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

Multi-axis machine tools are important units in modem production systems. T he complex structures of the machine tools produce an inaccuracy at the too l tip caused by kinematics parameter deviation resulting from manufacturing errors, assembly errors or quasi-static errors. To find out the error orig ins 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 an alyzing the measured data. The diagnosed errors could be taken under consid eration only by the precise description of the actual kinematics of the mac hine tools. By counting the new axes values by numerical iteration techniqu e 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 desire d position. This paper describes two ways to modify NC programs (implemente d in a postprocessor for CL-data or by extra NC program processor for ideal NC program) including modeling and measurement of real machine tools. Prac tice and application will be described in part two. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.