外文翻译基于单片机的汽车倒车防撞语音提示系统

1、外文资料:BaSed On nRF24El and TMC2023 automobileCOlliSion avoidance SyStem development andrealizationCar engineering department Of institute Of technology Of MUniChBy LORENZ FERDIDADPrOgreSS Of SOCiety With the development Of times, more and more CarS have entered Ordinary people" S family. ThOUgh

2、the highway terms is being updated, yet avoid the CrOWded CUrrent SitUatiOn Of getting On the Car Of UnaVOidabIe highway, in addition, the SPeed is improved gradually, the malignant traffic accident is happening all the time, have brought the enormous Iife and PrOPerty IOSS to PeOPle and the SOCiety

3、 Car anticollision SyStein Whether One Can Send OUt Seeing and hearing SUrVey device Of Warning SignaI in advance to driver It install, at car, Can SUrVeyJ attempt pedestrian, VehiCIe Or barrier around CIOSe the automobile body usually; Can Send OUt and COlIide the dangerous SignaI SOOn to ClriVer a

4、nd PaSSenger ahead Of time, impel driver bypass driver take emergency measure PUniSh SPeCiaI dangerous SitUatiOn even, avoid IOSSeS At present, though VariOUS COUntrieS StUdyJ PreVent SyStem Of COlliding from (USUalIy CalI the initiative SeCUrity SyStem in the WOrId) J but how COUId SOlVe the timid

5、and alert PrOblem better, PerPIeXing relevant WOrkerS all the time The researcher in the WOrId StUdieS through a Iarge number Of experiments, has already reached COmmOn understanding, if Want to SOIVe PrObIem described above effectiVeIy, the anticollision SyStem must have the following functions:I)M

6、USt be CaPabIe Of examining the angle, the azimUthal information Of the goal is essential for removing emptily and alertly(2)APt to PrOdUCe anti-interference PerfOrmanCe StrOng COmPIiCated transmission signal, COOPerate With real-time high-efficient SignaI deal With With goal measuring algorithms, i

7、n Order to remove emptily and alertl y.OnIy the above two POintS COmbine together and guarantee the SyStematiC dependability that the Car defends COlIiding CIOSeIy.1 TMC2023 ChiP and the nRF24El ChiP CharaCteriStiC introduced TMC2032 is One kind Of new entire digital COrrelatiOn instrument electric

8、CirCUitJ its COrreIatiOn WOrd Iength and the related threshold are PrOgrammabIe ThiS ChiP is the monolithic 64 CMOS entire numeral COrreIatiOn instrument Iarge SCaIe integrated CirCUit WhiCh AmeriCan TRW COrPOratiOn recent years PrOnIOted, its interior had three independent CIOCkS 8 displacements PO

9、SitiOnS registers (StOChaStic data register Al IOCaI COde register B and ShieId COde register M) ; MOreOVer also has 7 registers to USe for to IOad Pre-PIaCed Iimit O、64 between WilfUlly IOng StOChaStiC data and the IOCaI COde after the COrreIatiOn OPeration, by the three Salnit the CUShiOn 7 BCD CO

10、de output, and Iimit COmPare With the initialization in the COmParator, if the COrreIatiVe VaIUe is bigger than Or is equal to Iilnit, then the flag bit by IOWIy ChangeS high BeCaUSe has USed the advanced high SPeed CMOS PrOdUCtiOn CraftJ the ParalleI COrrelatiOn SPeed reaches as high as above 30MHZ

11、 BUt Widely applies to SynChrOniZatiOnJ the matched filtering, harms in the COde examination, the recording and the bar COde recognition, especially SUitS to the radar SignaI recognition. NRF24E1 is One kind Of OPerating frequency may achieve 2 4GHz the WireleSS radio frequency receiving and dispatc

12、hing chip, the Channel OPeratiOn time is Smaller than 200 mu s, the data rate is IMbPS outside, does not need to meet the SAW filter, is global general IOW COSt radio frequency SyStem IeVeI ChiP WhiCh the PreSent WOrId PrOmOteS for the first timeThe interior inlays has With 8,051 COmPatible micropro

13、cessors and 10 9 inputs A/D switches, may between Under the 1. 9V、3. 6V VOItage the Steady WOrk: The interior also inlays have impress the adjuster and the VDD VOItage monitoring device WireIeSS receiving and dispatching partially has With the nRF2401 SimiIar function, this function StartS by the in

14、ternal ParalIeI InOUth and internal SPI, each dueout SignaI SayS regarding the PrOCeSSOr all may take SeVerS CarrieS On the PrOgramlIIingJ Or gives the IiIiCrOPrOCeSSOr through the GPlO POrt biography. ChiP nRF24El may realize the WireleSS COmmUniCatiOn in WOrId PUbIiC frequency band SCOPe 2.4 '

15、 2. 5GHz ReCeiVeS and dispatches the PartiaI PaCkageS to include the frequency divider, the amplifier, the regulator and two receiving and dispatching UnitS The OUtPUt energy, the frequency band and Other radio frequency Parameter PaSSabIe radio frequency registers COnVenientIy have PrOgrammed the a

16、djustment Under the transmission pattern, the CUrrent COnSUmPtiOn OnIy has 10. 5mA; Under the receive pattern, the CUrrent COnSUmPtion Only has 18mA, therefore the POWer IOSS is QUite low.2 SyStemS Structures entire WraP information gathering SyStem is COmPOSed by five SetS Of radio frequencies IaUn

17、CheS and the receiving device, each Set Of IaUnCheS and the receive PartiaI basic electric CirCUitS all are same, these five SetS Of transmitter-receiver Set also is COnneCted With the DSP CentraI PrOCeSSOrJ the CentraI PrOCeSSOr is responsible for the data WhiCh CaICUIateS them to PaSS on, IIIakeS

18、the decision-making according to the actual SitUatiOn. EaCh Set Of IaUnCheS and receiving device StrUCtUre Iike Chart 1 ShOWS First by as the COre radio frequency transmission CirCUit PrOdUCeS the high frequency electromagnetic WaVe take nRF24El, then the modulation Signal WhiCh SendS by COrreIation

19、 OPerdtiOn ChiP TMC2032 to it CarrieS On the modulation, thus PrOdUCeS With Other radio frequency receiving and dispatching Unit different radio-frequency signals, PrePareS for full for the receive In Order to enable the electromagnetic WaVe SignaI to have the enough far PrOPagatiOn distance, but al

20、so needs to modulate after the SignaI to Carry On the enlargement, COmPIeteS this function the electric CirCUit is the merit PUtS the electric CirCUit Finally PaSSeS On airborne to a SUCh Signa1. When SendS OUt the electromagnetic WaVe meets When the ObStaele returns, first must after COrrelation OP

21、eMtiOn ChiP TMC2032 to it Carry On the recognition, if the Same group IaUnCheS Partially SendS receives, and further bequeaths this SignaI the radio frequency receive Part; OtherWiSe refuses to receive Then the receive Partially PrOdUCeS according to the electromagnetic WaVe in the airborne dissemin

22、ation The PhaSe moved CalCUlateS the time WhiCh its dissemination consumes, again CaICUIateS the ObStaCIe and this group Of receiving and dispatching PartiaI CiiStanCeS FinalIy gives this distance information the CentraI PrOCeSSOr CentraI PrOCeSSing monolithic COnfidential at the Same time the dista

23、nce information WhiCh PaSSeS On to five groups Of radio frequencies receiving and dispatching Unit makes the COmPUtat ion, Obtains ObStaCIe and VehiCIe SPatiaI POSitiOn WhiCh measured ReaCheS this POintJ the ObStaele information gathering WOrk basically completes, is Ieft OVer is bequeaths again thi

24、s COmPrehenSiVe information the higher Paraffin CentraI PrOCeSSOrJ IetS it make the final decisiOn-making3 receiving and dispatching UnitS SCheme Of arrangement and the COmPUtatiOn PrinCiPIe automobile in the middle Of the travel process, regarding the front ObStaCIeJ must be able to judge the ObSta

25、ele to be away from the COmPUtatiOnJ A, B, C three distinguish the representative to install in front Of the front Of a train three SUPerSOniC SenSOrS; E represents the obstacle; Then the EF expression from E to the horizontal PIane distance, FG represents the ObStaele to the front Of a train PIane

26、distance, AG expresses the ObStaCle to a VehiCIe Side distance The request is EF, FG and AG these three Can express the ObStaCIe and the automobile SPatiaI relative POSitiOn tangential Path SOIUtiOn as follows： In DeIta ABC, makes BD AC, COnneCtS ED and FD, then may ask DeIta ABC area S DeIta ABC, n

27、amely: S Delta the ABC = in the formula, S= (Tl+T2+T3), Tl, T2, T3 SeParateIy express Iine Segment AB, BC, the AC Iength therefore BD=2S DeIta ABC/AC in DeIta ADE, DiStanCe SI, S2, S3 and known distance Tl, T2, T3 Can SUrVey WhiCh the radio frequency receiving and dispatching SyStem SeParateIy repla

28、ce AE, BE, CE, AB, BC, AC, then may result in three WhiCh asks to be away from EF, FG, the AG VaIUe4 USeS related algorithm along With radio frequency in daily Iife WideSPread application, the PeOPIe gradually discovered the radio frequency range finder has the Certain flaw： (1) The USefUI effect is

29、 away from QUite short, Only depends On the enhancement emissive POWer to increase the SUrVey distance is Very limited; (2) The range finder PreCiSiOn mainly is decided by the echo SignaI SingIa to noise ratio, in the Certain SignaI to noise ratio SitUation, Only depends On before the increase the I

30、eVeI to enlarge the electric CirCUit the gain to imp:TOVe the measuring accuracy also is must Ofterl Iilnited In Order to SOIVe the above problem, in the automobile COlIiSiOn avoidance system, has COnCeiVed based On the PSeUdO-COde modulation radio frequency IaUnCh and the receiving SyStem. The Whit

31、e noise SPUrt VaIUe ObeyS the GaUSSian CiiStribUtiOn (normal distribUtiOn) ItS POWer SPeCtraI density in the Very Wide frequency band is even, moreover the autocorrelation function has delta the function ShaPe The PSeUdO-random COde although OnIy has two IeVeIs, but actually has the SimiIar White no

32、ise the related CharaCteriStiCJ OnIy is its SCOPe PrObabiIity distribution no IOnger ObeyS the GaUSSian CliStribUtiOn. Therefore, may USe the PSeUdO-random SeqUenCe the balanced CharaCteriStiCJ the tourist itinerary CharaCteriStiC and the COrreIatiOn CharaCteriStiC and SO On describes the White nois

33、e The PSeUdO-random COde is With the IOgiC OPeratiOn realization, the SignaI autocorrelation function SatiSfies: ObViOUsly, When P enough is big, the autocorrelation COeffiCient has the incisive two IeVeIS CharaCteriStiCJ approaches delta the function. In based On in the PSeUdO-random COde UItraSOni

34、C ranging, is PreCiSeIy SUrVeyS between the IaUnCh COde and the receive COde time delay USing the PSeUdO-COde autocorrelation function incisive CharaCte:TiStic, thus enhancement measuring accuracy The m SeqUenCe PSeUdO-random COde is the CyCIiCaI IOngeSt One kind Of SeqUenCe WhiCh PrOdUCeS by the Ii

35、nearity Shift register BeCaUSe its related CharaCteriStiC is fine, also is advantageous for the PrOdUCtion, therefore Obtained the WideSPread application. AeCOrding to the COrreIatiOn function definition, SUPPOSeS two functions Of time is xl (t), x2 (t), then is Called xl (t) autocorrelation functio

36、n; IS Called xl (t)J x2 (t) CrOSS COrreIatiOn function; HaS two kind Of QUeStiOnS in the SignaI examination theory: A kind examines the SignaIJ namely the basis receives Whether there is the COmPOSite SignaI (does SignaI add noise Or PUre noise) makes the SignaI jurdgement: AnOther kind estimates th

37、e ParameterJ Whether there is namely in examined in the SignaI foundation, to the SignaI Certain ParameterS (for example OSCilIatiOn amplitude, PhaSeJ frequency, PUlSe amplitude modulation ParIn and SO On) Or the PrOfiIe makes the estimate In order to enhance the anti-jamming, needs to Seek Under th

38、e disturbance COnditiOn to the SignaI best receive method The PeriOdiC SignaI COrreIatiOn function WaS StilI the PeriOdiC function, but disturbs the noise the COrreIatiOn function is delta the function. ACCOrding to these differences, may PiCk OUt USing the COrreIatiOn instrument IniXeS in the noise

39、 jamming the PeriOdiC Signa 1 In this kind Of USe time domain CharaCteriStiC difference examines the SignaI the met hod to be CalIed the COrreIatiOn recerive WayS IS different according to the reference signal, the COrreIatiOn recerive WayS divides into the autocorrelation recerive WayS and the mutu

40、al COrreIatiOn recerive WayS The autocorrelation recerive WayS is in is Unable to know for Certain the input PrOfiIe (Or data) in the SitUation, the USe auto-correlator to it WOrk autocorrelation function OPeration; The mutual COrrelatiOn recerive WayS is in may determine the reference SignaI in the

41、 SitUation, to inputs the PrOfiIe USing the COrreIatiOn instrument (Or data) makes the CrOSS COrreIatiOn function With the IOCaI SignaI the OPeration. In this design the reference SignaI is the IOCaI code, therefore USeS the mutual COrreIatiOn recerive WayS In radio frequency range measuring system,

42、 Whether there is not Only has to Carry On the examination to the echo signal, meanwhile must CarrieS On the PreCiSe SUrVey to the echo SignaI and the transmitting message time delay. ThiS Can accurately know the radio broadcast USeS the time, then figures OUt between the ObStaele and the VehiCIe di

43、stance ThiS article UtiIiZeS the advanced radio frequency technology and the StabIe reliable related algorithm, enable the automobile to have StrOngly guards against hits the ability The above SyStem design Plan in tested on the Car already to realize front, and Can SOlVe in the Certain degree throu

44、ghout is PUZZIing the COrreIatiOn WOrker, S two key QUeStiOn WhiCh states, namely has already had the keener take a bearing ability and the StrOnger antijamming ability, Iike this Can enable the automobile to have StrOngly guards against hits the ability AIthOUgh so, because in the middle Of the aut

45、omobile travel PrOCeSS is relating PerSOn, S safety, therefore its PerfOrmanCe also WaitS for further enhances, Strengthens the OVeralI SyStem the absolute security, then CarrieS On the PrOmOtiOn to it.基于nRF24E1与TMC2023的汽车防撞系统的研制与实现慕尼黑理工大学汽车工程系劳伦斯费迪南德随着时代的发展及社会的进步,越来越多的汽车进入了普通人的家庭。尽管 公路条件在不断改进,但仍然避免

46、不了公路上汽车拥挤的现状,再加上车速逐渐 提高，恶性交通事故无时无刻不在发生,给人们和社会带来了巨大的生命与财产 损失。汽车防撞系统是一种可向司机预先发岀视听告警信号的探测装置。通常它安装 在汽车上,能探测企图接近车身的行人、车辆或周围障碍物;能向司机及乘客提前 发出即将发生撞车危险的信号,促使司机其至撇开司机采取应急措施处理特殊险 情,避免损失。当前,尽管各国都在研究防碰撞系统(国际上通常称为主动安全系 统)，但怎样才能更好地解决虚警的问题，始终困扰着相关工作者。国际上的研究 者通过大量的实验研究，已经达成共识,若想有效地解决上述问题,防撞系统必须 具有如下功能：(1) 必须具备测角能力，L

47、J标的方位角信息对于去除虚警是必不可少的；(2) 易于产生抗干扰性能强的复杂发射信号，配合实时高效的信号处理和U 标检测算法,用以去除虚警。只有以上两点紧密结合起来才能保证汽车防碰撞系统的可黑性。1 TMC2023芯片和nRF24El芯片特点介绍TMC2032是一种新型的全数字相关器电路,其相关字长和相关门限可编程。 该芯片是美国TRW公司近年推出的单片64位CMOS全数字相关器大规模集成电路, 其内部有三个独立时钟的8位移位寄存器(随机数据寄存器A、本地码寄存器B 和屏蔽码寄存器M);另外还有一个7位寄存器用来装载预置的门限值。064之 间任意长的随机数据与本地码经相关运算后，以三态缓冲的7

48、位BCD编码输出， 并与预置的门限值在比较器中比较，若相关值大于或等于门限值，则标志位山低 变高。山于采用了先进的高速CMOS 产工艺，并行相关速率高达30MHZ以上。可 广泛应用于同步、匹配滤波、误码检测、记录及条形码识别中，尤其适合于雷达 信号的识别。nRF24El是一种工作频率可达到2. 4GHz的无线射频收发芯片,通道运算时间 小于200 s,数据速率为IMbps,不需要外接SAW滤波器,是U前世界首次推出的 全球通用的低成本射频系统级芯片。内部嵌有与8051兼容的微处理器和10位9 输入的A/D转换器,可以在1. 9V3. 6V之间的电压下稳定工作；内部还嵌有电压 调整器和VDD电压

49、监视器。无线收发部分有与nRF2401同样的功能,该功能由内 部并行口和内部SPl启动,每一个待发信号对于处理器来讲都可以作为中断进行 编程,或者通过GPlo端口传送给微处理器。芯片nRF24El可以在世界公用的频段 范Rl 2. 42. 5GHZ内实现无线通讯。收发部分包含有分频器、放大器、调节器和 两个收发单元。输出能量、频段和其它射频参数可通过射频寄存器方便地编程调 节。在发送模式下，电流消耗只有10. 5mA;在接收模式下，电流消耗只有18mA,所 以功耗相当低。2系统结构整套信息采集系统山五套射频发射与接收装置组成,每套发射与接收部分的 基本电路都是一样的,这五套收发装置乂与DSP中

50、央处理器相连，中央处理器负 责讣算它们传过来的数据,根据实际情况做出决策。每套发射与接收装置的结构如图1所示。首先由以nRF24El为核心的射频 发射电路产生高频电磁波,然后山相关运算芯片TMC2032送来的调制信号对其进 行调制,从而产生出与其它射频收发单元不同的射频信号,为接收做好充分准备。 为了使电磁波信号能够有足够远的传播距离，还需要对调制后的信号进行放大, 完成这个功能的电路是功放电路。最后把这样的一个信号传向空中。 M a ® SI!".! !Ign1t IIirHr?二疣 InrXCll x .,_ r严丄CI 'iWRF24EIe2如J I 卜HDH

51、当发出去的电磁波遇到障碍物返回时，首先要经过相关运算芯片TMC2032对之进 行识别，若是同组发射部分发出去的则收，并把这个信号进一步传给射频接收部 分;否则拒绝接收。然后接收部分根据电磁波在空中传播产生的相位移讣算出其 传播所耗的时间，再计算出障碍物与该组收发部分的距离。最后把这个距离信息 送给中央处理器。中央处理单片机要同时对五组射频收发单元传过来的距离信息 做出讣算,得出所测的障碍物与车的空间方位。到此,障碍物的信息釆集工作基本 完成,剩下的就是把这个综合信息再传给更高级的中央处理器，让其做出最后决 策。3收发单元的布置方案及计算原理汽车在行驶的过程当中，对于前方的障碍物，要能够判断其相对于汽车的空 间立体方位才能把询后、左右、上下的障碍物避开;而后面的