【導(dǎo)讀】現(xiàn)有超聲波雷達(dá)測速系統(tǒng)多采用單一的時(shí)差法測速或多普勒法測速，鑒于此，本文以單片機(jī)為核心，以超聲波換能器為收發(fā)元件，現(xiàn)了兩種方法的同時(shí)測量。理論分析表明，該系統(tǒng)的測量誤差小，測量精。度高，驗(yàn)證了系統(tǒng)的可行性。研究成果有一定的理論價(jià)值和應(yīng)用前景。從人們?nèi)粘Ｉ畹礁黝惞I(yè)生產(chǎn)以及科學(xué)研究，測速雷達(dá)為人類。社會(huì)的發(fā)展立下了汗馬功勞。隨著社會(huì)的飛速發(fā)展，由于超聲技術(shù)能夠有效的提。高生產(chǎn)效率，保障生產(chǎn)安全，降低生產(chǎn)成本，其應(yīng)用日益廣泛。更大作用，所以對(duì)于測速雷達(dá)的研究前景相當(dāng)廣泛。為7cm到25cm之間，最后一個(gè)是超聲波雷達(dá)其波長一般小于。而微波雷達(dá)則是利用多普勒效應(yīng)進(jìn)行速度測量，即無線電波。但微波雷達(dá)易受到其他電磁信號(hào)的干擾、低。用于對(duì)高速的測量。且系統(tǒng)制作簡便,成本低，以其節(jié)約性而更適用于大眾生活。量誤差增加，所以應(yīng)該把兩種測速方法集成在一個(gè)測速系統(tǒng)中去。與推廣超聲技術(shù)的歷史篇章。1922年，德國出現(xiàn)了首例超聲波治療的發(fā)明

　　

【正文】 xfd。 wela=0。 delayms(5)。 dula=1。 P0=table[ge] 。 dula=0。 P0=0xff。 wela=1。 P0=0xfb。 wela=0。 delayms(5)。 } 36 void display2(uchar bai,uchar shi,uchar ge) { dula=1。 P0=table[bai] 。 dula=0。 P0=0xff。 wela=1。 P0=0xdf。 wela=0。 delayms(5)。 dula=1。 P0=table[shi] 。 dula=0。 P0=0xff。 wela=1。 P0=0xef。 wela=0。 delayms(5)。 dula=1。 P0=table[ge] 。 dula=0。 P0=0xff。 wela=1。 P0=0xf7。 wela=0。 37 delayms(5)。 } void BanZhouQi() { _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 _nop_ ()。 } void FangBo() { SquareWave=1。 BanZhouQi()。 SquareWave=0。 BanZhouQi()。 SquareWave=1。 38 BanZhouQi()。 SquareWave=0。 } void ZhongDuan_Init() { TMOD=0X22。 //定時(shí)器 0,1 為工作方式 2，即 8位自動(dòng)重裝 IT0=1。 //外部中斷 0為下降沿觸發(fā) IT1=1。 //外部中斷 1為下降沿觸發(fā) TH0=11。 //12us（ 40KHz）中斷一次 TL0=11。 TH1=11。 //12us（ 40KHz）中斷一次 TL1=11。 EA=1。 EX0=1。 EX1=1。 ET0=1。 ET1=1。 } void main() { uchar a,b,c,d。 ZhongDuan_Init()。 //中斷初始化函數(shù) while(1) { if(Key_Start==0) //開始按鍵按下 39 { delayms(10)。 if(Key_Start==0) { flag0=1。 } } if(Key_Stop==0) //停止按鍵按下 { delayms(10)。 if(Key_Stop==0) { flag0=2。 } } if(flag0==1) { TR0=1。 FangBo()。 while(flag1==1)。 flag1=1。 num1=num*12。 num=0。 TR0=1。 FangBo()。 while(flag1==1)。 40 flag1=1。 num2=num*12。 num=0。 if(num1num2) speed1=(340*(num1num2))/(num1+num2)。 else speed1=(340*(num2num1))/(num1+num2)。 d=1000/(num3*12)。 if(d40) { speed2=340*((d40)/(d+40))。 } else { speed2=340*((40d)/(d+40))。 } if(flag2==2) { flag2=0。 } } if(flag0==2) { speed1=0。 } 41 a=speed1*100/100。 b=speed1*100%100/10。 c=speed1*100%10。 display1(a,b,c)。 a=speed2*100/100。 b=speed2*100%100/10。 c=speed2*100%10。 display2(a,b,c)。 } } void Timer0() interrupt 1 { num++。 } void Timer1() interrupt 3 { num3++。 } void Int0() interrupt 0 { TR0=0。 flag1=0。 } void Int1() interrupt 2 42 { flag2++。 if(flag2==1) TR1=1。 else { TR1=0。 flag2=0。 } } g an employment tribunal clai Employment tribunals sort out disagreements between employers and employees. You may need to make a claim to an employment tribunal if: ? you don39。t agree with the disciplinary action your employer has taken against you ? your employer dismisses you and you think that you have been dismissed unfairly. For more information about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。t appealed against the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal. Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept i. If you are worried about how the time limits apply to you, take advice from one of the anisations listed under Further help. Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation. Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the anisations listed under Further help. If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as a damagesbased agreement. In England and Wales, your solicitor can39。t charge you more than 35% of your pensation if you win the case. If you are thinking about signing up for a damagesbased agreement, you should make sure you39。re clear about the terms of the agreement. It might be best to get advice from an 43 experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by , click on nearest CAB. For more information about making a claim to an employment tribunal, see Employment tribunals. The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。s antiracism taskforce, is in London for the Football Association39。s 150th anniversary celebrations and will attend City39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport. For me it39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s 21 win. Michel Platini, president of European football39。s governing body, has also ordered an immediate investigation into the referee39。s actions. CSKA said they were surprised and disappointed by Toure39。s plaint. In a statement the Russian side added: We found no racist insults from fans of CSKA. Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been v