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Programmable designed for electro-pneumatic systems controller Abstract This project deals with the study of electro-pneumatic 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 study of automation design and the control processing of pneumatic systems with the electronic design based on microcontrollers to implement the resources of the controller.51246
1.Introduction
The automation systems that use electro-pneumatic technology are formed mainly by three kinds of elements: actuators or motors,sensors or buttons and control elements like valves. Nowadays,mostof 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 cntrol valves for the actuators are plugged as outputs. An internal program executes all the logic necessary to the sequence of the movements,simulates other components 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 aystem as many times as nended .therefore,time can be saved,risk of mistakes reduced and complexity can be increased using the same elements.
A conventional PLC,this is possible to find on the market from many companies,offers many resources to control not only pneumatic systems,but all kinds of system that uses electrical comonents .the PLC can be very versatile and robust 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,electro-pneumatic 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 alterative in this case is to create a specific controller that can offer the exactly size and resources that the project nends.this can be made using micrcontrollers 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 the 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 complexity and the application of it.It means that the project gets more independence from other companies,but at the same time the responsibility of the control of the system stays at the designer hands.
2.Electro-pneumatic system
On automation system one can find three basic components 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 components to execute the sequence of movements properly.For asimple direct sequence of movement an intuitive method can be used[1,5],but for indirect or more complex sequences the intuition can generate a very complicated circuit and signal mistakes.It is necessary to use another method that can save time of the project,make a clean circuit, can eliminate occasional signal overlapping and redundant circuits.
The presented method is called step-by-step or lgorithmic,it is valid for pneumatic and electro-pneumatic systems and it was used as a base in this work. The method consists of designing the systems based on standard circuits made for each change on the state of the actuators,these changes are called steps.