【正文】 B 的運(yùn)行速度的限制，而 B 速度由一個(gè)流動(dòng)的控制活瓣管理。 圖 5 A， B， C， D 傳動(dòng)裝置時(shí)間曲線 第三步，當(dāng) B 到達(dá)最后的位置時(shí)候 , C 停止立刻它的循環(huán)運(yùn)動(dòng)并且回到開始的位置。第四步，主動(dòng)器 D 快速往返來(lái)回運(yùn)動(dòng)一次。當(dāng) D 返回開始的位置時(shí)候 , A和 B 也同時(shí)返回，這是第五個(gè)步驟。我們把每個(gè)步驟的所有運(yùn)行統(tǒng)稱為 [2]. (A+) 表示主動(dòng)器 A 向前推動(dòng)，而 (A) 表示返回到開始的位置。這個(gè)系統(tǒng)共有有五個(gè)步驟。 利用他們我們可以用必需的邏輯語(yǔ)言設(shè)計(jì)整個(gè)的控制線路。 對(duì)于程序的最后運(yùn)行， 這些輔助設(shè)施十分的重要，因?yàn)樗麄兡苁咕€路有更多的功能。那一個(gè)線路能夠隨時(shí)停止序列而且將主動(dòng)器的狀態(tài)換成一個(gè)特定的位置。圖 7 和 8 顯示的是在沒(méi)有使用控制器的情況下會(huì)發(fā)生的一些結(jié)果。 圖 7 電氣圖表舉例 圖 8 電氣圖表舉例 另外的一些輔助設(shè)施也包括在這個(gè)系統(tǒng)中 ,比如自動(dòng)機(jī)械 / 手動(dòng)調(diào)控器，他們可以使系統(tǒng)不斷的循環(huán)工作；兩個(gè)開始控制鍵 ,他們能讓操作員手動(dòng)控制系統(tǒng)的開始和停止，這樣就減少了發(fā)生意外事件的危險(xiǎn)。但是 ,如前面提到的那樣 ,使用一個(gè) PLC 或特定的控制器 , 這種控制就變得比較容易的，而且系統(tǒng)的精密性也會(huì)提高。通過(guò)時(shí)間圖表 ,表 2 ，和圖 5 和 6描述了每一步驟的程序和系統(tǒng)的各個(gè)部件。 使用傳統(tǒng)的 PLC的 ,如圖 7， 8所示，在繪制接口處的電圖表時(shí)，要注意線路的邏輯。 那就是說(shuō)，使用傳統(tǒng)的 PLC ，使用者清楚各個(gè)操作之間的關(guān)系。 序列獨(dú)自被定義，但每一步驟只被輸入和輸出端描述。序列被 25個(gè)位元組所定義。 （圖 9 和 10） 7. 結(jié)論 這種控制器是專門為這一項(xiàng)目所設(shè)計(jì)的 。它不需要為了獲取微控制器里的資源而安裝外部記憶器或外部的定時(shí)器。 單獨(dú)使用內(nèi)部記憶 ,我們可以控制一個(gè)有 48個(gè)步驟的氣流系統(tǒng)，但是如果使用一個(gè)比較簡(jiǎn)單的系統(tǒng)，就會(huì)達(dá)到 60個(gè)步驟 .控制器的變成不使用 PLC 語(yǔ)言，而是用一個(gè)比較簡(jiǎn)單的和直覺(jué)的結(jié)構(gòu)。 一種 非常簡(jiǎn)單的機(jī)械語(yǔ)言能讓 設(shè)計(jì)者用四或五個(gè)位元組定義步驟所有結(jié)構(gòu)構(gòu)成。這種控制器雖然不能和商業(yè)的 PLC 相比，但是它原本就是為特定的的目的而設(shè)計(jì)的，所以很難說(shuō)哪一個(gè)好哪一個(gè)壞。 Programmable designed for electropneumatic systems controller This project deals with the study of electropneumatic systems and the programmable controller that provides an effective and easy way to control the sequence of the pneumatic actuators movement and the states of pneumatic system. The project of a specific controller for pneumatic applications join the stud y of automation design and the control processing of pneumatic systems with the electronic design based on microcontrollers to implement the resources of the controller. 1. Introduction The automation systems that use electropneumatic technology are formed mainly by three kinds of elements: actuators or motors, sensors or buttons and control elements like valves. Nowadays, most of the control elements used to execute the logic of the system were substituted by the Programmable Logic Controller (PLC). Sensors and switches are plugged as inputs and the direct control valves for the actuators are plugged as outputs. An internal program executes all the logic necessary to the sequence of the movements, simulates other ponents like counter, timer and control the status of the system. With the use of the PLC, the project wins agility, because it is possible to create and simulate the system as many times as needed. Therefore, time can be saved, risk of mistakes reduced and plexity can be increased using the same elements. A conventional PLC, that is possible to find on the market from many panies, offers many resources to control not only pneumatic systems, but all kinds of system that uses electrical ponents. The PLC can be very versatile and robust to be applied in many kinds of application in the industry or even security system and automation of buildings. Because of those characteristics, in some applications the PLC offers to much resources that are not even used to control the system, electropneumatic system is one of this kind of application. The use of PLC, especially for small size systems, can be very expensive for the automation project. An alternative in this case is to create a specific controller that can offer the exactly size and resources that the project needs [3, 4]. This can be made using microcontrollers as the base of this controller. The controller, based on microcontroller, can be very specific and adapted to only one kind of machine or it can work as a generic controller that can be programmed as a usual PLC and work with logic that can be changed. All these characteristics depend on what is needed and how much experience the designer has with developing an electronic circuit and firmware for microcontroller. But the main advantage of design the controller with the microcontroller is that the designer has the total knowledge of his controller, which makes it possible to control the size of the controller, change the plexity and the application of it. It means that the project gets more independence from other panies, but at the same time the responsibility of the control of the system stays at the designer hands 2. Electropneumatic system On automation system one can find three basic ponents mentioned before, plus a logic circuit that controls the system. An adequate technique is needed to project the logic circuit and integrate all the necessary ponents to execute the sequence of movements properly. For a simple direct sequence of movement a