数控424152.pptx

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1、 NC Technology Email: Numerical Control Technology 机电工程学院机电工程学院主讲：主讲：蒋廷彪蒋廷彪 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Ch4 COMPUTER NUMERICAL CONTROL UNIT 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Outline1.CNC system2.HARDWARE ARCHITECTURE OF CNC UNIT 3.CNC Software4.OPEN ARCHIT

2、ECTURE SYSTEM FOR CNC UNIT中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Introduction vMachine controls are divided into two types:v numerical control(NC)v computer numerical control(CNC).vNC controls have to read the program each time a part is run;they have no means of editing existing progr

3、ams.CNC controls can store and allow editing of loaded programs.v All machines built today are CNC machines.CNC unit is the heart of CNC machine.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:NC system The NC machine:1.control unit,which processes the commands from the input media.2.the drive

4、mechanisms3.the machine itself The most basic function of any NC machine is automatic,precise,and consistent motion control.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:The makeup of a linear axis of an NC machine中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNC SystemvDefinition(EIA)

5、:CNC system is a special computer system that is equipped with certain interface circuits and servo drivers,and can do part or all the works an NC system do by running the software stored in its memories.v EIA(EIA(美国电子工业协会美国电子工业协会)所属的数控标准化委员会的定义所属的数控标准化委员会的定义:“CNCCNC是用一个存储程序的计算机，按照存储在计算机内的读是用一个存储程序的

6、计算机，按照存储在计算机内的读写存储器中的控制程序去执行数控装置的部分或全部功能，在写存储器中的控制程序去执行数控装置的部分或全部功能，在计算机之外的唯一装置是接口计算机之外的唯一装置是接口”。vISO(ISO(国际标准化组织国际标准化组织)的定义的定义:“数控系统是一种控制系统，它自动阅读输入载体上事先给定数控系统是一种控制系统，它自动阅读输入载体上事先给定的数字，并将其译码，从而使机床移动和加工零件的数字，并将其译码，从而使机床移动和加工零件”。中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNC machining System

7、Logical structure of CNC machine tool中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNC machining System中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNCCNC系系统统的的组组成成从自动控制的角度来看，CNC系统是一种位置（轨迹）、速度（还包括电流）控制系统，其本质上是以多执行部件(各运动轴)的位移量、速度为控制对象并使其协调运动的自动控制系统，是一种配有专用操作系统的计算机控制系统。从外部特征来看，CNC系统是由硬件

8、（通用硬件和专用硬件）和软件（专用）两大部分组成的。中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNCCNC装置的装置的组组成和工作原理成和工作原理 CNC系统平台系统平台硬件硬件操作系统操作系统管理软件管理软件应用软件应用软件控制软件控制软件数控加工程序数控加工程序 接接口口被控设备被控设备 机机 床床 机器人机器人 测量机测量机 .中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNCCNC装置的装置的组组成和工作原理成和工作原理1.1.硬件结构硬件结构:CPUCPU，存

9、存储储器，器，总线总线、外外设设等等。2.2.软件结构软件结构：是一种用于是一种用于零件零件加工的、加工的、实时实时控制的、特殊控制的、特殊的（或称的（或称专专用的）用的）计计算机操作系算机操作系统统。系系 统统初始化初始化系统控制软件系统控制软件程序管理程序管理编辑编辑存储存储录放录放管理软件管理软件控制软件控制软件输入程序输入程序输出程序输出程序显示程序显示程序诊断程序诊断程序译码程序译码程序补偿计算补偿计算速度控制速度控制插补程序插补程序位控程序位控程序CNCCNC软件的构成软件的构成 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Emai

10、l:CNCCNC装置的装置的组组成和工作原理成和工作原理3.3.工作原理工作原理 通通过过各种各种输输入方式，接受机床加工零件的各种数据信息，入方式，接受机床加工零件的各种数据信息，经过经过CNCCNC装置装置译码译码，再，再进进行行计计算机的算机的处处理、运算，然后将各个坐理、运算，然后将各个坐标轴标轴的分量送到各控制的分量送到各控制轴轴的的驱动电驱动电路，路，经过转换经过转换、放大去、放大去驱动驱动伺服伺服电动电动机，机，带动带动各各轴轴运运动动。并。并进进行行实时实时位置反位置反馈馈控制，使各控制，使各个坐个坐标轴标轴能精确地走到所要求的位置。能精确地走到所要求的位置。简简要工作要工作过

11、过程：程：1 1）输入）输入：输入内容输入内容零件程序、控制参数和补偿数据。零件程序、控制参数和补偿数据。输输入入方方式式穿穿孔孔纸纸带带阅阅读读输输入入、磁磁盘盘输输入入、光光盘盘输输入入、手手健盘输健盘输 入，通讯接口输入及连接上级计算机的入，通讯接口输入及连接上级计算机的DNCDNC接口输入接口输入.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNCCNC装置的装置的组组成和工作原理成和工作原理2 2）译译码码：以以一一个个程程序序段段为为单单位位，根根据据一一定定的的语语法法规规则则解解释释、翻翻译译成成计计算算机机能能够够

12、识识别别的的数数据据形形式式，并并以以一一定定的的数数据据格格式式存存放放在在指指定定的的内内存存专专用用区内。区内。3 3）数据处理）数据处理：包括刀具包括刀具补偿补偿，速度，速度计计算以及算以及辅辅助功能的助功能的处处理等。理等。4 4）插补：）插补：插补的任务是通过插补计算程序在一条曲线的已知起点和终点插补的任务是通过插补计算程序在一条曲线的已知起点和终点之间进行之间进行“数据点的密化工作数据点的密化工作”。5 5）位位置置控控制制：在在每每个个采采样样周周期期内内，将将插插补补计计算算出出的的理理论论位位置置与与实实际际反反馈馈位置相比较，用其差值去控制进给伺服电机。位置相比较，用其差

13、值去控制进给伺服电机。6 6）I/OI/O处理：处理：处理处理CNCCNC装置与机床之间的强电信号输入、输出和控制。装置与机床之间的强电信号输入、输出和控制。7 7）显示：）显示：零件程序、参数、刀具位置、机床状态等。零件程序、参数、刀具位置、机床状态等。8 8）诊断：）诊断：检查一切不正常的程序、操作和其他错误状态。检查一切不正常的程序、操作和其他错误状态。中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNC unit CNC unit is the core of the whole CNC system.It is compos

14、ed of hardware and software.The hardware:microprocessors,electronic memory modules,I/O interfaces,and position control modules,etc.CNC software controls all functions of the machine and its efficiency of operation,and manages all local programming at the machine tool and graphic simulation of the cu

15、tting process if available.The hardware and the software work together to do all functions of CNC unit,which an ordinary NC system can never do.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:The main functions and features of CNC unit 1.Controlling function(the number of control axes and synch

16、ronously control axes)2.Preparatory function3.Interpolation function 4.Feed functionFeed Rate OverrideRapid motion 5.Spindle function 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:The main functions and features of CNC unit 6.Miscellaneous function7.Compensation function Tool length compensat

17、ion,cutter radius compensation,and tool nose radius compensation.Technical parameters compensation 8.Enhanced graphic display function 9.Selfdiagnosis function 10.Communication function 11.Programming function 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Functional interface between hardware

18、 and software in CNC unit 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:HARDWARE ARCHITECTURE OF CNC UNITCNC unit is the core of CNC system.The hardware comprising a CNC unit is made up of microprocessors,electronic memory modules,I/O interfaces,and position control modules,etc.,which is just

19、 like an ordinary computer system.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Types of CNC Unit vby the architecture of printed circuit boards1.Allinone board architecture 2.multifunctional modules architecture v by the number of microprocessors1.single microprocessor2.multi microprocessors

20、v by the manufacturing fashions1.ordinary personal computer architecture2.special purpose architecturev according to their opening degree 1.Close architecture2.PCpluginNC architecture3.NCpluginPC architecture4.software based open architecture of CNC unit中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology

21、 Email:Allinone board architecture vAllinone architecture CNC unit comprises main board,position control card,PLC card,displayer card,and power supply.Main board is a big printed circuit board;other functional cards are small size,each is installed in a card rack on the main board.中国电子科技集团公司科技与质量部中国

22、电子科技集团公司科技与质量部*NC Technology Email:Sketch map of Allinone board architecture中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Multifunctional modules architecturevIn this architecture,CNC unit is divided into several function modules.Its hardwa

23、re and software are designed with modularization method,that is to say,each function module is made of printed circuit of same size,and the control software of function modules are also designed in modularization.Hence,customers can establish their own CNC units by combining their selected function

24、modules into the card racks of a motherboard.CNC control module,position control card,PLC card,graph display card and communication card are familiar function modules.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:a holonomic CNC lath system 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email

25、:Single microprocessor architectureThere is only one microprocessor,which processes various NC tasks by timesharing in a centralized control way.in this architecture.Some CNC system,though having more than two processors,can only be called single microprocessor systems,because there is only one micr

26、oprocessor on duty of controlling and occupying the system bus,while the others cannot occupy the system bus and cannot access main memory.This architecture is simple and can be implemented easily,whereas,for reason of centralized controlling,its performances and abilities are limited by the byte le

27、ngth,data width,address ability,and calculating speed of microprocessor.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Multimicroprocessors architecturedistributed systemmaster-and-servant system bus based multi host microprocessor system.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Di

28、stributed systemthere is a communication network route between each two microprocessors.Interactions within microprocessors and shared resources are achieved via network communication technology 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email: Masterandservant system A processor is called maste

29、r microprocessor,others are servant microprocessors,and they are all independent systems.Only master microprocessor can control the bus,access the resources attached with the bus,control and monitor servant microprocessors,and coordinate the operations of servant microprocessors.中国电子科技集团公司科技与质量部中国电子

30、科技集团公司科技与质量部*NC Technology Email:Bus based multi CPU system 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Special purpose architecture CNC units of this architecture are designed and manufactured by different enterprises respectively.They have convenient layouts,compact structures,and high pe

31、rformances for special purpose,but have no general characters;hence,one CNC unit cannot be changed or substituted by another CNC unit,which is manufactured by a different enterprise.FANUC CNC system,SIEMENS CNC system,and AB system(American)are of this architecture 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*N

32、C Technology Email:Personal computer architecture CNC unit of this architecture base on industry computer(IPC)platform,and is built by plugging in certain control cards and NC software.IPC platform has made CNC unit cheaper and cheaper in price,and easily to be substituted when fault occurs IPCCNC u

33、nitCNC system中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Typical CNC UnitsSIEMENS(German)FANUC(Japan)ALLENBRANDLEY(American AB)HNC(HuaZhong Numerical Control systemBlueSky(ShenYang Institute of Computing Technology)中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:CNC SOFTWARE In CNC sys

34、tem,there are various kinds of software codes,which fall into two groups:user software and system software.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:User softwareUser software is also called part program,which is programmed and inputted by using numerical control language(such as APT)to i

35、ndicate the machining procedure of the part.It is compiled into a program with various Gcodes and Mcodes arranged according to the process sequence.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:System software CNC system software can be sorted into two packages:managing software and control s

36、oftware.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:The function of control software(1)Compiling the part codes inputted by users After receiving the part codes,compiler will translate,trim and store them into a specified format;decode the machining instructions in part codes and do decimal

37、binary transitions to coordinate data;calculate tools center path considering the offset of tool radius;precalculate some constants that will be used in interpolation calculation and speed control process,etc.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:The function of control software(2)Int

38、erpolation calculations(2)Interpolation calculations Interpolation calculation subroutine has the same functions with hardware interpolator in NC system,!,e.,to assign electrical pulses for axes.It is a strict real time program,and demands as less as possible number of instruction codes,that is to s

39、ay,to shorten the time for performing interpolation calculations,because the time is determinative to the feed speed of interpolation.In some CNC system,it is adopted to combine rough interpolation and fine interpolation 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:The function of control so

40、ftware(3)Tool compensation All types of CNC machine tools require some form(s)of compensation,such as tool length compensation,cutter radius compensation,and tool nose radius compensation.Though applied for different reasons on different machine types,all forms of compensation allow the CNC user to

41、allow for unpredictable conditions related to tooling.Generally speaking,if the CNC user is faced with any unpredictable situations during programming,it is likely that the CNC control manufacturer has come up with a form of compensation to deal with the problem.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC T

42、echnology Email:The function of control software(4)Speed control Speed control subroutine aims at controlling the speed of pulses assigning,i.e.controlling the frequency of interpolation calculation according to the setting speed code(or corresponding speed instruction)to guarantee the preset feed v

43、elocity.While there is an unexpected abrupt changing in velocity during machining,the speed control subroutine should automatically speed up or slow down the velocity to avoid pace loss in drive system.Speed control can be implemented totally by software method(software timer method),and can also be

44、 implemented by hardware means.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:The function of control software(5)Position controlPosition control is in the position loop of servo system.This work can be done by either software or hardware.Position control software compares interpolation calcul

45、ated position with real measured position in each sampling cycle,and control the motor using the difference.position control software can usually adjust the magnification of the position loop circuit,compensate the error of pitch of screws in each direction of axes,and compensate the nonreturntozero

46、 when reverse the motion,so that the location precision would be improved.中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Position control中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Managing Software managing software connects each function subroutine to hardware.Managing software is c

47、omposed of part program I/O;display of part program,tool position,system parameters,running status and alarm information,static and dynamic tool path;and diagnosis codes,by which CNC unit can carry out selfdiagnosis and spot the faults.It is also on duty of synchronizing various procedures.中国电子科技集团公

48、司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Managing SoftwareManaging software can be divided into two groups:one comprises the subroutines that tie to hardware,and another is independent of hardware.Software,which depends on hardware,manages and drives peripheral equipment,such as CRT displayer,key

49、board,and communication equipments,etc.,and performs real time processes,i.e.,interruption management and various processors management,which are all real time tasks.Independent software manages time,tasks,memory,and internal communications,and synchronizes various procedures.中国电子科技集团公司科技与质量部中国电子科技集

50、团公司科技与质量部*NC Technology Email:Parallel processing 中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Real time processing Interpolation Position control中国电子科技集团公司科技与质量部中国电子科技集团公司科技与质量部*NC Technology Email:Parallel processingParallel process means that computer implements two or more tasks at the s