【文章內(nèi)容簡(jiǎn)介】 ） 步進(jìn)電機(jī)的運(yùn)行控制： １） 轉(zhuǎn)速控制。接通起動(dòng)開(kāi)關(guān) X30。脈沖控制器產(chǎn)生周期為 0。 1 秒的脈沖，使移位寄存器移位產(chǎn)生八拍時(shí)序脈沖。通過(guò)四相八拍環(huán)行分配器使四個(gè)輸出繼電器 Y Y3 Y3 Y33 按照單雙八拍的通電方 式接通，其接通順序?yàn)椋? Y30—— Y Y31—— Y31——Y3 Y32——Y32——Y3 Y33——Y33——Y3Y30——Y30 其相應(yīng)于四相步進(jìn)電動(dòng)機(jī)繞組的通電順序?yàn)椋? PLC 功率放大器 步進(jìn)電動(dòng)機(jī) ＰＬＣ電氣和測(cè)控系統(tǒng)設(shè)計(jì) 20 A—— A、 B—— B—— B、 C—— C—— C、 D—— D—— D、 A—— A 調(diào)整 T200 的定時(shí)時(shí)間，步進(jìn)電機(jī)的接通順序不變，但間隔時(shí)間變化了。即 脈沖的頻率改變了，這樣可以通過(guò)軟件的辦法改變 T200 的定時(shí)時(shí)間來(lái)改變步進(jìn)電機(jī)的轉(zhuǎn)速，實(shí)現(xiàn)步進(jìn)電機(jī)的可調(diào)。 ２） 步數(shù)控制。改變步數(shù)控制 C230 的數(shù)值，將使步進(jìn)電動(dòng)機(jī)的步距改變。即可實(shí)現(xiàn)工件的 步距改變，有利于實(shí)現(xiàn)生產(chǎn)線布局的調(diào)節(jié)。 ３） 總之，改變 PLC 的控制程序，可實(shí)現(xiàn)步進(jìn)電動(dòng)機(jī)靈活多變的運(yùn)行方式，有利于實(shí)現(xiàn)設(shè)計(jì)的模塊化。 2)轉(zhuǎn)步條件圖。 在負(fù)載驅(qū)動(dòng)圖上加上名步序的轉(zhuǎn)步條件，構(gòu)成轉(zhuǎn)步條件圖，如圖所示。當(dāng)按下自動(dòng)起動(dòng)按鈕，機(jī)械手一、二、三的起動(dòng)有效時(shí)，機(jī)械手開(kāi)始動(dòng)作。按步序完成所有動(dòng)作，當(dāng)機(jī)械手一、二、三都又處于原位時(shí)完成一次工作過(guò)程，當(dāng)起動(dòng)信號(hào)再一次有效時(shí)步序又轉(zhuǎn)換為第一次工作狀態(tài)。以后，用類(lèi)似的方法完成一系列工藝過(guò)程的轉(zhuǎn)換。 ３） 狀態(tài)轉(zhuǎn)換圖和步進(jìn)梯形圖。它由負(fù)載驅(qū)動(dòng)圖和轉(zhuǎn)步條 件圖組合而成。圖中每個(gè)工藝過(guò)程，都由標(biāo)有編號(hào)的狀態(tài)器代替，編號(hào)可在 S500—S800 范圍內(nèi)選用。但不一定要連續(xù)排列。根據(jù)機(jī)械操作的工藝過(guò)程的狀態(tài)轉(zhuǎn)換圖，進(jìn)行編程，而不設(shè)計(jì)常規(guī)的繼電器順序。 (3)方式選擇等通用程序 1) 狀態(tài)的初始化。如圖所示。狀態(tài)初始化包括初始狀置位和中間狀態(tài)器復(fù)位。 1. 初始狀態(tài)置位。在選擇返回原位方式下， 按返回原位按鈕，則表示機(jī)器初始化條件的初始狀態(tài)器 S500、 S5 S550 置位，其作用是使自動(dòng)順序工作從原位開(kāi)始，依次逐步進(jìn)行轉(zhuǎn)換當(dāng)最后工序完成之后 S500、 S5S550 又分別置位。 而在依次工作期間，即使誤按了起動(dòng)按鈕，也不可能作另一次的起動(dòng)，因?yàn)榇藭r(shí)工序已不在原位， S500、 S5 S550 已處于不工作狀態(tài)。 2．中間狀態(tài)器復(fù)位。因?yàn)闋顟B(tài)器 S500—S800 均由后備電源支持，在失電時(shí)有可能是接通的。為防止順序控制動(dòng)作，通常需要在返回原位和手動(dòng)操作時(shí)，ＰＬＣ電氣和測(cè)控系統(tǒng)設(shè)計(jì) 21 對(duì)處于蹭狀態(tài)的狀態(tài)器進(jìn)行總復(fù)位。指令格式如圖。 F670K103 是總復(fù)位功能指令，包括 F671 的 K 編號(hào)到 F672 的 K 編號(hào)的所有器件。 2) 狀態(tài)器轉(zhuǎn)換禁止 如圖。當(dāng)用步進(jìn)梯形指令控制狀態(tài)器轉(zhuǎn)換時(shí)，激勵(lì)特殊功能繼電器 M574 動(dòng)作 ，則狀態(tài)器的自動(dòng)轉(zhuǎn)換就被禁止。 當(dāng)按下自動(dòng)按鈕時(shí)， M110 產(chǎn)生脈沖輸出，使 M574 斷開(kāi)，狀態(tài)器轉(zhuǎn)換禁止立即復(fù)位，進(jìn)行后工序處理。 1． 對(duì)自動(dòng)連續(xù)操作方式，狀態(tài)轉(zhuǎn)換禁止不受起動(dòng) X42 的影響，若按下停止按鈕時(shí)， M574 得電自保持，操作停止在現(xiàn)行工序。按起動(dòng)按鈕又可繼續(xù)下去。 2． 手動(dòng)方式及 PC 起動(dòng)時(shí)，都可使 M574 得電自保持，禁止?fàn)顟B(tài)轉(zhuǎn)換，直到按下起動(dòng)按鈕。 ３．６ 生產(chǎn)線控制總程序 按照?qǐng)D完整順序控制結(jié)構(gòu)安排，將通用程序塊、手動(dòng)程序塊、自動(dòng)程序塊用FX2N80MR PLC 的跳轉(zhuǎn)條件程序有機(jī)地連 接起來(lái)，即得到生產(chǎn)線步進(jìn)指令實(shí)現(xiàn)控制的總程序。 附加外文翻譯 外文文獻(xiàn) I , robot controller A sophisticated approach to kinematics is what differentiates robot controllers from more general purpose motion equipment. An interesting situation emerged recently when a manufacturer tried to put a vision system on an assembly line. The idea was to locate parts on a moving conveyor with a vision system ,then position a robotics arm to pick them up line at a time .Engineers there diligently worked out numerous displacement fudge factors to relate the locations of the conveyor end effectors and parts imaged by the camera . The fudge factors let the motion controller infer the physical location of a part from the vision system data , then direct the arm to the right place ＰＬＣ電氣和測(cè)控系統(tǒng)設(shè)計(jì) 22 to pick it up. Problem was , the relative position of the various ponents all changed every time the conveyor went back on line after servicing or maintenance . The factors so carefully puted became useless .This necessitated regular rounds of recalculating new displacements. At the root of these difficulties were some fundamental misunderstandings about how generalpurpose motion controllers differ from more specialized robot controllers. Hardwarewise, the two can look similar. Both frequently employ Pentiumbased processors or adopt a hybrid approach with a general CPU supervising one or more digital signal processors dedicated to servo loops. However, the software architecture of a robot controller differs dramatically from that of an ordinary motioncontroller software: It generally consists of a routine for closedloop position or v velocity control ,operator interface functions , and routine for supervisory tasks. An important point to note is at the supervisory level of control . Tasks there that relate to handling motion do not extend much past simply issuing position mands and individual axes. In other word ,the supervisory level is relatively simply. The supervisory level of robot controller is more sophisticated. For one thing , it is written with the idea that ,post robotic systems incorporate feedback from highlevel sensors that reside outside the positionencoderfeedback servo loops of individual axes. Typical examples include industrial vision system and force sensors. Most robotic work involves using information from these sensors to calculate the trajectory of a robot arm. To handle this calculation process, supervisory level software implements a trajectory planning algorithm. This algorithm relates the physical location of positioning elements, sensor feedback ,and the objects being positioned in terms of what’s called a world coordinate system. This is in contrast to generalpurpose motion equipment which tends to use a separate reference frame for each axis of motion . One benefit of a worldcoordinate system is that it can eliminate the need for fudge factors relating sensor data to the position of various ponents. The state of the art is such that straightforward setup routines can pute suck information automatically. Moreover, data gathered during setup goes into transformation calculations that determin