Three-Dimensional Measurement of Unaxisymmetrical Form by Contact type Measuring Equipment

Abstract

The purpose of the study is three-dimensional evaluation of unaxisymmetrical form by using a contact type measuring equipment. The characteristic of the proposed method is to be able to compensate six setting errors which are x, y, z-directional components and rotational components around x, y, z-axes. Algorism which is based on simplex method is proposed to search the errors. The merit of the proposed method is to be robust to multipolarity of the objective function. The function is composed of the sum of square deviations among measured data and reference model data. The errors to minimize the function are searched by the proposed method and are removed by coordinates transformation. The following facts are revealed by experiment : (1) The accuracy of three-dimensional evaluation is 0.7 μm (P-V), which is confirmed by measurement of a master paraboloidal mirror. (2) The measured results by the contact type measuring equipment and CMM resemble well.