Comparing the normal system performance ( curve 3) to degradation performance ( curves 1 and 2) , the output of QRA exists positive error under failed condition. So on the one hand, the redundant actuator can improve the reliability and safety greatly and the QRA can reach fault-tolerance level to FO/ FO/ FS; on the other hand, the performance of QRA will descend under failure occurring

4 Conclusions

Performance degradat ion and reliability analysis of QRA have been carried out based on control template and dynamic fault t ree. It has been shown that QRA can reach the fault-tolerant level of FO/FO/ FS; and it can operate under tw o failures.Through considering the parameter excursion of cont rol system, the combinat ion reliability of function and performance are calculated to realize the accurate reliability analysis of fault-tolerant control system. T he results indicate that QRA can operate and complete its flight mission in very high reliabiity.

Fig . 2 System step responses when short circuit of amplifier occurs

外文译文

余度舵机系统的性能降级与可靠性分析

余度舵机是电传飞控系统的关键部件, 其通道间存在着较严重的力纷争现象。在建立四余度舵机数学模型的基础上, 研究了力均衡算法, 对四余度舵机一次故障、二次故障情况下的性能降级和可靠性进行了仿真分析。仿真结果标明, 优化的力均衡算法可以有效解决力纷争的问题,四余度舵机可以在一次故障、二次故障的情况下持续工作。采用动态故障树分析方法进行了四余度舵机可靠性分

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