Compensation of static and transient thermal errors on CMMs

Using CMMs under normal workshop conditions necessitates to take into account the influence of environmental temperature on the machine structure. Non-standardised environmental conditions result in temperature dependent measurement errors. The paper presents a parametric approach to describe the relation between transient temperature distributions and resulting deformation of the CMM. The focus lies on broadening the temperature range in which the original accuracy specifications can be guaranteed. Starting from a correction scheme for uniform, invariant temperature situations, an approach for transient environmental loads is developed. Based on a limited number of temperature inputs, the required correction coefficients for the probe position are calculated.