外文翻譯---一種新型的液壓鍛造操作機(jī)的智能控制

1、<p><b>　　附錄（二）</b></p><p><b>　　原文：</b></p><p>　　Intelligent Control of a Novel Hydraulic Forging Manipulator</p><p><b>　　Abstract</b></p&

2、gt;<p>　　The increased demand for large-size forgings has led to developments and innovations of heavy-duty forging manipulators. Besides the huge carrying capacity, some robot features such as force perception, d

3、elicacy and flexibility, forging manipulators should also possess. The aim of the work is to develop a heavy-duty forging manipulator with robot features by means of combination of methods in mechanical, hydraulic, and c

4、ontrol field. In this paper, through kinematic analysis of a novel forging m</p><p>　　Introduction</p><p>　　The use of manipulators in open die or free forging can be traced back about 60 years

5、when development started in both Europe and the USA. Manipulators for heavy workpieces, that is, those in the region of 200 tons weight, have been developed steadily since that time, and currently there are a number of e

6、xamples of computer-controlled fully automatic forging manipulators being used . As a result of the practical use of the control system, the operators were released from mental stress, the train</p><p>　　Con

7、trol of the manipulators involves rotational control in the continuous rotation and incremental angle rotation modes. The manipulator position requires integrated control with the press to achieve inches per press stroke

8、 while compensating for workpiece length increase due to cross-section area reduction of workpiece . Vitscheff demonstrates the need for compliance control when robots are used to manipulate the workpiece during forging.

9、 Specifically, the external forces exerted on the manipul</p><p>　　An ASEA robot was used as an open-die forging manipulator. The ASEA robot has an inbuilt Intel microprocessor which controls its arm and gri

10、pper movements in five axes. The robot was used in conjunction with a fielding hydraulic press . The application of neural networks for compliance control of the forging robot was investigated. Effectiveness of the neura

11、l network-based compliance control module is evaluated through a full dynamic system simulation . An integrated forging plant, 25?MN open di</p><p>　　The increased demand for large-size forgings has led to d

12、evelopments and innovations all around the improvement of quality and productivity. Many efforts have been undertaken to research and develop heavy-duty forging manipulators. The researches in recent years focus on the m

13、echanisms of forging manipulator, such as kinematic modeling and analysis ; dynamic load analysis, dynamic stability, and behavior ; performance analysis and optimization .</p><p>　　The forging manipulator i

14、s not only an equipment with huge carrying capacity, but also a robot with delicacy and flexibility, capable of picking up and putting down workpieces gently with force perception. The compliance is another required capa

15、bility of heavy-duty forging manipulators. It is important of the promotion of quality, protection of manipulator, reduction of impact of heavy load, and energy saving. The overall aim of this work is to develop a heavy-

16、duty forging manipulator with robot</p><p>　　2. Model of Control Object</p><p>　　This work focuses on the novel track-mounted forging manipulator used for heavy-duty manipulations in integrated

17、open-die forging plants. This serial-parallel forging manipulator is newly designed in our institute. Its CAD model is shown in Figure 1.</p><p>　　Figure1: CAD model of the serial-parallel forging

18、manipulator.</p><p>　　3. Control Strategy</p><p>　　The whole forging process can be divided into three stages of prepress, inpress, and afterpress. During the periods of prepress and afterpress,

19、 operations of the forging manipulator are the same: the gripper grasps the workpiece then places it on the lower die. During the period of inpress, the forging manipulator complies with the deformation of the workpiece.

20、 The control strategy of forging manipulator in these three conditions is discussed as follows.</p><p>　　(a) Grasp the Workpiece</p><p>　　Firstly, the horizontal and vertical position of the gri

21、pper is adjusted, and the workpiece on the bench is clamped by the gripper. Then the workpiece is lifted up by lifting cylinders with a constant lifting force which is greater than the total weight of the workpiece, grip

22、per, and its support. When the expected height is exceeded, the position error will feed back to the constant force servosystem of lifting cylinders. This negative feedback of position makes the actual lifting force smal

23、ler </p><p>　　(b) Place the Workpiece</p><p>　　The workpiece is fed to the forging press, right over the lower die by the forging manipulator. Then decreasing the height setting value, the balan

24、ce of force and position of lifting cylinders is broken. The actual lifting force is smaller than the total weight of the workpiece, gripper, and its support. So the workpiece moves down with the gripper. The decent velo

25、city of the workpiece is determined by the change rate of the height setting value. When the workpiece touches the lower die, the pre</p><p>　　(c) Comply with the Workpiece</p><p>　　During forgi

26、ng, when the workpiece is pressed by the upper die, extra force is applied on the gripper by the deformed workpiece. The force causes an increase of the load in lifting cylinders. Meanwhile, the servosystem is trying to

27、keep the lifting force constant. As a result, the gripper moves down with the workpiece and applies the minimum reaction force on the deformed workpiece. When press is over, the upper die rises, and the external force ex

28、erted on the gripper disappears. The workpiece i</p><p>　　As discussed above, hybrid force/position control is the core principle in forging manipulator control. Figure 2 illustrates the hybrid con

29、trol system that incorporates these ideas. Force control is the base of the control loop. In the balanced state, expect that the actual lifting force is equal to the weight of the workpiece, gripper, and its support, sma

30、ller than the force setting value. The error of force should be compensated by another control variable. The negative feedback of error of po</p><p>　　Figure 2: Construct of the hybrid control system.&l

31、t;/p><p>　　Owing to the newly designed mechanism of the forging manipulator which is decoupled as discussed in Section 2, the motions of side shifting, tilting, damping, and lifting are independent, and an

32、y one of the motions has no effect on the others. The control of the forging manipulator is simplified and only related to lifting cylinders. During the whole period of forging process, front side-shifting cylinders, rea

33、r side-shifting cylinders, and tilting cylinders keep their positions all the time. Th</p><p>　　4. Pressure/Position Control Method of Hydraulic Servosystem</p><p>　　A block diagram of the overa

34、ll control scheme is shown in Figure3. The system is composed of controller, power amplifier, servovalve, cylinder, pressure sensor, and position sensor. </p><p>　　Figure 3: Block diagram of hybrid pres

35、sure/position control system.</p><p>　　Hybrid pressure/position control is very useful in manipulator lifting control where plunger cylinders are used. Based on this method, the intelligent control of forgin

36、g manipulator is realized.</p><p>　　5. Analysis of Intelligent Control</p><p>　　5.1. Automatic Identification of Pressure Value Settings</p><p>　　As shown in Figure 4, when the

37、 workpiece is grasped by the manipulator, the hybrid pressure/position control method is used, and the pressure and position command values are set with original ones of P0 and X0. The workpiece is lifted up wi

38、th a constant force created by hybrid control loop with command pressure P0. When the position command value X0 is exceeded, the negative position error feeds back to the pressure control loop, the actual

39、pressure in system begins to decrease and will stop dec</p><p>　　Figure 4: Illustration of the measurement of workpiece.</p><p>　　5.2. Automatic Identification of the Placement Height of Wo

40、rkpiece</p><p>　　As shown in Figure 5, supposing the workpiece is staying at a position with equilibrium of forces, decrease the command position X0 in a constant rate, then the balance has be

41、en broken. For the feedback of error of position increasing, the actual pressure will become smaller and try to go to another equilibrium state. The actual lifting force is less than the weight of the workpiece, gripper,

42、 and its support now. So the workpiece moves down until touching the lower die. At this moment, the actua</p><p>　　Figure5: Illustration of the placement of workpiece. </p><p>　　5.3. C

43、ompliance in Vertical Direction and Move Up Automatically</p><p>　　As shown in Figure 6, when the workpiece is pressed by the upper die, the load on cylinder will increase for the deformation of workpie

44、ce; this process is called “inpress.” In the mode of pressure/position control, the increased load makes the workpiece move down, and when X < X0, the position error feed back does not work. During this

45、 period, the force acting on the workpiece by manipulator increases from weight balance pressure to the command pressure P0, while it is still much smaller than th</p><p>　　Figure 6: Illustration of the

46、 compliance during forging steps.</p><p>　　6. Experiment Results</p><p>　　The experiments were executed on a real prototype of the novel hydraulic forging manipulator in our institute, as shown

47、in Figure 7. The mechanism and hydraulic system of the manipulator is identical with a rail-bound forging manipulator with a carrying capacity of 2000?kN and 4000?kNm load moment which is designed by our institute.

48、The main characteristics of this prototype are carrying capacity 60?kN, load moment 150?kNm, and installed power 130?kW. The hydraulic actuators are supplied by a co</p><p>　　Figure 7: Prototype of the

49、novel hydraulic forging manipulator.</p><p>　　Figure 8 demonstrates the measurement of the weight and the gravitational torque of workpiece. The controller attempts to maintain a constant pressure

50、4.2?MPa, and while the height of the workpiece position exceeds the preset command position 400?mm, the negative feedback of position works. When lifting cylinders stop moving, control returns to a stable steady state. T

51、he weight-balanced pressure can be identified from the curve, which is 3.55?MPa</p><p>　　Figure 8: Pressure curve in lifting cylinder.</p><p>　　Figure 9 depicts the process of pla

52、cing the workpiece on the lower die. While the command position signal diminished at a constant rate, the workpiece moved down trying to catch the rate. The touch of workpiece on the lower die can be detected by pressure

53、 changes in lifting cylinders. Lifting cylinders stayed on this position. The height of the workpiece placement can be found from the curve.</p><p>　　Figure 9: Position curve in lifting cylinder.</p&

54、gt;<p>　　The experiment results show that the technique is straightforward and feasible. All the supposed control methods have been realized on the prototype of the forging manipulator. The experimental datum form

55、s the base of further </p><p>　　research on intelligent control of heavy-duty forging manipulators.</p><p>　　7. Conclusions</p><p>　　A novel hydraulic forging manipulator is propose

56、d, with newly designed mechanism, intelligent control strategy, and improved hydraulic control method. The major motion mechanism is decoupled, thus the control of the forging manipulator is greatly simplified. Workpiece

57、s can be picked up and put down gently by forging manipulators with force perception. Moreover, the forging manipulator can comply with the external forces exerted on it by workpiece during forging steps. These are based

58、 on a new pr</p><p>　　References </p><p>　　E. Appleton, W. B. Heginbotham, and D. Law, “Open die forging with industrial robots.,”Industrial Robot, vol. 6, no. 4, pp. 191–194, 1979. View a

59、t Scopus</p><p>　　“Attaining practicality of freely programmable control of an open die forging press and forging manipulator by a computer,” Ishikawajima-Harima Engineering Review, vol. 17, no. 6, pp.

60、599–606, 1997.</p><p>　　R. A. Ridgeway, “Microprocessor utilization in hydraulic open-die forge press control,” IEEE Transactions on Industrial Electronics and Control Instrumentation, vol. 22, no. 3, p

61、p. 307–309, 1975. View at Scopus</p><p>　　V. Vitscheff, “A programmable manipulator for closed die forging,” in Proceedings of the 9th International Drop Forging Convention, Kyoto, Japan, 1977.<

62、/p><p>　　W. B. Heginbotham, A. K. Sengupta, and E. Appleton, “An ASEA robot as an open-die forging manipulator,” in Proceedings of the Second IFAC/IFIP Symposium, pp. 183–193, Stuttgart, Germany, 1979.<

63、/p><p>　　A. K. Sengupta, E. Appleton, and W. B. Heginbotham, “Ring forging with an industrial robot,” inProceedings of the 10th International Symposium on Industrial Robots, pp. 29–42, Milan, Italy, 1980.</p

64、><p>　　K. W. Lilly and A. S. Melligeri, “Dynamic simulation and neural network compliance control of an intelligent forging center,” Journal of Intelligent and Robotic Systems, vol. 17, no. 1, pp. 81–99, 1

65、996. View at Scopus</p><p>　　A. S. Melligeri and K. W. Lilly, “Application of neural networks in compliance control of an integrated robot/forge processing center,” in Advances in Manufacturing Sys

66、tems: Design, Modeling and Analysis, pp. 445–450, Elsevier, New York, NY, USA, 1993.</p><p>　　M. Baldassi, “Open die forging presses with manipulators,” Forging, vol. 14, no. 5, pp. 16–18, 2003.</p&g

67、t;<p><b>　　譯文：</b></p><p>　　一種新型的液壓鍛造操作機(jī)的智能控制</p><p><b>　　摘要</b></p><p>　　大尺寸鍛件的需求增加，導(dǎo)致重型鍛造機(jī)械手的發(fā)展和創(chuàng)新。重型鍛造機(jī)械手除了具有巨大的承載能力，還應(yīng)該具備一些機(jī)器人的感知力、精致和靈活性的功能。工作的目的

68、是通過液壓和控制領(lǐng)域相結(jié)合的方法來(lái)通過機(jī)械手開發(fā)一種重型鍛壓機(jī)械以實(shí)現(xiàn)機(jī)器人功能。在本文中，通過一種新型的鍛造操作機(jī)的運(yùn)動(dòng)學(xué)分析和控制策略的實(shí)現(xiàn)，實(shí)現(xiàn)鍛造機(jī)械手預(yù)定的功能和運(yùn)動(dòng)。且實(shí)現(xiàn)鍛造操作機(jī)的液壓執(zhí)行器的混合壓力/位置控制。該控制方法的可行性已由我們研究所的一個(gè)真正新型液壓鍛造操作機(jī)的實(shí)驗(yàn)原型證實(shí)。鍛造操作的智能控制與可編程邏輯控制器適用于工業(yè)應(yīng)用。</p><p><b>　　1.介紹</b

69、></p><p>　　開?；蜃杂慑懺鞕C(jī)械手的使用可以追溯到大約60年的時(shí)候就開始在歐洲和美國(guó)發(fā)展。也就是說(shuō)，自那時(shí)起，該區(qū)域的200噸較重的工件的機(jī)械手的已穩(wěn)步發(fā)展，目前有一些實(shí)施例，即所使用計(jì)算機(jī)控制的全自動(dòng)鍛造機(jī)械手。作為控制系統(tǒng)的實(shí)際使用結(jié)果，可使經(jīng)營(yíng)者被釋放精神壓力，減少操作員的訓(xùn)練期，鍛件質(zhì)量的均勻性被提高，且達(dá)到更高的生產(chǎn)速率。</p><p>　　操縱控制涉及在旋轉(zhuǎn)控

70、制中的不斷旋轉(zhuǎn)和增量角度旋轉(zhuǎn)模式。對(duì)于機(jī)械手的位置，要求集成控制實(shí)現(xiàn)按壓力控制，同時(shí)補(bǔ)償工件由于截面積減少而長(zhǎng)度增加。 vitscheff[4]表明，有必要時(shí)，機(jī)器人被用來(lái)操縱在鍛造過程中的工件合格。具體而言，是通過在鍛造工序的工件操縱器上施加外力，且必須是最小化，以避免損壞的機(jī)器人機(jī)構(gòu)。</p><p>　　ASEA機(jī)器人被用來(lái)作為一個(gè)開放式模鍛操作。 ASEA機(jī)器人有一個(gè)內(nèi)置的英特爾微處理器，用五根軸控制其手

71、臂和抓手運(yùn)動(dòng)。機(jī)器人應(yīng)用在相應(yīng)的液壓機(jī)中。類神經(jīng)網(wǎng)路合規(guī)控制的鍛造機(jī)器人的應(yīng)用已在研究?；谏窠?jīng)網(wǎng)絡(luò)的合規(guī)控制模塊的有效性是通過一個(gè)完整的動(dòng)態(tài)系統(tǒng)仿真評(píng)估。一個(gè)綜合鍛件廠，始建于1999年25 MN開模壓力機(jī)200kN和400KNM機(jī)器人。將工件放入預(yù)定位置，以旋轉(zhuǎn)和行程運(yùn)動(dòng)閉式液壓回路驅(qū)動(dòng)，以減少能源消耗和沖擊，且操縱者由綁定的兩個(gè)軌道以提高定位。軌道結(jié)合的鍛造操作機(jī)帶載能力為1600千牛，4000KNM負(fù)載力矩在JSW 2007年開

72、始運(yùn)作。操縱器支持直線運(yùn)動(dòng)，比如因?yàn)樘厥獾母軛U安排的剝離而精確和穩(wěn)定的定位 。</p><p>　　大尺寸鍛件的需求增加，導(dǎo)致了各地的改進(jìn)質(zhì)量和生產(chǎn)力的發(fā)展、創(chuàng)新。對(duì)研究和開發(fā)重型鍛造機(jī)械手已經(jīng)進(jìn)行了許多努力。近年來(lái)的研究專注于鍛造操作機(jī)的機(jī)制，如運(yùn)動(dòng)建模和分析;動(dòng)態(tài)負(fù)載分析、動(dòng)態(tài)穩(wěn)定性和動(dòng)作;性能分析和優(yōu)化。</p><p>　　鍛造操作機(jī)不僅是一個(gè)巨大的承載能力的設(shè)備，但也是一個(gè)微妙性

73、和靈活性，能夠拿起和放下工件并輕輕感知力的機(jī)器人。合規(guī)性是重型鍛造機(jī)械手需要的另一個(gè)能力。提高質(zhì)量，減少重負(fù)載的影響，保護(hù)操作者并能節(jié)能是很重要的。這項(xiàng)工作的總體目標(biāo)是通過機(jī)械手和機(jī)器人功能而開發(fā)一的種液壓和控制領(lǐng)域相結(jié)合的重型鍛壓機(jī)械。一種新型鍛造操作機(jī)的運(yùn)動(dòng)學(xué)分析正在實(shí)現(xiàn)。在此基礎(chǔ)上，操作者的控制策略建議考慮鍛造機(jī)械手的功能和作用。鍛造操作機(jī)的液壓執(zhí)行器的混合壓力/位置控制已經(jīng)實(shí)現(xiàn)。在我們研究所控制新型液壓鍛造操作機(jī)真實(shí)模型以達(dá)到智

74、能控制的目標(biāo)。</p><p><b>　　2.控制對(duì)象模型</b></p><p>　　今年工作重點(diǎn)放在另一個(gè)開放式模鍛廠重型操作的新型軌道式鍛造機(jī)械手。這系列并聯(lián)鍛造操作機(jī)是我們研究所的新設(shè)計(jì)。CAD模型如圖1中所示。</p><p>　　圖1：一系列鍛造操作并行CAD模型。</p><p><b>　　3

75、.控制策略</b></p><p>　　整個(gè)鍛造過程可分為press，inpress，afterpress三個(gè)階段。在press和afterpress期間內(nèi)，鍛造操作機(jī)操作是相同的即抓住工件然后把它放在下模抓手。在鍛造操作inpress期間，符合工件的變形。這三個(gè)條件的鍛造操作機(jī)的控制策略討論如下。</p><p><b>　?。╝）抓住工件</b><

76、;/p><p>　　首先，調(diào)整夾持器的水平和垂直位置，由夾持器在長(zhǎng)凳上夾緊工件。然后，工件被夾持器和升降氣缸以大于工件總重量的恒定提升力抬起。當(dāng)超出預(yù)期高度，位置誤差反饋恒力給起重缸伺服系統(tǒng)。這種負(fù)反饋的位置使實(shí)際提升力小于設(shè)定值。在均衡狀態(tài)下，實(shí)際的提升力等于工件的總重量，夾持器和支持力的誤差等于乘以一個(gè)系數(shù)的位置的誤差。</p><p><b>　　（b）放置工件</b&g

77、t;</p><p>　　工件被輸送到鍛壓機(jī)的壓力下，在下模鍛造操作。然后降低高度設(shè)定值，起升油缸力和位置的平衡被打破了。夾持器的支持實(shí)際提升力小于工件的總重量計(jì)。所以工件向下移動(dòng)機(jī)械臂。工件合宜的速度由高度設(shè)定值的變化率決定。當(dāng)工件接觸到下模，升降氣缸會(huì)發(fā)生很大變化，工件開始得到下模具中的壓力。在這一刻，保持高度設(shè)定值不變，那么起升油缸力和位置涉及到一個(gè)新的平衡。</p><p><

78、;b>　　(c)回應(yīng)工件</b></p><p>　　在鍛造過程中，當(dāng)工件由上模壓制，額外的力由變形工件施加在夾持器，力使舉升油缸的負(fù)載的增加。同時(shí)，該伺服系統(tǒng)試圖保持提升力常數(shù)。作為一個(gè)結(jié)果，手爪與工件向下移動(dòng)，將最小反應(yīng)力對(duì)工件變形。當(dāng)按下結(jié)束后，上模上升，而施加在夾持器外力消失。工件由一個(gè)恒定的提升力被抬到原來(lái)的位置。然后，機(jī)械手進(jìn)給搬運(yùn)工件。接下來(lái)壓力準(zhǔn)備。</p><

79、;p>　　如上所述，力/位置混合控制是鍛造機(jī)械手控制的核心原則。圖2這些想法說(shuō)明了混合控制系統(tǒng)。力控制是控制回路的基礎(chǔ)。在平衡狀態(tài)，預(yù)計(jì)實(shí)際升力等于工件、夾具的重量和它的支持，小于力設(shè)定值。力的錯(cuò)誤應(yīng)該被另一個(gè)控制變量的補(bǔ)償，且位置誤差的負(fù)反饋將被添加到控制回路。當(dāng)實(shí)際升降位置低于設(shè)定值的高度，位置誤差的反饋是零，爪在持續(xù)力下不斷提升。當(dāng)實(shí)際升降位置高度高于設(shè)定值的位置誤差，系統(tǒng)開始負(fù)反饋，而實(shí)際升力減小直至力和位置趨于平衡。&l

80、t;/p><p>　　圖2：混合動(dòng)力控制系統(tǒng)的構(gòu)建</p><p>　　新設(shè)計(jì)的鍛造操作機(jī)的機(jī)身部分，運(yùn)動(dòng)的側(cè)移、傾斜、阻尼和提升是獨(dú)立的，且運(yùn)動(dòng)的任何一個(gè)對(duì)其他部分沒有影響。鍛造操作機(jī)的控制被簡(jiǎn)化只與升降缸有關(guān)。在鍛造過程的整個(gè)期間，總是保持前側(cè)移缸，后側(cè)移位和傾斜缸。在水平方向上的工件的變形是由阻尼缸在inpress中吸收。合規(guī)時(shí)發(fā)生的變形阻力大于設(shè)定值的卸壓閥阻尼回路。取決于對(duì)減壓閥性能

81、的水平方向上的作用力，幾乎保持不變。</p><p>　　4.液壓伺服系統(tǒng)的壓力/位置控制方法</p><p>　　整體控制方案的框圖如圖3所示。該系統(tǒng)由控制器、功率放大器、伺服閥、氣缸、壓力傳感器、位置傳感器組成。</p><p>　　圖3：混合壓力/位置控制系統(tǒng)框圖</p><p>　　當(dāng)柱塞缸采用時(shí)，混合壓力/位置控制是非常有用的機(jī)械臂

82、升降控制?；谶@種方法，實(shí)現(xiàn)了對(duì)鍛造操作機(jī)的智能控制。</p><p><b>　　5.智能控制分析</b></p><p>　　5.1 壓力值設(shè)置的自動(dòng)識(shí)別</p><p>　　如圖4，當(dāng)工件被把持通過操作器，使用混合動(dòng)力壓力/位置控制方法，設(shè)定的壓力和位置命令值P0 和 X0的原始值。工件被一個(gè)恒定的壓力P0力升起，且位置的命令值X0超標(biāo)，

83、負(fù)位置誤差反饋到壓力控制回路，系統(tǒng)中的實(shí)際壓力開始減少，減少的重量直到平衡為止。在均衡狀態(tài)下，工件停止移動(dòng)，實(shí)際提升力等于工件的總重量、夾持器和支持力。記錄這個(gè)實(shí)際的平衡壓力，并用它在鍛造過程中的合規(guī)控制壓力設(shè)定值。</p><p>　　圖4：測(cè)量工件的插圖</p><p>　　5.2 自動(dòng)識(shí)別放置工件高度</p><p>　　如圖5所示，假設(shè)工件停留在一個(gè)與力量平

84、衡的位置，減少命令行的位置X0和恒定的速率，然后平衡將會(huì)被打破。對(duì)于反饋的錯(cuò)誤增加，實(shí)際壓力將變得更小，并嘗試去到另一個(gè)平衡狀態(tài)。實(shí)際提升力小于工件的重量、夾持器和支持力。因此，工件向下移動(dòng)，直到碰到下模。在這個(gè)時(shí)刻，實(shí)際的壓力迅速下降。根據(jù)壓力的變化率，能夠自動(dòng)識(shí)別工件的放置狀態(tài)。保持命令工件位置X0并放置在下模高度值。起升油缸的壓力和位置進(jìn)入到一個(gè)新的平衡。</p><p>　　圖5：插圖工件的位置</

85、p><p>　　5.3 在垂直方向上的合規(guī)性和自動(dòng)上移</p><p>　　在圖6所示，當(dāng)工件被上模按下時(shí)，在氣缸上的負(fù)載會(huì)增加工件的變形，這個(gè)過程被稱為“inpress?！币詨毫?位置控制模式，增加的負(fù)載使工件向下移動(dòng)，當(dāng)X<X0，位置誤差反饋不工作。在此期間，力作用在工件上的機(jī)械臂從重量平衡壓力命令壓力P0增加，而它仍然是遠(yuǎn)遠(yuǎn)小于壓力。因此，實(shí)現(xiàn)在垂直方向上的匹配。印刷機(jī)完成時(shí)，上模

86、向上移動(dòng)，這個(gè)過程叫做“afterpress，”缸上的負(fù)載減少。提升力使工件升降缸的壓力和位置向上移動(dòng)，直到進(jìn)入到一個(gè)新的平衡。</p><p>　　圖6：符合鍛造工序插圖</p><p><b>　　6．實(shí)驗(yàn)結(jié)果</b></p><p>　　實(shí)驗(yàn)是我們研究所的一個(gè)新型液壓鍛造操作機(jī)的原型，如圖7所示。我院設(shè)計(jì)的機(jī)械和液壓系統(tǒng)的操盤與??導(dǎo)軌結(jié)

87、合的帶載能力為2000KN，4000KNM負(fù)載力矩。這個(gè)原型的主要特點(diǎn)是承載能力60KN，負(fù)載力矩150KNM，裝機(jī)功率130KW。液壓致動(dòng)器所提供的恒定壓力的泵源由servoproportional位置換能器的閥控制?？删幊踢壿嬁刂破鲌?zhí)行所有的控制操作。</p><p>　　圖7：原型的新型液壓鍛造操作機(jī)</p><p>　　圖8演示了測(cè)量工件的重量和重力轉(zhuǎn)矩。控制器試圖保持一個(gè)恒定的4

88、.2兆帕壓力，而工件位置的高度超過預(yù)設(shè)的命令位置400毫米，負(fù)反饋的位置是正常的。當(dāng)起升油缸停止移動(dòng)，控制返回到穩(wěn)定狀態(tài)?？梢詮那€上確定的，這是3.55兆帕的重量平衡的壓力。</p><p>　　圖8：舉升缸壓力曲線</p><p>　　圖9描述出工件上的下模過程。雖然命令位置信號(hào)以恒定的速率減少，工件向下移動(dòng)試圖捕捉速率。在升降缸中下模具工件上的觸摸可以檢測(cè)到壓力的變化。起升油缸留在這

89、個(gè)位置。從曲線中可以發(fā)現(xiàn)工件放置的高度。</p><p>　　圖9：舉升缸位置曲線</p><p>　　實(shí)驗(yàn)結(jié)果表明，該技術(shù)是簡(jiǎn)單的和可行的。所有所謂的控制方法已經(jīng)實(shí)現(xiàn)了鍛造操作的原型。實(shí)驗(yàn)數(shù)據(jù)為重型鍛造機(jī)械手智能控制研究形成了基礎(chǔ)。</p><p><b>　　7．結(jié)論</b></p><p>　　新設(shè)計(jì)的機(jī)制和智能控

90、制策略，以及改進(jìn)的液壓控制方法，提出了一種新型的液壓鍛造操作方法。主要機(jī)制的解耦，從而大大簡(jiǎn)化了鍛造操作的控制。工件可以被鍛造機(jī)械手拿起和輕輕放下。此外，鍛壓機(jī)械手可以在鍛造工序中施加于工件合適的力。這些都是基于一個(gè)新的壓力控制方法和本文提出的液壓伺服系統(tǒng)的混合動(dòng)力車壓力/位置控制方法。所有液壓控制方法和智能控制策略已核實(shí)，并通過實(shí)驗(yàn)原型鍛造操作。這項(xiàng)工作為智能重型鍛造機(jī)械手的進(jìn)一步發(fā)展提供了理論和實(shí)踐基礎(chǔ)。</p>&l

91、t;p><b>　　參考文獻(xiàn)</b></p><p>　　1. E. Appleton, W. B. Heginbotham, and D. Law, “Open die forging with industrial robots.,”Industrial Robot, vol. 6, no. 4, pp. 191–194, 1979. View at Scopus<

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93、1997.</p><p>　　3. R. A. Ridgeway, “Microprocessor utilization in hydraulic open-die forge press control,” IEEE Transactions on Industrial Electronics and Control Instrumentation, vol. 22, no. 3, pp. 307

94、–309, 1975. View at Scopus</p><p>　　4. V. Vitscheff, “A programmable manipulator for closed die forging,” in Proceedings of the 9th International Drop Forging Convention, Kyoto, Japan, 1977.</p

95、><p>　　W. B. Heginbotham, A. K. Sengupta, and E. Appleton, “An ASEA robot as an open-die forging manipulator,” in Proceedings of the Second IFAC/IFIP Symposium, pp. 183–193, Stuttgart, Germany, 1979.</p

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98、 1996. View at Scopus</p><p>　　A. S. Melligeri and K. W. Lilly, “Application of neural networks in compliance control of an integrated robot/forge processing center,” in Advances in Manufacturing S

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