【正文】 他們的區(qū)別不會隨著荷載而改變。分別是G1 ， G2和G3在X軸上的投影。液壓挖掘機在施工機械領域中也發(fā)揮了重要作用。同時通過分析結(jié)構(gòu)和承重的動臂裝置，并將機械臂的力矩等效方程與旋轉(zhuǎn)法、參數(shù)估計估計法結(jié)合起來建立了液壓缸以等質(zhì)量等為參數(shù)的受力平衡參數(shù)方程。在本文，根據(jù)提出的模型，根據(jù)工程學和受力平衡，挖掘機臂液壓機構(gòu)模型簡化為連續(xù)均衡的液壓缸和流動均衡的電液比例閥；同時，確定了模型的參量的估計方法和等式。 電動液壓的比例閥門的流體運動方程在本文中，實驗性機器人挖掘機采取了LUDV系統(tǒng)。 電動液壓的比例系統(tǒng)簡化的模型 方程(4)—(6)在拉伯拉斯變換以后，簡化的模型可以表達為： (7)其中Y是y拉伯拉斯變換得到的；；bf=V1V2；a0=V1V2m；a1=BcV1V2；。比較方程（9）和Fc=mac，可以得出點B的等效質(zhì)量： (11) 液壓缸負載的估算 工作裝置對于O1等效力矩等式為： (12) 其中和分別表示O1點到 G1180。A) and the mode is verified.Key words: Excavator, Hydrauliccylinder proportional system, Load independent flow distribution (LUDV) system, Modeling, Parameter estimation1 IntroductionFor its high efficiency and multifunction, hydraulic excavator is widely used in mines，road building, civil and military construction，and hazardous waste cleanup areas．The hydraulic excavator also plays an important role in construction machines．Nowadays, macaronis and mobilization have been the latest trend for the construction machines．So，the automatic excavator gradually bees popular in many countries and is considered a focus．Many control methods can be used to automatically control the manipulator of excavator．Whichever method is used, the researchers must know the structure of manipulator and the dynamic and static characteristics of hydraulic system．That is, the exact mathematical models are helpful to design controller． However, it is difficult to model on timevariable parameters in mechanical structures and various nonlinearities in hydraulic actuators， and disturbance from outside．Researches on time delay control for excavator were carried out in Refs．NGUYE used fuzzy sliding mode control and impedance control to automate the motion of excavator’s manipulator． SHAHRAM et al adopted impedance control to the teleported excavator．Nonlinear models of hydraulic system were developed by some researchers. However, it is plicated and expensive to design controller, which 1imits its application．In this paper, based on the proposed model，the model of boom hydraulic system of excavator was simplified according to engineering and by considering the force equilibrium， continuous equation of hydraulic cylinder and flow equation of electrohydraulic proportional valve；at the same time，the estimation methods and equations for the parameters of model were developed．2 Overview of robotic excavatorThe backhoe hydraulic excavator studied is shown in ．In ，F(xiàn)c presents the resultant force of hydraulic cylinder, gravity of boom，dipper, bucket and so on at point B，whose direction is along cylinder AB； Fc can be deposed into Fcl and Fc2，and their directions are vertical and parallel to that of O1B，respectively；ac is the acceleration whose direction is same to that of Fc，and ac can be deposed into acl an d ac2 too；G1，G2 and G3 are the gravity centers of boom，dipper and bucket，respectively；ml，m2 and m3 are the masses of them，and their values can be given by experiment( m1=，m2= and m3=)；Ol，O2 and O3 are the hinged points；G1180。m, J3=the motional situation and the posture of excavator’s arm．Moreover，these parameters are time variable. So it is quite difficult to get accurate values and mathematic equations of these parameters. To solve t