【導(dǎo)讀】究工作及取得的研究成果。據(jù)我所知，除文中已經(jīng)注明引用的內(nèi)容外，本論文（設(shè)計(jì)）不包含其他個人已經(jīng)發(fā)表或撰寫過的研究成果。確說明并表示謝意。（設(shè)計(jì)）的電子版和紙質(zhì)版。有權(quán)將論文（設(shè)計(jì)）用于非贏利目的的。少量復(fù)制并允許論文（設(shè)計(jì)）進(jìn)入學(xué)校圖書館被查閱。保密的論文（設(shè)計(jì)）在解密后適用。事故的頻繁發(fā)生，給人們的生命和財(cái)產(chǎn)安全帶來了巨大損失。安全駕駛成為大家。種基于STC89C52單片機(jī)的倒車防撞報(bào)警系統(tǒng)。該系統(tǒng)采用軟、硬件結(jié)合的方法，具有模塊化和多用化的特點(diǎn)。問題的提出及研究意義········································································1. 國內(nèi)外研究現(xiàn)狀·····································&#183

　　

【正文】 州學(xué)院本科畢 業(yè)論文 (設(shè)計(jì) ) 29 LCD_send_data(digit[ge])。 //將百位數(shù)字的字符常量寫入 LCD LCD_send_data(39。 39。)。 //將百位數(shù)字 的字符常量寫入 LCD LCD_send_data(39。C39。)。 //將萬位數(shù)字的字符常量寫入 LCD LCD_send_data(39。M39。)。 //將萬位數(shù)字的字符常量寫入 LCD 瓊州學(xué) 院本科畢業(yè)論文（設(shè)計(jì)） 30 附錄 C 外文翻譯 : Ultrasonic wave examination development summary The high velocity, the high efficiency is the modern industry symbol, but this is the establishment above the high grade foundation. The design and the craft personnel should understand that,Must a anizational structure, stochastically has microscopically, the macroscopic flaw, may sometimes even be frequently only can depend upon not damages the examination technology the utilization only then to give to discover, appraisal. Certainly, this with dozens of year in every way value and the general jobholders39。 difficult endeavor, causes not to damage the examination technology to have certain ability in this aspect to concern. Now, in the industry developed country, not damages the examination in the product design, the development, the user departments already by the fruitful utilization, in 1981 American former president Reagan in not damaged the examination academic society 40th anniversary congress to US in the letter of congratulations to say: “You can give the airplane and the spatial flight vehicle, the power plant, the ships, the automobile and the building and so on bring a greater degree the reliability. Not has not damaged the examination, we not impossible to enjoy at present in these domains and other domain leading status.”Not damages the examination by the swift and violent potential to the depth development, the objective need is after all the biggest power which one specialty may develop. Our country not damages the examination technology is grows out of nothing, develops gradually from the lower stage to the application popular present stage level. Ultrasonic wave instrumentation development production, also presses this rule development change approximately. The 5039。s, our country starts from the overseas introduction ultrasonic wave instrument, many is the unwieldy electronic tubular instrument. If England39。s UCT2 ultrasonic wave instrumentation, reaches 24Kg again, various units do the 瓊州學(xué)院本科畢 業(yè)論文 (設(shè)計(jì) ) 31 experimental study work positively, has obtained the good effect in some project examination. At the end of the 5039。s at the beginning of 6039。s, the domestic scientific research unit imported Poland to produce the ultra acoustimeter, and carried on the imitation production. Afterwards, Shanghai Tongji University develops the CTS10 nonmetallic supersonic instrumentation, also is the electron tubular, instrument heavy approximately 20Hg. This instrument performance is stable, the profile is clear. But at that time this kind of instrument only then the individual scientific research unit used, the construction work department used not not many. Until 7039。s intermediate stages, because not damaged the examination technology still to be at the experimental stage, the promotion has not popularized, therefore the instrument big development, still has not used the electronic tubular UCT2,CTS10. In 1976, after National Construction mittee Office of Sciences managed holds the nation architectural engineering examination technology meeting, National Construction mittee not damaged the concrete the examination technology to list as the key attack project, the anization nation 6 unit cooperation attack. Henceforth, not damages the examination technology to start to enter has the plan, has the goal research stage. Along with the electronics industry rapid development, the transistor unit has replaced the electron tube ponent gradually, is more advantageous to not damages the examination technology the promoted popularization. If the Romanian N2701 ultrasonic wave reflectoscope reflector, is posed by the transistor discrete ponent, has the profile and the numerical code demonstrated, instrument weight 10Kg. The 7039。s, English Corporation promotes only has the heavy PUNDIT portable ultra acoustimeter. In October, 1978, Chinese Construction Academy of science developed JC2 portable ultrasonic wave instrumentation. This instrument uses the TTL line, the numerical code demonstrated that, the instrument weight is 5Kg. Develops same time the supersonic instrumentation also has SC2, CTS25, SYC2 ultrasonic wave instrumentation. Henceforth, our country had the ultrasonic wave instrument which own produce, not damaged the examination technology for the promoted application 瓊州學(xué) 院本科畢業(yè)論文（設(shè)計(jì)） 32 to lay the good foundation. The ultrasonic wave examination technology is our country prioritize and the promoted new technology, it has the high accuracy, not damages, merits and so on noncontact. At present, already widely applied at the machine manufacture, the electronic metallurgy, the navigation, the astronavigation, the petroleum chemical industry, industry domains and so on transportation. In addition, in the materials science, the medicine, domains and so on in biological science also occupies has the important status. Overseas was enhancing the ultrasonic ranging aspect to do the massive research, the domestic some scholars have also done the correlation research. Mainly is decided to the ultrasonic ranging precision by the ultrasonic propagation time and the ultrasonic wave which measured in the medium propagation velocity, in the two the propagation time precision influence is big, therefore the majority of literature use reduce the propagation time the uncertainty to increase the range finder precision. At present, the phase survey law and the sound spectrum outline analytic method or the two unify the method is main reduces the survey transmission uncertainty the method. The ultrasonic wave examination technology took not damages one of examination technology important methods, is playing the vital role in its developing process, it has provided the appraisal solid state material microscopic aniza tion and the correlation mechanics performance, examines its microscopic and the macroscopic discontinous effective general method. As a result of its signal highfrequency response, the ultrasonic wave examination early time only uses