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自动化专业英语原文和翻译Automation in the Manufacturing Industry: An OverviewIntroduction:Automation plays a crucial role in the manufacturing industry, revolutionizing production processes and enhancing efficiency. This article provides an in-depth analysis of the concept of automation in the manufacturing sector, highlighting its benefits, challenges, and future prospects. It also includes a translation of the text into English.Section 1: Definition and Importance of AutomationAutomation refers to the use of technology and machinery to perform tasks with minimal human intervention. In the manufacturing industry, automation is essential for streamlining operations, reducing costs, and improving product quality. It allows companies to achieve higher production rates, increased precision, and improved safety standards.Section 2: Benefits of Automation in Manufacturing2.1 Increased ProductivityAutomation enables manufacturers to produce goods at a faster rate, leading to increased productivity. With the use of advanced robotics and machinery, repetitive tasks can be performed efficiently, allowing workers to focus on more complex and creative aspects of production.2.2 Enhanced Quality ControlAutomated systems ensure consistency and accuracy in manufacturing processes, leading to improved product quality. By minimizing human error, automation reduces defects and variations, resulting in higher customer satisfaction and reduced waste.2.3 Cost ReductionAutomation helps in reducing labor costs by replacing manual work with machines and robots. Although initial investment costs may be high, long-term savings are significant due to increased efficiency and reduced dependence on human labor.2.4 Improved Workplace SafetyAutomation eliminates the need for workers to perform hazardous or physically demanding tasks. Robots and machines can handle tasks that pose risks to human health and safety, thereby reducing workplace accidents and injuries.2.5 Increased FlexibilityAutomated systems can be easily reprogrammed to adapt to changing production requirements. This flexibility allows manufacturers to respond quickly to market demands, introduce new products, and customize production processes.Section 3: Challenges in Implementing Automation3.1 Initial InvestmentImplementing automation requires substantial capital investment for purchasing and integrating machinery, software, and training. Small and medium-sized enterprises (SMEs) may face financial constraints in adopting automation technologies.3.2 Workforce AdaptationAutomation may lead to job displacement, as certain tasks previously performed by humans are now handled by machines. Companies need to provide training and re-skilling opportunities to ensure a smooth transition for their workforce.3.3 Technical ComplexityAutomation systems often involve complex integration of various technologies, such as robotics, artificial intelligence, and data analytics. Companies must have skilled personnel capable of managing and maintaining these systems effectively.Section 4: Future Trends in Automation4.1 Collaborative RobotsCollaborative robots, also known as cobots, are designed to work alongside humans, assisting them in tasks that require precision and strength. These robots can improve productivity and safety by working in close proximity to humans without the need for extensive safety measures.4.2 Internet of Things (IoT) IntegrationThe integration of automation systems with the Internet of Things allows for real-time monitoring and control of manufacturing processes. IoT enables seamless communication between machines, sensors, and data analytics platforms, leading to predictive maintenance and optimized production.4.3 Artificial Intelligence (AI)AI technologies, such as machine learning and computer vision, enable automation systems to learn and adapt to new situations. AI-powered robots can analyze data, make decisions, and perform complex tasks with minimal human intervention, revolutionizing the manufacturing industry.Conclusion:Automation has become an integral part of the manufacturing industry, offering numerous benefits such as increased productivity, enhanced quality control, cost reduction, improved workplace safety, and increased flexibility. While challenges exist, such as initial investment and workforce adaptation, the future of automation looks promising with the emergence of collaborative robots, IoT integration, and artificial intelligence. Embracing automation technologies will undoubtedly pave the way for a more efficient and competitive manufacturing sector.Translation:自动化在制造业中的应用：概述简介：自动化在制造业中扮演着重要的角色，革新了生产过程，提高了效率。
自动化专业英语原文和翻译引言概述：自动化专业是现代工程技术领域中的重要学科，涵盖了自动控制系统、机器人技术、工业自动化等多个方面。
在学习和实践中，掌握和理解自动化专业的英文术语和翻译是非常重要的。
本文将从五个大点出发，详细阐述自动化专业英语原文和翻译的相关内容。
正文内容：1. 自动控制系统（Automatic Control System）1.1 控制器（Controller）1.2 传感器（Sensor）1.3 执行器（Actuator）1.4 反馈（Feedback）1.5 稳定性（Stability）2. 机器人技术（Robotics）2.1 机器人（Robot）2.2 机械臂（Manipulator）2.3 传感器（Sensor）2.4 视觉系统（Vision System）2.5 自主导航（Autonomous Navigation）3. 工业自动化（Industrial Automation）3.1 自动化生产线（Automated Production Line）3.2 人机界面（Human-Machine Interface）3.3 传感器网络（Sensor Network）3.4 电气控制（Electrical Control）3.5 数据采集（Data Acquisition）4. 自动化软件（Automation Software）4.1 PLC编程（PLC Programming）4.2 HMI设计（HMI Design）4.3 数据分析（Data Analysis）4.4 模拟仿真（Simulation）4.5 系统集成（System Integration）5. 自动化工程（Automation Engineering）5.1 项目管理（Project Management）5.2 自动化设计（Automation Design）5.3 系统调试（System Debugging）5.4 故障诊断（Fault Diagnosis）5.5 性能优化（Performance Optimization）总结：综上所述，自动化专业英语原文和翻译是自动化工程师必备的技能之一。
自动化专业英语原文和翻译Automation in the field of engineering has revolutionized industries by streamlining processes, increasing efficiency, and reducing human error. As a result, it has become imperative for professionals in the automation industry to possess a strong command of English, particularly in terms of technical vocabulary and terminology. In this text, we will provide a comprehensive overview of the importance of English in the field of automation, along with a sample original text and its translation.Importance of English in Automation:English proficiency is crucial for professionals in the automation industry due to the following reasons:1. Global Collaboration: With the rise of multinational corporations and global supply chains, professionals in automation often collaborate with colleagues and clients from different countries. English serves as a common language of communication, enabling effective collaboration and knowledge sharing.2. Technical Documentation: Automation professionals frequently work with technical documents, such as user manuals, equipment specifications, and engineering drawings. These documents are often written in English, and a strong command of the language is necessary to understand and interpret them accurately.3. Research and Development: English is the predominant language in scientific research and development. Automation professionals need to stay updated with the latest advancements in the field, which are often published in English-language journals and research papers.4. International Conferences and Presentations: Professionals in automation often attend conferences and present their research or projects. English fluency is essential for effective communication and knowledge dissemination in such international forums.Sample Original Text:Title: The Role of Programmable Logic Controllers in Industrial AutomationIntroduction:Industrial automation has witnessed significant advancements in recent years, with programmable logic controllers (PLCs) emerging as a key technology. PLCs are computer-based control systems that automate various industrial processes. This article aims to explore the role of PLCs in industrial automation, their applications, and the benefits they offer.Applications of PLCs:PLCs find extensive applications in various industries, including manufacturing, automotive, oil and gas, and food processing. They are used to control and monitor processes such as assembly lines, robotic systems, material handling, and quality control. PLCs offer flexibility, scalability, and reliability, making them an integral part of modern industrial automation.Advantages of PLCs:1. Increased Efficiency: PLCs enable automation of repetitive tasks, leading to improved efficiency and reduced human error. They can perform complex calculations and logic operations at high speeds, resulting in faster and more accurate process control.2. Flexibility and Adaptability: PLCs can be easily programmed and reprogrammed to accommodate changes in production requirements. This flexibility allows for quick adjustments, minimizing downtime and maximizing productivity.3. Remote Monitoring and Control: PLCs can be connected to a network, enabling remote monitoring and control of industrial processes. This feature allows operators to access real-time data, diagnose issues, and make necessary adjustments from a centralized location.4. Cost Savings: By automating processes, PLCs help reduce labor costs, minimize material wastage, and optimize energy consumption. The long-term cost savingsassociated with PLC implementation make them a cost-effective solution for industrial automation.Conclusion:Programmable logic controllers play a vital role in industrial automation, offering numerous advantages such as increased efficiency, flexibility, remote monitoring, and cost savings. As the field of automation continues to evolve, proficiency in English becomes increasingly important for professionals to stay updated with the latest developments and effectively communicate their ideas and findings.Translation (Sample):标题：可编程逻辑控制器在工业自动化中的作用简介：近年来，工业自动化领域取得了重大发展，可编程逻辑控制器（PLC）成为关键技术。
自动化专业英语原文和翻译Automation in the Field of EngineeringIntroduction:Automation plays a crucial role in various industries, including the field of engineering. It involves the use of advanced technology and machinery to perform tasks with minimal human intervention. In this text, we will explore the significance of automation in the engineering sector and discuss its benefits and applications.1. Importance of Automation in Engineering:Automation has revolutionized the engineering industry by enhancing productivity, efficiency, and safety. It allows engineers to streamline processes, reduce errors, and optimize resource utilization. By automating repetitive and mundane tasks, engineers can focus on more complex and creative aspects of their work. This leads to improved project outcomes and overall customer satisfaction.2. Applications of Automation in Engineering:2.1 Industrial Automation:In manufacturing industries, automation is extensively used to control and monitor various processes. It involves the use of programmable logic controllers (PLCs), robots, and computer numerical control (CNC) machines. These technologies enable precise and consistent manufacturing, resulting in higher product quality, reduced production time, and increased output.2.2 Process Automation:Automation is also applied in process industries such as oil refineries, chemical plants, and power plants. It involves the use of distributed control systems (DCS) and supervisory control and data acquisition (SCADA) systems. These systems automate the monitoring and control of complex processes, ensuring efficient and safe operation.Automation minimizes the risk of human errors and improves the overall reliability and productivity of these industries.2.3 Building Automation:In the construction and building management sector, automation is employed to control and regulate various systems within buildings. This includes HVAC (heating, ventilation, and air conditioning), lighting, security, and energy management systems. Automation optimizes energy usage, enhances occupant comfort, and improves the overall operational efficiency of buildings.3. Advantages of Automation in Engineering:3.1 Increased Efficiency:Automation eliminates manual intervention, reducing the time required to complete tasks. This leads to increased efficiency and higher productivity in engineering processes. For example, automated assembly lines can produce products at a faster rate compared to manual assembly, thereby reducing production time and costs.3.2 Improved Accuracy and Precision:Automation ensures consistent and precise execution of tasks, minimizing errors caused by human factors. This is particularly crucial in industries where precision is vital, such as aerospace and automotive manufacturing. Automated systems can perform repetitive tasks with high accuracy, resulting in improved product quality and reliability.3.3 Enhanced Safety:Automation reduces the risk of accidents and injuries in the engineering industry. By replacing humans in hazardous or physically demanding tasks, automation improves workplace safety. For instance, robots can handle tasks involving heavy lifting or exposure to harmful substances, protecting workers from potential harm.3.4 Cost Savings:While initial investments in automation technologies may be significant, they often result in long-term cost savings. Automation reduces labor costs by minimizing the need for manual labor and increasing operational efficiency. Moreover, automation optimizes resource utilization, reduces waste, and lowers maintenance costs, leading to overall cost savings for engineering companies.4. Challenges and Considerations:4.1 Skill Requirements:The implementation of automation technologies requires skilled engineers who can design, develop, and maintain automated systems. Companies need to invest in training their workforce to adapt to the changing technological landscape and ensure a smooth transition to automation.4.2 Integration and Compatibility:Integrating automation systems with existing infrastructure and equipment can be challenging. Compatibility issues may arise between different automation components and software, requiring careful planning and coordination. It is essential to ensure seamless integration to maximize the benefits of automation.4.3 Security Concerns:As automation involves the use of interconnected systems and networks, cybersecurity becomes a critical consideration. Engineering companies must implement robust security measures to protect against potential cyber threats and ensure the integrity and confidentiality of sensitive data.Conclusion:Automation has become an integral part of the engineering industry, enabling increased productivity, efficiency, and safety. From industrial manufacturing to building management, automation offers numerous benefits, including improved accuracy, reduced costs, and enhanced workplace safety. However, it is crucial to address challenges such as skill requirements, integration issues, and cybersecurity concerns tosuccessfully implement automation in engineering processes. Embracing automation will undoubtedly pave the way for a more advanced and sustainable future in the field of engineering.。
自动化专业英语原文和翻译Automation in the Field of EngineeringIntroduction:Automation has become an integral part of various industries, including the field of engineering. It involves the use of technology and machines to perform tasks with minimal human intervention. This text aims to provide a comprehensive overview of automation in the engineering field, covering its importance, applications, and future prospects. Additionally, an English translation of the original text will be provided.Importance of Automation in Engineering:Automation plays a crucial role in improving efficiency, accuracy, and productivity in engineering processes. By automating repetitive and time-consuming tasks, engineers can focus on more complex and critical aspects of their work. It also reduces the risk of human errors, leading to higher quality output. Moreover, automation enables engineers to monitor and control systems remotely, enhancing safety and minimizing operational risks.Applications of Automation in Engineering:1. Manufacturing and Assembly: Automation is extensively used in manufacturing industries to streamline production processes. Automated systems can perform tasks such as assembly, welding, and material handling with precision and speed. This leads to increased production rates, reduced costs, and improved product quality.2. Robotics: Robotics is a significant application of automation in engineering. Robots are used in various sectors, including automotive, healthcare, and aerospace industries. They can perform complex tasks with high accuracy, consistency, and repeatability. Examples include robotic arms used in assembly lines and surgical robots in medical procedures.3. Control Systems: Automation is vital in control systems, which regulate and optimize various engineering processes. Programmable Logic Controllers (PLCs) and Distributed Control Systems (DCS) are commonly used to automate tasks such as temperature control, pressure regulation, and flow management. This ensures efficient operation and minimizes manual intervention.4. Energy Management: Automation plays a crucial role in energy management systems, optimizing energy consumption and reducing waste. Automated systems can monitor and control energy usage in buildings, factories, and power plants. This leads to energy savings, cost reduction, and environmental sustainability.Future Prospects of Automation in Engineering:The future of automation in engineering looks promising, with several emerging trends and technologies. Some of these include:1. Artificial Intelligence (AI): AI is revolutionizing automation by enabling machines to learn, adapt, and make decisions. Machine Learning algorithms can analyze vast amounts of data to optimize processes and predict failures. AI-powered systems can also perform complex tasks that were previously only possible for humans.2. Internet of Things (IoT): IoT connects various devices and systems, allowing them to communicate and share data. In engineering, IoT enables remote monitoring, predictive maintenance, and real-time data analysis. This leads to improved efficiency, reduced downtime, and enhanced decision-making.3. Digital Twin: A digital twin is a virtual replica of a physical system or process. It allows engineers to simulate and optimize operations, predict performance, and identify potential issues. Digital twins enable engineers to make informed decisions and improve system performance.4. Cybersecurity: As automation becomes more prevalent, ensuring the security of automated systems is crucial. Cybersecurity measures are essential to protect against potential threats and vulnerabilities. This includes implementing secure communication protocols, encryption techniques, and access control mechanisms.Translation:自动化在工程领域的应用介绍：自动化已成为包括工程领域在内的各个行业的重要组成部分。
自动化专业英语原文和翻译AbstractWith the rapid advancement of technology, automation has become an integral part of various industries. As a result, there is a growing demand for professionals who are proficient in both automation and English language skills. This document aims to provide a standard format for writing original texts and their translations in the field of automation.IntroductionAutomation, also known as automatic control, is the use of various control systems for operating equipment and machinery without human intervention. It involves the application of computer systems, robotics, and information technologies to streamline processes and increase efficiency. The automation industry is expanding rapidly across the globe, and professionals in this field are required to possess not only technical expertise but also strong English language skills to effectively communicate and collaborate with international partners.Original TextTitle: The Role of Automation in Manufacturing IndustryAutomation has revolutionized the manufacturing industry by significantly improving productivity and reducing human errors. This article explores the various applications of automation in manufacturing and its impact on production processes. It discusses the use of programmable logic controllers (PLCs), robotics, and computer numerical control (CNC) machines in automating tasks such as assembly, material handling, and quality control. Furthermore, it highlights the benefits of automation, including increased accuracy, faster production cycles, and reduced labor costs. The article concludes by emphasizing the importance of continuous innovation and adaptation to stay competitive in the dynamic manufacturing landscape.Translation标题：自动化在制造业中的作用自动化通过显著提高生产效率和减少人为错误，彻底改变了制造业。
自动化专业英语原文和翻译Automation in the Manufacturing IndustryIntroduction:Automation plays a crucial role in the manufacturing industry, revolutionizing the way products are produced. This article aims to provide a detailed overview of automation in the manufacturing industry, including its benefits, applications, and challenges. Additionally, a translation of this article into English will be provided.I. Definition and Benefits of Automation in the Manufacturing Industry:Automation refers to the use of technology and machinery to perform tasks with minimal human intervention. In the manufacturing industry, automation has numerous benefits, such as increased productivity, improved quality, reduced costs, enhanced safety, and reduced lead times. By automating repetitive and manual tasks, manufacturers can optimize their operations and achieve higher efficiency.II. Applications of Automation in the Manufacturing Industry:1. Robotic Assembly:Robotic assembly involves the use of robots to perform complex assembly tasks. These robots are equipped with sensors and programmed to perform precise movements, ensuring accurate and efficient assembly of products. This application of automation significantly reduces human error and increases production speed.2. Automated Material Handling:Automated material handling systems use conveyors, robotics, and automated guided vehicles (AGVs) to transport materials within a manufacturing facility. These systems improve efficiency by reducing manual material handling, minimizing the risk of damage, and optimizing inventory management.3. Computer Numerical Control (CNC) Machining:CNC machining involves the use of computer-controlled machines to fabricate parts and components. These machines follow pre-programmed instructions, resulting in precise and consistent output. CNC machining offers increased flexibility, faster production times, and improved accuracy compared to traditional manual machining methods.4. Industrial Internet of Things (IIoT):The Industrial Internet of Things (IIoT) refers to the network of interconnected devices, sensors, and machinery in a manufacturing environment. IIoT enables real-time data collection, analysis, and communication, allowing manufacturers to optimize processes, predict maintenance needs, and improve overall productivity.III. Challenges and Considerations in Implementing Automation:1. Cost of Implementation:Implementing automation in the manufacturing industry requires a significant upfront investment. Companies need to consider the cost of purchasing automation equipment, integrating it into existing systems, and training employees. However, the long-term benefits and cost savings outweigh the initial investment.2. Workforce Adaptation:Automation often leads to changes in job roles and responsibilities. While some tasks may be automated, new job opportunities arise in programming, maintenance, and supervision of automated systems. Companies must ensure that their workforce is properly trained and equipped to adapt to these changes.3. Cybersecurity:As automation relies heavily on interconnected devices and networks, cybersecurity becomes a critical concern. Manufacturers need to implement robust cybersecurity measures to protect sensitive data, prevent unauthorized access, and ensure the smooth operation of automated systems.IV. Conclusion:Automation has transformed the manufacturing industry, offering numerous benefits such as increased productivity, improved quality, and reduced costs. By leveraging technologies like robotics, automated material handling, CNC machining, and IIoT, manufacturers can streamline their operations and stay competitive in the global market. However, companies must carefully consider the challenges associated with implementing automation, including the cost of implementation, workforce adaptation, and cybersecurity. With proper planning and execution, automation can revolutionize the manufacturing industry and pave the way for a more efficient and sustainable future.Translation:自动化在制造业中的应用简介：自动化在制造业中扮演着至关重要的角色，彻底改变了产品生产的方式。
自动化专业英语原文和翻译Automation in the field of engineering has revolutionized various industries, making processes more efficient and reducing human error. As a result, there is a growing demand for professionals who are well-versed in automation technologies and can communicate effectively in English. In this text, we will provide a standard format for an original English text and its translation in the field of automation.Original English Text:Title: Automation in Manufacturing ProcessesIntroduction:Automation has become an integral part of manufacturing processes, with the aim of improving productivity, reducing costs, and ensuring consistent quality. This article explores the various aspects of automation in manufacturing and its impact on the industry.1. Definition of Automation:Automation refers to the use of technology and control systems to operate and control machinery and processes without human intervention. It involves the use of sensors, actuators, and computer systems to perform tasks that were previously carried out by humans.2. Benefits of Automation in Manufacturing:- Increased productivity: Automation allows for faster and more efficient production processes, leading to higher output and reduced lead times.- Cost reduction: By automating repetitive tasks, companies can reduce labor costs and minimize the risk of human error.- Improved quality control: Automation ensures consistent product quality by eliminating variations caused by human factors.- Enhanced safety: Dangerous tasks can be automated, reducing the risk of accidents and injuries in the workplace.3. Types of Automation in Manufacturing:a. Fixed Automation:Fixed automation involves the use of specialized machinery designed for a specific task or product. It is suitable for high-volume production with little or no variation in product design.b. Programmable Automation:Programmable automation utilizes computer-controlled systems that can be easily reprogrammed to perform different tasks or produce various products. It is suitable for medium-volume production with some level of product variation.c. Flexible Automation:Flexible automation combines the advantages of fixed and programmable automation. It involves the use of computer-controlled systems that can be reprogrammed to handle a wide range of products and tasks. It is suitable for low-volume production with high product variation.4. Challenges in Implementing Automation:While automation offers numerous benefits, its implementation can pose challenges. Some common challenges include:- High initial investment: Automation systems can be expensive to implement, requiring significant capital investment.- Workforce transition: Automation may lead to job displacement, requiring companies to provide retraining opportunities for affected employees.- Technical complexity: Implementing automation systems requires specialized knowledge and expertise, which may not be readily available.- Integration with existing systems: Integrating automation systems with existing machinery and processes can be complex and time-consuming.Conclusion:Automation has transformed manufacturing processes, offering increased productivity, cost reduction, improved quality control, and enhanced safety. Understanding the different types of automation and the challenges involved in its implementation is crucial for professionals in the field. As the demand for automation specialists continues to grow, proficiency in English communication is essential for effective collaboration and knowledge sharing in the global industry.Translation (Chinese):标题：制造过程中的自动化介绍：自动化已成为制造过程的重要组成部分，旨在提高生产效率，降低成本，并确保一致的质量。
自动化专业英语原文和翻译Automation in the Field of EngineeringIntroduction:Automation has become an integral part of various industries, including engineering. In this document, we will discuss the importance of automation in the field of engineering and its impact on productivity, efficiency, and safety. We will also provide a brief overview of the key terms and concepts related to automation in English, followed by their translations in Chinese.1. Importance of Automation in Engineering:Automation plays a crucial role in enhancing productivity and efficiency in the field of engineering. It involves the use of advanced technologies and systems to control and monitor various processes, reducing human intervention and minimizing errors. By automating repetitive tasks, engineers can focus on more complex and critical aspects of their work, resulting in improved overall performance.2. Key Terms and Concepts:2.1 Robotics:Robotics refers to the design, development, and application of robots in various industries. Robots are programmable machines that can perform tasks autonomously or with minimal human intervention. They are widely used in manufacturing, assembly lines, and hazardous environments.2.2 Control Systems:Control systems are a set of devices or software that manage and regulate the behavior of other devices or systems. They ensure that processes operate within desired parameters by monitoring and adjusting variables such as temperature, pressure, andspeed. Control systems are essential for maintaining stability and optimizing performance in engineering applications.2.3 Programmable Logic Controllers (PLCs):PLCs are specialized computers used to control and automate industrial processes. They receive input signals from sensors, process the data, and generate output signals to control actuators. PLCs are widely used in manufacturing, power plants, and transportation systems.2.4 Human-Machine Interface (HMI):HMI refers to the interface between humans and machines, allowing users to interact with automation systems. It includes displays, touchscreens, and control panels that provide real-time information and enable operators to monitor and control processes effectively.3. Benefits of Automation in Engineering:3.1 Increased Productivity:Automation reduces manual labor and speeds up processes, leading to increased productivity. With the help of robots and automated systems, tasks can be completed faster and more accurately, resulting in higher output and reduced production time.3.2 Improved Efficiency:Automation eliminates human errors and inconsistencies, ensuring consistent and precise results. It also optimizes resource utilization and reduces waste, leading to improved efficiency in engineering processes.3.3 Enhanced Safety:By automating hazardous or physically demanding tasks, automation improves safety in engineering environments. Robots and automated systems can handle dangerous materials or operate in extreme conditions, reducing the risk of accidents and injuries to human workers.3.4 Cost Savings:Although the initial investment in automation may be significant, it often leads to long-term cost savings. Automation reduces labor costs, minimizes material waste, and improves energy efficiency, resulting in overall cost reduction for engineering projects.4. Conclusion:Automation has revolutionized the field of engineering, providing numerous benefits such as increased productivity, improved efficiency, enhanced safety, and cost savings. Understanding the key terms and concepts related to automation is essential for professionals in the field. By embracing automation, engineers can unlock their full potential and drive innovation in various industries.自动化在工程领域的重要性介绍：自动化已成为包括工程在内的各个行业中不可或者缺的一部份。
Part ⅤSensors and TransmittersIn a feedback control system, the elements of a process-control systemare defined interms of separate functional parts of the system . The four basic components of controlsystems are thesensors, transmitter , controller , and final control elements . Thesecomponents per form the three basic operations of every control system: measurementdecision, and action.Sensors and transmitters perform the measurements operation of control system. Thesensor produces a phenomenon, mechanical, or the like related to the process variable that itmeasures. The function of transmitter in turn is to convert the signal from sensor to the formrequired by the final control device. The signal, therefor e, is related to the process variable.Two analog standards are in common u se as a means of representing the range ofvariables in control systems. For electrical systems we use a range of electric current carriedin wires , and for pneumatic systems we use a range of gas pressure carried in pipes . Thesesignals are used primarily to transmitvariable information over some distance, such as to andfrom the control room and the plant .Fig .5 . 9 shows a diagram of a process- controlinstallation where current is used to transmit measurement data about the controlled variableto the control room, and gas pressure in pipes is used to transmit a feedback signal to a valveto change flow as the controlling variable .Fig .5 .9 Electrical current and pneumatic pressures are the most common means of information transmitter in the industrial environmentCurrent signal The most common current transmission signal is 4 to 20 mA . Thu s , inthe preceding temperature example, 20℃might be represented by 4 mA, and 120℃by 20 mA, with all temperatures in between represented by a proportional current . The gain is略That is , we can say that the gain of sensor/ transmitter is ratio of the span of the output tothe span of input .Current is used instead of voltage because the system is then les s dependent on load . Voltage is not used for transmission because of its susceptibility to changes of resistance inthe line .Pneumatic signals The most common standard for pneumatic signal transmitter is 3 to15 psi . In this case, when a sensor measures some variable in a range it is converted into a proportionalpressure of gas in a pipe . The gas is usually dry air .The pipe may be many hundreds of meters long , but as long as there is no leak in the system the pressure will be propagated down the pipe . This English system standard is still widely used in the U .S ., despite the move to the SI system of units . The equivalent SI range that will eventually be adopted is 20 to 100 kPa.The two cases presented show that the gain of the sensor/ transmitter is constant over its completeoperating range . For most sensor/ transmitter this is the case; however , there are some in stances , such as a differential pressure sensor used to measure flow, when this is not the case . A differential pressure sensor measures the differential pressure ,h, across anorifice . This differential pressure is related to the square of the volumetric flow rate F . Thatis F2 ah .The equation that describes the output signal form an electronicdifferential pressure transmitter when used to measure volumetric flow with a range of 0～F maxgpm isM F = 4 + 16 F2/ ( F max )2Where MF = output signal in mAF = Volumetric flowFrom this equation the gain of the transmitter is obtained as follows:K′r = d MF/ d F = 216 F/ ( F max )2with a nominal gainK′T = 16/ F maxThis expression shows that the gain is not constant but rather a function of flow . T he greater the flow is , the greater the gain . So the actual gain varies from zero to twice the nominal gain .This fact results in a nonlinearly in flow control system . Nowadays most manufacturesoffer differential pressure transmitters with built-in square root extractor s yielding a line r transmitter .The dynamic response of most sensor/ transmitter s is much faster than the process . Consequently , their time constants and dead time can often beconsidered negligible andthus , their transfer function is given by a pure gain . However , when the dynamics must be considered , it is usual practice to represent the transfer function of the instrument by a first-orderor second-order system:G( s) = K / ( T s + 1)or G( s) = K / ( T2 s + 2 Tξs + 1)WORDS AND TERMS3 .1 Numerical ControlNumerical control is a system that uses predetermined instructions to control a sequenceof manufacturing operations. The instructions are coded numerical values stored on sometype of input medium, such as punched paper tape , magnetic tape, or a common memory for program storage . The instructions specify such things as position ,direction , velocity , and cutting speed . A partprogram contains all the instructions required to produce a desiredpart . A machine program contains all the instruction s required to accomplish a desired process . Numerical control machines per form operations such as boring , drilling , grinding , milling , punching , routing , sawing , turning , winding ( wire ) , flame cutting , knitting( garments ) , riveting , bending , welding , and wire processing .Numerical control ( NC) has been refer red to as flexible automation because of therelative ease of changing the program compared with changing cams , jigs , and templates .The same machine may be used to produce any number of different parts by using different programs . The numerical control process is most justified when a number of different partsare to be produced on a particular machine: it is seldom used to produce a single par t continually on the same machine . Numerical control is ideal when a part or process is defined mathematically . With the increasing u se of computer- aided design (CAD) , more and more processes and products are being defined mathematically . Drawings as we k now them have become unnecessary ―a part that is completely defined mathematically can be manufacturedby computer-controlled machines . A closed-loop numerical control machine is shown in Fig .5 .13 .The NC process begins with a specification ( engineering drawing or mathematicaldefinition ) that completely defines the desired par t or process . A programmer uses the specification to determine the sequence of operations necessary to produce the par t or carry out the process . The programmer also specifies the tools to be used , the cutting speeds , and the feed rates . The programmer uses a special programming language to prepare a symbolic program . APT ( Automatically Programmed Tools ) is one language used for this purpose . A computer converts the symbolic program into the part program or the machine program . In the past , the pa r t or machine program was stored on paper or magnetic t ape . The numerical control machine operator fed the tape into the machine and monitored the operation . If a change was necessary , a new tape had to be made . Now, it is possible to store the programin a common database with provision for on-demand distribution to the numerical control machine . Graphicterminals at the matching center allow operators to review programs and make changes if necessary .The x position controller moves the work piece horizontally in the direction indicated bythe + x a r row . The position controller moves the milling machine head horizontally in the direction indicated by the + yarrow . The z position controller moves the cutting tool vertically as indicated by the + z arrow . The following actions are involved in changing the x-axis position .( 1 ) The control unit reads an instruction in the program that specifies a+ 0 .004-inch ( in .) change in the x position . ( 2 ) The control unit send s a pulse to the machine actuator . (3 ) The machine actuator rotates the lead screw and advances the x- axis position + 0 .001 in . (4 ) the position sensor measures the + 0 .001-in . measured motion and sends another pulse . Steps ( 1 ) through ( 5 ) are repeated until the measured motion equals the desired + 0 .004 in .Computerized numerical control ( CNC ) was developed to utilize the storage andprocessing capabilities of a digital computer . CNC uses a dedicated computer to accept the input of instructions and to perform the control functions required to produce the part . However , CNC was not designed to provide the information exchange demanded by the recent t r end toward computer-integrated manufacturing (CIM) . The idea of CIM is to“get the right information- to the right person- at the right time- to make the right decision .”“I t link s all aspects of the business-f rom quotation and order entry through engineering , process planning , financial reporting , manufacturing , and shipping-in an efficient chain of production .”Direct numerical control ( DNC ) was developed to facilitate computer-integrated manufacturing . DNC is a system in which a n umber of numerical control machines are connected to a central computer for real- time access to a common database of part programs and machine programs . General Electric used a central computer connected to DNC machines through a communication s network in the automation of its steam turbine-generator operation s (STGO) .“A typical turbine-genera tor consists of more than 100 , 000 parts , someof which are manufactured in thousands of different configurations to meet the specific needs of each custom-designed unit . Through the CIM system, customers can specify a needed par t and receive replacement components that suit the original configuration of more than 4 , 000 operating STGO installations . In some cases , the small-parts shop can now manufacture and ship some emergency parts the same day the order is received .”4 .1 Relay ControllersAn industrial control system typically involves electric motors , solenoids , heaters orcooler , and other equipment that is operated from the ac power line . Thus , when a control system specifies that a“conveyor motor be turned on ,”it may mean starting a 50-HP motor . This is not done by a simple toggle switch .Instead , one would logically assume that a small switch may be used to energize a relay with contact ratings that can handle the heavy load , such as that shown in Fig .5 .16 . In this way , the relay became the primary control elementof discrete-state control systems .When an entire control system is implemented u sing relays , the system is called a relay sequencer . A relay sequencer consists of a combination of many relays , including specialtime-delay types , wired up to implement the specified sequence of events . Inputs are switches and push buttons that energize relay , and outputs are closed contacts that can turn lights on or off , start motor s , energize solenoids , and so on .The wiring of a relay control system can be described by traditional schematic diagrams ,such as those shown in Fig .5 .16 . Such diagrams are cumbersome , however , when many relays , each with many contacts , are used in a system . Simplified diagrams have been gradually adopted by the industry over the years . As an example of such simplification , a relay’s contacts need not be placed directly over the coil symbol , but can go anywhere in the circuit diagram with a number to associate them with a particular coil . These simplifications resulted in the ladder diagram in use today .Ladder DiagramsThe ladder diagram is a symbolic and schematic way of representing both the system hardware and the process controller . It is called a ladder diagram because the various circuit devices connected in parallel across the ac line form something that looks like a ladder , with each parallel connection a“rung”on the ladderIn the construction of a ladder diagram , it is understood that each rung of the ladder is composed of a number of conditions or input states and a single command output . The nature of the input states determines whether the output is to be energized or not energized . T he following example illustrates many features of a ladder diagram construction and its application to control problems .Example: The elevator shown in Fig .5 .17 employs a platform to move objects up anddown . The global objective is that when the UP button is pushed , the platform carriessomething to the up position , and when the DOWN but ton is pushed , the plat form carries something to the down position .The following hardware specifications defined the equipment used in the elevator :Output elements:M1 = Motor to drive the platform upM2 = Motor to drive the platform downInput elements:LS1 = NC limit switch to indicate UP positionLS2 = NC limit switch to indicate DOWN positionST ART = NO push button for STARTSTOP = NO push button for STOPUP = NO push button for UP commandDOWN = No pus h but ton for DOWN commandThe following narrative description indicates the required sequence of events for theelevator system .1 .When the START but ton is pushed , the platform is driven to the down position .2 .When the STOP button is pushed , the platform is halted at whatever position itoccupies at that time .3 .When the UP button is pushed , the platform, if it is not in downward motion , isdriven to the up position .4 .When the DOWN but ton is pushed , the platform, if it is not in upward motion , isdriven to the down position .Prepare a ladderdiagram to implement this control function .SolutionLet us prepare a solution by breaking the requirements into individual tasks . Forexample, the firsttask is to move the platform to the down position when the STARTbut ton is pushed .This task can be done by using the START but ton to latch a relay , whose contacts also energize M2 ( the down motor ) . The relay is released , stopping M2 , when the LS2 limitswitch open s . Pushing START energizes CR1 if L S2 is not open ( platform not down ) .CR1is latched by the contacts across the START button . Another set of CR1 contacts starts M2to drive the platform down . When L S2 opens , indicating the full down position has been reached ,CR1 is released , unlatched , and M2 stops . These two rungs will operate only whenthe START button is pushed .For the STOP sequence , let us assume a relay CR3 is the master control for the rest ofthe system . Because STOP is a NO switch , we cannot use it to release CR3 . Instead , we use STOP to energize another relay ,CR2 , and use the NC contacts of that relay to release CR3 .This is shown in Fig .5 .18 . You can see that when START is pushed ,CR3 in rung 4 isenergized by the latching of the CR1 contact and the NC contact of CR2 . When STOP ispushed ,CR2 in rung 3 is energized , which causes the NC contact in rung 4 to open andrelease CR3 .Finally , we come to the sequences for up and down motion of the platform . In eachcase, a relay is latched to energize a motor if CR3 is energized , the appropriate button hasbeen pushed , the limit has not been reached , and the other direction is not energized . T he entire ladder diagram is shown in Fig .5 .17 . A NC relay connection is used to ensure that theup motor is not turned on if the down motor is on , and vice versa . Also , it was necessary to add a contact to rung 2 to be sure M2 could not star t if there was up motion and some joke r pushed the START button .Part Ⅵ1.1Transmission of Electrical EnergyElectrical energy is carried by conductors such as overhead transmission lines and underground cable . Although these conductors appear very ordinary , they possessimportant electrical proper ties that greatly affect the transmission of electrical energy . In this section , we study these proper ties for several types of transmission lines: high volt age , low-voltage, high-power , aerial lines , and underground lines .Principal components of a power distribution systemIn order to provide electrical energy to consumers in usable form, a transmission and distribution system must satisfy some basic requirements . Thu s the system must1 .Provide, at all times , the power that consumers need2 .Maintain a stable, nominal voltage that does not vary by more than±10%3 .Maintain a stable frequency that does not vary by more than±0 .1 Hz4 .Supply energy at an acceptable price5 .Meet standards of safety6 .Respect environmental standards .Fig .6 .1 shows an elementary diagram of a transmission and distribution system .I tconsists of two genera ting station s G1 and G2 , a few substations , an inter connecting substation and several commercial , residential , and industrial loads . The energy is carriedover lines designated extra-high voltage ( EH V ) , high volt age ( H V ) , medium voltage(MV) , and low voltage ( LV ) . This voltage classification is made according to a scale of standardized voltage .Transmission substations ( Fig .6 .1 ) serve to change the line voltage by mean s of step-upand step-down transformers and to regulator it by means of static vary compensators , synchronous condensers , or transformers with variable taps .Distribution substations change the medium voltage to low voltage by means of step-down transformers , which may have automatic tap-changing capabilities to regulate the lowvoltage . The low voltage ranges from 120/ 240V single phase to 600V, 3-phase . I t serves to power private residences , commercial and institutional establishments , and small industry .Interconnecting substations serve to tie different power systems together , to enablepower exchanges between them, and to increase the stability of the overall network .These sub stations also contain circuit breakers , fuses , and lightning arresters , toprotect expensive apparatus , and to provide for quick isolation of faulted lines from the system . In addition , control apparatus , power measuring devices , disconnect switches , capacitors , inductors , and other devices may be part of a substation .Electrical power utilities divide their power distribution systems into two major categories:1 .Transmission systems in which the line voltage is roughly between 115kVand 800kV .2 .Distribution systems in which the voltagegenerally lies between 120V and 69kV .Distribution systems , in turn , are divided into medium-voltage distribution systems ( 2 .4kV to 69 kV ) and low-voltage distribution systems (120V to 600V) .Type of power linesThe design of a power line depends upon the following:1 .The amount of active power it has to transmit2 .The distance over which the power must be carried3 .The cost of the power line4. Esthetic considerations , urban congestion , ease of installation , and expectedload growthWe distinguish four types of power lines ,according to their voltage class:1 .Low- voltage ( L V) lines provide power to buildings , factories , and houses to drive motors , electric stoves , lamps , heater s , and air conditioners . The lines are insulated conductors , usually made of aluminum, often extending from a local pole-mounted distribution transformer to the service entrance of the consumer . The lines may be overhead or underground , and the transformer behaves like a miniature substation .2 .Medium- voltage ( MV) lines tie the load centers to one of the many substation s of the utility company . The voltage is usually between 2 .4kV and 69kV . Such medium-voltage radial distribution systems are preferred in the larger cities . In radial systems the transmission lines spread out like fingers from one or more substation s to feed power to various load centers , such as high- rise buildings , shopping centers , and colleges .3 .High-voltage ( H V) lines connect the main substations to the generating stations .T he lines are composed of aerial wire or underground cable operating at voltages below 230kV . In this category we also find lines that transmit energy between two power systems , to increase the stability of the network .4 .Extra-high- voltage ( E H V) lines are used when gene rating stations are very far fromthe load centers . We put these lines in a separate class because of their special electricalproperties . Such lines operate a t volt ages up to 800kV and may be as long as 1, 000 km .Components of a HV transmission lineA transmission line is composed of conductors , insulators , and supporting structures . Conductors . Conductors for high-volt age lines are always bare . Stranded copper conductors , or steel-reinforced aluminum cable ( ACSR ) are used . ACSR conductor s are usually prefer red because they result in a lighter and more economical line . Conductor s have to be spliced when a line is very long . Special care must be taken so that the joints have low resistance and great mechanical strength .Insulators . Insulators serve to support and anchor the conductors and to insulate themfrom ground . Insulators areusually made of porcelain , but glass and other synthetic insulating materials are also used .Supporting structures . The supporting structure must keep the conductors at a safeheight from the ground and at an adequate distance from each other . For voltages below70 kV, we can use single wooden poles equipped with cross-arms , but for higher voltages , twopoles are used to create an H-frame, the wood is treated with creosote or special metallic salts to prevent it from rot ting . For very high-voltage lines, we always use steel towers made of galvanized angle-iron pieces that are bolted together .The spacing between conductors must be sufficient to prevent arc-over under gusty wind conditions . The spacing has to be increased as the distance between towers and as the line voltages become higher .Construction of a lineOnce we know the conductor size, the height of the poles , and the distance between the poles ( span ) , we can direct our attention to stringing the conductor s . A wire supported between two points ( Fig . 6 .2 ) does not remain horizontal , but loops down at the middle . The vertical distance between the straight line joining the points of support and the lowest point of the conductor is called sag . The tighter the wire, the smaller the sag will be .Before under taking the actual construction of a line it is important to calculate the permissible sag and the corresponding mechanical pull . Among other things , the summer to winter temperature range must be taken into account because the length of the conductor varies with the temperature . Thus , if the line is strung in the winter , the sag must not betoo great , otherwise the wire will stretch even more during the summer heat , with the result that the clearance to ground may no longer be safe . On the other hand , if the line is installed in the summer , the sag must not be too small otherwise the wire , contracting in winter , may become so dangerously tight as to snap . Wind and sleet add even more to the tractive force, whichmay also cause the wire to break .2 .1 Grounding and Ground-Fault ProtectionT he importance of proper grounding for elect rical systems in buildings is oftenunder estimated . Unde r normal conditions , an elect rical system can continue to ope rate satisfactorily ( that is , deliver power to the utilization equipment ) even without prope r grounding . It is not until an abnormal condition has occur red , and after eithe r someone has been injured, equipment has been damaged , or a fir e has been star ted , that it is realized that imprope r or faulty grounding was the r eason . T her efore, a good understanding of the functions of grounding is essential for the proper design , in stallation , and maintenance of an electrical system . In most cases , the con nection is made by direct metallic contact withearth . The large mass of the ear th then serves as a zero potential r eferencepoint .T he study of grounding must begin by identifying the differ ent aspects of grounding:system grounding , equipment grounding lightning protection grounding , and staticelectricity grounding . Fig .6 .4 shows the basic difference between system grounding and equipmentgrounding .System grounding is the intentional elect rical connection to ground of one of the cur r ent- car rying conductors of the elect ricalsystem . Equipment grounding is the connection to ground of all the nonelectrical conductive materials that enclose or ar e adjacent to the energized conductor s . T he electrical code r equires that all equipment must be prope rly grounded , except in very ra re special cases . However , the application of system grounding is not so universal . Certain types of systems , such as the 120/ 240 volt , single-phase, threewire and the 208Y/ 120 volt , three-phase, four-wire syst ems used to supply lighting havealways been grounded . On the other hand , the 480 and 600 volt , three-phase syst ems usedto supply loads such as motor s have until recently us ually been operated ungrounded .①System grounding . The intentional connection to grounding of one of the current-carrying conductionsof the system .②Equipment grounding . The connection to grounding of all the nonelectrical conductive ma terials thatenclose or ar e adjacent to the energized conductors .T he primary purpose for grounding an electrical system is one of safety, that is , to limitthe potential to ground that otherwise could occur f rom accidental contact with highervoltage syst ems or f rom t ransientovervoltages . However ,ther e ar e other important benefits associa ted with grounded sy stems , as follows :1 .Se rvice r eliability is improved: The transient over voltage condition s tha t a re possiblewith ungrounded systems cannot occur . With the elimination of this overvolt age stressing of the ins ulation , fewer ground faults should occur ove r the operating life of grounded sy stems .2 .Much simpler to locate the first ground fault : With proper coordination , theovercur rent device ( circuit breake r or fuse ) near est to the fault operates to disconnect the faultedcircuit , thu s leaving the balance of the system operating .3 .Ground-fault protection can be easily added: Arcing ground faults can be difficult todetect and therefore require special attention .4 .Provides two voltage levels on the same system: Single-phase loads such as lighting can be connected across the line- to-neutral voltage (120 volts on a 208Y/ 120 volt system) . Three-phase loads such as motors can then be connected across the line- to-line voltages (208 volts) .As is the case with most arrangements ,ther e a re some drawbacks to the use ofgrounded systems , as follows :1 .T he fir st ground fault r esults in the immediate s hutdown of par t of the system .2 .T he re can be very high ground- fault cur rents on bolt ed-type faults . These largecur rents must flow over the equipment grounding circuit .Protective relayT he protective relay is defined as a device that causes an abrupt change in an elect ricalcontrol circuit when the measured quantity to which it responds changes in a prescribed manner .T he elect ricalcontrol circuit is usually the t rip circuit of a circuit breaker , and the measured quantity is the powe r circuit cur rent and/ or voltage as r epresented by the instrument t ransformer s .Protective r elays can be divided into two fundament al types elect romechanical relays and solid-state r elays . Elect romechanical r elays have been the standard for many year s and , in spite of the development of the newer solid-state units , ar e still widely used because of their proven r eliability . Solid- st ate units , since they have no moving par ts , have gr eater accuracy andfaste r reset times than elect romagnetic relays . However , solid-state relays have the drawback that they can initiat e false tripping of the circuit breaker s becau se they may imprope rly react to spurious t ransient voltage spikes . These transientvoltages , which may only last for a few microseconds , can be the r esult of disruption on the power system, suchas the switching of a powe r circuit . A solid-star e relay must have a filtering system thatblocks any chance of these transient conditions f rom t riggering any of its detection circuits . Electromagnetic relays , on the othe r hand , are inherently immune to t ransient disturbances . Solid-state r elays can offer the same operating cha racteristicsand , in fact , usually use the same type of hou sing and t erminalar r angements , so they ar e virtually inter changeable with electromagnetic units .。
