離心泵的設(shè)計及其密封含9張CAD圖,離心泵,設(shè)計,及其,密封,cad
附錄
英文翻譯
鞋楦掃描機的控制系統(tǒng)的開發(fā)
1 引言
在全球制鞋業(yè)中，中國制鞋業(yè)可謂異軍突起。短短的十多年，中國一躍升為全球最大的鞋類生產(chǎn)國和出口國。制鞋業(yè)的迅猛發(fā)展也帶動了鞋楦業(yè)，鞋子的樣式越來越多，就要求鞋楦也要不斷翻新，這促成了鞋楦從耐用品變成易耗品。機械鞋楦機采用的是仿形加工的原理，它實現(xiàn)了鞋楦加工的批量生產(chǎn)，帶來了鞋楦業(yè)的飛速發(fā)展。但是機械鞋楦機也有其不可避免的缺點：首先，從產(chǎn)品角度來講，它加工出來的鞋楦的鞋幫兩側(cè)，總有幾道較明顯的縱痕，鞋楦很不光滑，這對于要求越來越高的制鞋業(yè)來說，是不能滿足要求的；其次，機械鞋楦機在實現(xiàn)鞋楦的縮放時，需要工人憑經(jīng)驗手工調(diào)整機器，這對工人要求比較高；再次，也是最重要的，傳統(tǒng)的加工方法無法建立工件尺寸的文件，也無法做任何的外形修改。
2 數(shù)控鞋楦機的數(shù)字化逆向工程系統(tǒng)
數(shù)控鞋楦機可以避免機械鞋楦機的缺點。數(shù)控鞋楦機采用數(shù)字化的逆向工程系統(tǒng)，數(shù)字化的逆向工程系統(tǒng)在對鞋楦模型進行三維掃描后，得到模型的三維數(shù)據(jù)文件，通過處理數(shù)據(jù)文件（如表面光滑處理，插值處理等），實現(xiàn)對鞋楦模型的縮放，并能改變鞋楦加工表面的螺旋線的螺距，從而改善加工表面的質(zhì)量。同時，所得數(shù)據(jù)文件可以存入電腦，需要時可再調(diào)出來，同一類型的鞋楦只需掃描一次，管理非常方便。顯然，這樣的數(shù)字化逆向工程系統(tǒng)才是滿足現(xiàn)代鞋楦業(yè)的發(fā)展的。數(shù)控鞋楦機的數(shù)字逆向工程流程圖如圖1所示：
??? 圖1 數(shù)控鞋楦機的數(shù)字逆向工程流程圖
國外的數(shù)控鞋楦機到目前為止已經(jīng)非常完善了，在實際應(yīng)用中也得到極大肯定。我們國內(nèi)由于種種原因，起步較晚，所以筆者所在實驗室在參考國外機器的前提下，以實際應(yīng)用作為主要目的，進行數(shù)控鞋楦機的研制，為國內(nèi)在該領(lǐng)域的企業(yè)提供一些參考。該數(shù)控鞋楦機有兩部分組成，一部分是掃描機，它通過掃描得到鞋楦的三維數(shù)據(jù)，另一部分是刻楦機，它利用掃描得到的三維數(shù)據(jù)加工出鞋楦。本文主要討論鞋楦掃描機的控制系統(tǒng)設(shè)計，只有掃描得到的數(shù)據(jù)文件準確，才能保證加工出來的鞋楦的質(zhì)量，因此鞋楦掃描機是實現(xiàn)鞋楦加工的基礎(chǔ)和前提。
3 鞋楦掃描機的掃描原理
首先，簡要介紹一下鞋楦掃描機的掃描原理，如下圖2所示。
??? 圖2 鞋楦掃描機的掃描原理圖
如上圖所示，X軸帶動鞋楦的自轉(zhuǎn)，Y軸為指向鞋楦中心線，Z軸在鞋楦長度方向移動，即掃描輪移動的方向。鞋楦掃描機采用接觸式測量方式，所用測量工具為掃描輪，它安裝在Y軸方向，掃描輪靠在鞋楦上，其后面由氣泵頂著，掃描輪隨著鞋子的運動而前后移動，掃描輪后面的光柵尺采集鞋楦數(shù)據(jù)。
4 鞋楦掃描機的控制系統(tǒng)概述
鞋楦掃描機采用PC機作為上位機，利用面向?qū)ο蟮恼Z言VC＋＋進行軟件設(shè)計、開發(fā)，通過運動控制卡驅(qū)動系統(tǒng)并采集三根軸的數(shù)據(jù)，得到掃描數(shù)據(jù)文件，以用于加工。上位機作為掃描機的操作界面，完成數(shù)據(jù)分析、處理以及對執(zhí)行機構(gòu)的控制等任務(wù)。運動控制卡作為控制核心，完成發(fā)送及接收脈沖。伺服電機接受板卡發(fā)送的脈沖，驅(qū)動各個軸運動，同時，伺服電機編碼器反饋給運動控制。整個控制系統(tǒng)簡圖如下圖3所示。
??? 圖3 控制系統(tǒng)總框圖
下面主要介紹運動控制卡，伺服電機以及光柵尺的選擇及控制
4．1 運動控制卡的選擇及控制
? 在掃描系統(tǒng)中，運動控制卡是整個系統(tǒng)的核心，因此選擇合適的運動控制卡是很重要的。
??? 在掃描過程中，運動控制卡需要控制Z軸和X軸的伺服電機，運動控制卡不僅要發(fā)送脈沖給電機驅(qū)動器，同時接受伺服電機編碼器反饋的脈沖數(shù)。運動控制卡還接受光柵尺反饋信號。由于是采集鞋楦三維的數(shù)據(jù)，采樣點越密集，加工出來的產(chǎn)品越光滑。在本系統(tǒng)中，設(shè)定鞋楦轉(zhuǎn)一圈需要采樣幾百個點，因此對運動控制卡的驅(qū)動輸出脈沖要求比較高，對編碼器輸入頻率也有一定要求，控制軸數(shù)要求三軸。綜合考慮各種性能以及經(jīng)濟性等,選擇深圳雷賽公司的DMC3000系列運動控制卡。
??? 本系統(tǒng)的運動控制卡是基于PCI總線的高性能運動控制卡，可控制多達四軸步進或伺服電機。此系列具有即插即用、最高4MHz脈沖頻率、S曲線減振功能、編碼器反饋、隨時變速等高級功能。
??? 本運動控制卡的每一軸的兩個信號輸出口PUL和DIR可用來輸出脈沖和方向信號，這兩個輸出口可以由程序設(shè)成正脈沖+反脈沖（雙脈沖）模式或脈沖+方向模式（單脈沖）。本系統(tǒng)采用脈沖+方向形式，并設(shè)定脈沖為差分輸出方式，在差分輸出模式下，每一個信號可以被差分成一對相異的信號。使用差分輸出方式可有效的減少傳輸中的干擾，提高可靠性。X軸和Z軸的伺服電機驅(qū)動器接收來自運動控制卡的脈沖和方向信號。
?? 本運動控制卡可同時控制四根軸，每一軸都有三對差分的A相、B相和Z相輸入信號，EA和EB信號用來進行位置計算，EZ信號用作原點索引信號。每一軸都有一個原點開關(guān)信號，通過機械原點信號輸入來查找該軸的原點，可通過軟件設(shè)定原點開關(guān)模式。每一軸都有兩個位置限位信號EL+（正向限位）和EL-（反向限位），可通過軟件設(shè)定限位開關(guān)模式。在本系統(tǒng)中，X軸和Z軸的伺服電機編碼器反饋的脈沖信號都接入運動控制卡。由于每根軸運動初始有個起始位，因此需要用原點信號，軟件通過搜索原點信號來確定起始位。X軸為旋轉(zhuǎn)方向，不需要正反限位，只采用一個原點信號。Z軸除了原點信號外，還接入正負兩個位置限位信號，兩個限位起保護作用。通用數(shù)字輸入輸出口也可用來接一些開關(guān)信號。
對于單軸運動，按照運動距離來分,本運動控制卡有定長運行模式和連續(xù)運行模式。按照運動速度來分，本運動控制卡有梯形速度運行模式和S曲線運行模式。S曲線運行模式用來讓一根軸以S曲線速度運行指定脈沖數(shù)，S曲線運行模式可以有效消除并改善加減速時的振動，使運動非常平滑。如下圖4所示:
??? 圖4 S曲線速度及加速度
由于S曲線運行模式較于梯形速度運行模式的優(yōu)點，本系統(tǒng)中均采用S曲線運行模式。在掃描開始前，為了測量鞋楦的底板直長，需要將鞋楦轉(zhuǎn)過一定角度，這時采用定長運行模式。在掃描過程中，Z軸和X軸執(zhí)行同時但獨立的運動，并且是連續(xù)運動。同時保證這兩根軸以一定的比例速度運動。實際情況證明，本運動控制卡能滿足本系統(tǒng)的要求，實現(xiàn)鞋楦數(shù)據(jù)的三維掃描，從而得到鞋楦三維據(jù)文件。
4．2 伺服電機的選擇及控制
由于本控制系統(tǒng)對實時性要求比較高，運動控制卡發(fā)送脈沖給電機驅(qū)動器，要求電機立即發(fā)脈沖，不得延遲，不得有誤。因此本控制系統(tǒng)不能采用步進電機，而必須采用伺服電機系統(tǒng)。同時伺服電機具有控制精度高，較強的過載能力，速度響應(yīng)性能好，運行性能可靠等一系列優(yōu)點。在本系統(tǒng)中，我們選用Panasonic全數(shù)字式交流伺服驅(qū)動器MSDA0231A1A，配置的伺服電機為MSM022A1。驅(qū)動器所帶電機的額定輸出功率為1.5kw，旋轉(zhuǎn)編碼器為增量型2500P/r，輸入電源為3相220V，額定速度為2000r/m。
本系統(tǒng)中要求到位比較準確迅速，由于在鞋楦轉(zhuǎn)一圈（即X軸轉(zhuǎn)動一圈）需要采樣幾百個點，因此對伺服系統(tǒng)的響應(yīng)要求比較高。同時，伺服電機的參數(shù)對掃描質(zhì)量也有一定影響。在系統(tǒng)采用的控制模式下，將伺服電機的參數(shù)調(diào)整到比較好的情況，主要是以下幾個參數(shù)。
1．參數(shù)NO.10（第一位置環(huán)增益）定義位置控制的響應(yīng)曲線，增益設(shè)定越高，定位時間越快。
??? 2．參數(shù)NO.11（第一速度環(huán)增益）和參數(shù)NO.10一起獲得伺服系統(tǒng)的總響應(yīng)曲線。盡可能設(shè)定高增益。
??? 3．參數(shù)NO.15（速度前饋）設(shè)定位置控制中速度前饋量。在電機恒速運轉(zhuǎn)時，若將此值設(shè)為100％，位置偏差幾乎為零。此值設(shè)定得較高，可在較小的位置偏差獲得較快反應(yīng)，但可能會導(dǎo)致超調(diào)。
通過對NO.46，NO.4B參數(shù)的設(shè)置，可以很方便的與各種頻率的指令脈沖相匹配，以達到理想的控制分辨率(角度/脈沖)。二者的值差異過大會造成控制精度下降。所以推薦設(shè)置NO.46/NO.4B(即：電子齒輪比)為：1/50<電子齒輪比<20。
4．3 光柵尺的選擇及控制
??在本控制系統(tǒng)中，光柵尺用于采集Y軸數(shù)據(jù)，它安裝在掃描輪的后面，在掃描過程中，掃描輪不斷前后移動，從而帶動光柵尺移動，光柵尺采集到的脈沖信號反饋到運動控制卡。結(jié)合實際應(yīng)用情況，考慮精度、可靠性、經(jīng)濟性等各種因素，我們選用FAGOR MVX-225線性光柵尺。它采用的玻璃鍍鉻刻度柵距為20um，精度為±5um，分辨率為1um，其輸出信號為差動TTL信號，輸出信號周期“T”為4um，最大速度為60m/min。由于在本系統(tǒng)中，光柵尺需要不停前后移動，而該光柵尺讀數(shù)頭移動采用滾動軸承，可最小限度減小磨損，大大提高使用壽命，該光柵尺的移動壽命超過9000km。
??FAGOR反饋系統(tǒng)提供的電信號是通過鍍刻在直尺上的鉻線柵格，通過光電處理轉(zhuǎn)換成電信號。FAGOR反饋系統(tǒng)用紅外線發(fā)光二極管作為光源，這種光源具有安全、可靠和壽命長的特點。
??為在測量中提供一個絕對參考點，在線性光柵尺臨近反饋刻線的某些位置提供參考點標記信號。此標記信號是由特定的刻線產(chǎn)生的一個脈沖，當(dāng)運行通過該點時能確定機床的絕對位置，這主要是為防止數(shù)控機床掉電后軸意外移動而產(chǎn)生誤差。FAGOR線性光柵尺每隔50mm就有一個參考點標記Io。此標記產(chǎn)生的信號，是和反饋信號同步的，目的是為保證可靠的測量重復(fù)精度。實際情況證明，F(xiàn)AGOR MVX-225線性光柵尺能夠滿足本系統(tǒng)的控制要求。
5 結(jié)束語
?? 如上，運動控制卡，伺服系統(tǒng)和光柵尺構(gòu)成了鞋楦掃描機的數(shù)字控制系統(tǒng)。實際證明，整個控制系統(tǒng)運作非常穩(wěn)定，將掃描得到的數(shù)據(jù)文件用于鞋楦刻楦機加工，加工出來的產(chǎn)品很光滑，完全避免了機械鞋楦機的缺點，能夠滿足市場的需求。
參考文獻：
??? 1．許智欽 孫長庫 編著 《3D逆向工程技術(shù)》 中國計量出版社
??? 2．深圳雷賽DMC3000控制板硬件手冊
??? 3．深圳雷賽DMC3000控制板軟件手冊
??? 4．Panasonic交流伺服電機驅(qū)動器MINAS A系列使用說明
??? 5．FAGOR光柵尺使用說明
Last scanner control system development
1 Introduction
In the global footwear industry, which has been China's footwear industry is. A short period of 10 years, China has risen remarkably, to the world's largest footwear producer and exporter. The rapid development of the footwear industry was driven by the shoe last industry, more and more shoe styles, and also requires constant renovation shoe last, which led to the shoe last from durable goods become consumables. Mechanical shoe last copying machine is used for processing principle, it implements the shoe last of the production process, bringing the shoe last, the rapid development of industry. But mechanical shoe last machine also has its inevitable drawbacks: First, from the product perspective, it processed by the upper sides of the shoe last, the more obvious Weijidao longitudinal marks, shoe last very smooth, as this request increasing the shoe-making industry, it is unable to meet the requirements of Secondly, mechanical machines in the shoe last of shoe last zoom, manual adjustment of the workforce to use their experience machines, which require workers relatively high; again, and most important, the traditional processing methods unable to establish workpiece size of the document, they can not do anything to modify the shape.
2 NC-shoe last two figures of reverse engineering system
Last CNC machine can be avoided mechanical shoe last machine shortcomings. CNC machine using digital shoe last of the reverse engineering system, the digital system in the reverse engineering of the shoe last model 3D scanning, are three-dimensional model of data files, by addressing data file (such as dealing with a smooth surface, interpolation processing, etc.) Implementation of the shoe last scalable model, and change the shoe last machined surface of the helix pitch, thereby improving the quality of surface machining. At the same time, the data files can be stored in computer may need to tune out the same type of shoe last only one scan, management is very convenient. Clearly, the number of such reverse engineering system to meet modern shoe last is the development of the industry. NC-figure shoe last reverse engineering flowchart in Figure 1 below:
Zoom appearance code revision
Last Model
3D Scanning
Data Processing
Computer-assisted analysis
Construction of 3D model
Computer aided manufacturing
Rapid Tooling
Last products
Figure 1 NC shoe last for the number of reverse engineering flowchart
???? Last abroad NC machine has been very well so far, in the practical application has been greatly affirmed. Our domestic Due to various reasons, a late start, the author of the reference laboratory in foreign machinery under the premise of the practical application as the main purpose of NC Machine for shoe last for domestic enterprises in the area to provide some reference. Last of the NC machines composed of two parts, part scanner, be it by scanning the shoe last three-dimensional data, and the other part is carved Last machine, which uses a three-dimensional scan data processing by the shoe last. This paper mainly discusses the shoe last scan machine control system design, only by scanning the data files accurately, to ensure processing by the quality of the shoe last, shoe last scan machine of shoe last is the basis and premise for processing.
3 shoe last scanners scan Principle
First, a brief introduction to the shoe last scanner scanning principle, as shown in Figure 2.
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???? Figure 2 shoe last scanners scan schematic
???? As shown below, driven shoe last X-axis of rotation, Y-axis is at the center shoe last, in the Z-axis length shoe last move, that is, the direction of mobile scanning round. Last scanner using contact measurement, measurement tools used for scanning round, it installed in the Y-axis direction, scanning round rely on the shoe last, behind by the pump withstand, scanning round of the campaign with the shoes before and after moving, behind the wheel grating scanning device data acquisition shoe last.
4 shoe last scan machine control system outlined
?? Last scanner using PC as a PC, using the object-oriented language VC + + software design, development, through the Motion Control Card drive system and three-axis collection of data by scanning data files, for use in processing. PC operating as a scanner interface, complete data analysis, processing and the implementation of the control, and other tasks. Motion Control Card as a control center, sending and receiving complete pulse. Accept board sent servo motor pulse, drive shaft various campaigns At the same time, servo motor encoder feedback to the motion control. Diagram of the control system are shown in Figure 3.
No. 0-axis encoder feedback signals
Optical grating feedback system
DMC3000
No.2-axis encoder feedback signals
No. O-axis and the direction of the output pulse
Section 0.1 axis origin and spacing signal
No. 1-axis and the direction of the output pulse
Various axis limit switch
C-axis servo system
Z-axis servo system
No. 1-axis encoder feedback signals
Figure 3 diagram of the control system
???? Below are introduced Motion Control Card, servo motor and optical grating choice and control.
4.1 Motion Control Card choice and control
?? In the scanning system, the Motion Control Card is the core of the whole system, choose a suitable motion control card is very important.
?? In the scanning process, the motion control card and the need to control the X-axis Z-axis servo motors, motion control card not only to send pulses to the motor drives,
servo motor at the same time accept encoder feedback pulses. Motion Control Card also accepted optical grating feedback signal. Because it is collecting shoe last three-dimensional data, the more intensive sampling and processing the products more smooth. In this system, setting shoe last lap to the needs of hundreds of point sampling, the Motion Control Card Driver output pulse requirement is relatively high, the encoder input frequency of a certain request, a few requirements triaxial control axis. A mix of different properties, as well as economic, as well as their choice of Shenzhen Company, the mine DMC3000 series Motion Control Card.
?? Motion Control of the system is based on the PCI bus card, high-performance motion control card can control up to 4-axis stepper or servo motor. This series of plug-and-play with a maximum pulse frequency of 4 MHz, the S-curve damping function, encoder feedback, and advanced features such as variable speed at any time.
?? Motion Control Card of the axis of each of the two signal outputs can be used to PUL and DIR output pulse and direction signal, which can be output from the two procedures are set to pulse-pulse + (double-pulse) + pulse mode or direction mode ( single pulse). The system uses pulse + direction form, and set the pulse for the differential output, in the differential output mode, a signal can be divided into a different bad signal. The use of differential output can be an effective way to reduce transmission interference, and improve reliability. X-axis and the Z-axis servo motor drive from the Motion Control Card to receive the signal pulse and direction.
The Motion Control Card may simultaneously control four-axis, the axis of each have three pairs of differential phase A, B and Z of the input signal, EA and EB signal used for position, the signal for the origin EZ index signal. Each axis has a switching signal origin through the mechanical origin of the signal input shaft to find the original point of origin can be set through the software switch-mode. Each axis has two locations spacing signal EL + (positive spacing) and EL-(reverse Limit), the limit set by switch-mode software. In this system, the X-axis and the Z-axis servo motor feedback encoder pulse signal have access Motion Control Card. Since the initial movement of each axis there is a start bit, it was necessary to signal to the original point, the search software to determine the origin signal the start bit. X axis rotation direction, do not limit pros and cons, using only a signal origin. Apart from the Z-axis
origin signal, but also limit access plus or minus two position signals from the two limit protection. I universal digital input and output can also be used to access some of the switch signal.
The single campaign, according to campaign-distance, the motion control card, the mode of operation and continuous operation mode. According to the velocity, the trapezoidal motion control card that runs at S-curve pattern and operation mode. S-curve model used to run a shaft that runs at the S-curve designated pulse number of S-curve model can be run effectively and to improve acceleration and deceleration eliminate the vibration, so that movement is very smooth. Figure 4 shows the following:
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???? Figure 4 S-curve velocity and acceleration
?? Since S curve in a trapezoidal mode runs at the merits of this system are used in the operation mode S-curve. Before the start of the scan, in order to measure the floor straight shoe last longer need to shoe last turn certain angle, and then use fixed-length operation mode. In the scanning process, the Z-axis and the X-axis but at the same time the implementation of an independent movement, and movement is continuous. This two-axis at the same time guarantee a certain percentage of the speed sports. Actual circumstances, the Motion Control Card of the system can meet the requirements of shoe last of the three-dimensional data scanning, and thus gained three-dimensional data files shoe last.
4.2 servo motor control and choice
Since the control system for the real-time requirement is relatively high, motion control card sent to the motor drive pulses to the pulse motor immediately, not delayed, not wrong. Thus the control system could not be used stepper motor and servo motor systems must be used. At the same time servo motor control with high accuracy, strong Guozainaili, speed response performance, and reliable operation of a series of advantages. In this system, we have selected Panasonic Digital MSDA0231A1A AC servo drives, servo motor configuration for MSM022A1. Bring the drive motor rated output power of 1.5 kw, incremental rotary encoder for the P-2500 / r, 3-phase input power for 220 V, rated speed of 2000 r / m.
Request to place the system more accurate rapidly, as in the shoe last lap to (X-axis rotation lap) needs hundreds of sampling point, the response of the servo system requirements relatively high. At the same time, the servo motor parameters on the quality of scanning has a certain impact. Used in the control system mode, the servo motor will be adjusted to the parameters of a better situation, mainly the following parameters.
??1. NO.10 parameters (location of the first loop gain) definition of the position control response curve, the higher gain settings, the faster positioning time.
???2. NO.11 parameters (first speed loop gain) and the parameters NO.10 servo system with access to the total response curve. As far as possible, high-gain settings.
???3. NO.15 parameters (speed feed-forward) to set the pace in the position control of feedforward. In the constant speed motor running, if this value as a 100% position deviation almost zero. This value is set higher, so to a lesser position error was faster response, but it may lead to overshoot.
??By NO.46, NO.4B parameter settings can be very convenient with a variety of command pulse frequency matched to achieve the desired control resolution (angle / pulse). The value of the difference between the two caused the decline in control accuracy. It is recommended settings NO.46/NO.4B (ie: electronic gear ratio): 1 / 50
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