内容简介：: 南京理工大学泰州科技学院毕业设计（论文）任务书系部：机械工程系专业：机械工程及自动化学生姓名：郑铭学号：05010152设计(论文)题目：支座体加工工艺及关键工序工装设计起迄日期:2008年 3月09 日 6月14日设计(论文)地点:南京理工大学泰州科技学院指导教师:王栓虎专业负责人:龚光容发任务书日期: 2009年 2 月 26 日任务书填写要求1毕业设计（论文）任务书由指导教师根据各课题的具体情况填写，经学生所在专业的负责人审查、系部领导签字后生效。此任务书应在第七学期结束前填好并发给学生；2任务书内容必须用黑墨水笔工整书写或按教务处统一设计的电子文档标准格式（可从教务处网页上下载）打印，不得随便涂改或潦草书写，禁止打印在其它纸上后剪贴；3任务书内填写的内容，必须和学生毕业设计（论文）完成的情况相一致，若有变更，应当经过所在专业及系部主管领导审批后方可重新填写；4任务书内有关“系部”、“专业”等名称的填写，应写中文全称，不能写数字代码。学生的“学号”要写全号；5任务书内“主要参考文献”的填写，应按照国标GB 77142005文后参考文献著录规则的要求书写，不能有随意性；6有关年月日等日期的填写，应当按照国标GB/T 74082005数据元和交换格式、信息交换、日期和时间表示法规定的要求，一律用阿拉伯数字书写。如“2008年3月15日”或“2008-03-15”。毕业设计（论文）任务书1本毕业设计（论文）课题应达到的目的：支座体是某企业产品中的关键零件之一，生产量比较大。为了保证产品质量，提高加工效率，需要对其加工工艺进行优化设计，并在关键工序使用组合机床或专用机床进行加工。本课题即以此为背景，要求学生根据企业生产需要和支座体零件的加工要求，首先完成零件的加工工艺规程设计，在此基础之上，选择其关键工序之一进行专用夹具及加工用组合机床设计，并完成必要的设计计算。通过这样一个典型环节综合训练，达到综合训练学生运用所学知识，解决工程实际问题的能力。2本毕业设计（论文）课题任务的内容和要求（包括原始数据、技术要求、工作要求等）：本课题要求学生在对支座体的加工要求、零件的结构工艺性进行认真分析的基础上，首先对零件的加工工艺规程做出优化设计，并对其关键工序之一进行专用夹具及加工用组合机床设计。具体任务及要求如下：（1）调查研究、查阅及翻译文献资料，撰写开题报告；（2）支座体加工要求、零件的结构工艺性分析；（3）支座体加工工艺规程设计；（4）支座体关键工序的专用夹具设计；（5）支座体关键工序的组合机床设计；（6）必要的设计计算与分析；（7）文档整理、撰写毕业设计说明书及使用说明书。设计技术要求包括：（1）生产纲领 50000件/年（2）夹具采用液压驱动（3）组合机床采用液压滑台（4）每次加工一个零件毕业设计（论文）任务书3对本毕业设计（论文）课题成果的要求包括毕业设计论文、图表、实物样品等：（1）开题报告、文献综述、资料翻译；（2）支座体加工工艺过程综合卡及各工序工序卡；（3）支座体零件图及夹具装配图；（4）组合机床设计资料（三图一卡）；（5）毕业设计说明书。 4主要参考文献：1 裘愉弢主编. 组合机床M. 第1版.北京：机械工业出版社，1995.2 金振华主编.组合机床及其调整与使用M. 第1版.北京：机械工业出版社，1990.3 沈延山.生产实习与组合机床设计D.第1版.大连：大连理工大学出版社，1989.4 上海市大专院校机械制造工艺学协作组编著.机械制造工艺学M（修订版）.福建科学技术出版社，1996.5 王华坤，范元勋编.机械设计基础M.北京：兵器工业出版社，2000.6 冯辛安等编.机械制造装备设计M. 北京：机械工业出版社,1998.7 陈日曜主编.金属切削原理M. 第2版.北京：机械工业出版社,1992.8 方子良等编.机械制造技术基础M.上海：上海交通大学出版社，2004.9 刘秋生，李忠文主编.液压传动与控制M.北京：宇航出版社，1994.10 陈于萍，周兆元等.互换性与测量技术基础M. 第2版.北京：机械工业出版社,2005.11 东北重型机械学院等合编.机床夹具设计手册M.上海：上海科学技术出版社，1979.12机械设计手册联合编写组. 机械设计手册M. 第2版.北京：机械工业出版社,1987.毕业设计（论文）任务书5本毕业设计（论文）课题工作进度计划：起迄日期工作内容2009年3月09日 3 月15 日3月16日 3 月29 日3月30日 4 月19 日4月20日 5 月03 日5月04日 5 月31 日6月01日 6 月07 日6月08日 6 月14 日熟悉毕业设计要求。查阅资料，完成外文资料翻译工作撰写开题报告及文献综述支座体加工工艺规程设计（至少提出2个方案，进行分析比较，最后决定一个较优的方案）夹具设计（至少提出2个方案，进行分析比较，最后决定一个较优的方案）组合机床设计（完成三图一卡）文档整理、撰写毕业设计说明书。论文答辩所在专业审查意见：负责人： 2009年月日系部意见：系部主任： 2009年月日南京理工大学泰州科技学院毕业设计(论文)前期工作材料学生姓名:郑铭学号：05010152系部:机械工程系专业:机械工程及自动化设计(论文)题目:支座体加工工艺及关键工序工装设计指导教师:王栓虎副教授材料目录序号名称数量备注1毕业设计(论文)选题、审题表12毕业设计(论文)任务书13毕业设计(论文)开题报告含文献综述14毕业设计(论文)外文资料翻译含原文15毕业设计（论文）中期检查表12009年5月.Automation in Construction 10 2001 477486rlocaterautconSemi-automatic control system for hydraulic shovelHirokazu Araya), Masayuki KagoshimaMechanical Engineering Research Laboratory, Kobe Steel, Ltd., Nishi-ku, Kobe Hyogo 651 2271, JapanAccepted 27 June 2000AbstractA semi-automatic control system for a hydraulic shovel has been developed. Using this system, unskilled operators canoperate a hydraulic shovel easily and accurately. A mathematical control model of a hydraulic shovel with a controller wasconstructed and a control algorithm was developed by simulation. This algorithm was applied to a hydraulic shovel and itseffectiveness was evaluated. High control accuracy and high-stability performance were achieved by feedback plusfeedforward control, nonlinear compensation, state feedback and gain scheduling according to the attitude. q2001 ElsevierScience B.V. All rights reserved.Keywords: Construction machinery; Hydraulic shovel; Feedforward; State feedback; Operation1. IntroductionA hydraulic shovel is a construction machinerythat can be regarded as a large articulated robot.Digging and loading operations using this machinerequire a high level of skill, and cause considerablefatigue even in skilled operators. On the other hand,operators grow older, and the number of skilledoperators has thus decreased. The situation calls forhydraulic shovels, which can be operated easily bywxany person 15 .The reasons why hydraulic shovel requires a highlevel of skill are as follows.1. More than two levers must be operated simulta-neously and adjusted well in such operations.)Corresponding author.E-mail address: arayahrknedo.go.jp H. Araya .2. The direction of lever operations is differentfrom that of a shovels attachment movement.For example, in level crowding by a hydraulicshovel, we must operate three leversarm, boom,.bucket simultaneously to move the top of a bucket.along a level surface Fig. 1 . In this case, the leveroperation indicates the direction of the actuator, butthis direction differs from the working direction.If an operator use only one lever and other free-doms are operated automatically, the operation be-comes very easily. We call this system a semi-auto-matic control system.When we develop this semi-automatic controlsystem, these two technical problems must be solved.1. We must use ordinary control valves for auto-matic control.2. We must compensate dynamic characteristicsof a hydraulic shovel to improve the precisionof control.0926-5805r01r$ - see front matter q2001 Elsevier Science B.V. All rights reserved.PII: S0926-5805 00 00083-2()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486478Fig. 1. Level crowding of an excavator and frame model of anexcavator.We have developed a control algorithm to solvethese technical problems and confirm the effect ofthis control algorithm by experiments with actualhydraulic shovels. Using this control algorithm, wehave completed a semi-automatic control system forhydraulic shovels. We then report these items.2. Hydraulic shovel modelTo study control algorithms, we have to analyzenumerical models of a hydraulic shovel. The hy-draulic shovel, whose boom, arm, and bucket jointsare hydraulically driven, is modeled as shown in Fig.2. The details of the model are described in thefollowing. 2.1. Dynamic model 6Supposing that each attachment is a solid body,from Lagranges equations of motion, the followingexpressions are obtained:22JuqJ cosuyuuqJ cosuyuuqJ sinuyuuqJ sinuyuuyK sinust.11l1212213133121221313311122J cosuyuuqJuqJ cosuyuuyJ sinuyuuqJ sinuyuuyK sinust.1212122223233121212323322222J cosuyuuqJ cosuyuuqJuyJ sinuyuuqJ sinuyuuyK sinust.131312323233313131232333331 .2.2where,Js m 1q m q m 1 q I ;Js111g1231112m 1 1qm 1 1; Jsm 1 1; Jsm 12q21g231g31331g3222g2m 12qI ; Jsm 1 1; Jsm 12qI ; K s3222332g3333g331.m 1qm 1 qm 1g;K s m 1qm 1g;1g1213122g233K sm 1g; and gsgravitational acceleration.33g3uis the joint angle,tis the supply torque, 1 isiiithe attachment length, 1is the distance betweengithe fulcrum and the center of gravity, m is the massiof the attachment, I is the moment of inertia aroundithe center of gravity subscripts is13, mean boom,.arm, and bucket, respectively .2.2. Hydraulic modelEach joint is driven by a hydraulic cylinder whoseflow is controlled by a spool valve, as shown in Fig.3. We can assume the following:1. The open area of a valve is proportional to thespool displacement.2. There is no oil leak.3. No pressure drop occurs when oil flows throughpiping.()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486479Fig. 2. Model of hydraulic shovel.4. The effective sectional area of the cylinder isthe same on both the head and the rod sides.In this problem, for each joint, we have thefollowing equation from the pressure flow character-istics of the cylinder:ViA h sKX P ysgn XPyP2(. .ii0iisii1i1iKwhen,KscB2rgP sP yP0ii1i1i2iwhere, A seffective cross-sectional area of cylin-ider; h scylinder length; X sspool displacement;iiP ssupply pressure; P scylinder head-side pres-si1isure; P scylinder rod-side pressure; V soil vol-2iiume in the cylinder and piping; B sspool width;igsoil density; Ksbulk modulus of oil; and csflow coefficient.2.3. Link relationsIn the model shown in Fig. 1, the relation be-tween the cylinder length change rate and the attach-mentrotationalangularvelocityisgivenas .follows: 1 boomfu.11h1su1OA OC sinuqb.1111sy,22(OA qOC q2OA OC cosuqb.111111 .2 arm.fu,u212h2suyu21.O A O C sinuyuqbqa22222122sy,22(.O A qO C q2O A O C cosuyuqbqa222222222122 .3 bucketwhenO D sO B sB C sC D33333333YhA B B C sinuyuqgyaqu.3333332332fu,ussy.3 .32322Yuyu(A BqB Cq2A B B C cosuyuqgyaqu.323333333332332()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486480Fig. 3. Model of hydraulic cylinder and valve.2.4. Torque relationsFrom the link relations of Section 2.3, the supplytorquetis given as follows, taking cylinder frictioniinto consideration:tsyfuP1 A qfu,uP1 A.1111121222qfu,uP1 A y Cfuu.32333c1111qsgnuFfu4. ./1111tsyfu,uP1 A y Cfu,uuyu./221222c221221qsgnuyuFfu,u.5/212212tsyfu,uP1 A y Cfu,uuyu./332333c332332qsgnuyuFfu,u.5/323323Where, Cis the viscous friction coefficient andciF is kinetic frictional force of a cylinder.i2.5. Response characteristics of the spoolSpool action has a great effect on control charac-teristics. Thus, we are assuming that the spool hasthe following first-order lag against the referenceinput.1XX sX .5 .iiTSq1spiWhere, XXis the reference input of spool dis-iplacement and Tis a time constant.spi3. Angle control systemAs shown in Fig. 4, the angleuis basicallycontrolled to follow the reference angleuby posi-gtion feedback. In order to obtain more accuratecontrol, nonlinear compensation and state feedbackare added to the position feedback. We will discussdetails of these algorithms as follows.3.1. Nonlinear compensationIn the ordinary automatic control systems, newcontrol devices such as servo valves are used. In oursemi-automatic system, in order to realize the coexis-tence of manual and automatic operations, we mustuse the main control valves, which are used inmanual operation. In these valves, the relation be-tween spool displacement and open area is nonlinear.Then, in automatic operation, using this relation, thespool displacement is inversely calculated from therequired open area, and the nonlinearity is compen-.sated Fig. 5 . .Fig. 4. Block diagram of control systemu.()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486481Fig. 5. Nonlinear compensation.3.2. State feedbackBased on the model discussed in Section 2, if thedynamic characteristics for boom angle control arelinearized in the vicinity of a certain standard condi-tionspool displacement X, cylinder differential10.pressure P, and boom angleu, the closed-loop11010transfer function can be expressed byKpusug6 .1132a s qa s qa sqK210pwhere, Kis position feedback gain; andpfuACfu.1101c1110a sq02 AP yP.KP yP(1s111001s1110XJqJ cosuXqJ cosuXquX?4.10111221323a s12 A fuP yP.1110s1110CfuV.c11101qA KKP yP(101s1110V JqJ cosuXqJ cosuXquX?4.1111221323a s.2A fuKKP yP.(111001s1110This system has a comparatively small coefficienta , so the response is oscillatory. For instance, if in1our large SK-16 hydraulic shovel, Xis 0, the10coefficients are given as a s2.7=10y2, a s6.001=10y6, a s1.2=10y3. Addingthe acceleration2feedback of gain K , to this the upper loop in Fig.a.4 , the closed loop transfer function is given asKpusu.7 .1r132a s q a qKs qa sqK.21a0pAdding this factor, the coefficient of s2becomeslarger, thus, the system becomes stable. In this way,acceleration feedback is effective in improving theresponse characteristics.However, it is generally difficult to detect acceler-ation accurately. To overcome this difficulty, cylin-der force feedback was applied instead of accelera-.tion feedback the lower loop in Fig. 4 . In this case,cylinder force is calculated from detected cylinderpressure and filtered in its lower-frequency portionwx7,8 . This is called pressure feedback.4. Servo control systemWhen one joint is manually operated and anotherjoint is controlled automatically to follow the manualoperation, a servo control system must be required.For example, as shown in Fig. 6, in the level crowd-ing control, the boom is controlled to keep the arm.end height Z calculated fromuanduto refer-12ence Zr. In order to obtain more accurate control, thefollowing control actions are introduced.()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486482 .Fig. 6. Block diagram of control system Z .4.1. Feedforward controlCalculating Z from Fig. 1, we obtainZs1 cosuq1 cosu.8 .1122 .Differentiating both sides of Eq. 8 with respectto time, we have the following relation,Z1 sinu22usyyu.9 .121 sinu1 sinu1111The first term of the right-hand side can be taken.as the expression feedback portion to convert Z tou, and the second term of the right-hand side is the1.expressionfeedforward portionto calculate howmuchushould be changed whenuis changed12manually.Actually,uis determined using the difference2value of Du. To optimize the feedforward rate,2feedforward gain Kis tunned.ffThere may be a method to detect and use the arm.operating-lever condition i.e. angle instead of armangular velocity, since the arm is driven at an angu-lar velocity nearly proportional to this lever condi-tion.4.2. Adaptie gain scheduling according to the atti-tudeIn articulated machines like hydraulic shovels,dynamic characteristics are greatly susceptible to theattitude. Therefore, it is difficult to control the ma-chine stably at all attitudes with constant gain. Tosolve this problem, the adaptive gain schedulingaccording to the attitude is multiplied in the feedback.loop Fig. 6 . As shown in Fig. 7, the adaptive gain.KZ or Kuis characterized as a function of twovariables,uXand Z.uXmeans how the arm is22extended, and Z means the height of the bucket.5. Simulation resultsThe level crowding control was simulated byapplying the control algorithm described in Section 4to the hydraulic shovel model discussed in Section 2.In the simulation, our large SK-16 hydraulic shovel.was employed. Fig. 8 shows one of the results. Fiveseconds after the control started, load disturbance()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486483Fig. 7. Gain scheduling according to the attitude.was applied stepwise. Fig. 9 shows the use of feed-forward control can reduce control error.6. Semi-automatic control systemBased on the simulation, a semi-automatic controlsystem was manufactured for trial, and applied to theSK-16 shovel. Performance was then ascertained byfield tests. This section will discuss the configurationand functions of the control system.6.1. ConfigurationAs illustrated in Fig. 10, the control system con-sists of a controller, sensors, manmachine interface,and hydraulic control system.The controller is based on a 16-bit microcomputerwhich receives angle input signals of the boom, arm,and bucket from the sensor; determines the conditionof each control lever; selects control modes andcalculates actuating variables; and outputs the resultsfrom the amplifier as electrical signals. The hy-Fig. 8. Simulation result of level crowding.draulic control system generates hydraulic pressureproportional to the electrical signals from the electro-magnetic proportional-reducing valve, positions thespool of the main control valve, and controls theflow rate to the hydraulic cylinder.In order to realize high-speed, high-accuracy con-trol, a numeric data processor is employed for theFig. 9. Effect of feedforward control on control error of Z.()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486484Fig. 10. Schema of control system.controller, and a high-resolution magnetic encoder isused for the sensor. In addition to these, a pressuretransducer is installed in each cylinder to achievepressure feedback.The measured data are stored up to the memory,and can be taken out from the communication port.6.2. Control functionsThis control system has three control modes,which are automatically switched in accordance withlever operation and selector switches. These func-tions are the following .1 Level crowding mode: during the manual armpushing operation with the level crowding switch,the system automatically controls the boom and holdsthe arm end movement level. In this case, the refer-ence position is the height of the arm end from theground when the arm lever began to be operated.Operation of the boom lever can interrupt automaticcontrol temporarily, because priority is given to man-ual operation. .2Horizontal bucket lifting mode: during themanual boom raising operation with the horizontalbucket lifting switch, the system automatically con-trols the bucket. Keeping the bucket angle equal tothat at the beginning of operation prevents materialspillage from the bucket. .3Manual operation mode: when neither thelevel crowding switch nor the horizontal bucket lift-ing switch are selected, the boom, arm, and bucketare controlled by manual operation only.The program realizing these functions is primarilywritten in C language, and has well-structured mod-ule to improve maintainability.7. Results and analysis of field testWe put the field test with the system. We con-firmed that the system worked correctly and theeffects of the control algorithm described in Chaps. 3and 4 were ascertained as follows.7.1. Automatic control tests of indiidual attach-mentsFor each attachment of the boom, arm, and bucket,the reference angle was changed 58 stepwise fromthe initial value, and the responses were measured;thus, the effects of the control algorithm described inChap. 3 were ascertained.()H. Araya, M. KagoshimarAutomation in Construction 10 2001 477486485Fig. 11. Effect of nonlinear compensation on boom angle.7.1.1. Effect of nonlinear compensationFig. 11 shows the test results of boom lowering.Because dead zones exist in the electro-hydraulicsystems, steady-state error remains when simple po-sition feedback without compensation is applied OFF.in the figure . Addition of nonlinear compensation.ON in the figure can reduce this error.7.1.2. Effect of state feedback controlFor the arm and bucket, stable response can beobtained by position feedback only, but adding ac-celeration or pressure feedback can improve fast-re-sponse capability. As regards the boom, with onlythe position feedback, the response becomes oscilla-tory. Adding acceleration or pressure feedback madethe response stable without impairing fast-responsecapability. As an example, Fig. 12 shows the testresults when pressure feedback compensation wasapplied during boom lowering.7.2. Leel crowding control testControl tests were conducted under various con-trol and operating conditions to observe the controlFig. 12. Effect of pressure feedback control on boom angle.Fig. 13. Effect of feedforward control on control error of Z.characteristics, and at the same time to determine theoptimal control parameters such as the control gains.shown in Fig. 6 .7.2.1. Effects of feedforward controlIn the case of position feedback only, increasinggain Kto decrease error DZ causes oscillation duepto the time delay in the system, as shown by AOFFBin Fig. 13. That is, Kcannot be increased. Apply-ping the feedforward of the arm lever value describedin Section 4.1 can decrease error without increasingKas shown by AONB in the figure.p7.2.2. Effects of compensation in attitudeLevel crowding is apt to become oscillatory at theraised position or when crowding is almost com-pleted. This oscillation can be prevented by changinggainKaccording to the attitude, as has beenpdiscussed in Section 4.2. The effect is shown in Fig.14. This shows the result when the level crowdingwas done at around 2 m above ground. Compared tothe case without the compensation, denoted by OFFin the figure, the ON case with the compensationprovides stable response.Fig. 14. Effect of adaptive gain control on control error of Z.()H. Araya, M. KagoshimarAutomation in Construction 10 2001 4774864867.2.3. Effects of control interalThe effects of control int

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