Method of calculating the speed of a compact tool during shaping of precision optical surfaces

摘要

A method of calculating a control program for machines designed to correct the shape of optical surfaces with a compact tool is described. This approach, based on the use of equidistant trajectories, allows us to simplify the representation of the surface as a set of two-dimensional error profile cross-sections and calculate the control action independently in each section. In this case, the tool, by analogy with the concepts of control theory, is represented as an aperiodic link. Its input is the "tool speed" signal, and its output is the "removal value" signal. To calculate the required input signal, it is possible to avoid using the deconvolution operation, replacing it with proportional control along with an iterative calculation using a model of the result of processing. The influence of the step size of equidistant trajectories on the residual waviness is then analyzed. Examples of machined aspherical surfaces are given. (C) 2019 Optical Society of America