单斗挖掘机泵控液压驱动系统的精确模型---外文原文及其翻译.doc

外文原文及其翻译 翻译原文： Mathematical Modeling for Pump Controlled System of Hydraulic Drive Unit of Single Bucket Excavator Digging Mechanism Juma Yousuf Alaydi * Industrial Eng. Dept., IUG, Palestine Abstract： Industrial robots have turned out to be an everyday occurrence for engineers during the last twenty years. Increasing efficiency is one of the hottest research topics in hydraulic system. The comparison between two types of hydraulic control systems, which are the valve, controlled system and the pump-controlled system is essential area of researching. Hydraulic actuator with pump-controlled system is equipped in high power mining excavators and forestry equipment in order to increase efficiency. The purpose of this paper is to build a mathematical model for a hydraulic actuator with pump-controlled system. The boom of single bucket excavator is modeled and simulated as an example. The scheme of this system is presented and itemized. The model of these items is simulated and the control circuits are presented as well as the simulation results. Keywords: Hydraulic system; Pump controlled system; Valve controlled system; hydraulic drive unit; single bucket excavator; mathematical modeling; and simulation; 1. Introduction Hydraulic actuation devices may be linear or rotary and are usually referred to as pistons or motors, respectively. A pump or a valve giving four basic hydraulic power elements and two basic over-all systems may control these two actuation devices: pump controlled and valve controlled. Such hydraulic power elements is simply a combination the of principal power device in all hydraulic systems [1]. The pump-controlled system consists of a variable delivery pump supplying fluid to an actuation device. The fluid flow is controlled by the stroke of the pump to vary output speed and the pressure generated matches the load. It is usually difficult to closely couple the pump to the actuator and this causes large contained volumes and slow response [2]. The val