Volumetric calibration of multi-axis machine tools through parametric way

Abstract

A methodology was implemented to evolve the volumetric errors of multiaxis machine tools through a parametric way. The volumetric error was calibrated and evaluated in the workspace arbitrarily by implementing parametric methods and techniques. In parametric method linear displacement errors and angular displacement errors were measured through a laser interferometer with combination of a newly developed three-line measuring method to measure the prismatic joints for efficient and quick error meterage. Besides these, squareness errors between the axes were also quantified by using reversal method. Volumetric accuracy portrayed the real error picture between the workpiece and cutting tool or end effectors or a measuring probe. So positional errors, straightness errors, angular errors and squareness errors were quantified and transformed into volumetric accuracy by using generalized homogenous transformation matrices, whereas forward kinematics technique was used as a tool. Measured results can be used to compensate the volumetric errors to achieve high precision in manufacturing and measurement through physical compensation, making correction, adjustment or improvement through software. Reported here is the volumetric accuracy results carried on a multi-axis CNC milling machine under controlled environmental conditions and as per the standard procedure and practice.