汽车主动悬架电子控制单元设计

1、第 26 卷第 5期vol. 26, no. 5西 华 大 学 学 报 自 然 科 学 版journal of xihua university natural science2007 年 9 月sep. 2007文章编号: 1673-159x( 2007) 05 -0020 -02收稿日期: 2007-04 -12作者简介: 黄榕清( 1946 -) , 男, 广东增城人, 高级工程师, 广东省汽车维修专家组副组长。汽车主动悬架电子控制单元设计黄榕清,许迎东 ,向铁明( 华南理工大学汽车工程学院, 广东 广州 510640)摘要: 使用 at89c52 芯片作为控制芯片, 以车身垂向加速度作

2、为控制目标, 设计了一种以 1/ 4 车辆振动模型为基础的主动悬架电子控制单元。 控制单元采集垂向加速度及变化率作为输入信号, 经过模糊控制算法处理,输出控制信号实现对车身振动的控制。 实验结果表明, 该控制单元能够很好的抑制车身的振动。 悬架的控制单元的研究设计, 对缩小与国际水平的差距, 有着非常现实的意义。关键词: 悬架控制单元; 单片机; at89c52中图分类号: u469. 11文献标识码: a悬架是汽车车身和车轮之间的一切传力连接装置的总成 。它把路面作用于车轮的支承力、 牵引力 、制动力和侧向反力等所产生的力矩传递到车身上 ,来保证汽车的正常行驶。悬架系统是汽车重要的组成部分

3、,汽车悬架系统的性能是影响汽车行驶平顺性、 操纵稳定性和安全性的重要因素。随着电子技术的发展 , 微型计算机用于悬架的控制 ,ecu 实时采集汽车状态信号经过分析处理 ,来控制和调节悬架的各种参数, 在很大程度上提高了汽车的整体性能。我国在悬架系统方面的研究 ,主要集中在控制理论和控制算法上, 并在这些领域取得了一定的成绩,但对控制单元的研究相对比较少,国内目前仍然无汽车公司能够独立设计并生产投放市场的成熟悬架控制单元 。本文利用单片机技术和模糊控制理论,设计了一种主动悬架的控制单元,以期缩小与国际水平的差距。1 电子控制单元的主要功能该电子控制单元以 1/4 车辆振动模型为基础 ,采用车身的

4、垂向加速度作为输入信号和控制目标 1,控制单元主要包括了采样保持电路、a/d 转换电路、 控制处理电路、 控制输出电路、显示电路( 包含 6 位 led 显示器) 等电路组成 。控制单元加电或复位后,系统进行初始化 ,初始化完成后开始连续采集车身的垂向加速度信号 , 根据采集来的信号进行模/数转换 ,使用 3次加速度的平均值作为输入信号送入控制处理模块, 按照预先编写好的数字控制程序,驱动电机调节悬架的阻尼 2, 来改善汽车的平顺性 ,操作稳定性等性能 。同时 , 显示器 led 显示各工作状态的信号。显示器采用静态显示技术, 工作过程显示 work 字样, 一旦程序出错, 就显示err 字样

5、 ,此时就需要复位或者掉电重起。控制系统采用模糊控制策略 , 模糊控制系统对环境变化不敏感, 具有较高的鲁棒性, 在数字控制领域得到广泛运用。2 系统组成2. 1 硬件系统整个控制系统原理如图 1 所示 。单片机采用atmel 公司的 at89c52 芯 片, 内 含 8k flashrom 、256k ram 。采样保持电路使用巴特沃兹( butterworth) 低通有元滤波器对采集的加速度信号进行滤波放大, 采样保持器使用 lf298 芯片 , 该芯片是由双极型绝缘栅场效应管组成的采用 - 保持电路,具有采样速度快, 保持下降速度慢 ,精确度高等特点 。图 1控制原理结构示意图电路图见图

6、 2 所示。a/d 器转换使用 ad574芯片 ,该芯片采用 cmos 工艺, 是一种逐次逼近型的 a/d 装换器, 其数字输出端口通过所存器与at89c52 的 p2 口相连。实现采集的信号数字化 ,然后输入的功能 。图 2采样保持电路为了能够在操作过程中监视控制单元的工作情况,使用了静态显示电路( 如图 3 所示) ,来显示控制单元的工作情况, 例如复位、 工作、程序异常等情况。采用74ls 244 芯片作为显示电路线片。74ls 244 是总线驱动器,可以接 6个 led 显示器,每个均配有一个74ls 377 所存器,用 at89c52 的 p0口来驱动。图 3静态显示电路图 4驱动电

7、路驱动器使用步进电机 , 用单片机芯片的 p1 口的 p1. 0-p1. 3 来连接 步进电机 , 接 口电路使用74ls04所存器 。为了抗干扰或者避免一旦驱动电路发生故障 ,造成功率放大器中的高电平信号进入单片机烧毁器件 ,因而在驱动器和单片机之间加一级光电隔离器 3, 其电路图见图 4。时钟电路部分使用外接晶体和电容构成并联谐振电路,使用 30pf 电容和 10mhz 晶体作为主振频率。晶体和电容尽可能和单片机芯片靠近, 以减小寄生电容 。控制单元整体硬件结构如图 5 所示 。图 5控制器系统原理图2. 2 单片机软件的编制整个软件系统由主程序模块 、采样保持电路模块、 a/d 转换模块

8、、模糊控制算法模块和步进电机驱动模块组成 。主程序主要完成系统初始化, 显示控制 ,驱动步进电机控制等功能, 而步进电机调节节流阀的节流口开度大小 ,就能调节悬架阻尼系统 ,优化整车的性能 。图 6系统软件总体框图a/d 转换模块是系统在加电初始化或者因为复位原因初始化后 ,开始进行对采集垂直加速度信号进行 a/d 转换,计算机连续 3 次采集加速度的平均值作为电子控制单元的输入信号。在此用一个循环结构,判断采样转化次数 , 循环结束返回主程序,否则继续进行下一次a/d 的循环转换 ,转换模块流程图略。模糊控制模块是整个软件系统的比较重要的部分, 直接影响主动悬架的性能 。模糊( 下转 49

9、页)21第 5 期黄榕清 等: 汽车主动悬架电子控制单元设计3 结论利用 protel 软件对电铁并联电容补偿装置过电压进行仿真分析 ,得到电抗器在投入运行时, 要承受到交流峰值 50kv 的过电压 ; 在断路器开断电容器组时, 电抗器要承受 91. 2kv 的冲击过电压 。得到电抗器烧毁的原因是电抗器在投入或者断路器开断电容器组时高幅值过电压作用的结果。提出在电容器和电抗器之间并联 1 台 10kv 氧化锌避雷器 ,并利用此电抗器过电压保护对策进行实际运行验证 ,证明其电抗器过电压保护对策的正确性 。参考文献 1 李彦吉. 并联电容补偿装置的故障分析与保护设计 j . 铁道标准设计, 200

10、6( 4) . 2 刘让雄, 杨春江, 杨嗣光. 电容补偿装置中电抗器烧损原因与保护措施 j . 高电压技术, 1999( 3) . 3 张高峰. 浅谈并联电容器组电抗器的过电压保护 j . 西铁科技, 2002( 4) . 4 刘学. 限制并联电容补偿装置过电压的措施 j . 电气化铁道, 2005( 2) . 5 梁曦东. 高电压工程 m . 北京: 清华大学出版社, 2003.( 编校: 夏书林)( 上接 21页)控制器的控制规则是基于模糊条件语句描述的语言控制 ,用 e 表示悬架垂向加速度的误差量 ,ec 表示误差变化量 u 表示控制量( 具体规则参阅模糊控制技术相关资料) 4 5 。

11、根据对系统的分析得到模糊控制程序流程图如图 7所示。图 7模糊控制模块3 结束语本控制单元在 1. 5hz、3 hz、 5 hz、7hz、 8 hz 频率的单频激振垂向加速度实验中能很好的抑制垂向加速度的峰值 ,由于本文侧重控制单元结构设计和控制原理 ,各频率实验下的加速度-时间对比图将另择文讨论。控制单元连续准确的采集车身垂向加速的信号,并根据振动信号的变化 , 通过控制策略, 处理器发出相应的控制指令,调节阻尼, 从而对车身的加速的实施了控制 。虽然整个系统是 1/4 车辆振动模型基础上的 ,但是对于研究改善悬架性能及悬架控制单元的设计有一定的价值, 且控制单元使用了常用的芯片,成本低 ,

12、使用方便, 同时具有一定的应用价值。参考文献 1 孙仁云. 汽车电器与电子技术 m . 北京: 机械工业出版社,2006. 2 金达峰, 黄兴惠, 等. 主动油气悬架实验模型的研制 j . 汽车工程, 2000( 2) . 3 潘新民, 王燕芳. 微型计算机控制技术 m . 北京: 电子工业出版社, 2003. 4 sharkawy , a . adaptive fuzzy control of active suspensionsystems j .journal of engineering and applied science.2005, au-gust . 5 高东杰, 谭杰, 林红

13、权. 先进控制技术运用 m . 北京: 国防工业出版社, 2003. 6 aoyama y, kawabata k , hasegawa s, kobari. developmentof full active suspension by nissan c . sae paper 901747, 1990.( 编校: 周剑华)49第 5 期褚晓锐 等: 并联电容补偿装置中电抗器过电压保护的研究vol. 26, no. 5journal of xihua university natural science2007abstractsstructure analysis of the recipr

14、ocating sealring in fracturing pumpzhu wei -bing( institute of m echanical engineering and automa-tion, xihua university , chengdu 610039 china) , zhou xi-rong , et al.jou rnal of xihua university. v. 26, no. 5. pp. 1 -2, 5/2007.( issn 1673-159x; in chinese)abstract: the life -span of the plunger an

15、d sealis animpor-tant index for evaluating the performance of a fracturing pumpwhile the material and the structure of the seal ring are two vitalfactors.this paper focuseson the contacting stress between theplunger and the seal ring , and analyzes the effect of the sealring structure parameters on

16、the contacting stress. at the sametime, the structure of the seal ring is optimized.it providestheoretical support for the structure design of the seal ring .key words: fracturing pump; reciprocating seal ring; struc -ture; contacting stressexperimental investigation into the coordinatedmanipulation

17、 of a dual-arm modular robotshi lei( beijing university of technology , beijing 100022 china) ,su li -ying , et al. journal of xihua university . v . 26,no. 5. pp. 3-6, 5/2007. ( issn 1673-159x; in chinese)abstract: in this paper, a method for the coordinated ma-nipulation of a dual -arm robot is in

18、troduced based on the feed-back from optotrak 3020.the kinematics constraint relationsare analyzed and the constrained equations are obtained.theposition and location of the end effector are gained by optotrak3020.finally, the experiment of nut and bolt mating for dual -arm robot is conducted.key wo

19、rds: dual -arm robot; kinematics; feedback;coordi-nated manipulationanalysis and study on the embedded test con-trol system for measuring incompact material byspherical methodsheng jian-jun( service center of energy saving t echnology .zhenjiang jiangsu 212000 china) , shan chun -xian, et al. jou rn

20、alof xihua university . v . 26, no. 5. pp. 7 -10, 5/2007. ( issn1673-159x; in chinese)abstract:measuringheatconductioncoefficientwithspherical method is a main part in pyrology testing.the systemis developed using the mode of embedded real -time intelligentnumber control and the method of average te

21、mperature of multi-spots, which makes the tested results reflect the real tempera-ture of the material and largely reduces the degree of dispersion.in addition, the system has a function of leak-free inspection.at last, the system is verified by experiments, and the resultsshow that many advantages,

22、 such as high precision, nice repeti-tion, low price and simple operation, are attained.key words: heat conduction coefficient; incompact materi-al; embedded; micro automation equipment;test controlnewimagesegmentationforrobot-soccerbased on k -means clusteringtang lei( robot research institute, xih

23、ua university , chengdu610039 china) , wang qiang. jou rnal of xihua universi-ty . v. 26, no. 5. pp. 11 -13, 5/2007. ( issn 1673 -159x; in chinese)abstract: image segmentation is a key approach of imagemanipulation and a crucial technology of robot-soccer vision sys-tem.this paper presents an image

24、segmentation method basedon rough set theory and k-means clustering .the experimentalresult indicates that the method can improve veracity and stabil-ity of image segmentation.key words: robot-soccer;rough;set k-means clustering ;image segmentationlatest advances in cutting tool technologyused on nc

25、 machine toolswu neng-zhang( school of mechanical engineering and automa-tion, xihua university , chengdu 610039 china) . journal of xi-hua university . v. 26, no. 5. pp. 14-19, 5/2007. ( issn 1673 -159x; in chinese)abstract: cutting tool used on nc machine tools is one ofthe important facilities in

26、 nc processing technology , and playsavital role to assure the efficient implementation of manufactur -ing technology.the author describes the latest advances in cut-ting tool technology used on nc machine tools based on a lot ofrelevant literatures at home and abroad in this paper, which in-cludes

27、new toolmaterials with high hardnessand strength, vari-ous coating techniques, novel tool configurations, modern no -tions for cutting tool design, tool fixing manner and interfacetechnology with the spindle of machine tool.key words: cutting tools used on nc machine tool;toolmaterial; design method

28、;tooling systemdesign of electronic control unit for vehicleactive suspensionhuang rong-qing (south china universityoftechnology ,guangzhou 510640 china) , xu ying-dong , et al. journal of xi-hua university . v. 26, no. 5. pp. 20-21, 5/2007. ( issn 1673 -159x; in chinese)abstract: this paper present

29、s the design of electronic con-trol unit for active suspension based on a quarter of vibrationmodel. at89c52 is used as its main control chip in the systemand verticalacceleration isemployed as control aim.the controlunit collects vertical acceleration and its rate as input signal.the system generat

30、es output signal to restrain the body vibra-tion after fuzzy control operation.the experiment result indi-cates that the control unit can restrain the vehicle vibration.the study and design of the control unit for active suspensionare helpful to fill the gap between international leveland that ofchi

31、na in vehicle control system.key words: control unit;singlechip; at89c52study on the mixing ratio for the blended fuelof acid-n-butanol-methanol-dieselhan zhi-qiang( school of transportation and automotive engi-neering , xihua university , chengdu 610039 china) , huang hai -bo ,et al. journal of xih

32、ua university . v. 26, no. 5. pp. 22-25,5/2007. ( issn 1673 -159x ; in chinese)abstract: consumption of diesel is more than that of gaso-line in the situation of energy shortage.therefore, finding asubstitute fuel is urgent. in the study, the authors used the or-thogonal design approach to arrange d

33、iesel -methanol -n-butanol -oleic acid in pairs or groups, and then searched for an optimalresult from the experiments in a diesel engine. the results showthat blending some methanol、n-butanol and oleic acid into dieselwill not decrease thepowerperformance of diesel enginezs1100, but can reduce the

34、fuel consumption about five percentto twenty percent.at the same time, the soot is reduced inheavy loadfor diesel engine due to the existence of methanol andn -butanol in the blended fuel.key words: blended fuel; diesel/methanol;orthogonal de-sign; equilibrium arrangement in pairs or groupsforecasti

35、ngalgorithmoftrafficaccidentbased on rough set theoryyi zheng-jun( college of mathematics and physics, chongqing u-niversity , chongqing 400044 china) , zhang ye-ting , et al. jour-nal of xihua university. v . 26, no. 5. pp. 26-28, 5/2007.( issn 1673-159x; in chinese)abstract: through analyzing the

36、historical data of trafficaccident, this paper divides traffic accidents into different type,and summarizes the reasonsinducing traffic accident with differ-ent features( caused by human reason, road reason, car reason,weather reason).the authorsestablish a mapping rule betweenthese reasons and traf

37、fic accident using rough set theory , andbuild a quick and easy fusion algorithm for warning of traffic ac -cident.by using the algorithm database installed on the car,one can build a system to forecast traffic accidents, so the drivercan make the correct regulative measure based on the monitorsyste

38、m and prevent the occurrence of traffic accident.key words: traffic accident; warning ; rough setresearch on the least space among non-signal-ized at-grade intersections in a diamond interchangexiao hui-hui( school of automobile and traffic engineering ,jiangsu university , zhenjiang jiangsu 212013

39、china) , chang yu -lin,et al. journal of xihua universit y. v . 26, no. 5. pp. 29 -32,5/2007. ( issn 1673-159x; in chinese)abstract: this paper analyzes the least space among thenon-signalized at-grade intersections in the diamond interchangecombined with the characteristics of the diamond interchan

40、geusing queuing theory and gap acceptance theory .there arethree constituting parts:the shortest parking queue on the sub-ordinate road from the main road, the shortest length of chang-ing road on subordinate road and the net space between the twoat-grade intersections.the authors analyze the three

41、parts andfinally educe the theoretic model of the space.this model isconfirmed by an example, and is helpful for the engineeringpractice of diamond interchange, such as layout, design, con-struction and administration.key words: diamond interchange;at -grade intersection;non-signalized; space; modelanalysis of road traffic flow affected by buslea