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外文文献The Numerical Control Engine Bed Transformsnumerical control system development summary brief history and tendency In 1946 the first electronic accounting machine was born in the world, this indicated the humanity created has been possible to strengthen and partially to replace the mental labor the tool. It with the humanity these which in the agriculture, the industry society created only is strengthens the physical labor the tool to compare, got up the quantitive leap, entered the information society for the humanity to lay the foundation. After 6 years, in 1952, computer technology applied to the engine bed , the first numerical control engine bed were born in US. From this time on, the traditional engine bed has had the archery target change. Since nearly half century, the numerical control system has experienced two stages and six generation of development. Numerical control (NC) stage (1952 1970) The early computer operating speed is low, was not big to then science computation and the data processing influence, but could not adapt the engine bed real-time control request. The people can not but use numeral logic circuit to build to become an engine bed special purpose computer to take the numerical control system, is called the hardware connection numerical control (HARD-WIRED NC), Jian Chengwei numerical control (NC). Along with the primary device development, this stage has had been through repeatedly three generations, namely 1952 first generation of - electron tube; 1959 second generation of - transistor; 1965 third generation - small scale integration electric circuit. Computer numerical control (CNC) stage (in 1970 present) In 1970, the general minicomputer already appeared and the mass production. Thereupon transplants it takes the numerical control system the core part, from this time on entered the computer numerical control (CNC) the stage (which should have computer in front of the general two characters to abbreviate). In 1971, American INTEL Corporation in the world first time the computer two most cores part - logic units and the controller, used the large scale integrated circuit technology integration on together the chip, called it the microprocessor (MICROPROCESSOR), also might be called the central processing element (to be called CPU). The microprocessor is applied to 1974 in the numerical control system. This is because minicomputer function too strong, controlled an engine bed ability to have wealthily (therefore once uses in controlling the Taiwan engine bed at that time, called it group control), was inferior to used the microprocessor economy to be reasonable. Moreover then small machine reliability was not ideal. The early microprocessor speed and the function although insufficiently are also high, but may solve through the multi-processor structure. Because the microprocessor is the general-purpose calculator core part, therefore still was called the computer numerical control. In 1990, PC machine (personal computer, domestic custom had called microcomputer) the performance has developed to the very high stage, may take the numerical control system core part the request. The numerical control system henceforth entered based on the PC stage. In brief, the computer numerical control stage has also experienced three generations. Namely 1970 fourth generation of - minicomputer; 1974 five dynasties - microprocessor and 1990 sixth generation - (overseas was called PC-BASED) based on PC. Also must point out, although overseas already renamed as the computer numerical control (namely CNC). Also must point out, although overseas already renamed as the computer numerical control (namely CNC), but our country still the custom called the numerical control (NC). Therefore we daily say numerical control, the materially already was refers to computer numerical control. the numerical control future will develop tendency 1 open style continues to, to develop based on the PC sixth generation of direction 2 approaches and the high accuracy development 3 develops to the intellectualized direction (1) applies the adaptive control technology (2) introduces the expert system instruction processing (3) introduces the breakdown to diagnose the expert system (4) intellectualized numeral servo drive engine bed numerical control transformation necessity From on microscopic looked below that, the numerical control engine bed has the prominent superiority compared to the traditional engine bed, moreover these superiority come from the computer might which the numerical control system contains. 1 may process the traditional engine bed cannot process the curve, the curved surface and so on the complex components.2 may realize the processing automation, moreover is the flexible automation, thus the efficiency may enhance 3 7 times compared to the traditional engine bed.3 processings components precision high, size dispersion degree small, makes the assembly to be easy, no longer needs to make repairs.4 may realize the multi- working procedures centralism, reduces the components in engine bed between frequent transporting. 5 has auto-alarm, the automatic monitoring, automatic compensation and so on the many kinds of autonomy function, thus may realize long time nobody to safeguard the processing. 6 advantage which derives by above five. 中文译文数控机床改造数控系统发展简史及趋势 1946年诞生了世界上第一台电子计算机,这表明人类创造了可增强和部分代替脑力劳动的工具。它与人类在农业、工业社会中创造的那些只是增强体力劳动的工具相比,起了质的飞跃,为人类进入信息社会奠定了基础。6年后,即在1952年,计算机技术应用到了机床上,在美国诞生了第一台数控机床。从此,传统机床产生了质的变化。近半个世纪以来,数控系统经历了两个阶段和六代的发展。 数控(NC)阶段(19521970年) 早期计算机的运算速度低,对当时的科学计算和数据处理影响还不大,但不能适应机床实时控制的要求。人们不得不采用数字逻辑电路搭成一台机床专用计算机作为数控系统,被称为硬件连接数控(HARD-WIRED NC),简称为数控(NC)。随着元器件的发展,这个阶段历经了三代,即1952年的第一代-电子管;1959年的第二代-晶体管;1965年的第三代-小规模集成电路。 计算机数控(CNC)阶段(1970年现在) 到1970年,通用小型计算机业已出现并成批生产。于是将它移植过来作为数控系统的核心部件,从此进入了计算机数控(CNC)阶段(把计算机前面应有的通用两个字省略了)。到1971年,美国INTEL公司在世界上第一次将计算机的两个最核心的部件-运算器和控制器,采用大规模集成电路技术集成在一块芯片上,称之为微处理器(MICROPROCESSOR),又可称为中央处理单元(简称CPU)。 到1974年微处理器被应用于数控系统。这是因为小型计算机功能太强,控制一台机床能力有富裕(故当时曾用于控制多台机床,称之为群控),不如采用微处理器经济合理。而且当时的小型机可靠性也不理想。早期的微处理器速度和功能虽还不够高,但可以通过多处理器结构来解决。由于微处理器是通用计算机的核心部件,故仍称为计算机数控。 到了1990年,PC机的性能已发展到很高的阶段,可以满足作为数控系统核心部件的要求。数控系统从此进入了基于PC的阶段。 总之,计算机数控阶段也经历了三代。即1970年的第四代-小型计算机;1974年的第五代-微处理器和1990年的第六代-基于PC(也就是为PC-BASED)。 数控未来发展的趋势 1继续向开放式、基于PC的第六代方向发展 基于PC所具有的开放性、低成本、高可靠性、软硬件资源丰富等特点,更多的数控系统生产厂家会走上这条道路。至少采用PC机作为它的前端机,来处理人机界面、编程、联网通信等问题,由原有的系统承担数控的任务。PC机所具有的友好的人机界面,将普及到所有的数控系统。远程通讯,远程诊断和维修将更加普遍。 2向高速化和高精度化发展 这是适应机床向高速和高精度方向发展的需要。 3向智能化方向发展 随着人工智能在计算机领域的不断渗透和发展,数控系统的智能化程度将不断提高。 (1)应用自适应控制技术 数控系统能检测过程中一些重要信息,并自动调整系统的有关参数,达到改进系统运行状态的目的。 (2)引入专家系统指导加工 将熟练工人和专家的经验,加工的一般规律和特殊规律存入系统中,以工艺参数数据库为支撑,建立具有人工智能的专家系统。 (3)引入故障诊断专家系统 (4)智能化数字伺服驱动装置 可以通过自动识别负载,而自动调整参数,使驱动系统获得最佳的运行。 机床数控化改造的必要性 从微观上看,数控机床比传统机床有以下突出的优越性,而且这些优越性均来自数控系统所包含的计算机的威力。 1 可以加工出传统机床加工不出来的曲线、曲面等复杂的零件。 由于计算机有高超的运算能力,可以瞬时准确地计算出每个坐标轴瞬时应该运动的运动量,因此可以复合成复杂的曲线或曲面。 2 可以实现加工的自动化,而且是柔性自动化,从而效率可比传统机床提高37倍。 由于计算机有记忆和存储能力,可以将输入的程序记住和存储下来,然后按程序规定的顺序自动去执行,从而实现自动化。数控机床只要更换一个程序,就可实现另一工件加工的自动化,从而使单件和小批生产得以自动化,故被称为实现了柔性自动化。 3 加工零件的精度高,尺寸分散度小,使装配容易,不再需要修配。 4 可实现多工序的集中,减少零件 在机床间的频繁搬运。 5 拥有自动报警、自动监控、自动补偿等多种自律功能,因而可实现长时间无人看管加工。 6 由以上五条派生的好处。
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