【摘要】 测量数据的精确定位是实现复杂曲面加工检测的关键,针对其在初始变换估计和最近点计算等方面存在的问题,提出一种快速、精确的定位方法。该方法以曲面的曲率为联系特征,建立起满足角度、距离约束的对应关系,能够实现测量数据的初始定位,从而为后续迭代算法向全局最优收敛提供一个良好的初始变换。进而以Bernstein多项式算术运算为基础,给出一种新的最近点计算方法,能够克服传统方法需要给定初始迭代点的不足。最后利用基于最小二乘的迭代算法完成测量数据定位的精确调整,达到全局最优的目标。试验结果显示,所提出的方法快速、可靠,并且具有良好的定位精度。更多还原

【Abstract】 Optimal localization of free-form shaped parts is a key issue in precision inspection. Aiming at the problems on estimate of the initial transformation and the calculation of closest points, an effective and exact localization method is presented. First, this method establishes the corresponding rela-tionships between two free-form surfaces with constraints of angle and distance by means of the surface features of the Gaussian curvature and the mean curvature. Then the rough localization is realized. Using the robust arithmetic for multi-variate Bernstein-form polynomials, a novel algorithm to cal-culate closest point is proposed. An improved iterative algo-rithm is used in the exact adjustment of localization to ensure the global optimization. Experiment results demonstrate the feasibility of the proposed method.更多还原