【正文】 17 3)三相六拍 ： A→AB→B→BC→C→CA→A ； 按以上順序通電，步進(jìn)電機(jī)正轉(zhuǎn)，按相反方向通電，步進(jìn)電機(jī)反轉(zhuǎn)。 (3)控制模型的順序向步進(jìn)電機(jī)輸入 控制脈沖。所以，我們可以考慮借助累加器 A 來實(shí)現(xiàn)步進(jìn)電機(jī)的通電，可以把一個(gè)時(shí)序字節(jié)放在累加器 A 中，在每個(gè)采樣時(shí)刻累加器 A 左移或右移一位，經(jīng)輸出口輸出。下面以三相單三拍和三相雙三拍為例來研究累加器中時(shí)序字節(jié)的轉(zhuǎn)移。示意圖如圖 所示。示意圖如圖 33 所示。 rZ－轉(zhuǎn)子齒數(shù) 。 －控制繞組相數(shù)， =3。在程序設(shè)計(jì)時(shí)，將 50 步化為二進(jìn)制為 32H， 32H作為步數(shù)控制量就可以了?？梢园巡竭M(jìn)電 機(jī)所要走的步數(shù)放在寄存器乳中，轉(zhuǎn)向標(biāo)志存放在程序狀態(tài)寄存器用戶標(biāo)志位 PSW 的 FO(地址 D5H)中，當(dāng) FO 的值為 “ 0” ，步進(jìn)電機(jī)正轉(zhuǎn) ； 當(dāng)FO 的值為 “ 1” 時(shí)，步進(jìn)電機(jī)反轉(zhuǎn)，假如步進(jìn)電機(jī)的正轉(zhuǎn)模型為 O1H， 03H， 02H， 06H， 04H， OSH 存放在 8751 片內(nèi)數(shù)據(jù)存儲(chǔ)器 20H25H 中， 26H 中存放結(jié)束標(biāo)志 OOH。用程序延時(shí)方法編程的流程圖，如圖 34 所示。一般來講，步進(jìn)電機(jī)的一個(gè)弱點(diǎn)，就是運(yùn)行中丟步，為了使步進(jìn)電機(jī)在運(yùn)行中不出現(xiàn)丟步現(xiàn)象，一般要小于或等于步進(jìn)電機(jī) “ 回應(yīng)頻率 ” 人，在該頻率下，步進(jìn)電機(jī)可以任意啟動(dòng)、停止或反轉(zhuǎn)而不發(fā)生失步現(xiàn)象。當(dāng)步進(jìn)電機(jī)走過的距離比較長時(shí)，需要低速啟動(dòng)，高速運(yùn)轉(zhuǎn)，然后降低速度，最后停止。那么實(shí)現(xiàn)變速控制的基本思想是改變控制頻率。 L1~L3 分別代表各個(gè)不同運(yùn)行階段的步長， f 代表步進(jìn)電機(jī)當(dāng)前運(yùn)行頻 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 21 率。在各個(gè)不同的運(yùn)行階段，根據(jù)程序執(zhí)行不同的控制程序，這樣減小因步進(jìn)電機(jī)丟步對(duì)控制過程的影響，這對(duì)于國產(chǎn)的步進(jìn)電機(jī)效果會(huì)更好些。 表 31 數(shù)據(jù)存儲(chǔ)定義 存儲(chǔ)器字節(jié)位置 20H 21H 22H 23H 24H 25H 26H 控制模型數(shù)據(jù) 01H 03H 02H 06H 04H 05H 00H 表 32 數(shù)據(jù)存儲(chǔ)定義 存儲(chǔ)器字節(jié)位置 27H 28H 29H 2AH 2BH 2CH 2DH 控制模型數(shù)據(jù) 01H 05H 04H 06H 02H 03H 00H 表 數(shù)據(jù)存儲(chǔ)定義 位地址 標(biāo)志內(nèi)容 70H 運(yùn)行方式 :0 代表恒速， 1 代表變速 71H 變速方式 :0 代表降速， 1 代表升速 72H 恒速變向 :0 代表正轉(zhuǎn)， 1 代表反轉(zhuǎn) 73H 升速轉(zhuǎn)向 :0 代表正轉(zhuǎn)， 1 代表反轉(zhuǎn) 74H 降速轉(zhuǎn)向 :0 代表正轉(zhuǎn)， 1 代表反轉(zhuǎn) 75H 程序結(jié)束標(biāo)志 :02 代表程序結(jié)束 由上面的工作，可以得到總控制程序流程圖，如圖 a） ， b）所示。 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 24 圖 流程圖 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 25 謝 辭 時(shí)間過的真快，轉(zhuǎn)眼近 2 個(gè)月的畢業(yè)設(shè)計(jì)即將結(jié)束了，我的心情非常激動(dòng)。在此，謹(jǐn)借論文完成之機(jī)，向所有關(guān) 心我、鼓勵(lì)我、支持我、幫助我的人們致以誠摯的謝意。在設(shè)計(jì)中的每一點(diǎn)提高都來源于 孫 老師的悉心教導(dǎo)和同學(xué)們的熱情幫助。 在畢業(yè)設(shè)計(jì)完成之際，感謝 孫 老師對(duì)我的悉心指導(dǎo)和 一起學(xué)習(xí)和工作的同學(xué)給我學(xué)習(xí)上的幫助和支持，謝謝您們帶給我快樂和幫助 ！ 同時(shí) ， 感謝三年來關(guān)心和幫助過我的所有老師，沒有您們的關(guān)心和幫助，三年的大學(xué)生活將不會(huì)這樣充實(shí)和有意義的度過。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 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。s antiracism taskforce, is in London for the Football Association39。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 21 win. Michel Platini, president of European football39。s actions. CSKA said they were surprised and disappointed by Toure39。 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?？傆X得自己自己似乎應(yīng)該去做點(diǎn)什么 ，或者寫點(diǎn)什么。 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。t really grow up, it seems is not so important。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 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 29 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。 Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time. 原來，這個(gè)世界上，對(duì)某個(gè)事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時(shí)間。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(gè)人的時(shí)候，自己的想法總是特別地清晰。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時(shí)候是最后又打 起了退堂鼓。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。 Those were broken into 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 30 various shapes of stationery。 Have declared the end of the encounter that haven39。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場還沒有開始就宣告了終結(jié)的邂逅計(jì)劃 …… 那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 31 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。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters). cause there 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 32