工業(yè)機械手設計及運動結構分析【六自由度機械手】
工業(yè)機械手設計及運動結構分析【六自由度機械手】,六自由度機械手,工業(yè)機械手設計及運動結構分析【六自由度機械手】,工業(yè),機械手,設計,運動,結構,分析,自由度
中期報告
題目:專用機械手設計與工程分析
系 別
專 業(yè) 班 級
姓 名
學 號
導 師
2011年 3月 15 日
撰寫內(nèi)容要求(可加頁):
一.設計(論文)進展狀況
1.外文翻譯已經(jīng)做好《 Industrial to Robot Arm》(University Of Groningen);
2. 驅動系統(tǒng)的選擇。工業(yè)機器人的驅動系統(tǒng)是直接驅動使各部件動作的機構,對工業(yè)機器人的性能和功能影響很大。它為執(zhí)行系統(tǒng)各部件提供動力,并驅動其動作。工業(yè)機器人驅動方式主要有機械、液壓、電動、氣動四種。這四種方式各自都有自己不同的特點。在實際應用中,工業(yè)機器人還有可能用到組合的驅動方式,或者在一個機器人的不同關節(jié)部位,可采用不同的驅動方式。
3. 機械手的設計方案。a.手爪的開合方式:滑槽杠桿式回轉型、雙支點連桿杠桿式、齒輪齒條杠桿式、手爪平行開閉式;b.手爪開合的驅動方式:氣壓驅動、液壓驅動、電機驅動;c.手臂的擺動:利用步進電機驅動和直齒輪傳動來實現(xiàn)手臂的擺動;e機械手臂的轉動:利用步進電機驅動和錐齒輪傳動來實現(xiàn)機器人的旋轉運動。
二.存在問題及解決措施
1.在建模方面要求建立專用機械手等的實體裝配模型。對實體裝配模型進行工程簡化。
2. 在工程分析方面要求合理確定約束條件,分析機械手手指在生產(chǎn)中的變形量并對強度進行校核。
3. 運動分析方面要求提取六自由度機械手手指的速度,加速度,特性。并輸出運動規(guī)律曲線 。
4.機械手的轉動功能。本課題的機械手轉動功能的實現(xiàn)是由步進電機驅動和錐齒輪傳動來實現(xiàn)。
前期已開展工作:
調(diào)研和收集資料,熟悉Mastercam等機械手設計的相關軟件,學習運用Mastercam
進行模具設計;調(diào)查有關的機械手的設計,學習別人的設計思路,為自己設計的展開做好準備。
三.后期工作安排
第7~8周:要求依據(jù)設計參數(shù),設計生產(chǎn)線專用機械手的方案,結構。選擇驅動電機。
第8~14周:建立專用機械手等的實體裝配模型。對實體裝配模型進行工程簡化。
第14~16周:要求合理確定約束條件,分析機械手在生產(chǎn)中的變形量并對強度進行校核。
第16~18周:分析結論撰寫論文。
指導教師簽字:
年 月 日
注:1. 正文:宋體小四號字,行距22磅;標題:加粗 宋體四號字
2. 中期報告由各系集中歸檔保存,不裝訂入冊。
任務書
系別 專業(yè) 班姓名 學號
1. 設計題目: 工業(yè)機械手設計及運動結構分析
2.題目背景和意義: 機械手是模仿著人手的部分動作,按給定程序、軌跡和要求實現(xiàn)自動抓取、搬運或操作的自動機械裝置。在工業(yè)生產(chǎn)中應用的機械手被稱為“工業(yè)機械手”。生產(chǎn)中應用機械手可以提高生產(chǎn)的自動化水平和勞動生產(chǎn)率:可以減輕勞動強度、保證產(chǎn)品質量、實現(xiàn)安全生產(chǎn);尤其在高溫、高壓、低溫、低壓、粉塵、易爆、有毒氣體和放射性等惡劣的環(huán)境中,它代替人進行正常的工作,意義更為重大。,通過該設計旨在鍛煉學生運用現(xiàn)代設計方法基本原理進行設計和工程分析,使學生受到機械工程師基本訓練。
3.設計的主要內(nèi)容(理工科含技術指標):題目內(nèi)容主要包括三個方面,專用機械手設計,建模和工程分析:
A. 在設計方面要求依據(jù)設計參數(shù),設計生產(chǎn)線專用機械手的方案,結構。
B.在建模方面要求建立專用機械手等的實體裝配模型。對實體裝配模型進行工程簡化。
C. 在工程分析方面要求合理確定約束條件,分析機械手手指在生產(chǎn)中的變形量并對強度進行校核。
D. 運動分析方面要求提取六自由度機械手手指的速度,加速度,特性。并輸出運動規(guī)律曲線
E. 整個機械臂安裝在一個回轉支座上,回轉角度范圍為360度;大臂可做升降運動;小臂相對于大臂可擺動,擺動范圍為60-120度;小臂末端的手腕也可以擺動,擺動范圍為-60度到+60度;手腕的末端安裝一機械手,機械手具有開閉能力,用于直徑30-45mm工件的抓取,工件長度350mm,重量8kg。
4.設計的基本要求及進度安排(含起始時間、設計地點): 地點:校內(nèi)
第1周:收集資料,借閱參考書,下載相關英文文獻。
第2~8周:要求依據(jù)設計參數(shù),設計生產(chǎn)線專用機械手的方案,結構。選擇驅動電機。
第8~14周:建立專用機械手等的實體裝配模型。對實體裝配模型進行工程簡化。
第14~16周:要求合理確定約束條件,分析機械手在生產(chǎn)中的變形量并對強度進行校核。
第16~18周:分析結論撰寫論文。
5.畢業(yè)設計(論文)的工作量要求
① 實驗(時數(shù))*或實習(天數(shù)): 2周
② 圖紙(幅面和張數(shù))*: A01.5張
③ 其他要求: 論文(字數(shù)):20000字左右;外文翻譯(字數(shù)): 不少于1500英文單詞 ;
參考文獻(篇數(shù)):不少于 15篇(其中期刊文獻不少于5篇,外文文獻不少于3篇,其中一篇外文文獻為外文翻譯內(nèi)容),要求在正文中標注。
指導教師簽名: 年 月 日
學生簽名: 年 月 日
系主任審批: 年 月 日
說明:1本表一式二份,一份由學生裝訂入冊,一份教師自留。
2 帶*項可根據(jù)學科特點選填。
外文資料翻譯
系 別 機電信息系
專 業(yè)
班 級 7
姓 名
學 號
外文出處 University Of Groningen
附 件 1. 原文; 2. 譯文
2011年3月
1
Industrial to Robot Arm
Robot is a type of mechantronics equipment which synthesizes the last research achievement of engine and precision engine, micro-electronics and computer, automation control and drive, sensor and message dispose and artificial intelligence and so on. With the development of economic and the demand for automation control, robot technology is developed quickly and all types of the robots products are come into being. The practicality use of robot products not only solves the problems which are difficult to operate for human being, but also advances the industrial automation program. Modern industrial robots are true marvels of engineering. A robot the size of a person can easily carry a load over one hundred pounds and move it very quickly with a repeatability of +/-0.006 inches. Furthermore these robots can do that 24 hours a day for years on end with no failures whatsoever. Though they are reprogrammable, in many applications (particularly those in the auto industry) they are programmed once and then repeat that exact same task for years.
At present, the research and development of robot involves several kinds of technology and the robot system configuration is so complex that the cost at large is high which to a certain extent limit the robot abroad use. To development economic practicality and high reliability robot system will be value to robot social application and economy development. With the rapid progress with the control economy and expanding of the modern cities, the let of sewage is increasing quickly: With the development of modern technology and the enhancement of consciousness about environment reserve, more and more people realized the importance and urgent of sewage disposal. Active bacteria method is an effective technique for sewage disposal,The lacunaris plastic is an effective basement for active bacteria adhesion for sewage disposal. The abundance requirement for lacunaris plastic makes it is a consequent for the plastic producing with automation and high productivity. Therefore, it is very necessary to design a manipulator that can automatically fulfill the plastic holding. With the analysis of the problems in the design of the plastic holding manipulator and synthesizing the robot research and development condition in recent years, a economic scheme is concluded on the basis of the analysis of mechanical configuration, transform system, drive device and control system and guided by the idea of the characteristic and complex of mechanical configuration, electronic, software and hardware. In this article, the mechanical configuration combines the character of direction coordinate and the arthrosis coordinate which can improve the stability and operation flexibility of the system. The main function of the transmission mechanism is to transmit power to implement department and complete the necessary movement. In this transmission structure, the screw transmission mechanism transmits the rotary motion into linear motion. Worm gear can give vary transmission ratio. Both of the transmission mechanisms have a characteristic of compact structure. The design of drive system often is limited by the environment condition and the factor of cost and technical lever. ''''The step motor can receive digital signal directly and has the ability to response outer environment immediately and has no accumulation error, which often is used in driving system. In this driving system, open-loop control system is composed of stepping motor, which can satisfy the demand not only for control precision but also for the target of economic and practicality. On this basis,the analysis of stepping motor in power calculating and style selecting is also given. The analysis of kinematics and dynamics for object holding manipulator is given in completing the design of mechanical structure and drive system. Kinematics analysis is the basis of path programming and track control. The positive and reverse analysis of manipulator gives the relationship between manipulator space and drive space in position and speed. The relationship between manipulator’s tip position and arthrosis angles is concluded by coordinate transform method. The geometry method is used in solving inverse kinematics problem and the result will provide theory evidence for control system. The f0unction of dynamics is to get the relationship between the movement and force and the target is to satisfy the demand of real time control. in this chamfer, Newton-Euripides method is used in analysis dynamic problem of the cleaning robot and the arthrosis force and torque are given which provide the foundation for step motor selecting and structure dynamic optimal ting. Control system is the key and core part of the object holding manipulator system design which will direct effect the reliability and practicality of the robot system in the division of configuration and control function and also will effect or limit the development cost and cycle. With the demand of the PCL-839 card, the PC computer which has a. tight structure and is easy to be extended is used as the principal computer cell and takes the function of system initialization, data operation and dispose, step motor drive and error diagnose and so on. A t the same time, the configuration structure features, task principles and the position function with high precision of the control card PCL-839 are analyzed. Hardware is the matter foundation of the control. System and the software is the spirit of the control system. The target of the software is to combine all the parts in optimizing style and to improve the efficiency and reliability of the control system. The software design of the object holding manipulator control system is divided into several blocks such as system initialization block, data process block and error station detect and dispose model and so on. PCL-839 card can solve the communication between the main computer and the control cells and take the measure of reducing the influence of the outer signal to the control system. The start and stop frequency of the step motor is far lower than the maximum running frequency. In order to improve the efficiency of the step motor, the increase and decrease of the speed is must considered when the step motor running in high speed and start or stop with great acceleration. The increase and decrease of the motor’s speed can be controlled by the pulse freque ncy sent to the step motor drive with a rational method. This can be implemented either by hardware or by software. A step motor shift control method is proposed, which is simple to calculate, easy to realize and the theory means is straightforward. The motor'''' s acceleration can fit the torque-frequency curve properly with this method. And the amount of calculation load is less than the linear acceleration shift control method and the method which is based on the exponential rule to change speed. The method is tested by experiment. A t last, the research content and the achievement are sum up and the problems and shortages in main the content are also listed. The development and application of robot in the future is expected.
The purpose of manipulator control is to maintain the dynamic response of a computer-based manipulator in accordance with some prespecified system performance and desired goals. In general, the dynamic performance of a manipulator directly depends on the efficiency of the control algorithms and the dynamic model of the manipulator. The control problem consists of obtaining dynamic models of the physical robot arm system and then specifying corresponding control laws or strategies to achieve the desired system response and performance.?
Current industrial approaches to robot arm control treat each joint of the robot arm as a simple joint servomechanism. The servomechanism approach models the varying dynamics of a manipulator inadequately because it neglects the motion and configuration of the whole arm mechanism. These changes in the parameters of the controlled system sometimes are significant enough to render conventional feedback control strategies ineffective. The result is reduced servo response speed and damping, limiting the precision and speed of the end-effector and making it appropriate only for limited-precision tasks. Manipulators controlled in this manner move at slow speeds with unnecessary vibrations. Any significant performance gain in this and other areas of robot arm control require the consideration of more efficient dynamic models, sophisticated control approaches, and the use of dedicated computer architectures and parallel processing techniques.
In the industrial production and other fields, people often endangered by such factors as high temperature, corrode, poisonous gas and so forth at work, which have increased labor intensity and even jeopardized the life sometimes. The corresponding problems are solved since the robot arm comes out. The robot arms can catch, put and carry objects, and its movements are flexible and diversified. It applies to medium and small-scale automated production in which production varieties can be switched. And it is widely used on soft automatic line. The robot arms are generally made by withstand high temperatures, resist corrosion of materials to adapt to the harsh environment. So they reduced the labor intensity of the workers significantly and raised work efficiency. The robot arm is an important component of industrial robots, and it can be called industrial robots on many occasions. Industrial robot is set machinery, electronics, control, computers, sensors, artificial intelligence and other advanced technologies in the integration of multidisciplinary important modern manufacturing equipment. Widely using industrial robots, not only can improve product quality and production, but also is of great significance for physical security protection, improvement of the environment for labor, reducing labor intensity, improvement of labor productivity, raw material consumption savings and lowering production costs.
There are such mechanical components as ball footbridge, slides, an air control mechanical hand and so on in the design. A programmable controller, a programming device, stepping motors, stepping motors drives, direct current motors, sensor, switch power supply, an electromagnetism valve and control desk are used in electrical connection. The programmable controller output two lines pulses to stepping motors drives to drive the two stepping motors drives on beam and vertical axis; direct current motors drive the rotation of the base and the hand; sensors send signals of location to the mainframe, and the mainframe sends directive to control the extension and contraction, up and down, moves location; the mainframe send signals to control the opening and closing of the hand to carry objects. Related parameters can be changed according to request of the changes of the objects and movement flow at any time change the relevant parameters in the design, so it has great flexibility and operability.
5
工業(yè)機械手
機器人是典型的機電一體化裝置,它綜合運用了機械與精密機械、微電子與計算機、自動控制與驅動、傳感器與信息處理以及人工智能等多學科的最新研究成果,隨著經(jīng)濟的發(fā)展和各行各業(yè)對自動化程度要求的提高,機器人技術得到了迅速發(fā)展,出現(xiàn)了各種各樣的機器人產(chǎn)品?,F(xiàn)代工業(yè)機器人是人類真正的奇跡工程。一個像人那么大的機器人可以輕松地抬起超過一百磅并可以在誤差+-0.006英寸誤差范圍內(nèi)重復的移動。更重要的是這些機器人可以每天24小時永不停止地工作。在許多應用中(特別是在自動工業(yè)中)他們是通過編程控制的,但是他們一旦編程一次,他們可以重復地做同一工作許多年。機器人產(chǎn)品的實用化,既解決了許多單靠人力難以解決的實際問題,又促進了工業(yè)自動化的進程。
目前,由于機器人的研制和開發(fā)涉及多方面的技術,系統(tǒng)結構復雜,開發(fā)和研制的成本普遍較高,在某種程度上限制了該項技術的廣泛應用,因此,研制經(jīng)濟型、實用化、高可靠性機器人系統(tǒng)具有廣泛的社會現(xiàn)實意義和經(jīng)濟價值。 由于我國經(jīng)濟建設和城市化的快速發(fā)展,城市污水排放量增長很快,污水處理己經(jīng)擺在了人們的議事日程上來。隨著科學技術的發(fā)展和人類知識水平的提高,人們越來越認識到污水處理的重要性和迫切性,科學家和研究人員發(fā)現(xiàn)塑料制品在水中是用于污水處理的很有效的污泥菌群的附著體。塑料制品的大量需求,使得塑料制品生產(chǎn)的自動化和高效率要求成為經(jīng)濟發(fā)展的必然。 本文結合塑料一次擠出成型機和塑料抓取機械手的研制過程中出現(xiàn)的問題,綜述近兒年機器人技術研究和發(fā)展的狀況,在充分發(fā)揮機、電、軟、硬件各自特點和優(yōu)勢互補的基礎上,對物料抓取機械手整體機械結構、傳動系統(tǒng)、驅動裝置和控制系統(tǒng)進行了分析和設計,提出了一套經(jīng)濟型設計方案。采用直角坐標和關節(jié)坐標相結合的框架式機械結構形式,這種方式能夠提高系統(tǒng)的穩(wěn)定性和操作靈活性。傳動裝置的作用是將驅動元件的動力傳遞給機器人機械手相應的執(zhí)行機構,以實現(xiàn)各種必要的運動,傳動方式上采用結構緊湊、傳動比大的蝸輪蝸桿傳動和將旋轉運動轉換為直線運動的螺旋傳動。機械手驅動系統(tǒng)的設計往往受到作業(yè)環(huán)境條件的限制,同時也要考慮價格因素的影響以及能夠達到的技術水平。由于步進電機能夠直接接收數(shù)字量,響應速度快而且工作可靠并無累積誤差,常用作數(shù)字控制系統(tǒng)驅動機構的動力元件,因此,在驅動裝置中采用由步進電機構成的開環(huán)控制方式,這種方式既能滿足控制精度的要求,又能達到經(jīng)濟性、實用化目的,在此基礎上,對步進電機的功率計一算及選型問題經(jīng)行了分析。 在完成機械結構和驅動系統(tǒng)設計的基礎上,對物料抓取機械手運動學和動力學進行了分析。運動學分析是路徑規(guī)劃和軌跡控制的基礎,對操作臂進行了運動學正、逆問題的分析可以完成操作空間位置和速度向驅動空間的映射,采用齊次坐標變換法得到了操作臂末端位置和姿態(tài)隨關節(jié)夾角之間的變換關系,采用幾何法分析了操作臂的逆向運動學方程求解問題,對控制系統(tǒng)設計提供了理論依據(jù)。機器人動力學是研究物體的運動和作用力之間的關系的科學,研究的目的是為了滿足是實時性控制的需要,本文采用牛頓-歐拉方法對物料抓取機械手動力學進行了分析,計算出了關節(jié)力和關節(jié)力矩,為步進電機的選型和動力學分析與結構優(yōu)化提供理論依據(jù)。 控制部分是整個物料抓取機械手系統(tǒng)設計關鍵和核心,它在結構和功能上的劃分和實現(xiàn)直接關系到機器人系統(tǒng)的可靠性、實用性,也影響和制約機械手系統(tǒng)的研制成本和開發(fā)周期。在控制主機的選用上,采用結構緊湊、擴展功能強和可靠性高的PC工業(yè)控制計算機作為主機,配以PCL-839卡主要承擔系統(tǒng)功能初始化、數(shù)據(jù)運算與處理、步進電機驅動以及故障診斷等功能;同時對PCL-839卡的結構特點、功能原理和其高定位功能等給與了分析。硬件是整個控制系統(tǒng)以及極限位置功能賴以存在的物質基礎,軟件則是計算機控制系統(tǒng)的神經(jīng)中樞,軟件設計的目的是以最優(yōu)的方式將各部分功能有機的結合起來,使系統(tǒng)具有較高的運行效率和較強的可靠性。在物料抓取機械手軟件的設計上,采用的是模塊化結構,分為系統(tǒng)初始化模塊、數(shù)據(jù)處理模塊和故障狀態(tài)檢測與處理等幾部分。主控計算機和各控制單元之間全部由PCL-839卡聯(lián)系,并且由該卡實現(xiàn)抗干擾等問題,減少外部信號對系統(tǒng)的影響。 步進電機的啟停頻率遠遠小于其最高運行頻率,為了提高工作效率,需要步進電機高速運行并快速啟停時,必須考慮它的升,降速控制問題。電機的升降速控制可以歸結為以某種合理的力一式控制發(fā)送到步進電機驅動器的脈沖頻率,這可由硬件實現(xiàn),也可由軟件方法來實現(xiàn)。本文提出了一種算法簡單、易于實現(xiàn)、理論意義明確的步進電機變速控制策略:定時器常量修改變速控制方案。該方法能使步進電機加速度與其力矩——頻率曲線較好地擬合,從而提高變速效率。而且它的計算量比線性加速度變速和基于指數(shù)規(guī)律加速度的變速控制小得多。通過實驗證明了該方法的有效性。 最后,對論文主要研究內(nèi)容和取得的技術成果進行了總結,提出了存在的問題和不足,同時對機器人技術的發(fā)展和應用進行了展望。
研究機械手控制的目的是保持以計算機為基礎的機械手的動態(tài)響應,以便與一些預先設定的系統(tǒng)性能和理想目標保持一致。一般情況下,機械手的動態(tài)性能直接依賴于控制算法的效率和機械手的動態(tài)模型??刂茊栴}包括獲得自然的機械手系統(tǒng)的動態(tài)模型,然后指定相應的控制規(guī)則或步驟以達到想要的系統(tǒng)響應和性能。
目前的工業(yè)機械臂控制將每一個機械臂的聯(lián)合看做一個簡單的聯(lián)合伺服。伺服方法不能充分地模仿不同的動力學機械手,因為它忽略了機械手整體的運動和配置。這些控制系統(tǒng)的參數(shù)的變化有時是足夠重要,以至于使常規(guī)的反饋控制方法失效。其結果是減少了伺服響應的速度和阻尼,限制了精度和最終效應的速度,使系統(tǒng)僅適用于有限精度的工作。機械手以這種方式控制速度降低而沒有不必要的震動。任何在這一領域和其它領域的機械臂性能增益要求更有效率的動態(tài)模型、精密的控制方法、專門的計算機架構和并行處理技術。
在工業(yè)生產(chǎn)和其他領域內(nèi),由于工作的需要,人們經(jīng)常受到高溫、腐蝕及有毒氣體等因素的危害,增加了工人的勞動強度,甚至于危及生命。自從機械手問世以來,相應的各種難題迎刃而解。機械手可在空間抓、放、搬運物體,動作靈活多樣,適用于可變換生產(chǎn)品種的中、小批量自動化生產(chǎn),廣泛應用于柔性自動線。機械手一般由耐高溫,抗腐蝕的材料制成,以適應現(xiàn)場惡劣的環(huán)境,大大降低了工人的勞動強度,提高了工作效率。機械手是工業(yè)機器人的重要組成部分,在很多情況下它就可以稱為工業(yè)機器人。工業(yè)機器人是集機械、電子、控制、計算機、傳感器、人工智能等多學科先進技術于一體的現(xiàn)代制造業(yè)重要的自動化裝備。廣泛采用工業(yè)機器人,不僅可以提高產(chǎn)品的質量與產(chǎn)量,而且對保障人身安全,改善勞動環(huán)境,減輕勞動強度,提高勞動生產(chǎn)率,節(jié)約原材料消耗以及降低生產(chǎn)成本,有著十分重要的意義。
本設計所用機械部件有滾珠絲杠、滑軌、氣控機械抓手等。電氣方面有可編程控制器(PLC)、編程器、步進電機、步進電機驅動器、直流電機、光電傳感器、開關電源、電磁閥、旋轉碼盤、操作臺等部件??删幊炭刂破靼l(fā)出兩路脈沖到步進電機驅動器,分別驅動橫軸、豎軸的步進電機運轉;直流電機拖動底座和手爪的旋轉;接近開關、微動開關、旋轉碼盤將位置信號反饋給主機,由主機發(fā)出指令來實現(xiàn)對手臂的伸縮、上下、轉動位置的控制;主機發(fā)信號到氣動電磁閥,以控制手爪的張合來抓放物體。本設計可根據(jù)工件的變化及運動流程的要求隨時更改相關參數(shù),具有很大的靈活性和可操作性。
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