【正文】 ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jump When he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely. If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。 Have declared the end of the encounter that haven39。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說，是自以為是的精神寄托罷了。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個人的時候，自己的想法總是特別地清晰。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。 The end of our life, and can meet many things really do? 而窮盡我們的一生，又能遇到多少事情是真正地非做不可？ During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it. 一字開頭的年齡已經(jīng)到了尾聲。s 21 win. Michel Platini, president of European football39。s antiracism taskforce, is in London for the Football Association39。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。在設(shè)計過程中，老師給予了悉心的指導(dǎo)，最重要的是給了 我解決問題的思路和方法，并且在設(shè)計環(huán)境和器材方面給予了大力的幫助和支持，在此 ，我對老師表示最真摯的感謝 。這三個月的設(shè)計是對過去所學(xué)知識的系統(tǒng)提高和擴(kuò)充過程 ,為今后的發(fā)展打下了良好的基礎(chǔ)。經(jīng)過自己不斷的努力以及老師的耐心指導(dǎo)和熱情幫助，本設(shè)計已經(jīng)基本完成。 （ 3）自動檢測停車線并自動停車。本系統(tǒng)能實(shí)現(xiàn)如下功能： （ 1） 自動沿預(yù)設(shè)軌道行駛小車在行駛過程中，能夠 自動檢測預(yù)先設(shè)好的軌道，實(shí)現(xiàn)直道和弧形軌道的前進(jìn)。amp。P12==0) { P14=0,P15=1,P16=0,P17=1。//直走 } if(P10==1amp。amp。P11==0amp。P12==0) //右中測 左走 { P14=0,P15=1,P16=1,P17=0。 } if(P10==1amp。P11==0amp。amp。 } 開始 前進(jìn) 掃描 I/O 口，是否檢測到黑線 Y 左邊 右邊 左轉(zhuǎn) 右轉(zhuǎn) N 基于單片機(jī)的智能小車設(shè)計 14 } 避障模塊 避障框圖 如圖 所示。break。 if(P10==0||P11==0) //進(jìn)入壁障標(biāo)志口 dr=4。amp。P26==1amp。amp。 主程序框圖 圖 主程序框圖 啟動 循跡 是否檢測到停止線 停止 是否檢測到 障礙 N Y 避障 Y N 河北化工醫(yī)藥職業(yè)技術(shù)學(xué)院畢業(yè)論文 13 循跡模塊 循跡框圖 如圖 。過程控制程序主要是使單片機(jī)按一定的方法進(jìn)行計算，然后再輸出，以便控制生產(chǎn) 。因此， 軟件設(shè)計在微機(jī)控制系統(tǒng)設(shè)計中占重要地位。 IN1~ IN4：輸入端，輸入端電平和輸出端電平是對應(yīng)的 。 GND：共地接法。 （ 4）可編程輸入 /輸出引腳（ 32 根） STC89C52 單片機(jī)有 4 組 8 位的可編程 I/O 口，分別位 P0、 P P P3口，每個口有 8位（ 8根引腳），共 32 根。該器件采用 ATMEL 搞密度非易失存儲器制造技術(shù)制造， 與工業(yè)標(biāo)準(zhǔn)的 MCS51 指令集和輸出管腳相兼容。 圖 圖 循跡原理圖 河北化工醫(yī)藥職業(yè)技術(shù)學(xué)院畢業(yè)論文 9 主控電路的設(shè)計與原理分析 本模塊主要是對采集信號進(jìn)行分析，同時控制 電機(jī)，起停。在小車行駛過程中不斷地向地面發(fā)射紅外光， 當(dāng)紅外光遇到白色地面時發(fā)生漫發(fā)射，反射光被裝在小車上的接收管接收；如果遇到 黑線則紅外光被吸收，則小車上的接收管接收不到信號 ，再通過 LM324作比較器來采集高低電平，從而實(shí)現(xiàn)信號的檢 測。 在 L298N 的輸出端分別正確的接上小車的左右兩個直流 電機(jī)，通過 L298N 的輸出電流控制左右兩個直流電機(jī)的停止或者前進(jìn)，例 如左輪不轉(zhuǎn)右輪向前就做左轉(zhuǎn)的動作，右輪不轉(zhuǎn)左輪向前就做右轉(zhuǎn)的動作，如圖 和圖 所示。1腳和 15 腳下管的發(fā)射極分別單獨(dú)引出以便接入電流采 樣電阻，形成電流傳感信號。 L298N 芯片可以驅(qū)動兩個二相電機(jī)，也可以驅(qū)動一個 四相電機(jī)，輸出電壓最高可達(dá)50V，可以直接通過電源來調(diào)節(jié)輸出電壓；可以直 接用單片機(jī)的 IO 口提供信號；而且電路簡單，使用比較方便。通過測試此種方案就能很好的實(shí)現(xiàn)小車 避開障礙物，且充分的利用資源而不浪費(fèi)。因此決定采用使用功率三極管作為功率放大器的輸出控制直