【作者】 陆保印；

【导师】 龚俊；

【作者基本信息】 兰州理工大学 ， 机械制造及其自动化， 2010， 硕士

【摘要】 本文研究了喷涂机器人喷枪轨迹的设计与优化,该设计与优化的目的是要确定一条使得工件表面涂层厚度差异达到最小的喷枪最优轨迹。全文主要由以下几个部分组成：1.首先阐述了喷涂机器人喷枪轨迹优化的研究背景、意义、发展历程、喷涂机器人离线编程的主要结构、轨迹优化研究概况与现阶段存在的问题以及本文所作的主要工作。2.根据已有的实验数据,通过理论分析建立了涂层生长速率新模型,对其进行了曲线仿真拟合。以工作面上任意一点涂层厚度和工作面涂层平均厚度的方差最小作为衡量涂层均匀性的标准,对沿指定空间路径的喷枪轨迹优化问题进行研究,由于涂层生长新模型应用在平面喷枪轨迹优化时较复杂,提出了运用最小二乘法将该方程拟合成为简单的β分布方程进行求解。3.研究了小曲率复杂曲面上喷枪轨迹设计与优化问题。由于现有涂层生长速率函数表达式过于复杂,故采用实验方法建立了表达式较为简单的涂层生长速率模型。对复杂曲面进行喷涂作业时,在小曲率复杂曲面的分片原则下,对曲面进行分片,并在每片上进行轨迹设计。为保证曲面上涂层厚度的均匀性,要对面片交界处喷枪轨迹进行优化,针对多面片组合优化时出现涂层干涉的问题,提出变喷枪高度的方法进行优化。4.研究了大曲率柱面上喷涂轨迹设计与优化问题。在现有涂层生长速率模型的基础上,运用自由曲面上涂层厚度建模原理推导出圆柱面上的3D涂层厚度模型。提出了将柱面通过最小二乘圆弧逼近的思想,将柱面分片成若干圆柱面片的组合,柱面上的喷涂轨迹优化问题可近似看做圆柱面来处理,并在每个圆柱面片上建立喷枪轨迹优化目标函数,讨论了两圆柱面片交界处的涂层厚度计算方法及喷枪轨迹优化问题。本文对主要的设计方案进行了仿真计算。仿真结果表明,本文提出的数学模型以及各种喷枪轨迹设计、优化方法均可获得良好的效果。更多还原

【Abstract】 This thesis is undertaken on the design and optimization of spray-gun trajectory for spray-painting robot.The objective of the design and optimization is to determine a trajectory that results in minimal variation in accumulated film thickness on the surface of a workpiece.1.Firstly,the general situation and background about paining robot research and the developing about research are discussed. And then the frame of off-line programming system and the major problems of research are given. Finally some problems,which are studied in this thesis are illtroduced.2. According to the experimental data, founding the new model of paint desposition and simulating the peripheral curve of distribution off film base on theoretical analysis. The paint thickness at any point deviation from the average paint thickness required minimum, the variation in paint thickness can be as a standard of coating uniformity. Research on the problem of trajectory optimization along the designated path. Because it is more complex to use this equation when the trajectory optimization of in-plane spray painting is carried on, a method of fitting this equation to a simpleβ-distribution-equation is come up by the least square method.3. Trajectory design and optimization for painting robot of complex surface with small curvature is discussed. Because the current paint deposition rate function is too complicated, the paint deposition rate function on a plane according to the experiment data is provided. A complex surface with small curvature is divided into several patches under the principle of sharding and trajectory optimization for each patch is performed. In order to satisfy the material uniformity requirements, trajectory at the junction of patches need optimized. For the interferential problem of coating distribution appeared in the progress of the integrated spraying trajectory optimization on numerous patches, the method of changing the spray gun’s height and optimizing the distance of trajectory is advanced.4. Trajectory design and optimization for painting robot of cylinder with large curvature is discussed. On the basis of current paint deposition rate function, the modeling principle of coating thickness on free surface is used, and the spray gun 3D model was deduced in cylndrical surface. The method of least squares approximation for cylindrical surface was proposed, cylindrical surface fractionize into the combination of cylndrical surface, the trajectory optimization problem in cylindrical surface can be approximated as cylndrical surface to deal with,and trajectory optimization objective function was established in each cylndrical surface, the calculation method of coating thickness and optimization algorithms are developed to integrate the trajectories on the intersecting area of two patch.In this thesis, simulations are made for major design schemes.The results of simulations have shown that the model and the tool planning algorithms are feasible.更多还原