外文翻譯--挖掘機(jī)臂液壓系統(tǒng)的模型化參量估計(jì)-其他專業(yè)-資料下載頁(yè)
2025-01-19 10:10本頁(yè)面
【導(dǎo)讀】首先介紹了液壓挖掘機(jī)的一個(gè)改裝的電動(dòng)液壓的比例系統(tǒng)。根據(jù)負(fù)載獨(dú)立流量分。配系統(tǒng)的原則和特點(diǎn)，以動(dòng)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(gè)力平衡方程和一個(gè)液壓缸的連續(xù)性方程。結(jié)果顯示壓力的差異并不會(huì)改變負(fù)載，然后假設(shè)穿過(guò)閥門的液壓油與閥芯的位移成正比并且不受負(fù)載。影響，提出了一個(gè)電液控制系統(tǒng)的簡(jiǎn)化模型。同時(shí)通過(guò)分析結(jié)構(gòu)和承重的動(dòng)臂裝置，量等為參數(shù)的受力平衡參數(shù)方程。最后用階躍電流控制電液比例閥來(lái)測(cè)試動(dòng)臂液壓缸。中液壓油的階躍響應(yīng)。根據(jù)實(shí)驗(yàn)曲線，閥門的流量增益系數(shù)被確定為。×10-4m3/，并驗(yàn)證了該模型。目前，機(jī)電一體化和自動(dòng)化已成為施工機(jī)械發(fā)展的最新趨勢(shì)。在許多國(guó)家逐漸變得普遍并被認(rèn)為重點(diǎn)。在圖中，F(xiàn)c表示液壓缸，動(dòng)臂的重力，斗桿，基于SWE-85型原有的液壓系統(tǒng)，把先導(dǎo)液壓控制系統(tǒng)更換為先導(dǎo)電液控制系統(tǒng)。因此，液壓機(jī)構(gòu)內(nèi)部和外在泄漏的。其中Bc是黏阻止的系數(shù)，單位是N·s/m。
【正文】 that all parameters in the simplified model are related to the structure。 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 cylinder The 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： ?s in111 BOcBOc lFlFM ?? BOcBOc lala 11 s in1 ?? ?? where M and ? are the torque and angular acceleration of manipulator to O1，respectively。 BQl1 is the length from point O1 to point B． According to the rotating law： M=J? ,we get (8) w BOcBOc lJalF11 /s ins in ?? ? that is BOcc lJaF12/? （ 9） where J is the equivalent moment inertia of manipulator to point O1,kgm2， and it can be written as follows： 312111 233222211 GOGOGO lmJlmJlmJJ ?????? (10) J1, J2 and J3 are the moment inertia of boom， dipper and bucket to their own bary center respectively． The values of them can be obtained by dynamic simulation based on the dynamic mode, J1=m, J2=m, J3=m. Comparing Eqn． (9)with Fc=mac， the equivalent mass at point B can be given： BOlJm 12/? (11) Estimation for load on hydraulic cylinder The equivalent moment equation of manipulator to O1 is ??? ??? 3121111 321s i n GOGOGOBOc glmglmglmlF ? (12) where ?? 2111 , GOGO lland ?31GOl are the length from pointO1 to point G1180。 ， G2180。and G3180。；，respectively． Then， the counter force of load is ? ? ?s i n1312111 321 BOGOGOGOc lglmglmglmF ??? ??? (13) Estimation for flow gain coefficient of valve The 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 in ． At the same time， the curve verifies Eqn． [11]． Based on the experiment curve， the range of KqKl can be identified according to Eqns.(1)and(4)． And then， according to data in ， we can get： KqKl=104m3/(sA)． w Flow of boom cylinder under electrohydeaulic proportional value controlled by step current 5 Conclusions （ 1） The mathematic model of electro— hydraulic system is developed according to the characteristics of excavator． It is assumed that the flow across the valve is directly proportional to the size of valve orifice， and the influence of intemal and extemal leakage of hydraulic system is ignored． The simplified model can be obtained： )](/[)]()([)( 212021 asasasssFbsXbsY cv ???? where represent the displacement of piston and the displacement of spool． （ 2） From the model of electro— hydraulic system， we can obtain the equivalent mass BOlJm 12/? ， bearing force )(31211 3121 ??? ??? GOGOGOl lmglmglmF , flow gain coefficient of value KqKl=104m3/(sA) ， where KI is the current gain of electro— hydraulic proportional valves． From: Journal of Central South University (English) 2021 Vol 15 No. 3 pages 382386
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