摘要
摩擦是大多數(shù)機(jī)械系統(tǒng)中不可避免的一種現(xiàn)象，由于摩擦?xí)矸€(wěn)態(tài)誤差，影響系統(tǒng)的動態(tài)特性以及系統(tǒng)精度的提高，摩擦問題已經(jīng)成為當(dāng)前研究的熱點(diǎn)。在機(jī)械手臂系統(tǒng)中，關(guān)節(jié)摩擦嚴(yán)重影響了機(jī)械手臂系統(tǒng)性能的提高，使得手臂在運(yùn)動過程中產(chǎn)生誤差。低速時摩擦的非線性環(huán)節(jié)對機(jī)械手臂系統(tǒng)的影響尤為突出，因此必須采取合理的措施消除關(guān)節(jié)摩擦帶來的影響。
本文將減小關(guān)節(jié)摩擦對機(jī)械系統(tǒng)的影響作為主要目的，首先對摩擦模型進(jìn)行了討論，并選定LuGre摩擦模型為研究重點(diǎn)；接著對磨削機(jī)械手臂的運(yùn)動學(xué)，工作空間以及動力學(xué)進(jìn)行了研究；分析了關(guān)節(jié)摩擦在機(jī)械系統(tǒng)中的影響，并采用自適應(yīng)控制對關(guān)節(jié)摩擦進(jìn)行補(bǔ)償。并將該理論應(yīng)用于機(jī)械手臂系統(tǒng)中，針對磨削機(jī)械手臂運(yùn)動過程中的關(guān)節(jié)摩擦現(xiàn)象進(jìn)行了自適應(yīng)補(bǔ)償研究，建立了機(jī)械手臂摩擦控制原型系統(tǒng)。
本文的主要研究內(nèi)容如下：
(1)結(jié)合摩擦學(xué)領(lǐng)域的最新成果，對幾種重要的摩擦模型進(jìn)行研究。對比分析不同摩擦模型的優(yōu)點(diǎn)和缺點(diǎn)，選取LuGre摩擦模型作為文章的研究對象，并實(shí)現(xiàn)了LuGre摩擦模型在預(yù)滑階段和滑動階段的仿真。
(2)推導(dǎo)了六自由度磨削機(jī)械手臂的運(yùn)動學(xué)模型，并對其工作空間進(jìn)行了求解；采用拉格朗日方法建立了磨削機(jī)械手臂的動力學(xué)模型，并重點(diǎn)分析了關(guān)節(jié)摩擦對磨削機(jī)械手臂的影響情況。
(3)從理論上證明了LuGre摩擦的自適應(yīng)摩擦補(bǔ)償方法能夠消除關(guān)節(jié)摩擦對機(jī)械手臂系統(tǒng)的影響，通過仿真實(shí)驗(yàn)對比分析了采用PID控制、采用自適應(yīng)庫侖摩擦補(bǔ)償和采用自適應(yīng)LuGre摩擦補(bǔ)償?shù)确椒▽C(jī)械手臂的影響情況，驗(yàn)證了使用LuGre自適應(yīng)摩擦補(bǔ)償方法的實(shí)用性。
(4)借助Visual C++、MATLAB、UG等軟件完成了磨削機(jī)械手臂仿真原型系統(tǒng)的開發(fā)，實(shí)現(xiàn)了自動化建模，裝配和仿真等功能，為機(jī)械手臂的設(shè)計提供了理論基礎(chǔ)。



關(guān)鍵詞：LuGre摩擦；機(jī)械手臂；動力學(xué)；關(guān)節(jié)摩擦；摩擦補(bǔ)償







Abstract
The friction is a kind of phenomenon that inevitable in most mechanical system, and it will bring steady-state error, influence the dynamic characteristics of the system and the accuracy of system, so friction problem has become the focus of research. In the mechanical arm system, the joint friction has a serious impact on performance improvement of the system, and makes errors in the process.The influence of nonlinear friction when mechanical arm system in low speed is particularly outstanding, therefore must take reasonable measures to eliminate the effects of joint friction.
This paper will reduce joint friction on the influence of the mechanical system as the main purpose, first the friction model was discussed, and LuGre friction model was selected for study; Then studyed the kinematics, work space, and dynamics of the grinding the mechanical arm; Analyzes the friction in the system in mechanical joint influence, and by using the adaptive control on joint friction to compensate. And applies this theory in the mechanical arm system, has conducted the auto-adapted compensation research in view of the grinding mechanical arm rate process in joint friction phenomenon, established the mechanical arm to rub the control prototype system.
The main research of this paper are as follows:
(1) According to the latest achievements of tribological field, choose several important friction models for research. Give a comparative analysis the advantages and disadvantages of the different friction models, select LuGre friction model as the research object, and realized the simulation of its dynamic characteristics in the Pre-slippery stage and sliding stage.
(2) Derived the kinematics model of 6-DOF the grinding mechanical arm, and its working space are solved; By using Lagrange method to establish the dynamics model of the grinding mechanical arm, and analyses the joint friction on the influence of the grinding the mechanical arm.
(3) Proved LuGre friction adaptive compensating friction can be good to eliminate joint friction on the influence of mechanical arm system in theory, through the simulation experiment is compared with that of PID control, using adaptive coulomb friction compensation and using adaptive LuGre friction compensation method to the influence of the mechanical arm, verify the use of LuGre adaptive friction compensation method is practical.
(4) With Visual C++, MATLAB, UG software etc. completed the development of grinding mechanical arm simulation system, realized the automation of modeling, assembly and simulation, and other functions, for the design of mechanical arm provides theory basis.



Key words: LuGre Friction;The Mechanical Arm;Dynamics;Joint Friction;Friction Compensation

目 錄
摘要 I
Abstract III
第1章 緒論 1
1.1課題的研究意義 1
1.2 國內(nèi)外研究現(xiàn)狀及分析 2
1.2.1 機(jī)械系統(tǒng)摩擦力模型的研究現(xiàn)狀 2
1.2.2 機(jī)械手臂動力學(xué)研究現(xiàn)狀 3
1.2.3 含摩擦環(huán)節(jié)的系統(tǒng)動力學(xué)研究現(xiàn)狀 4
1.2.4 機(jī)械手臂關(guān)節(jié)摩擦補(bǔ)償?shù)难芯楷F(xiàn)狀 5
1.3 論文主要研究內(nèi)容與結(jié)構(gòu) 6
1.3.1 主要研究內(nèi)容 6
1.3.2 本文的結(jié)構(gòu) 8
1.4 本章小結(jié) 9
第2章 摩擦模型的研究及LuGre模型的仿真 10
2.1 摩擦的四個階段 10
2.2 現(xiàn)有摩擦模型的介紹 12
2.2.1 Dahl摩擦模型 13
2.2.2 Bliman-Sorine摩擦模型 14
2.2.3 鬃毛摩擦模型 15
2.2.4 Karnopp摩擦模型 15
2.2.5 Stribeck摩擦模型 16
2.2.6 LuGre摩擦模型 16
2.3 LuGre摩擦模型..