Machining, Measurement, and Control Laboratory

Indirect Measurement of Volumetric Accuracy for Three-Axis and Five-Axis Machine Tools : A Review
Soichi Ibaraki and Wolfgang Knapp

The volumetric accuracy of machine tools is represented by a map of position and orientation error vectors of the tool over the volume concerned. Numerical compensation for volumetric error is possible in many latest commercial CNCs for machine tools. This paper reviews indirect measurement schemes for machine tool kinematics, in which the tool center position is measured as the superposition of error motions of linear or rotary axes. Each error motion can be separately identified by best-fitting a set of measured tool center positions to the kinematic model of machine tools. Indirect measurement schemes for the kinematics of three orthogonal linear axes, as well as the fiveaxis kinematics with two rotary axes, will be reviewed.
Keywords: volumetric accuracy, indirect measurement, machine tools, kinematic model.