Environmental conditions compensation for a length measurement system based in laser interferometry for machine tool volumetric verification

Abstract

Abstract Measurement systems based in laser interferometry have been usually used in industry for volumetric verification. The behaviour of these systems rely on the wavelength of the laser used and so the estimation of the refractive index of the ambient air is a fundamental step in the measurement process. The environmental conditions can be measured with an environmental compensation unit and several equations can be used to estimate the refractive index. When several measurement systems are needed to measure the position of the machine tool head simultaneously during a volumetric verification, the information of the environmental control unit has to be applied to all the measurements in order to compensate the measurement result with the ambience conditions. This can be done estimating an adequate compensation model from the environmental data. In this work the Ciddor equation has been used to adjust compensation models based in regression curves.