挖掘机液压系统的节能技术分析

文章对挖掘机中液压系统的节能效果进行了分析,指出了传统的恒功率控制技术在挖掘机满载工作条件下能够充分地利用发动机的功率;负流量控制、负荷传感控制大大减小了挖掘机在超载时、微动操作及换向阀处于中位时的能量损失.特别是负荷传感控制还具有与负载无关的控制性能.为挖掘机液压控制技术国产化提供参考.     

挖掘机主动防熄火控制研究

在分析挖掘机传统防熄火功能的基础上,对挖掘机主动防熄火控制进行了研究.通过研究,提出基于马达功率与发动机最大功率的关系,进行主动防熄火控制.采用挖掘机主动防熄火控制,可以避免发动机熄火、转速波动等问题.     

液压挖掘机分工况控制中泵-发动机的匹配

讨论了液压挖掘机分工况控制泵-发动机功率匹配问题,阐述了分工况控制节能的原理,提出达到节能和工作速度兼顾的泵-发动机匹配方案.     

挖掘机液压系统控制性能分析

介绍了挖掘机液压系统的功率参数与流量控制机理,从液压系统的功率角度分析了液压挖掘机的功率控制方式,从挖掘机负流量液压系统与正流量液压系统的工作原理方面分析了其控制性能及优缺点,并总结了挖掘机负流量液压系统与正流量液压系统的技术价值、应用场合及改善方向。     

液压挖掘机基于轨迹规划的控制优化

提出一种对液压挖掘机动臂、斗杆及铲斗实施协同优化控制以实现挖掘动作的精确有效操作.基于对液压挖掘机连杆机构的运动学分析,利用运动轨迹求逆的方法规划液压控制系统三个执行器协同工作以控制末端的运动轨迹,将挖掘机的复杂控制分解为几个单一系统的协同控制问题.研究结果表明所提出的方法可实现挖掘机的自动挖掘及自动平整操控,并为实现挖掘机的智能控制开辟了一条新的途径.     

电控节能技术在挖掘机中的应用与发展

挖掘机的电控节能技术是实现功率匹配的重要技术,也是挖掘机电控系统的核心技术.简单回顾了国外挖掘机电控节能控制系统的特点,分析了国产挖掘机电控系统的发展和与国外挖掘机存在的差距,指出了挖掘机的电控节能系统将融合多种新技术,朝着智能化电液控制和节能控制方向发展.     

挖掘机液压系统的节能控制研究

挖掘机是一种功率较大的机械设备,在现代化工程建设中具有重要的应用价值。在科学技术的推动下,液压挖掘机取代了传统的机械挖掘机,通过液压控制系统能够快速完成操作,但是在具体的控制过程,液压挖掘机会产生大量的损耗,因此,加强挖掘机液压系统的节能控制研究十分必要。本文对挖掘机液压系统能耗进行了简单分析,并挖掘机液压系统的节能控制措施。     

小型挖掘机仪表电子控制单元的设计与实现

论文以Cortex-M4微控制器MK10DN512VLL10作为主控芯片,设计了一款应用于沃尔沃小型挖掘机EC60C的仪表电子控制单元（IECU）.介绍了指针式仪表中步进电机的指数形曲线速度控制算法,并设计了包括运行模式、设定模式、服务模式在内的多种模式,方便挖掘机驾驶员阅读与操作.     

中大型液压挖掘机功率交叉控制系统

挖掘机中的各种节能控制,归根到底都是通过调节液压泵排量实现的。现有的挖掘机最常用的是恒功率控制系统（如液压挖掘机的左右行走操作）,此控制系统两泵的排量永远一致,能够使两个需要同步的作业保持一致。而当做单一操作时,这就意味着部分多余油液要泄掉,使系统出现发热等一系列的问题,造成液压功率的损失。     

液压挖掘机功率匹配与效率控制技术研究

液压挖掘机节能控制中,常用工况下每一档工作控制泵与发动机的局部功率匹配变化,同时挖掘机功率随着外界负载变化。针对负载敏感液压系统的全功率匹配,本文的控制策略对匹配的理论计算和测试数据分析主要包括理论计算及图表与样机测试数据分析。此外,液压挖掘机功率匹配与效率控制的目标:解决负载、变量泵、柴油机三者的动态匹配问题,使挖掘机在工作时达到高效、节能的性能指标。     

大型正铲液压挖掘机斗杆升降回路及特性

在设计目前国内斗容和机重最大的矿用液压挖掘机液压控制系统中,为减小使用成本,采用交流电动机驱动变量液压泵组作为动力源。为满足工作效率要求,斗杆举升过程采用四台液压泵供油,通过四组比例多路阀(主控阀)阀外合流来满足斗杆的速度要求,为降低能耗,提出在斗杆下降过程依靠自重和专用的比例节流阀进行流量再生的控制方法,加快斗杆下降速度,提高系统工作效率。分析斗杆采用流量再生方法下降的前提条件,对斗杆液压缸在一个工作循环内的压力变化进行机电液一体化的联合仿真研究,按照仿真确定的参数设计并制造样机,试验测试表明,挖掘机加载最大试验负载25 kN时,所设计的液压控制系统可以满足斗杆满载举升所需要的压力及速度要求,斗杆下降采用流量再生方法后,下降时间由32 s缩短至18 s,下降速度明显加快,且下降结束阶段无液压冲击。通过试验,验证了挖掘机液压控制方案的正确性,为今后国内设计和制造更大型的液压挖掘机积累了数据和经验。     

Digital Servo Control of a Robotic Excavator

An electro-hydraulic control system is designed and implemented for a robotic excavator known as the Lancaster University Computerised and Intelligent Excavator (LUCIE). The excavator is being developed to autonomously dig trenches without human intervention. Since the behavior of the excavator arm is dominated by the nonlinear dynamics of the hydraulic actuators and by the large and unpredictable external disturbances when digging, it is difficult to provide adequate accurate, quick and smooth movement under traditional control methodology, e.g., PI/PID, which is comparable with that of an average human operator. The data-based dynamic models are developed utilizing the simplified refined instrumental variable (SRIV) identification algorithm to precisely describe the nonlinear dynamical behaviour of the electro-hydraulic actuation system. Based on data-based model and proportional-integral-plus (PIP) methodology, which is a non-minimal state space method of control system design based on the true digital control (TDC) system design philosophy, a novel control system is introduced to drive the excavator arm accurately, quickly and smoothly along the desired path. The performance of simulation and field tests which drive the bucket along straight lines beth demonstrate the feasibility and validity of the proposed control scheme.     

New knowledge-based genetic algorithm for excavator boom structural optimization

Due to the insufficiency of utilizing knowledge to guide the complex optimal searching, existing genetic algorithms fail to effectively solve excavator boom structural optimization problem. To improve the optimization efficiency and quality, a new knowledge-based real-coded genetic algorithm is proposed. A dual evolution mechanism combining knowledge evolution with genetic algorithm is established to extract, handle and utilize the shallow and deep implicit constraint knowledge to guide the optimal searching of genetic algorithm circularly. Based on this dual evolution mechanism, knowledge evolution and population evolution can be connected by knowledge influence operators to improve the conflgurability of knowledge and genetic operators. Then, the new knowledge-based selection operator, crossover operator and mutation operator are proposed to integrate the optimal process knowledge and domain culture to guide the excavator boom structural optimization. Eight kinds of testing algorithms, which include different genetic operators, arc taken as examples to solve the structural optimization of a medium-sized excavator boom. By comparing the results of optimization, it is shown that the algorithm including all the new knowledge-based genetic operators can more remarkably improve the evolutionary rate and searching ability than other testing algorithms, which demonstrates the effectiveness of knowledge for guiding optimal searching. The proposed knowledge-based genetic algorithm by combining multi-level knowledge evolution with numerical optimization provides a new effective method for solving the complex engineering optimization problem.     

Motion Planning Based Coordinated Control for Hydraulic Excavators

Hydraulic excavator is one type of the most widely applied construction equipment for various applications mainly because of its versatility and mobility. Among the tasks performed by a hydraulic excavator, repeatable level digging or flat surface finishing may take a large percentage. Using automated functions to perform such repeatable and tedious jobs will not only greatly increase the overall productivity but more importantly also improve the operation safety. For the purpose of investigating the technology without loss of generality, this research is conducted to create a coordinate control method for the boom, arm and bucket cylinders on a hydraulic excavator to perform accurate and effective works. On the basis of the kinematic analysis of the excavator linkage system, the tip trajectory of the end-effector can be determined in terms of three hydraulic cylinders coordinated motion with a visualized method. The coordination of those hydraulic cylinders is realized by controlling three electro-hydranlic proportional valves coordinately. Therefore,the complex control algorithm of a hydraulic excavator can be simplified into coordinated motion control of three individual systems.This coordinate control algorithm was validated on a wheeled hydraulic excavator, and the validation results indicated that this developed control method could satisfaetorily accomplish the auto-digging function for level digging or flat surface finishing.     

Mechanism optimal design of backhoe hydraulic excavator working device based on digging paths

In order to solve the problem that hydraulic excavator in the real working process cannot meet the design requirements and reveals insufficient digging force, a new method on mechanism optimal design of backhoe hydraulic excavator working device based on digging paths is introduced and discussed in this paper. Considering the characteristics of consecutive digging process of hydraulic excavator, a digging path is composed of bucket digging trajectories and arm digging trajectories. The feasible working region is divided into a series of uniform paths according to the working position of boom. The practical digging performance of excavator is evaluated based on the digging force parameters under combined work condition of the discrete points on the digging paths. It is turned out that the method is more accurate to analyze excavator’s real-world digging performance via the analysis of some practical cases. Based on the new digging performance analysis method, the optimization mathematical model is built to ensure the digging force under combined work condition and the average digging force of every operating path as big as possible. The layout design of hinge position on the working device is optimized through genetic algorithm. The optimization result shows that a certain model of an excavator’s maximum digging force on the customary digging paths is improved by 10% and the average digging force is improved by 4% after the optimization on the working device of the excavator with weak digging force.     

A study on the reduction of uncertainty in the measurement of power tool vibration

To increase accurateness and reliability of the evaluation of power tool vibration transmitted to an operator, it is necessary to measure the grip and feed forces during the measurement of hand-transmitted vibration. In the study a system was invented to measure the vibration and the grip and/or feed force, which consists of a measurement handle and a PC with a data acquisition system and the corresponding software. Strain gages and an accelerometer were mounted on the handle surface for the simultaneous measurement of the forces and the vibration. The program in the system makes it possible to monitor the grip and feed force during the tool operation so that the operator keeps the applying forces within the pre-determined range. Investigating the vibration total values, frequency-weighted root-mean-square accelerations at the handle, obtained in repetition for each power tool with control of the grip and feed force showed more consistency than those measured without force control. By using the system the experimenter can reduce uncertainty in measurement of hand-held power tool vibration.     

液压挖掘机神经网络模糊节能控制系统的研究

通过对液压挖掘机功率匹配的分析,提出了将泵的功率曲线设定在发动机的功率曲线之上的功率匹配方法,研究了神经网络模糊比例-微分-积分(NN-Fuzzy-PID)控制技术在挖掘机节能控制系统上的应用.试验结果证明了提出的节能方法和 NN-Fuzzy-PID 控制算法在挖掘机节能控制系统上的可行性.NN-Fuzzy-PID 控制器能根据不同的环境和作业工况进行参数自调整,具有自学习的功能.研究结果为进一步研究开发智能化挖掘机提供了依据.     

国产WK系列挖掘机润滑系统润滑油的选用

WK系列挖掘机的润滑系统对设备关键部件的使用寿命起到了至关重要的作用,对于适用于设备的良好品质润滑油的选用就显得举足轻重,为此,根据以往挖掘机用油以及设计改进,对设备用油的选型和注意事项做了阐述.     

横河CS3000中AOA技术的应用

AOA是横河公司的先进操作技术，是对过程控制中提高操作效率、工厂增值的重要解决方案。用户只需通过Exaplog（事件分析软件包）、Exapilot（操作效率改进软件包），即可实现AOA管理。通过应用AOA技术，可使操作人员能方便地控制各种参数，操作简单，确保系统稳定运行，提高了系统安全性，同时降低了运行人员的劳动强度，提高了工作效率。该项技术正广泛地应用于化工、炼油、电力等行业。     

大型矿用液压挖掘机动臂运行及能效特性

作为大型矿用液压挖掘机的主要工作装置,重型机械臂在作业中主要做往复循环运动,下降过程中所具有的动势能会因控制阀口的节流效应转化为热能损失掉,该部分能量占发动机输出能量的20％以上,造成巨大能量浪费和废气排放.针对以上问题,提出在原双液压缸动臂驱动系统的基础上增设一个与液压蓄能器相连的独立储能液压缸,实现对重载机械臂动势...