Generation of Parametric Kinematic Error-Correction Functions from Volumetric Error Measurements

A rapid arid convenient means of acquiring a knowledge of the kinematic errors of a machine or mechanism can be helpful in the diagnosis of the source of these errors and in their mechanical or software correction. However, direct measurement of kinematic errors is often difficult and time consuming. Volumetric error measurements are often more easily made. It therefore is desirable to be able to obtain parametric functions describing kinematic errors from volumetric error measurements rather than by measuring the kinematic errors themselves. Three phases in the generation of kinematic error functions from volumetric error measurements are described in this paper: establishing a kinematic model, acquisition of volumetric error measurements, and determination of the parametric error functions from the volumetric error measurements. These functions can be used to diagnose the source of errors. They also represent kinematic errors in a compact form suitable for software-based real-time error correction in machine motion controls.