应用于电气系统的可编程序控制器中英文翻译、电气自动化外文文献翻译、机电一体化外文翻译

外文原文： 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. 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 used1,5,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. The first part is to design those kinds of standard circuits for each step,the next task is to link the standard circuits and the last part is to connect the control elements that receive signals from sensors, switches and the previous movements,and give the air or electricity to the supply lines of each step.In Figs.(1) and (2) the standard circuits are drawn for pneumatic and electro-pneumatic system.It is possible to see the relations with the previous and the next steps. 3.the method applied inside the controller The result of the method presented before is a sequence of movements of the actuator that is well defined by stepas .It means that each change on the position of the actuators is a new state of the system and the transition between states is calld step. The standard circuit described before helps the designer to define the states of the systems and to define the condition to each change between the states. In the end of the design,the system is defined by a sequence that never chances and states that have the inputs and the outputs well defined.The inputs are the condition for the transition and the outputs are the result of the transition. All the configuration of those steps stays inside of the microcontroller and is executed the same way it was designed. The sequence of strings are programmed inside the controller with 5 bytes；each string has the configuration of one step of the process There are two bytes for the inputs,one byte for the outputs and two more for the other configurations and auxiliary functions of the step.After programming,this sequence of strings is saved inside of a non-volatil Memory of the microcontroller,so they can be read and executed. The controller task is not to work in the same way as a conventional PLC,but the purpose of it is to be an example of a versatile controller that is design for an specific area.A conventional PLC process the control of the system using a cycle where it makes an image of the inputs,execute all the conditions defined by the configuration programmed inside,and then update the state of the outputs. This controller works in a d ifferent way,where it read the configuration of the step,wait the condition of inputs to be satisfied,then update the state or the outputs and after that jump to the next step and start the process again. It can generate some limitations,as the fact that this controller cannot execute, inside the program,movements that must be repeated for sometime,but this problem can be solved with some external logic components.Another limitation is that the controller cannot be applied on systems that have no sequence.These limitations are a characteristic of the system that must be analyzed for each application. 4.Characteristics of the controller The controller is based on the MICROCHIP microcontroller PICF8776,7with 40 pins,and it has all the resources neened for this project.it has enough pins for all the comonents,serial communication implemented in circuit,EEPROM memory to save all the configuration of the system and tne sequence of steps.For the execution of the main program,it offers comlete resources as timers and interruptions. The list of resources of the controller was created to explore all the capacity of the microcontroller to make it as complete as possible.during the step,the program chooses how to use the resources reading the configuration string of the step.this string has two bytes for digital inputs,one used as a mask and the other one used as a value expeced.one byte is used to configure the output or time-out.the EEPROM memory inside is 256 bytes length that is enough to save the string of the steps,with this characteristic it is possoble to save between 48 steps(table1). The controller(FIG.3)has also a display and some buttons that are used with an interactive menu to program the sequence of steps and other configurations. 4.1. Interaction components For the real application the conteoller must have some elements to interact with the final user and to offer a complete monitoring of the system resources that are available to the designer while creating the logic control of the pneumatic system(Fig.3). Intercative mode of work； function available on the main program for didactic purposes,the use gives the signal to execute the step. LCD display,which shows the status of the system,values of inputs,outputs,timer and statistics of the sequence execution. Beep to give important alerts,stop ,start and emergency. Led to show power on and others to show the state of iputs and outputs. 4.2. security To make the final application works property ,a correct configuration to execute the steps in the right way is needed,but more then that it must offer solutions in case of bad functioning or problems in the execution of the sequence.The controller offers the possibility to configure two internalvirtual circuits that work in parallel to the principal.These two circuits can be used as emergency or reset buttons and can return the system to a certain state at any time.There are two inputs that work with interruption to get an immediate access to these functions.It is possible to configure the position,the buttons and the value of time-out of the system. 4.3. User interface The sequence of strings can be programmed using the interface elements os the controller.A computer interface can be used to generate the user program easily.With a good documentation the final user can use the interface to configure the strings of bytes that define the steps of the sequence.But it is possible to create a program with visual resources that works as a translator to the user, it changes his work to the values that the controller understands. To implement the communication between the computer interface and the controller a simple protocol with check sum and number of bytes is the minimum requirementas to guarantee the integrity of the data. 4.4.Firmware The main loop works by reading the strings of the steps from the EEPROM memory that has all the information about the steps.In each step,the status of the system is saved on the memory and it is shown on the display too.Depending of the user configuration,it can use the interruption to work with the emergency circuit or time-out to keep the system safety .In Fig.4,a block diagram of micro controller main program is presented. 5.Example of electro-pneumatic system The system is not a representation of a specific machine,but it is made with some common novements and components found in a real one.The system is composed of four actuators.The actuators A,B and C are double acting and D-single acting.Actuator A advances and stays in specified position till the end of the cycle,it could work fixing an object to the next action for example(Fig.5),it is the first step.When a reaches the end position,actuator C starts his work together with B,making as many cycles as possible during the advancing of B.It depends on how fast actuator B is advancing；the speed is regulated by a flowing control valve.It was the second step.B and C are examples of actuators working together,while B pushes an object slowly,C repeats ins work for some time When B reaches the final position,C stops immediately its cycle and comes back to the initial position.The actuator D is a single acting one with spring return and works together with the back of C,it is the third step.D works making very fast forward and backward movement,just one time.Its backward movement is the fourth step.D could be a tool to make a hole on the object. When Dreaches the initial position,A and B return too,it is the fifth step.Fig.6 show the first part of the designing process where all the movements of each step should be defined2. (A+)means that the actuator A moves to the advanced position and (A?) to the initial position. The movements that happen at the same time are joined together in the same step. Th system has five steps.These two representations of the system. (Figs.5 and 6)together are enough to describe correctly all the sequence. With them is possible to design the whole control circuit with the necessary logic components.But till this time,it is not a complete system,because it is missing some auxiliary elements that are not included in this draws because they work in parallel with the main sequence. These auxiliary elements give more function to the circuit and are very important to the final application,the most important of them is the parallel circuit linked with all the others steps.That circuit should be able to stop the sequence at any time and change the state of the actuators to a specific position.This kind of circuit can be used as a reset or emergency buttons. The next figs.7 and 8 show the result of using the method without the controller.Theese pictures are the electric diagram of the control circuit of the example,including sensors,buttons and the coils of the electrical valves. The auxiliary elements are included,like the automatic/manual switcher that permit a continuous work and two start buttons that make the qperator of a machine use their two hands to start the process,reducing the ridk of accidents. 6.Changing the example to a user program In the previous chapter ,the electro-pneumatic circuits were presented,used to begin the study of the requires to control a system that work with steps and must offer all the functional elements to be used in a real application .but,as explained above,using a PLC or this specific conteoller ,the control becomes easier and the complexity can be increase also. With the time diagram,the step sequence and the elements of the system described in Table 2 and Figs.5 and 6 it is possible to the new programming allows that the configuration of the steps be separated,like described by the method .The sequence is defined by itself and the steps are described only by the inputs and outputs for each step. Table 5 shows how the user program is saved inside the controller, this is the program that describes the control of the exanple shown before. The sequence can be defined by 25 bytes these bytes can be divded in five strings with 5 bytes each that define each step of the sequence (Figs.9 and 10) 7.conclusion The controller developed for this work (Fig .11)shows that it is possible to create a very useful programmable controller based on microcontroller. External memories that the miscrocontroller offers inside Outside the microcotroller , there ara only components to implement the outputs , inputs , analoginputs , display for the interface and the serial communication. Using only the internal memory , it is possbel to control a pneumatic system that has a sequence with 48 stsps if all the resources for all steps ara used , but it is possble to reach sixty steps in the case of a simpler system . The programming of the controller dose not use PLC languages , but a configuration that is simple and intuitive , With electro-pneumatic system , the programming follows the same technique that was used before to design the system , but here the designer workes directly with the states or steps of the system. With a very simple machine language the designer can define all the configuration of the step using four or five bytes.It depends only on his experience to use all the resources of the controller.The controller task is not to work in the same way as a commercial PLC but the purpose of it is to be an example of a versatile controller that is designed for a specific area.Because of that ,it is not possible to say which one works better ；the system made with microcontroller is an alternative that works in a simple way.译文： 应用于电气系统的可编程序控制器 摘要 此项目主要是研究电气系统以及简单有效的控制气流发动机的程序和气流系统的状态。它的实践基础包括基于气流的专有控制器、自动化设计、气流系统的控制程序和基于微控制器的电子设计。 1 简介 使用电气技术的自动化系统主要由三个组成部分：发动机或马达，感应器或按钮，状如花瓣的控制零部件。现在，大部分的系统逻辑操作的控制器 都被程序逻辑控制器（ PLC） 所取代。 PLC 的感应器和开关是输入端，而发动机的直接控制阀是输出端，其中有一个内部程序操控所有运行必需的逻辑，模拟其他的装置如计算器、定时器等，对整个系统的运行状态进行控制。 因为可以根据需要无数次创建和模拟这样的系统，所以藉由 PLC 的使用，此项目有灵活的优点。因此，可以节省时间，减少失误的危险，同时在使用相同材料的情况下，它可以更加精密。 市场上的许多家公司都使用了常规的 PLC，它不仅可以用气流系统来控制，还可以用各种电气设备。 PLC 的用途广泛，可以应用于许多工业生产中，甚至 用于建筑物的安全和自动化系统中。 由于以上的各种特性，在一些实际应用中 PLC 提供了很多的资源，甚至包括不控制系统的资源，电气系统就是一种这样的应用。对于自动化的工程， PLC 的使用是比较昂贵的，尤其是对那些小型的系统。 针对这种情况可行的一种办法是创建一个可提供特定尺寸和功能的控制器 3，4。这种控制器可以根据微控制器来制作。 这种基于微控制器的控制器适用范围比较小，只能用于一个类型的机器或者可以用做一个像普通 PLC 一样可以被编程的控制器，那样它就可以通过可变化的逻辑程序来进行各种作业。所有的这些特性根据具 体需要的不同而不同，具体的设计者的经验的不同而不同。但是这种设计的主要优点在于设计人员非常了解自己的控制器，可以自由掌握控制器的大小尺寸，改变它的功能。这就意味着此项目有更多的独特性，但同时系统的控制也由它的设计者所控制。 2 电气系统 人们可以从一个自动化系统中找到三个上文中提到的基本部件，外加一个控制系统的逻辑线路。只有成熟先进的技术能做出特定的逻辑线路和执行正确操作所需要的部件升级。 对于一个简单的运动，系统自动程序可以完成，但是对于间接或更加复杂的运动，系统的程序就会产生复杂的线路和错误的信号。这是 就需要另一种方法可以节省时间，产生清晰线路，能够防止偶然的信号交叠和线路堵塞。 这种方计的不同标准的线路基法叫循序渐进式或规则系统，它对气流和电气系统非常有效，而且也是此项目的一个基础。它包括根据发动机状态各个不同变化所设础上的系统。 第一步是为每个步骤设计那些种标准的线路。第二步是联编标准的线路，最后一步是连接接收来自感应器，开关和先前的运动信号，同时把空气或电传送给每个步骤的补给线。如图中所示， (1)和 (2) 标准线路是为气流的和电气系统服务 .我们能够很清楚的看到每一步骤和下一个步骤之间的联系。 3 控制器内部的应用原理 上述方法可以使发动机的每一个运动都被很好地用步骤来定义。这也就是说发动机的每一次运动变化都是系统的一个新的状态，而两个不同状态之间的转变叫做步骤。 先前提到的标准线路可以帮助设计人员定义系统的不同状态和不同步骤的变化所带来的不同环境。在设计的最后阶段，系统中会有一个从来不变化的序列和明确的输入和输出端。我们把一个序列从输入端输入，经过转换后，由输出端输出。 这些步骤的所有过程都是在微控制器内部进行的，并且以同样的方式在运行着。部件的序列在控制器里被 5 个位元组规划 ； 每个部分都有 程序的一个步骤结构。输入端有二个位元组 ,输出端有一个，其他结构部分和附加功能步骤有两个。 在编程之后，部件序列被内部微控制器的记忆所储藏，因此，他们是可读的而且可以运行。 不同于传统的 PLC，这种控制器的工作目的是成为特定领域设计的多用控制器。传统的 PLC 的系统运行程序是一个循环的线路：输入一个图像 ,运行所有的内部程序 , 然后升级输出的状态。 这一个控制器以不同的方式工作 ,它读取步骤的结构 ,等待输入 ,然后升级或输出，然后直接跳跃到下一个步骤，开始另一次的程序运行。 它也有局限性，例如这种控制器有时会不执 行指令，在同一程序指令下，会出现某一个运行的反复等等，但是这一个问题可以通过外部的逻辑运行解决。另外，这中控制器在没有序列的系统上不能够被应用。这些局限性也是这个系统的特性，这种系统的每一个应用都必须要有相应的系统分析。 4 控制器的特色 这种控制器以微集成电路微控制器 PIC16F8776,7 为基础 ,它拥有全部此次项目所需要的资源。它有足够的插孔，线路连续通讯 EEPROM 记忆解救系统的所有结构和步骤的序列。它提供了项目所需要的所有的运行，例如定时器和分岔等。 我们做出了控制器的资源目录，想尽可能 的使它变的完善。在步骤的运行过程中，程序自动选择如何读取每一步骤的结构。这个操作有两个位元组位于电子输入处。一个位元组位于输出端，还有一个被用作内部定时器，类似输入或暂停功能。 EEPROM 记忆内部是 256 位元组，可以储藏所有步骤的运行 ,即可以储藏 48 个步骤之间的所有运行。 除了一个互动菜单外，这种控制器还有一个控制台和一些指令按钮，他们一起控制各个步骤的运行和连续性，也控制其他的一些装置。 4.1 交互作用 在实际运行操作中，控制器需要有一些辅助设备帮助它和使用者进行互动，可以提供可靠的操作监控，同时 对气流系统进行逻辑控制。 （ 1）交互工作模式： 在主要的程序中，使用者可以根据指导发出信号来进行具体步骤的操作 （ 2） LCD 平台可以显示系统工作的状态，衡量输入，输出，计时器和运行的数据等。 （ 3）嘀嘀声用来提示重要警示，停止，开始和一些紧急情况的发生 （ 4）亮灯表示接通电源，和输入，输出状态。 4.2 安全性 如果想正常运行程序，必须保证每一个步骤都正确的执行。更重要的是，应该有预防运行故障和问题的解决方法。控制器提供了这种可能性