A Simple Evaluation Method for Form Deviation of Planar Curve Contour Based on Coordinate Measurement

Abstract

In this paper we propose a simple evaluation method for form deviation of complex planar curve contours based on coordinate measurement data. Using this method, the contour curve is expressed in terms of its optimum interpolation circular arcs, whose interpolation accuracy can be specified arbitrarily, and the form deviation is defined as the deviation between the points of measurement and the arcs. The geometrical form deviation of the profile is evaluated using the least squares method. It has been demonstrated that the difference between the deviation definitions, relative to the contour curve or to the arcs, is not larger than the circular interpolation accuracy. In other words, the accuracy of the evaluation can be sufficiently guaranteed. The method is easy and convenient for engineering applications. An actual evaluation example for a planar cam profile is shown. The result confirms the validity of the proposed method.