复杂曲面布点策略与误差评定方法研究-机械制造及其自动化专业论文.docxVIP

摘要 随着现代制造业的快速发展，人们对零部件轮廓构造提出多元化要求的同 时，对零部件表面质量的要求也相应提高。加工质最推动着几何量检测技术的发 展。布点方法与误差评定算法对提高检测质量和效率有着直接的影响。本文主要 对复杂曲丽的布点策略和误蒙评定方法进行了研究。 本文首先对复杂曲面测点分布问题进行了研究，提出了一种基于距离的曲 ‘线、曲回布点方法。根据曲线由曲丽的关系，在对曲线布点方法进行研究的基础 上，将其扩展来解决幽面的采样问题。根据加工要求对曲线进行初始测点分割， 然后逐层求精、法代选点，实现了曲线的自适应布点。进而应用初始网格点与基 ‘ 于距离的选代选点相结合的采样方法，实现了曲面测点的自适应分布。该方法使 测点能够随曲丽曲旦在变化进行疏密分布，有效的反映曲面的拓扑倍息。 其次，对复杂曲面的误差评定方法进行了研究。利用最小二乘法构建误是评 定的目标的数。通过对齐局部坐标系和构建点对约束条件，优化了初始条件，然 后应用法代最近点 (ICP) 算法，对影响曲回位移与旋转的六个参数进行优化， 从而完成了复杂曲丽轮廓度误慧的评定工作。根据加工中的基准情况和曲面成型 理论，针对大坡度以及曲率变化平缓的曲而提出了投影转换坐标、用平面度最小 区城法求解的方法。 最后利用仿真实验对上述算法进行了相关验证。采用基于距离的曲面布点方 法，对仿真曲面进行自适应布点，并通过添加误差项来模拟真实测点，然后应用 ICP法和投影法分别对其进行了误差评价。实验表明，文中方法稳定有效，具有 实用性。 、‘ 关键词z 复杂曲丽布点策略形位误第最小工乘法投影法 飞， ABSTRACT With the rapid development of modem manufacturing indus町， diversification r叫uirements on 由e parts contour struc阳re are promoted ，while requirements of the surface quality are correspondingly increased. Development of geometric measurement is promoted by high processing quality. Improvement of inspection 咱 quality and efficiency is directly affected by point distribution method and error evaluation algorithm.ηle point distribution strategy and error evaluation on sculpture 咱 surface 缸e mainly studied in 由is paper. First of aU，point distribution is studied based on surface processing sampling problems and a new method of sampling on 创刊 and surface based on dis伽c is approved. In view of curve-surface relationship ，白e method of point distribution on the. curve .is studied and then it is extended 阳 address the issue of surface sampling. Curve is divided by initial measurement points according to prωessing rl叫uirement and 曲en adaptive point distribution is achieved by refmement and iterative search. Adaptive point distribution on surface is rea1ized by the method on combination of initial grid points and iterative points b制。d on distance. Point density distribution can be varied with the change of surface curva阳re and surface topology information is effectively re