中型液压挖掘机工作装置液压系统半实物仿真平台设计与实现

发布时间：2018-01-08 04:33

本文关键词：中型液压挖掘机工作装置液压系统半实物仿真平台设计与实现　出处：《福州大学》2014年硕士论文　论文类型：学位论文

【摘要】：液压挖掘机的工作装置是挖掘机作业过程中的主要执行装置,其性能直接决定了挖掘机的工作效率。新开发的挖掘机在设计与选配液压元件时,需要对液压元件(尤其是多路阀主阀芯)进行反复调试和优化,使其满足工作装置的性能需求。数值仿真方法是指导液压元件结构设计与优化的重要手段,然而在实际工况中,对于普遍采用节流调速的中型液压挖掘机而言,其液压系统的性能受负载影响较大,仅通过数值仿真无法对真实工况下随机变化的负载力进行准确模拟,导致对挖掘机工作装置液压系统的仿真结果与实际情况差距较大。为了弥补上述液压系统数值仿真过程中存在的不足,本文将数值仿真技术与虚拟仪器测试技术相结合,设计并建立了挖掘机工作装置液压系统“半实物仿真平台”,并对工作装置液压系统进行研究。本文的主要工作内容及特色如下：首先,介绍了挖掘机工作装置液压系统的基本组成及其工作原理；研究了主泵的负流量控制、总功率控制与转速感应控制的原理及特性；分析了工作装置液压系统的基本回路。其次,分析了主泵的数学模型及多路阀中主换向阀的结构,并据此分别建立了基于AMESim的主泵及主换向阀的仿真模型；重点研究了主换向阀的阀口特性,提出了一种新的非全周开口滑阀阀口等效过流面积计算方法：建立了工作装置液压系统的数值仿真模型,并根据实测数据对模型中的参数进行了准确设置。然后,研究了工作装置油缸负载力的测试方法,并在此基础上制定了基于NI CompactRIO硬件平台的挖掘机实时测试系统总体方案；构建了测试硬件系统,并提出了一种新的采集SSI信号的方法；分模块开发了测试软件系统的FPGA程序、RT程序及上位机程序。最后,研究了测试系统上位机程序与数值仿真模型的数据通讯接口,并结合测试系统与数值仿真模型建立了挖掘机工作装置液压系统的半实物仿真平台；对动臂、斗杆和铲斗分别进行了单动作实时仿真,同时对仿真结果进行实验分析。本文的主要贡献在于将虚拟仪器测试技术与数值仿真技术相结合,设计并建立了中型液压挖掘机工作装置液压系统的半实物仿真平台,并利用其对挖掘机液压系统进行研究,为挖掘机液压元件与系统的设计、分析与研究提供了一种新的思路,具有很好的工程应用价值。
[Abstract]:The working device of hydraulic excavator is the main executing device in the working process of excavator, and its performance directly determines the working efficiency of excavator. The newly developed excavator is designed and equipped with hydraulic components. It is necessary to debug and optimize the hydraulic components (especially the main valve spool) repeatedly to meet the performance requirements of the working device. Numerical simulation method is an important means to guide the structural design and optimization of hydraulic components. However, in the actual working conditions, the performance of hydraulic system is greatly affected by the load for the medium hydraulic excavator which generally adopts throttling speed regulation. It is impossible to accurately simulate the load force of random variation under real working condition by numerical simulation only. As a result, the simulation result of hydraulic system of excavator working device is far from the actual situation, in order to make up for the deficiency in the process of numerical simulation of hydraulic system mentioned above. In this paper, the numerical simulation technology and virtual instrument testing technology are combined to design and establish the "Hardware-in-the-Loop Simulation platform" for hydraulic system of excavator working device. The main contents and characteristics of this paper are as follows: firstly, the basic composition and working principle of hydraulic system of excavator working device are introduced. The principle and characteristics of negative flow control, total power control and speed induction control of main pump are studied. The basic circuit of the hydraulic system of the working device is analyzed. Secondly, the mathematical model of the main pump and the structure of the main reversing valve in the multi-way valve are analyzed. The simulation models of the main pump and the main reversing valve based on AMESim are established respectively. The characteristics of the valve opening of the main reversing valve are studied emphatically, and a new method of calculating the equivalent overflow area of the valve opening is proposed. The numerical simulation model of the hydraulic system of the working device is established. The parameters of the model are set accurately according to the measured data. Then, the measuring method of the load force of the working device cylinder is studied. On this basis, the overall scheme of real-time testing system of excavator based on NI CompactRIO hardware platform is established. The testing hardware system is constructed, and a new method of collecting SSI signal is proposed. The FPGA program RT program and the host computer program of the test software system are developed. Finally, the data communication interface between the upper computer program and the numerical simulation model of the test system is studied. The hardware-in-the-loop simulation platform of hydraulic system of excavator working device is established by combining test system and numerical simulation model. The single action real-time simulation of arm, bucket and bucket is carried out, and the simulation results are analyzed. The main contribution of this paper is to combine virtual instrument testing technology with numerical simulation technology. The hardware-in-the-loop simulation platform of hydraulic system of working device of medium hydraulic excavator is designed and established, and the hydraulic system of excavator is studied by it, which is the design of hydraulic components and system of excavator. The analysis and research provide a new way of thinking and have good engineering application value.
【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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