哈工大數(shù)控大作業(yè)完美版

1、第一作業(yè) 調(diào)研報告11.1調(diào)研內(nèi)容11.2工作量與要求11.3正文1The development and application of NC machine tool servo system2第二作業(yè)：典型曲線數(shù)字積分法插補方法132.1目的132.2要求13 2.3 DDA法雙曲線插補的積分表達式13 2.4終點判別15 2.5插補舉例15第三作業(yè)：加工中心零件加工編程173.1目的和要求173.2數(shù)控機床設備173.3加工工藝制訂193.4要完成的程序編寫任務22數(shù)控技術課程（2015）大作業(yè)院 （系）專 業(yè) 姓 名學 號班 號 任課教師完成日期 哈爾濱工業(yè)大學機電工程學院2015年5

2、月數(shù)控大作業(yè)第一作業(yè) 調(diào)研報告1.1調(diào)研內(nèi)容請以課堂所學習的知識為基礎，自主選擇課程中所涉及的任一知識點進行調(diào)研?？梢哉{(diào)研知識點的發(fā)展脈絡，也可以重點介紹該知識點的發(fā)展現(xiàn)狀、爭議與未來發(fā)展趨勢。請?zhí)峤唤华氁粺o二的報告1.2工作量與要求1. 報告需用英文撰寫，可計算機打印，也可手寫，但最后封面需手工簽名。2. 格式請參照本科生畢業(yè)論文要求（見教務處網(wǎng)站），總字數(shù)不少于2000字。3.在調(diào)研報告的最后，請列出參考的主要文獻（英文學術刊物上正式發(fā)表的文獻不少于5篇）或網(wǎng)址，并在正文中標注引用。4. 如果出現(xiàn)雷同，兩位同學均無成績。1.3正文The development and applicatio

3、n of NC machine tool servo systemSince the invention of NC machine tool in 1950s, servo system has been the indispensable component of the NC machine tool. With the rapid development of new materials, electronic power and controlling system, the servo system has evolved from the step-by-step system

4、to DC system and then to AC system. As the blossom of AC servo technology, AC servo system will replace the DC system wholly and take up the dominant position in the family of servo system. With the electronic power conversion unit as actuator and controller as core , Servo system which contains the

5、 servo driver and servo motor constitutes the main part of the electric-driving and automatic control system . When working, firstly the servo system will receive the signal from NC devices, and then drive the motion of machine tool as well as ensure the accuracy and speediness of movement under the

6、 guidance of pulse command . Usually, precision and speed of the NC machine tool and other technical indicators mainly depend on the servo system itself1. The improvement and assortment of NC servo systemAt present, engineers tend to assess the quality by reference to several important indicators, s

7、uch as precision, speed and so on. Therefore, a NC servo system must meet these requirements.High precisionUnlike the traditional manufacturing which can be manually handled to regulate and compensate errors, the NC servo system has a high demand on positioning accuracy and repeated positioning accu

8、racyQuick repose characteristicQuick response is one of important indicators of servo systems dynamic quality which requires the servo system following the command signal with minimum error as well as quick repose and high stability. Once receiving the instruction of manipulator, the working machine

9、 can restore the original state of equilibrium quickly after a short regulation or a disturbance from outer space.Wide speed rangeDue to the difference in work piece materials, cutting tool and process requirements, servo system must have wide speed range, so as to ensure that the CNC machine in any

10、 circumstances can get the optimal cutting condition. Thus the machine tool can satisfy the requirement of high speed machining as well as the requirement of low speed feed.The speed range is generally larger than 1 to 10000. when the machine is working in a low cutting speed which ask for a larger

11、stable torque output, NC servo system must maintain a good reliability.Good reliabilitythe usage of machine tool is frequent, usually with 24 hours continuous work, so the servo system must have good working reliability.Servo system of NC machine tool can be divided into open loop control system and

12、 closed loop control system according to the presence of feedback test components. Drive control Unit transforms feeding instructions to perform signal needed by actuator, and then actuator convert this signal into mechanical displacement.In Open loop control system, there is no feedback detecting c

13、omponents and comparing control links. On the contrary, these are essential part of a closed-loop control system.The composition of servo systemServo system can be classified into the feed drive system and the spindle drive system on the basis of function and usage. Besides,the NC servo system can a

14、lso be sorted into open loop control system and the closed loop control system in light of the presence of feedback detecting element.In addition, according to the difference of actuators, servo system can be divided into stepping servo system, dc servo system and ac servo system.Stepping servo syst

15、emBefore the 1960 s,the stepping servo system is based on step motor driven hydraulic servo motor or characterized by power stepping motor as direct drive,and servo system uses open-loop control.Stepping servo system works with the pulse signal, and its speed and turning Angle depends on the frequen

16、cy or the number of Instruction pulses.Because there is no testing and feedback loop, the precision of the stepper motor step depends on the step angle, the accuracy of the gear transmission clearance and so on, its accuracy is low. stepping motor is easy to appear vibration phenomenon when working

17、in the low frequency,and its output torque decreases with increment of speed. Because the stepping servo system is the open loop control, step motor in the start of machine with the over-high frequency or large load showslost or blocked phenomenon and prone to appear phenomenon of high speed oversho

18、ot in the braking of the machine tool. At the same time, step motor speed accelerating from 0 to working speed requires longer time and slower speed response. But because of its simple structure, easy adjustment, and good working reliability and the low prices, the stepping system is a good choice i

19、n many many occasions of low occasions.Dc servo systemAfter 60 and 70 s, most of numerical control system adopts dc servo system. Dc servo motor has a good wide range speed performance, large output torque, and strong overload capacity. servo system also has evolved from open loop control into close

20、d-loop control, thus in the industry as well as its related fields gains the more extensive or aboard application. However, with the rapid development of modern industry, the corresponding equivalents such as precision CNC machine tools, industrial robots make higher and higher requirements to the e

21、lectrical servo system, especially the precision, reliability and otherperformance.The traditional dc motor uses a mechanical commutator, faced up with many problems in the application process, such as brush and commutator wear easily, maintenance work is heavy and the cost of it is high. Commutator

22、 reversing would produce sparks, the maximum speed of the motor and the application environment is limited;Dc motor has a more complex structure, higher cost,and prone to interfere other deviceswork.Ac servo systemThe existence of these problems, limiting the dc servo system in high precision, high

23、performance requires the application of servo drive occasion.Because hard-overcoming weakness of dc motor, people have been seeking the development of ac servo motor to replace the dc motor whose advantage is limited by mechanical commutor and brush to satisfy the needs of various application fields

24、, especially in the field of high precision and high-performance servo drive .But because the ac motor has strong coupling, nonlinear characteristics, so control is very complete and the high-performance application has been limited. Since the 1980 s, with the boom of the new technology such as elec

25、tronic electricity, the modern control theory, and the breakthrough in the field of vector control algorithm, the original problems of AC motor which has bothered so many engineers has been solved, and ac servo development faster and faster.The characteristics of the ac servo systemIn addition to go

26、od stability, good rapidity,and high precision,servo motor system has a series of other advantages.with out the limitation of commutator circumferential speed and armature reactance potential numerical element, the speed limit ofAC motor can be design higher than DC motor in the same given motor. wi

27、th a wide range of speed regulation, the most ac servo motor speed ratio can reach 1:50000,and high-performance servo motor speed ratio can even amount to ver . Meet the numerical control machine tool drive, wide speed range and small static rate request. good torque speed characteristic AC motor as

28、 the constant torque output, i.e. within its rated speed output rated torque, in for a constant power output above the rated speed.And torque overload capacity, can overcome the inertia moment of inertia load moment at start-up.Meet the machine tool servo system, large output torque, good dynamic ac

29、cordingly, high positioning accuracy demands.The research status of domestic ac servoAc servo system consists of the ac servo system based on asynchronous motor and the ac servo system on the base of synchronous motor.At present machine mainly adopts a permanent magnet synchronous ac servo system.In

30、 the field of ac servo research, the Japan, the United States and Europe are in the forefront.In the mid 1980s, Japan yaskawa company has successfully developed the worlds first ac servo drive.Then FANUC, Mitsubishi, Panasonic and other companies have launched their own ac servo system. Most of thes

31、e products from aboard companies are based on the asynchronous motor. However,domestic institutes has set up late in ac servo system with asynchronous motor,and so far there are still no products available. Many domestic researchers put much importance on the research of permanent magnet synchronous

32、 motor servo system. Huazhong university of science and technology, Beijing machine tool research institute, xi an micro motor research institute, shenyang institute of automation of Chinese academy of sciences, lanzhou electric factory etc have started out in the research of AC servo system and are

33、 expected to launch their own products. DA98 all-digital ac servo drive unit from guangzhou NC manufacturing company has already knock at the door of high-precision servo driver industry in our country, broken the monopoly of foreign countries , and initiated a new era belonging to our national bran

34、ds.Ac servo signal and numerical control system interface have three different modes, which can also divided into three stages.Domestically, Guangzhou CNC DA98 which belongs to the first generation and is also a epoch-making servo drive, at the same time, it is first all-digital domestic ac servo dr

35、ive unit, pulse command it accept direction. The second generation is EDB series delegated by Aston, it can not only accept pulse command signal, but also receive the signal from the speed control and torque control analog input.The third generation is networked ac servo system.Networked servo syste

36、m is the organic combination of industrial field-bus technology and full digital ac servo,which enables users to adjust the parameters according to load conditions and saves some unstable factors such as drift produced by analog circuits. Based on field bus network control technology,the servo syste

37、m the microprocessor and field bus interface in all type ac motor servo drive, form independent of intelligent digital servo control unit, it directly connected to the industrial field bus, it formed a new type of network control system based on field-bus.Reduced the number of hardware and the attac

38、hment, the structure of intelligent units on independent, to the outside world and realize data sharing between each other, but also can use other field control equipment, easy to extend.So far, the network communication server product in domestic has not yet mature.Robotics institute of Beijing uni

39、versity of aeronautics and astronautics development design a network based on DSP + FPGA + ASIPM ac servo control system, the principle prototype has been got preliminary validation of the three-dimensional carving machine.currently, the most server drive adopt high-speed DSP processors,which promot

40、e the movement of all kinds of advanced control algorithms in the use of new type of drive. Mostly, suppliers of servo system employ the structure of DSP + CPLD (FPGA) on the hardware. Because the DSP and CPLD (FPGA) can repeat programming,they are easy to realize modular re-configurable of the ac s

41、ervo system.As long as the software for corresponding different system configurations, including the control algorithm can control and asynchronous motor, permanent magnet synchronous servo motor, brush-less dc motor, and through the reconfiguration of FPGA can also drive dc motor and three phase in

42、duction of stepping motor.Its for NC machine tool upgrade and innovation has left a lot of space.The development tendency of ac servoWith the constant improvement of productive forces, the ac servo system will be sophisticated in the direction of the integration, intelligent and network .integration

43、 By using a single and multi-function control unit, the servo system can achieve position control and speed control function through the setting of software and constitute a half closed loop feedback unit configuration or full closed loop control system of high accuracy through the external interfac

44、e elligentServer intelligent control mode, such as internal programming can achieve a certain trajectory in advance and control the surrounding IO port as well as the adjustment of master-slaves following with electronic CAM, workServer implementation is distributed by network.

45、The servers modulation could be reconstructed with low cost .conclusionThe modern NC machine tool is developing rapidly in the direction of high speed and high precision.As the essential component of the NC machine tool,servo system has gradually equated to ac servo system which has several incompar

46、able advantages compared with other servo systems. With the progress of the ac servo technology, it will gradually replace dc servo system overall.參考文獻1Tryling, David P.Simpleservouses.ProQuest Journal,2009.2J. Cao；Z.W. Li；Z.X. Meng.Development Of ANcServoSystemBased On Fuzzy Adaptive Control.Key en

47、gineering materials,2009.3Fusaomi&Nagata.Development of CAM system based on industrial robotic servo controller without using robot languag.Robotics and Computer Integrated Manufacturing,2013.4Mulan WangKaiyun XuChuan HeLei Zhou.Research on Servo System for CNC Machine Tool Driven by Permanent Magne

48、t Synchronous Torque Motor.Materials Engineering and Automatic Control,20125Xu, KaiyunLi, NingLin, JianHe, Chuan.Development of linear servo control system for CNC machine tool based on DSP.International Conference on Mechatronic Science, Electric Engineering and Computer,2011第二作業(yè)：典型曲線數(shù)字積分法插補方法2.1目的

49、數(shù)字積分插補方法是實現(xiàn)數(shù)控插補功能的重要方法之一。除平面直線和圓弧外，數(shù)字積分法法也可以實現(xiàn)多坐標插補聯(lián)動以及描繪如二次曲線甚至高次曲線等各種函數(shù)曲線，精度也能滿足要求，在一些專用數(shù)控機床和高檔數(shù)控系統(tǒng)中得到了廣泛的應用。因此，深入理解數(shù)字積分插補方法是掌握數(shù)控加工知識的重要內(nèi)容之一。2.2要求試參照直線和圓弧DDA插補方法，推導如下任一曲線的DDA法插補公式，要求有完整的推導過程，畫出插補器的結構框圖，討論終點判別方法，并給出一個插補過程實例。1） 拋物線插補 2） 橢圓插補 3） 螺旋線插補 導程為P，螺旋升角4）其他線型2.3 DDA法雙曲線插補的積分表達式對于雙曲線對時間t求導,得到

50、由此可以導出，第一象限逆橢圓弧在兩個方向上的速度分量 試中K為一常數(shù)。上試說明速度分量是隨著動點變化的，令動點變化的，令動點的坐標，則可得DDA插補雙曲線弧插補積分表達式 顯然用DDA法進行橢圓弧插補時，是對切削點即時坐標與的數(shù)值分別進行累加，若累加器產(chǎn)生溢出，則在相應坐標方向進給一步。2.4插補器結構框圖根據(jù)橢圓DDA插補積分表達式可知其插補方法如下：每產(chǎn)生一個控制脈沖，X、Y積分器迭代累加一次，溢出時相應坐標軸進給一次，Y積分器的溢出還要對X被積函數(shù)寄存器進行修正，X積分器的溢出還要對Y被積函數(shù)寄存器進行修正。畫出插補器結構框圖如圖所示圖 3-1 雙曲線插補器結構框圖JVX、JVY分別為X

51、、Y被積函數(shù)寄存器JRX、JRY分別為X、Y積分累加器為插補控制脈沖，分別為X、Y軸溢出脈沖2.4終點判別分別判斷XY坐標軸進給步數(shù)，當XY坐標均到達終點時插補結束。2.5插補舉例插補第一象限雙曲線，起點為(6,0)，終點為(10,8)，插補脈沖計算過程如表3-1所示，插補軌跡如圖3-2所示。兩坐標進給步數(shù)分別為4和8，一旦某坐標進給步數(shù)達到要求則停止該坐標方向的插補運算。表 3-1 插補運算過程運算次序X積分器X終Y積分器Y終JVX(yi)JRX(yi) XJVY(xi)JRY(xi)Y0000000000 101001100000010001000000000101001100110010

52、002000000000101001101100010003000000000101001100010101114000100010101001101000001115000100100101001101110001106000100110101001100100101007001001010100001101010001008001001110100001100000101009001110100100001100110001001000111101010000110110000100110011000011000011000101010012010001000100001111001001

53、0013010010000100001110000101001401011101010000111011100100150101001011000011111100010016010101110100010000110100111701101101010001000111000011180110001111000100001101001119011110100100010011111000112001110001110001001100010011圖 3-1 雙曲線插補軌跡第三作業(yè)：加工中心零件加工編程3.1目的和要求本作業(yè)通過給定一臺數(shù)控機床具體技術參數(shù)和零件加工工藝卡，使學生對數(shù)控機床具體

54、參數(shù)、加工能力和加工工藝流程有直觀了解和認識。同時，鍛煉學生解決實際加工問題的能力。1了解加工中心的具體技術參數(shù)，加工范圍和加工能力；2了解實際加工中，從零件圖紙分析到制定零件加工工藝過程； 3按照加工工藝編寫指定的工序的零件數(shù)控加工程序。 3.2數(shù)控機床設備 （1）機床結構 主要由床身、銑頭、橫進給、升降臺、冷卻、潤滑及電氣等部分組成。XKJ325-1數(shù)控銑床配用GSK928型數(shù)控系統(tǒng)，對主軸和工作臺縱橫向進行控制，用戶按照加工零件的尺寸及工藝要求，先編成零件的加工程控，最后完成各種幾何形狀的加工。（2）機床的用途和加工特點 本機床適用于多品種中、小批量生產(chǎn)的零件，對各種復雜曲線的凸輪、孔、樣板弧形糟等零件的加工效能尤為顯著；該機床高速性能好，工作穩(wěn)定可靠，定位精度和重復精度較高，不需要模具就能確保零件的加工精度，減少輔助時間，提高勞動生產(chǎn)率。（3）加工中心的主要技術參數(shù) 數(shù)控機床的技術參數(shù)，反映了機床的性能及加工范圍。表1 TH5640D立式加工中心的主要技術參數(shù)名稱參數(shù)工作臺工作臺尺寸mm 400550T型槽mm 18H8允許負載kg 600 主軸主軸錐孔No BT40主軸直徑mm 85 主周轉(zhuǎn)速(標準型/高速型)rpm 22.5-2250/45-4500 主軸電機kw 5.5/7.5 行程移動范圍mm 1000500470主軸端面至工作臺面距離mm150-620(3