挖掘机机液工作系统动力学与控制研究

发布时间：2018-03-15 10:33

本文选题：挖掘机　切入点：机液耦合　出处：《福州大学》2014年硕士论文　论文类型：学位论文

【摘要】：液压挖掘机以其作业场所广泛和较高的工作效率在工程装备领域占有重要的地位。但是挖掘机的作业环境复杂,甚至比较恶劣,其工作系统的负载压力变化频繁,驾驶者操纵挖掘机作业的工作强度大。因此,对挖掘机机液工作系统的动态特性以及辅助操纵控制的研究是相当有必要的。本文从动力学的角度出发,以某挖掘机的机液工作系统为对象,对其机构的运动学、动力学以及其液压系统进行数学分析和建模仿真研究,分析该工作系统的动态特性,最后,对挖掘机辅助操纵控制进行探索性研究。主要工作如下：在广泛阅读挖掘机相关文献的基础上,论述了进行挖掘机机液工作系统研究的背景和意义,国内外对该课题的研究和发展现状。应用机器人学理论,建立了该工作系统机构的运动学、动力学数学模型,应用Matlab软件的机器人学工具箱进行其运动学建模仿真,测定其作业空间和铲斗斗尖的轨迹规划：采用AMESim软件的平面机构库和标准液压库建立简单的机液工作系统,模拟铲斗和斗杆复合动作挖掘的工况,对其进行动力学特性仿真。深入研究挖掘机负载独立流量分配(LUDV)液压系统的主要组成部分和正常运行时的工作原理,对其重要部件负载敏感变量泵和多路换向阀进行工作原理分析和建模仿真研究,搭建了较完整的负载独立流量分配系统AMESim模型,通过机液耦合接口与机构的AMESim模型联立,实现了挖掘机机液工作系统联合仿真平台模型的建立。在AMESim仿真平台下,模拟挖掘机的典型工况,对其机液工作系统在特定工况下的动态特性,进行了较详细的仿真研究。分析结果表明,本文所建立的机液工作系统具有良好的操纵性和抗流量饱和特性,在流量饱和时,多个液压缸能够协调的进行伸缩运动,不受外部负载的影响。设计了挖掘机机液工作系统的模糊PID辅助操纵控制系统,采用AMESim与Matlab/Simulink软件进行了系统模型和联合仿真平台的建立,模拟较真实的作业工况,对工作系统中的液压缸运动进行控制仿真研究。结果表明,与单独PID控制相比,模糊PID控制技术对挖掘机机液工作系统具有较好的控制效果。
[Abstract]:Hydraulic excavator plays an important role in the field of engineering equipment because of its extensive working place and high working efficiency. However, the working environment of excavator is complex, even worse, and the load pressure of its working system changes frequently. Therefore, it is necessary to study the dynamic characteristics of the hydraulic working system of the excavator and the auxiliary control of the excavator. In this paper, from the point of view of dynamics, it is necessary to study the dynamic characteristics of the hydraulic working system of the excavator. Taking the hydraulic working system of a excavator as an object, the kinematics and dynamics of the mechanism and its hydraulic system are studied by mathematical analysis and modeling and simulation, and the dynamic characteristics of the working system are analyzed. The main work is as follows: on the basis of extensive reading of the relevant documents of excavator, the background and significance of the research on hydraulic working system of excavator are discussed. Based on the theory of robotics, the kinematics and dynamics mathematical models of the working system are established, and the kinematics modeling and simulation are carried out by using the robotics toolbox of Matlab software. The working space and the trajectory planning of bucket tip were measured. The plane mechanism library and standard hydraulic system of AMESim software were used to set up a simple working system to simulate the working condition of excavating the bucket and bucket pole. The main components of hydraulic system of excavator load independent flow distribution (LUDVV) and the working principle during normal operation are studied. In this paper, the working principle of load sensitive variable pump and multi-way directional valve are analyzed and simulated. The AMESim model of load independent flow distribution system is set up, and the AMESim model of the mechanism is combined by the coupling interface of mechanism and liquid. The model of joint simulation platform for hydraulic working system of excavator is established. Under the AMESim simulation platform, the dynamic characteristics of the hydraulic working system of excavator under specific working conditions are simulated, and the typical working conditions of excavator are simulated. The simulation results show that the system has good maneuverability and resistance to flow saturation. The fuzzy PID auxiliary control system of hydraulic working system of excavator is designed, and the system model and joint simulation platform are established by using AMESim and Matlab/Simulink software. The control simulation of hydraulic cylinder motion in the working system is carried out. The results show that the fuzzy PID control technology has a better control effect on the hydraulic working system of excavator than that of the single PID control.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU621

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