基于PLC的活塞式空氣壓縮機控制系統(tǒng)設(shè)計
基于PLC的活塞式空氣壓縮機控制系統(tǒng)設(shè)計,基于PLC的活塞式空氣壓縮機控制系統(tǒng)設(shè)計,基于,plc,活塞,空氣壓縮機,控制系統(tǒng),設(shè)計
中文資料
淺析步進電機的PLC控制技術(shù)與發(fā)展趨勢
1、概述:
隨著微電子技術(shù)和計算機技術(shù)的發(fā)展,可編程序控制器有一了突飛猛進的發(fā)展,其功能已遠遠超出了邏輯控制、順序控制的范圍,它與計算機有一效結(jié)合,可進行模擬最控制,具有一遠程通信功能等。有-人將其稱為現(xiàn)代丁業(yè)控制的三大支柱(即PLC,機器人,CAD/CAM)之一,目前可編程控制器廣泛應(yīng)用于冶金、礦業(yè)、機械、輕丁等領(lǐng)域,為工業(yè)自動化提供了有一力的工具。PLC控制的步進電機開環(huán)伺服機構(gòu)應(yīng)用于組合機床自動生產(chǎn)線上的數(shù)控滑臺控制,可省去該單元的數(shù)控系統(tǒng),使該單元的控制系統(tǒng)成本降低。
2、步進電機的基本特點:
(1)、一般步進電機的精度為步進角的3-5%且不累積。
(2)、步進電機外表允許的最高溫度步進電機溫度過高首先會使電機的磁性材料退磁,從而導致力矩下降乃至于失步,因此電機外表允許的最高溫度應(yīng)取決于小同電機磁性材料的退磁點;一般來講,磁性材料的退磁點都在攝氏130度以上,有一的甚至高達攝氏200度以上,所以步進電機外表溫度在攝氏80-90度完全正常
(3)、步進電機的力矩會隨轉(zhuǎn)速的升高而下降。當步進電機轉(zhuǎn)動時,電機各相繞組的電感將形成一個反向電動勢;頻率越高,反向電動勢越大在它的作用大,電機隨頻率(或速度)的增大而相電流減小,從而導致力矩下降。
(4)、步進電機低速時可以正常運轉(zhuǎn),但若高于一定速度就無法啟動,并伴有一嘯叫聲步進電機有一個技術(shù)參數(shù):空載啟動頻率,即步進電機在空載情況下能夠正常啟動的脈沖頻率,如果脈沖頻率高于該值.,電機不能正常啟動,可能發(fā)生丟步或堵轉(zhuǎn)。在有一負載的情況下,啟動頻率應(yīng)更低如果要使電機達到高速轉(zhuǎn)動,脈沖頻率應(yīng)該有一加速過程,即啟動頻率較低,然后按一定加速度升到所希望的高頻.步進電動機以其顯著的特點,在數(shù)字化制造時代發(fā)揮著重大的用途伴隨著小同的數(shù)字化技術(shù)的發(fā)展以及步進電機本身技術(shù)的提高,步進電機將會在更多的領(lǐng)域得到應(yīng)用。
3、步進電機控制系統(tǒng)的組成:
步進電機是一種將電脈沖轉(zhuǎn)化為角位移的執(zhí)行機構(gòu)。當步進驅(qū)動器接收到一個脈沖信號,它就驅(qū)動步進電機按設(shè)定的方向轉(zhuǎn)動一個固定的角度稱為“步距角”,它的旋轉(zhuǎn)是以固定的角度一步一步運行的。可以通過控制脈沖個數(shù)來控制角位移最,從而達到確定位的目的;同時,可以通過控制脈沖頻率來控制電機轉(zhuǎn)動的速度和加速度,從而達到調(diào)速的目的步進電機.可以作為一種控制用的特種電機,利用其沒有累積誤差精度為百分百的特點,泛應(yīng)用于各種開環(huán)控制。
4、步進電機的PLC制技術(shù):
應(yīng)使輸入步進電機的輸入脈沖總數(shù)和脈沖頻率受到相應(yīng)的控制。因此在控制軟件上設(shè)置一個脈沖總數(shù)和脈沖頻率可控的脈沖信號發(fā)生器;對于頻率較低的控制脈沖,可以利用PL的定時器構(gòu)成,脈沖頻率可以通過定時器的定時常數(shù)控制脈沖周期,脈沖總數(shù)控制則可以設(shè)置一脈沖計數(shù)器C10當脈沖數(shù)達到設(shè)定值時,計數(shù)器C1。動作切斷脈沖發(fā)生器回路,使其停止,伺服機構(gòu)的步進電機無脈沖輸入時便停止運轉(zhuǎn),伺服執(zhí)行機構(gòu)定位當伺服執(zhí)行機構(gòu)的位移速度要求較高時,可以用PLC的高速脈沖發(fā)生器. 不同的PLC其高速脈沖的頻率可達4000 6000Hz. PLC用來產(chǎn)生控制脈沖,通過PLC編程輸出一定數(shù)最的方波脈沖,控制步進電機的轉(zhuǎn)角,可編程控制器輸出的控制脈沖按步進電機的通電順序分配到相應(yīng)的繞組。PLC控制的步進電機可以以采用軟件環(huán)行分配器,硬件環(huán)行分配器采用軟環(huán)占用的PLC資源較多,特別是步進電機繞組相數(shù)大于四時,對于大型生產(chǎn)線應(yīng)該充分考慮采用硬件環(huán)行分配器,雖然硬件結(jié)構(gòu)稍微復雜些,但可以節(jié)省占用PLC的輸出輸入點數(shù),目前市場有一多種專用芯片可以選用.步進電機功率驅(qū)動器PLC輸出的控制脈沖放大到幾十至上百倍, 伏特、幾安到幾十幾安的驅(qū)動能力,一般PLC的輸出接口具有一定的驅(qū)動能力,而通常的晶體管內(nèi)流輸出接口的負載能力僅為十幾到幾十伏特、幾十到幾百毫安,但對于功率步進電機則要求幾十到上百伏特,幾安到幾十安的驅(qū)動能力,因此應(yīng)該采用驅(qū)動器對輸出脈沖進行放大。
5、國內(nèi)外電機的發(fā)展趨勢:
(1)、繼續(xù)沿著小型化的方向發(fā)展隨著電動機本身應(yīng)用領(lǐng)域的拓寬以及各類整機的不斷小型化,要求與之配套的電動機也必須越來越小,在57, 42機座號的電動機應(yīng)用了多年后,現(xiàn)在其機座號向3 9, 3 5,30, 25方向向下延伸。
(2)、對電動機進行綜合設(shè)計即把轉(zhuǎn)速位置傳感器,減速齒輪等和電動機本體綜合設(shè)計在一起,這樣使其能方便地組成一個閉環(huán)系統(tǒng),因而具有一更加優(yōu)越的控制性能。
(3)、向五相和三相電動機方向發(fā)展.目前,泛應(yīng)用的二相和四相電動機,其振動和噪聲較大,而五相和三相電動機具有優(yōu)勢性而就這兩種電動機而言,五相電動機的驅(qū)動電路比三相電動機復雜,因此三相電動機系統(tǒng)的性能價格比要比五相電動機更好一些我國的情況有一所小同,直到20紀紀八十年代,一直是磁阻式步進電動機占統(tǒng)治地位,混合式步進電動機是80年代后期才開始發(fā)展,至今仍然是兩種結(jié)構(gòu)類型同時并存。盡管新的混合式步進電動機完全.可能替代磁阻式電動機,但磁阻式電動機的整機獲得了長期應(yīng)用,對于它的技術(shù)也較為熟悉,特別是典型的混合式步進電動機的步距角與典型的磁阻式電動機的步距角不一樣,用戶改變這種結(jié)構(gòu)小是很客易的,這就使得兩種機型并存的局面難以在較短時問內(nèi)改變。這種現(xiàn)狀對步進電動機的發(fā)展是不利的。
英文資料
The shallow treads into the PLC control technique and development trend of electrical engineering
1. Say all:
Along with the micro-electronics technique and the calculator technical hair Exhibition, the programmable preface controller has an advance by leaps and bounds of hair Exhibition, its function has already outrun a logic control far and far, in proper order The scope of control, it has an effect to combine with calculator, can enter Go to imitate to control most, have along range correspondence function etc.. Have-The person is called it the modern D industry controls of three pay pillar greatly(namely PLC, robot, CAD/CAM)it a, currently programmable controller BE applied in metallurgy extensively, Mineral industry, machine, light Class D realm, automate for the industry Provided to there is the tool of one dint The PLC controls of tread to open the wreath servo organization into the electrical engineering should Used for combining tool machine to produce an on-line number to control a slippery pedestal to control automatically Make, can the province go to the number of that unit to control system, making that unit The cost of controling the system lowers.
2、Tread into the basic characteristics of electrical engineering:
(1)、tread generally into the accuracy of the electrical engineering for tread into Cape of 3-5% and don't accumulate.
(2)、tallest temperatures which enter electrical engineering outward appearance and allow tread and lead into the electrical engineering temperature high can make the magnetism material of electrical engineering back first, cause the dint descend thus is as for lose a step, so the electrical engineering outward appearance allow of the tallest temperature should be decided by small back with electrical engineering magnetism material and order; Speak generally, the magnetism material backs to order all above have in 130 C an of even be up to 200C above, so tread completely normal into the electrical engineering outward appearance temperature in 80-90C.
(3)、dints which enter electrical engineering would with turn to go up but descend soon,While treading to turn to move into the electrical engineering, electrical engineering each electricity feeling which round a set mutually will become one anti- to electromotive force; The frequency is more high, anti- to electromotive force more big ,big in its function, the electrical engineering enlarges with the frequency(or speed) but mutually the electric current let up, causing the dint descend thus.
(4)、 can revolve normally when 4 enter electrical engineering low speed, but if high in certain the speed can't start, and the companion have a roar the interjection tread to have a technique parameter into the electrical engineering: empty carry start frequency, then tread into electrical engineering at empty carry under circumstance can start normally of pulse frequency, if the pulse frequency is high in should be worth., The electrical engineering can't start normally, the possible occurrence throws a step or blocks up to turn. Under the situation that there is one load, the start frequency should be much lower if want to make the electrical engineering attain high speed to turn to move, the pulse frequency should have an acceleration process, then start the frequency is lower, then press certain acceleration to rise the high hoped. Tread to show the characteristics of with it into the electric motor, turn ages of manufacturing to develop important use to accompany with in the numeral small together of numeral turn technical of development and tread into the electrical engineering technical exaltation,tread will get an application in more realms into the electrical engineering.
3、enter an electrical engineering control system to constitute:
Tread is a kind of performance organization that will give or get an electric shock a pulse conversion to move for the Cape into the electrical engineering. When tread to receive to a pulse signal into the actuator, it drives a step to press the direction of enactment to turn to move an angle for fixing to be called "tread to be apart from Cape" into the electrical engineering, it revolves one-step circulate with the fixed angle one step. Can pass control pulse piece to control a Cape to move to attain the purpose of assurance most and thus; Can pass control pulse frequency to control electrical engineering to become dynamic speed and acceleration in the meantime, the purpose attained to adjust thus soon treads into the electrical engineering. Can be the special kind electrical engineering that a kind of control uses, make use of it didn't accumulate error margin accuracy to 100 to divide 100 of characteristics, be suffused with to apply in various open a wreath control PLC which enter electrical engineering technique.
4、make the importation tread to be subjected to a homologous control into total amount and pulse frequency of the importation pulse of electrical engineering. Establish the pulse signal occurrence that a pulse total amount and pulse frequency can control a machine therefore and in control,software; Can make use of PL in fixed time a machine composing for the frequency lower control pulse, the pulse frequency can pass in fixed time machine in fixed time constant control pulse period, the pulse amounts control then can establish a the pulse counter C10 be when the pulse number attain initial value, count machine C1.The action cuts off pulse back track, making it stop, the servo organization tread into the electrical engineering have no the pulse input then stop operation,servo performance organization fixed position be servo performance organization of when move speed to have higher request, can use PLC high-speed pulse,Different PLC it the frequency of high-speed pulse can reach to 4000-6000Hzses. The PLC is used to produce control pulse, passing PLC plait distance exportation several pulses certainly the control treads to turn Cape into the electrical engineering, programmable controller output's control the pulse enters electrical engineering to switch on electricity sequence to assign by the step homologous of round a set. The PLC controls of tread can go an allotment machine by adoption software wreath into the electrical engineering, the hardware wreath goes allotment machine to adopt the PLC resources that the soft wreath takes up more, Tread especially to round a set to count mutually into the electrical engineering big should consider adoption hardware wreath to go allotment machine well for large production line at 4, although the hardware structure is a little bit a little more complicated, can save an exportation importation of taking up the PLC point, the market has a various appropriation chips to choose touse currently. Tread to enlarge to several ten highest hundred folds into the output's control of the actuator PLC of the electrical engineering power pulse, volt, several Anne arrive several ten several Anne s drive an ability, the exportation of general PLC connects to have to certainly drive an ability, but inside usual transistor flow exportation to connect an oscular load ability only for ten several arrive several ten volts, several ten arrive several 100 million Anne but tread to then have several request into the electrical engineering to the power ten arrive up 100 volts, several Anne arrive several ten Anne s drive an abilityso should adopt an actuator to output the pulse carry on enlarging.
5、The development trend of 5 domestic and international electrical engineering: (1)、continue along small scaled direction development turned along with electric motor application the realm open widely and each kind of whole machine is continuously small scaled to turn, the electric motor which requests with its kit have to also more and more small, at 57, the electric motor of 42 machine seat numbers applies many after years, now its machine seat number to 39,35,30,25 directions get down extension.
(2 )、right nesses of electric motors carry on comprehensive design namely turn soon position to spread a feeling machine, decelerate the wheel gear etc. and electric motor essence to synthesize design together, so make it be able to constitute 1 to shut wreath system expediently, as a result have one more superior control function.
(3)、to five mutually with three mutually the electric motor direction develop,Be suffused with currently applied of two mutually with four mutually the electric motor, its vibration and voice are bigger, but five mutually with three mutually the electric motor have advantage but in regard to these two kinds of electric motors, five mutually the electric motor drive electric circuit compare three mutually electric motor complications, so three mutually the function price of electric motor system than want than five mutually the electric motor is a little bit better our country of the circumstance have small one together, until 20 Ji,Ji,80's, has been is the type of to tread to share governance position into the electric motor, the mixture type tread into the electric motor is after 80's to expect just start developing, still is two kinds of structure types up to now in the meantime keep both. Though new of the hybrid type tread into the electric motor completely. May act for the type electric motor, but the whole machine of the type electric motor acquire to apply over a long period of time, to its technique also compare in order to acquaint with, especially typical of hybrid type's treading to tread type electric motor of being apart from the Cape and typical model to tread into the electric motor be different apart from the Cape the customer changes this kind of structure small is the guest is easy very much, this make two kinds of models keep both of the situation is hard to change in shorter the hour ask. This kind of present condition is disadvantageous to the development which treads into the electric motor.
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