Accurate size evaluation of cylindrical components

作者：Ramaswami Hemant; Anand Sam^*

来源：International Journal of Advanced Manufacturing Technology, 2010, 49(9-12): 1079-1092.

DOI：10.1007/s00170-009-2461-5

• Size
• Actual value
• Open uniform B-spline curve
• Cylinder
• Particle swarm optimization

The objective of this paper is to develop a methodology to calculate the size of a cylindrical profile accurately per American National Standards Institute (ANSI) standards. The ANSI Y14.5.1M-1994 standard defines the size of a cylinder as the size of the largest ball rolling on a spine such that all points on the surface of the cylinder are external to it or the size of the smallest ball rolling on a spine such that all points on the surface of the cylinder are internal to it. Current methods of size evaluation reduce the complexity of the spine and model it as a straight line. In this paper, a methodology is presented to evaluate the control points of the spine modeled as an open uniform B-spline curve of a prespecified degree based on points collected on the surface of the cylinder. This provides a quantitative measure of the size of the cylinder in accordance with ANSI standards. The formulations to evaluate the maximum inscribing spine and the minimum circumscribing spine are presented as multilevel optimization problems. The outer level optimization is used to identify the optimal set of control points for the spline representing the path of the rolling ball. The inner level optimization is used to find the nearest point on the spline corresponding to every point in the dataset. The optimization formulation presented in this paper has been used to calculate the true size of cylinders for several published, simulated, and real datasets. These results are then compared to traditional estimates for size of a cylinder. The results indicate that the method presented for calculating the size of a cylinder conforms better to the ANSI standards as compared to other methods, such as the maximum inscribed, minimum circumscribed, and least squares cylinders, which have been traditionally used as indicators of size of a cylinder [1]. Further analysis is presented to observe the effect of sample size on the results of the algorithm. It is observed that with an increase in the sample size, the difference between the results of the presented algorithm and the traditional methods increases with the presented method providing more accurate estimates.

• 出版日期2010-8