外文资料译文

外文资料译文

机电一体化

机电一体化是机械与电子的结合，它指的是利用精密工程、控制理论、计算机科学以及传感器和执行器的协同作用来设计改进产品和工艺。

标准的衣服烘干机通常由一个机械定时器控制。用户根据衣服的大小、湿润程度调节定时器。如果定式装置设置有误，干燥周期就会太短而导致衣服还没干，或者机器运转太久而浪费能量。

但是，衣服烘干机上可能会安装一个基于传感器的反馈系统，使得机器测出衣物或排除空气的湿度，当衣服干了的时候就自动关闭。结果运作性能提高且降低了能耗。因为主要和机电控制系统中元件的成本有关，所以经过再设计的烘干机甚至可能更便宜。

计算机的硬盘驱动器，如希捷科技的猎豹，就是机电一体化设计的最好的例子之一。因为他响应快，精度高，鲁棒性好。

许多美国培训的设计工程师会说，改良烘干机是更新发展而不是传统设计实践的结果，“更聪明”的电子控制取代了可靠但相对不那么准确的机械设备。然而在世界的其他许多地方，设计工程师们会说再设计的烘干机遵循机电一体化的原则。

机电一体化并不是什么新鲜玩意儿，它只是将最新的技术应用于精密机械工程、控制理论、计算机科学和电学当中，使得设计出的工艺能够生产功能更多、适应性更强的产品。当然，这是多年来许多有远见的设计师和工程师们一直在做的事情。

大约30年前这个尴尬的词首次在日本诞生。从那以后，机电一体化就表示机械与电子的协同结合。这个词的意思比传统术语——机电要更宽泛一些，多指静电或电磁设备的使用。它也是一种不固定的、样式繁多并不断演变的概念，有1001种定义，其中有许多定义由于太宽泛或太狭隘，表面上作为非主流应用。

但是，机电一体化不仅限于语义。这是一个重要的设计趋势，对产品开发过程、制造产品的国际竞争和未来几年机械工程教育的本质都有着显著的影响，并且成功的机械工程师很有可能成为团队领导或工程经理。

一、机电一体化的定义

对于在日本茨城县日立公司机械工程实验室工作的山口贵史来说机电一体化是“设计出快捷、性能精确的产品的方法。这些特性可以通过考虑机械设计和伺服控制、传感器、电子的使用来实现”。他补充说这也使得设计的鲁棒性很重

要。例如，电脑磁盘驱动器就是一个成功应用机电一体化的重要实例，他说：“磁盘驱动器需要支持快速访问、精确定位以及对各种扰动的鲁棒性”。

对于哥伦布的俄亥俄州立大学机械工程系副教授乔乔·里泽尼来说，机电一体化是“传统设计方法和传感器、仪器仪表技术、驱动和执行技术、实时嵌入式微处理器系统以及实施软件的融合。”他说，机电一体化（机电）产品表现出一定的特点，包括将许多机械功能更换为电子功能，从而得到更大的灵活性和简单的设计或编程、在复杂系统中实现分布式控制的能力以及进行自动化数据收集和报告的能力。

伯克利加利福尼亚大学的机械工程教授孙正义说：“机电一体化只是好的设计实践。其基本思想是将新控件从机械装置中提取出新的性能水平。”这意味着使用现代化的、符合成本效益的技术改进产品和工艺的性能和灵活性。在许多情况下，利用计算机和控制技术产生一个比单纯的机械方法更加优雅的设计方法。据孙正义——同时也是由电子工程师协会和ASME联合出版的机电一体化IEEE/ASME交易季刊的主编——说，如果对所做的事有一个除机械方法外的好主意，设计自由度就会增加，成果有所改善。

该期刊首次于1996年3月出版，是表明“这一跨学科领域的重要性已得到公认”的另一个迹象。交易涵盖一系列相关技术领域，包括建模设计、系统集成、执行器和传感器、智能控制、机器人、制造业、运动控制，振动和噪声控制、器件和光电系统以及汽车系统。

二、机电一体化的起源

20世纪60年代末，一个日本安川电机公司的工程师首先将机电一体化用于电机的计算机控制。这个词在日本仍然很受欢迎，并且多年来一直在欧洲普遍使用。虽然机电一体化作为一个研究和实践的领域，在英美两国获得工业界和学术界认可的进程很缓慢，但是越来越多的本科和研究生院校开设机械类课程正体现着机电一体化在世界范围内所表现出的日益突出的地位。

许多工程师认为机电一体化是发展的机器人。早期的机械手还无法协调动作，没有感应反馈，主要得益于动力学、运动学、控制、传感技术和高级编程的研究进展。现代技术使得机器人更灵活并因此更加有用，其同类电池能够用于新一代高性能的设计，适应各种机械。

20世纪70年代，机电一体化主要与应用在诸如自动开门器、自动售货机和自动对焦相机等产品的伺服技术有关。据《交易》的编辑说，简单的实现方法，包括先进控制方法的早期使用。

20世纪80年代，由于信息技术的引进，工程师们开始将微处理器嵌入机械系统以提高它们的性能。数控机床和机器人变得更加紧凑，而汽车上如电子发动

机控制系统和防抱死制动系统被广泛应用。

到了90年代，通信技术加入，使得产品可以与大规模网络相连。这一发展实现了机械手远程操作等功能。同时，新的、更小的——甚至微型传感器和执行器技术越来越多地应用于新产品。微机电系统，如触发汽车空气袋的微型硅加速度计，是后者的应用实例。

和这些发展可能同样重要的是，在名为机电一体化的工程领域解释它们的这一想法遭到大量质疑。“这当然是吸引人的话，”身为俄亥俄州立大学的名誉教师兼ASME工作人员的控制专家厄内斯特·O·戴比林说，“但它是进化而非革命、发展。因为计算机小而相对便宜设计师将其打造成产品就很有意义。机电一体化的确与所有其他的技术——计算机、软件、先进控制、传感器、执行器等——的熟悉程度使得先进产品成为可能。”

密歇根州迪尔伯恩的福特研究实验室的高级技术专家达沃尔·赫罗瓦特也表达了类似的意见：“该词指出了一个领域，它可能不是一个单一的领域。机电一体化是混合技术，有助于设计出更好的产品。”

但是，机电一体化已被定义，它的意思是“我们现在有可行的技术对从烤面包机到汽车的各级机械系统实现计算机控制，”伯克利的机械工程教授大卫·M·奥斯兰德如是说。他对这个课题提出了一个非常广义的观点。“你控制或调节功率的任一系统都是计算机控制的候选人。对任一机械元件你可能会问：它的目的是什么？它传递能量吗？或者它的目的是控制和协调？计算机、软件和电子一般能更有效地实现第二项功能——更简单、更便宜、更灵活。”他强调，比起以往的概念，这种方法构成了对机械系统如何工作的完全不同的看法。“这是从外部控制角度来看的机械。”

《交易》（1996.6）发表了比利时机器人研究员亨德里克M.J.凡.布鲁塞尔的观点，遵循一个类似的基本主题，但重点不同。他写道：“过去，机器和产品设计几乎完全是机械工程师的工作。机械工程师设计出机器之后，控制和软件工程师补充控制和规划问题的解决方案。”

这种顺序的工程方法通常会造成设计欠佳。“最近，机械设计受到了微电子、控制工程和计算机科学发展的深刻影响，”凡·布鲁塞尔写道。“作为高性能机器设计的坚实基础，需要的是为不同的工程学科之间的交叉增效。这正是机电一体化的目的所在；它是机械设计的一种并行工程的观点。”然后他给出了所研究的定义：“机电一体化包括控制运动灵活生成所需的知识库和技术。”

凡·布鲁塞尔继续说：“机器行为的一个基本特征是控制和/或协调一个或多个机器元件动作的发生。所需动作的生成和协调，如要满足的日益增长的性能和精度的要求，是机电一体化存在的理由。”

凡·布鲁塞尔指出灵活性限制了传统机械装置产生各种动作。它们创造执行器和驱动元件的运动之间的复杂函数关系的潜能也会受到阻碍。纯机械驱动系统的另一个限制是其本身缺乏准确性，这是由摩擦、间隙、风误差、共振、尺寸误差等造成的。

“消除或简化执行器和驱动元件间‘受迫运动’的机构可以减轻这些阻碍，”他写道。相反，每个驱动元件具有一个驱动电机和一个位置传感器。运动控制器在不同元件的运动之间生成所需关系。“运动同步功能是从易出错的硬件机制转变为灵活的软件控制器。采用机电一体化的方法，大量的运动是可以同步的，即使相互之间距离很远。”

凡·布鲁塞尔说，在外力的作用下，一系列诸如振动和噪声的副作用会影响机械零件和工具的功能行为。被动阻尼的处理是有效的，但是其适用性有限。“机电一体化的方法可以提供更加有效的解决方案。根据合适的传感器获得的振动和噪声水平的状态信息，振动由分布在结构中的执行器抵消。机器元件就变得活跃（智能结构）了。”适应性结构这个术语可以用于“机构的行为可以无机械修改地随意改变时。”

Mechatronics

A blend of mechanics and electronics, mechatronics has come to mean the synergistic use of precision engineering, control theory, computer science, and sensor and actuator technology to design improved products and processes.

The standard clothes dryer is typically controlled by a mechanical timer. The user adjusts the timer according to the size and dampness of the load. If the timing device is not set properly, the drying cycle may be too short and the laundry may come out wet, or the machine could run long and waste energy.

A clothes dryer, however, might be fitted with a sensor-based feedback system that lets the machine measure the moisture content of the fabrics or the exhaust air, and turn itself off when the load is dry. Operating performance is enhanced and energy use is lowered as a result. The redesigned dryer might even be cheaper to buy, depending mainly on the cost of the components that comprise the electromechanical control system.

The computer disk drive, such as Cheetah from Seagate Technology, is one of the best examples of mechatronic design because it exhibits quick response, precision, and robustness.

Many U.S.-trained design engineers would say that the improved dryer is the result of up-to-date but conventional design practices. A reliable yet relatively inaccurate mechanical device was replaced by a "smarter" electronic control. In much of the rest of

the world, however, design engineers would say that the dryer redesign followed the principles of mechatronics.

Mechatronics is nothing new; it is simply the application of the latest techniques in precision mechanical engineering, controls theory, computer science, and electronics to the design process to create more functional and adaptable products. This, of course, is something many forward-thinking designers and engineers have been doing for years.

The vaguely awkward word was first coined in Japan some 30 years ago. Since then, mechatronics has come to denote a synergistic blend of mechanics and electronics. The word's meaning is somewhat broader than the traditional term electromechanics, which to many connotes the use of electrostatic or electromagnetic devices. It is also an amorphous, heterogeneous, and continually evolving concept with 1,001 definitions, many of which are so broad or so narrow to be of seemingly marginal use.

Mechatronics is more than semantics, however. It's a significant design trend that has a marked influence on the product-development process, international competition in manufactured goods, the nature of mechanical engineering education in coming years, and quite probably the success mechanical engineers will have in becoming team leaders or engineering managers.

1.Defining Mechatronics

For Takashi Yamaguchi, who works at Hitachi Ltd.'s Mechanical Engineering Laboratory in Ibaraki, Japan, mechatronics is "a methodology for designing products that exhibit fast, precise performance. These characteristics can be achieved by considering not only the mechanical design but also the use of servo controls, sensors, and electronics." He added that it is also very important to make the design robust. Computer disk drives, for example, are a prime example of the successful application of mechatronics: "Disk drives are required to provide very fast access, precise positioning, as well as robustness against various disturbances," he said.

For Giorgio Rizzoni, associate professor of mechanical engineering at Ohio State University in Columbus, mechatronics is "the confluence of traditional design methods with sensors and instrumentation technology, drive and actuator technology, embedded real-time microprocessor systems, and real-time software." Mechatronic (electromechanical) products, he said, exhibit certain distinguishing features, including the replacement of many mechanical functions with electronic ones, which results in much greater flexibility and easy redesign or reprogramming，the ability to implement distributed control in complex systems，and the ability to conduct automated data collection and reporting.

"Mechatronics is really nothing but good design practice," said Masayoshi Tomizuka, professor of mechanical engineering at the University of California, Berkeley. "The basic idea is to apply new controls to extract new levels of performance from a mechanical device." It means using modern, cost-effective technology to improve product and process performance and flexibility. In many cases, the application of computer and controls technology yields a design solution that is more elegant than the purely mechanical approach. By having a good idea of what can be done using other than mechanical means, design freedom increases and results improve, according to Tomizuka, who is also editor-in-chief of the quarterly IEEE/ASME Transactions on Mechatronics jointly published by the Institute for Electrical and Electronics Engineers and ASME.

The journal, first published in March 1996, is another indication that the importance of this interdisciplinary area is being recognized. Transactions covers a range of related technical areas, including modeling and design, system integration, actuators and sensors, intelligent control, robotics, manufacturing, motion control, vibration and noise control, microdevices and optoelectronic systems, and automotive systems.

2.The Roots of Mechatronics

Mechatronics was first used in terms of the computer control of electric motors by an engineer at Japan's Yaskawa Electric Co. in the late 1960s. The word has remained popular in Japan, and has been in general use in Europe for many years. Although mechatronics has been slow to gain industrial and academic acceptance as a field of study and practice in Great Britain and the United States, its increasingly prominent place worldwide is shown by the growing number of undergraduate and postgraduate mechatronics courses now being offered.

Many engineers would contend that mechatronics grew out of robotics. Early robotic arms, then unable to coordinate their movements and without sensory feedback, benefited greatly from advances in kinematics, dynamics, controls, sensor technology, and high-level programming. The same battery of modern technologies that made robots more flexible and thus more useful was then brought to bear on the design of new generations of high-performance, adaptable machinery of all kinds.

In the 1970s, mechatronics was concerned mostly with servo technology used in products such as automatic door openers, vending machines, and autofocus cameras. Simple in implementation, the approach encompassed the early use of advanced control methods, according to Transactions editors.

In the 1980s, as information technology was introduced, engineers began to embed microprocessors in mechanical systems to improve their performance. Numerically

controlled machines and robots became more compact, while automotive applications such as electronic engine controls and antilock-braking systems became widespread.

By the 1990s, communications technology was added to the mix, yielding products that could be connected in large networks. This development made functions such as the remote operation of robotic manipulator arms possible. At the same time, new,

smaller--even microscale--sensor and actuator technologies are being used increasingly in new products. Microelectromechanical systems, such as the tiny silicon accelerometers that trigger automotive air bags, are examples of the latter use.

As significant as these developments may seem, a good deal of skepticism remains about the idea of codifying them in an engineering field called mechatronics. "It's certainly a catchy word," said controls expert Ernest O. Doebelin, professor emeritus at Ohio State and an ASME Fellow, "but it's an evolutionary, rather than revolutionary, development. Now that computers are small and relatively cheap, it just makes sense for designers to build them into products. Mechatronics is really the familiarity with all the other technologies--computers, software, advanced controls, sensors, actuators, and so

forth--that make the advanced products possible."

Similar sentiments were expressed by Davor Hrovat, senior staff technical specialist at the Ford Research Laboratory in Dearborn, Mich.: "The word singles out an area that perhaps is not a single area. Mechatronics is mixture of technologies and techniques that together help in designing better products."

However mechatronics is defined, it means "we now have viable technology for computer control of mechanical systems at all levels, from toasters to autos," said David M. Auslander, professor of mechanical engineering at Berkeley. He takes a very generalized view of the topic. "Any system in which you control or modulate power is a candidate for computer control. For any mechanical component you can ask the question: What is its purpose? Does it transmit power? Or is its purpose control and coordination? Computers, software, and electronics can generally do this second function more efficiently--simpler, cheaper, with much more flexibility." This approach, he emphasized, constitutes a totally different view of how mechanical systems work compared with previous conceptions. "This is a machine viewed from the controls outward.”

The view of Belgian robotics researcher Hendrik M. J. Van Brussel, published in Transactions (June 1996), follows a similar fundamental theme but with a different emphasis. "In the past, machine and product design has, almost exclusively, been the preoccupation of mechanical engineers," he wrote.” Solutions to control and programming

problems were added by control and software engineers, after the machine had been designed by mechanical engineers.”

This sequential-engineering approach usually resulted in suboptimal designs. "Recently, machine design has been profoundly influenced by the evolution of microelectronics, control engineering, and computer science," Van Brussel wrote. "What is needed, as a solid basis for designing high-performance machines, is a synergistic cross-fertilization between the different engineering disciplines. This is exactly what mechatronics is aiming at; it is a concurrent-engineering view of machine design." He then offered his working definition of the term: "Mechatronics encompasses the knowledge base and the technologies required for the flexible generation of controlled motion."

An essential feature in the behavior of a machine, Van Brussel continued, is the occurrence of controlled and/or coordinated motion of one or more machine elements. "The generation and coordination of the required motions, such that the increasingly growing performance and accuracy requirements are satisfied, is the raison d'etre of mechatronics."

Van Brussel pointed out that traditional mechanisms are limited in their flexibility in generating a wide variety of motions. Also restricted is their potential for creating complex functional relationships between the motion of the actuator and that of the driven element. Yet another limitation of purely mechanical drive systems is their inherent lack of accuracy, caused by friction, backlash, wind-up errors, resonances, dimensional errors, and so forth.

"These restrictions can be alleviated by eliminating or simplifying the 'forced-motion' mechanism between actuator and driven elements," he wrote. Instead, each driven element is provided with a drive motor and a position sensor. A motion controller generates the required relationships between the motions of the different driven elements. "The motion synchronization function is shifted from the error-prone hardware mechanism to the flexible software controller. By applying the mechatronics approach, a large number of motions can be synchronized, even at long distances away from each other."

Under external forces, a range of secondary effects such as vibration and noise can adversely affect the functional behavior of machine elements and instruments, according to Van Brussel. Passive damping treatments are available, but they have limited applicability. "The mechatronic approach can provide more effective solutions. Based on the state information about vibration and noise levels, captured by appropriate sensors, the vibrations are counteracted by actuators distributed over the structure. The machine elements become active (smart structures)." The term adaptive structures can be used

"when the behavior of the structure can be changed at will, without mechanical modifications."