Error analysis and compensation for the volumetric errors of a vertical machining centre using a hemispherical helix ball bar test

Abstract

Machining accuracy is directly influenced by the quasi-static errors of a machine tool. Since machine errors have a direct effect upon both the surface finish and geometric shape of the finished workpiece, it is imperative to measure the machine errors and to compensate for them. A laser measurement system to identify geometric errors of a machine tool has disadvantages, such as a high cost, a long calibration time and the usage of a volumetric error synthesis model. In this study, we proposed a novel analysis of the geometric errors of a machine tool using a ball bar test without using a complicated error synthesis model. Also, a statistical analysis method was employed to derive geometric errors using a hemispherical helix ball bar test. According to the experimental result, we observed that geometric errors of the vertical machining centre were compensated by 88%.

Volumetric Error Compensation in Five-Axis CNC Machining Center Through Kinematics Modeling of Geometric Error

“…Another indirect measurement is that of contour measurement, with multiple axes moving along a predefined path simultaneously [32]. Circular paths with two linear axes moving simultaneously [33], circular paths with two linear axes and one rotary axis moving simultaneously [34] and three-dimensional helix paths with three linear axes moving simultaneously [35,36] are all possible trajectories for indirect measurements. Commercially available measuring equipment capable of contour measurement includes 3D ball plates [37], laser tracers [38], the R-test system and the DBB [39] etc.…”

Characterisation of 1D opto-electronic sensors and their application to angular self-centring probes for machine-tool verification

“…Although this method is the most accurate, its main problem is that it is very time consuming. Recently, there has been a growing interest in quick checking systems of the general state of the MT [3][4][5][6]. However, these techniques, although less time consuming, are not able to provide all the geometrical errors of the MT.…”

Measuring geometrical errors of linear axis of machine tools based on the laser tracker

“…For example, researchers have proposed several displacement approach by measuring the positioning errors 22 lines, 15 lines, 14 lines and 9 lines in the machine tool work zone to identify 21 geometrical error components of three axes machine [10][11][12][13]. Because of the utilizing the laser interferometer system, laser interferometer methods in these two categories still have some disadvantages, such as long calibration time and requirement of experienced and skilful operator [14]. W. T. Lei and Y. Y. Hsu etc developed a 3D probe-ball system to test the geometrical errors of five-axis machine tool and the accuracy enhancement is performed successfully [1,7,9].…”