An Innovative Non-Contact Surface Measurement Solution for Asphere, Deep Parabolic, and Ogive Radome Geometries

摘要

OptiPro Systems is developing a non-contact measurement system using state of the art motion control while minimizing the axes of motion during the measurement. The goal is to precisely scan concave and convex surfaces of aspheric, deep parabolic, and ogive shapes without the limitations associated with other measurement methods. The metrology systems will use different computer controlled slicing techniques to create a topographical surface map of the surface form with a high accuracy non-contact probe.rnTo achieve this precise scan the measurement system will incorporate sub-micrometer precision air bearings for the linear and rotary axes motion to minimize the effect of non-repeatable mechanical errors. Calibration of the measurement system will use high precision reference spheres. Finite element modeling and estimate has been used to predict and possibly compensate for mechanical flexures.rnOptiPro has built a "breadboard" measurement system using a Professional Instruments air bearing and a ST1L white light measurement pen. The results from the measurement of a near full hemispheric dome measurement will be presented as well as a comparison to the same dome measured using a stitching interferometer. The final system will incorporates complete computer controlled axes requiring as little operator training and set up as possible. The prototype system will utilize a non-contact pen for measurement. Current developments include the utilization of the STIL white light pen and the OptiGauge optical probe which utilizes invisible 1310 nm infrared light. The current system design and performance will be presented.