Modeling, measurement and error compensation of multi-axis machine tools. Part I: theory

Multi-axis machine tools are important units in modem production systems. The complex structures of the machine tools produce an inaccuracy at the tool tip caused by kinematics parameter deviation resulting from manufacturing errors, assembly errors or quasi-static errors. To find out the error origins of these machine tools it is always necessary to have good mathematical models of the machine tools. These models can be used for measuring and analyzing the measured data. The diagnosed errors could be taken under consideration only by the precise description of the actual kinematics of the machine tools. By counting the new axes values by numerical iteration technique of the defective axes from the cutter location data (CL-data) or from the ideal NC program it may be possible to position the tool tip to the desired position. This paper describes two ways to modify NC programs (implemented in a postprocessor for CL-data or by extra NC program processor for ideal NC program) including modeling and measurement of real machine tools. Practice and application will be described in part two. (C) 2000 Elsevier Science Ltd. All rights reserved.