挖掘機-外文翻譯-外文文獻中英翻譯(編輯修改稿)

　

【文章內容簡介】 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 ，Fc 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。，G2180。and G3180。are projections of Gl，G2 and G3 on x axis，respectively． The arm of excavator was considered a manipulator with three degrees of freedom (three inclinometers were set on the boom，dipper and bucket，respectively)．In tracking control experiment，the objective trajectories were planed based on the kinematic equation of excavator’s manipulator．Then，the motion of boom，dipper an d bucket was set by the controller．In order to suit for automatic contro1．the normal hydraulic control excavator should be retrofitted to electrohydraulic controller．Based on original hydraulic system of SW E85．The hydraulic pilot control system was replaced by an electrohydraulic pilot control system．The retrofitted hydraulic system is shown in ．In this work，because boom，dipper an d bucket are of the same characteristics，the hydraulic system of boom was taken as an example．In the electrohydraulic pilot control system，the pilot electro—hydraulic proportional valves were derived from adding proportional relief valves on the original SXl4 main valve，and hydraulic pilot handle was substituted by electrical one．The retrofitted system of excavator was still the LUDV system ()of Rexroth with good controllability．In ，y is the displacement of piston；Q1 and Q2 are the flows in and out to the cylinder respectively；pl，p2，ps and pr are the pressures of head and rod sides of cylinder, system and return oil，respectively；A1 and A2 are the areas of piston in the head and rod sides of cylinder, respectively； xv is the displacement of spool；m is the equivalent mass of load. Schematic diagtam of excavator’s arm Schematic diagram of retrofitted electrohydraulic system of excavator Schematic diagram of LUDV hydraulic system after retrofitting3 Model of electrohydraulic proportional s