【正文】 ere dead band，A． Flow equation of electrohydraulic proportional valveIn this work，LUDV system was adopted in the experimental robotic excavator．According to the theory of LUDV system，the flow equation can be gotten： (2)(3)=where is the springsetting pressure of load sense valve，MPa；cd is the flow coefficient m5／(N.4 Parameters estimationFrom the process of modeling and Eqn．(7)，it is clear that all parameters in the simplified model are related to the structure。and G3180。m.Comparing Eqn．(9)with Fc=mac，the equivalent mass at point B can be given： (11) Estimation for load on hydraulic cylinderThe equivalent moment equation of manipulator to O1 is (12)where and are the length from pointO1 to point G1180。a0=V1V2m。G2180。A) 。 ，G2180。考慮到機(jī)械手的坐標(biāo)軸心O1，機(jī)械手的轉(zhuǎn)矩和角加速度可考慮如下：(8)其中的M 和 分別是工作裝置對O1的轉(zhuǎn)矩和角加速度。4 參量估計(jì) 從塑造的過程和方程(7)中可以得到在確切的簡化的模型中與結(jié)構(gòu)，運(yùn)動情況以及挖掘機(jī)動臂的體位有關(guān)的所有參量。當(dāng)前，外在泄漏可以通過密封技術(shù)控制。根據(jù)LUDV系統(tǒng)的理論，可以得到流體運(yùn)動方程： （2）(3)=其中是負(fù)荷傳感閥門的壓力差，單位為 MPa；cd是徑流系數(shù)，單位為m5／(N為了適應(yīng)自動控制，普通液壓控制挖掘機(jī)應(yīng)改造電動液壓控制挖掘機(jī)。2 挖掘機(jī)機(jī)械臂概述 液壓挖掘機(jī)的挖掘研究結(jié)果如圖1。 每種使用方法，研究員必須知道操作器結(jié)構(gòu)和液壓機(jī)構(gòu)的動態(tài)和靜態(tài)特征。最后用階躍電流控制電液比例閥來測試動臂液壓缸中液壓油的階躍響應(yīng)。根據(jù)負(fù)載獨(dú)立流量分配（ LUDV ）系統(tǒng)的原則和特點(diǎn)，以動臂液壓系統(tǒng)為例并忽略液壓缸中的油大量泄漏，建立一個力平衡方程和一個液壓缸的連續(xù)性方程。關(guān)鍵詞：挖掘機(jī)，電液比例系統(tǒng)，負(fù)載獨(dú)立流量分配（ LUDV ）系統(tǒng)，建模，參數(shù)估計(jì)1 引言由于液壓挖掘機(jī)具有高效率、多功能的優(yōu)點(diǎn)，所以被廣泛應(yīng)用于礦山，道路建設(shè)，民事和軍事建設(shè)，危險(xiǎn)廢物清理領(lǐng)域。關(guān)于挖掘機(jī)時(shí)滯控制的研究已經(jīng)有人在研究了。和 G3180。在這系統(tǒng)中，因?yàn)閯颖?，斗桿和鏟斗具有相同的特點(diǎn)，將動臂的液壓系統(tǒng)作為一個例子。在圖4中，ps，p1s,和分別表示系統(tǒng)壓力、負(fù)荷傳感閥門壓力和它們的壓力差；壓力系統(tǒng)的實(shí)驗(yàn)曲線顯示三種不同的壓力值。當(dāng)油流進(jìn)汽缸無桿腔并且進(jìn)入到有桿腔內(nèi)時(shí)，連續(xù)性方程可以寫成：(5)其中 V1 和V2 分別表示流入及流出的液壓缸液體的體積，單位是m3；是有效體積模量（包括液體，油中的空氣等），單位是N/m2。要解決這個問題，本文提出了估計(jì)方程和方法來估算模型中的這些重要參數(shù)。并且寫成如下式子： (10)J1, J2 和 J3分別是動臂，斗桿和鏟斗對各自的中心的慣性力矩；它們的值可以通過模擬動態(tài)模型得出J1=用于這項(xiàng)工作的儀器為多系統(tǒng)5050型。簡化模型可以得到： ，其中Y（s）和Xv(s)分別是活塞和閥芯的位移。s)；w is the area gradient of orifice，m2／m；ρ is the oil density, kg／m3。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 this problem，those important parameters of model were estimated approximately by the estimation equation and method proposed in this work． Equivalent mass estimation for load on hydraulic cylinderThe load of boom hydraulic cylinder(it is assumed there is no external load)consists of boom，dipper and bucket．In ，boom，dipper and bucket rotate around points O1，O2 and O3，respectively．So their motions are not straight line motions about the cylinders, that is to say, their motion directions are different from Y in Eqn.(5)．So，m in Eqn.(6)cannot be simply regarded as the sum mass of boom，dipper and bucket．Considering O1 at an axis of manipulator, the torque and angular acceleration can begiven as follows：(8)where M and are the torque and angular acceleration of manipulator to O1，respectively。；，respectively．Then，the counter force of load is (13) Estimation for flow gain coefficient of valveThe flow of pump can be measured by flow transducer． The instrument used in this work was Multi—system 5050．The step response of flow of boom cylinder under the electro—hydraulic proportional valve controlled by the step curent is shown