并联结构3D打印机的运动学分析与精度研究

发布时间：2018-11-25 19:56

【摘要】：3D打印技术已经经历近四十年发展历程,其中基于熔融沉积(FDM)的技术是在目前几大3D打印技术中应用最为广泛的技术。因为该技术的成本低,可供打印的材料广泛等方面,基于FDM的3D打印技术得以应用在各行各业中,几乎可以应用在制造业中的任何行业。基于该打印技术原理的打印设备是涉及了机械、电气、控制、信息和材料等多个学科,属于典型的多学科复杂交叉的机电系统。本文结合基于FDM的3D打印技术和并联机构技术,设计了一台并联结构的3D打印机,并完成样机的设计制造,样机的系统主要是由机械系统、硬件控制系统以及软件系统三大系统组成,在阐述系统的组成中介绍了并联结构3D打印机的打印成型过程。为本文的研究重点并联结构3D打印机的运动学分析以及成型精度的研究奠定了研究基础。首先,从并联结构3D打印机的机械本体结构入手,分析了机械本体机构的运动学特性,分析得到了并联结构3D打印机的机构自由度以及运动的形式。随后,对并联结构3D打印机的运动学方程进行推导,得到了运动学的正反解方程,并结合虚拟样机软件ADAMS对机构的运动学特性进行验证,证实了这类并联机构运用在3D打印机中是可行的。其次,从机械结构的误差和打印的工艺参数两个方面分析了影响并联结构3D打印机的打印模型成型精度,并对机械的模型误差进行误差建模。并且建立简化的误差模型,分离误差模型中位姿误差和位置误差,分析不同来源的几何误差对打印头输出末端的误差影响。最后,针对打印工艺参数对中的关键的参数,即分层厚度?、打印头温度T0、工作平台温度T1、打印头的运动速度四个关键参数。设计正交试验分析在不同的尺寸方向上,关键参数的不同参数水平对尺寸精度的影响程度。基于不同因素的是否显著影响的条件下,提出了不同方向上的误差补偿方程,对为实际的应用中提高并联结构3D打印机的打印精度提供了理论基础。
[Abstract]:3D printing technology has been developed for nearly 40 years, among which the technology based on fused deposition (FDM) is the most widely used in several major 3D printing technologies. Because of its low cost and wide range of printing materials, 3D printing technology based on FDM can be applied in various industries, almost any industry in manufacturing industry. The printing equipment based on the principle of the printing technology involves mechanical, electrical, control, information and materials and so on. Combined with 3D printing technology based on FDM and parallel mechanism technology, this paper designs a 3D printer with parallel structure, and completes the design and manufacture of the prototype. The system of the prototype is mainly composed of mechanical system. Hardware control system and software system are made up of three systems. The printing process of parallel 3D printer is introduced in this paper. It lays a foundation for the kinematics analysis and the research of forming accuracy of 3D printer with parallel structure. Firstly, starting with the mechanical structure of the parallel 3D printer, the kinematics characteristics of the mechanism are analyzed, and the degree of freedom and the form of motion of the parallel 3D printer are obtained. Then, the kinematics equation of 3D printer with parallel structure is deduced, and the forward and inverse kinematics equations are obtained, and the kinematics characteristics of the mechanism are verified with the virtual prototype software ADAMS. It is proved that this kind of parallel mechanism is feasible in 3D printer. Secondly, from two aspects of the error of mechanical structure and the process parameters of printing, the paper analyzes the accuracy of the printing model of 3D printer with parallel structure, and models the error of the model of machine. A simplified error model is established to separate the position error and position error from the error model and to analyze the effect of geometric errors from different sources on the errors at the output end of print head. Finally, aiming at the key parameters of printing process parameters, that is, delamination thickness?, printing head temperature T0, working platform temperature T1, and printing head moving speed four key parameters. The orthogonal test was designed to analyze the degree of influence of different parameter levels of key parameters on dimensional accuracy in different dimension directions. The error compensation equations in different directions are proposed based on whether different factors are significantly affected or not, which provides a theoretical basis for improving the printing accuracy of parallel 3D printers in practical applications.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP334.8

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