All position-independent and position-dependent geometric error measurement and identification of the precision of a horizontal boring machine tool

Abstract

 Geometric error is the main obstacle that affects the quasi-static accuracy of horizontal boring machine tool. To improve quasi-static performance, the error terms that all PIGEs and PDGEs must be measurement and identified precisely. This study proposes a novel methodology for measuring and identifying that the above two types of geometric errors based on DBB for rotary axis. The error terms of linear axis are identified from measurement model based on exponential product method and a preset measure trajectory, and the measure coordinate system be unified together with reference coordinate to lower the uncertainty of identification accuracy, and then Elastic Net method and improved weight function IGG3-LTS method are established to identify the PIGEs and PDGEs of rotary and linear axes respectively. This method has the advantage that measurement with built in-sensors method that synchronously without interfering with the running state of the machine tool, and neither the inaccuracy of reference-frame misalignment nor installation error of the measuring instrument affects the geometric error identification results of linear axis. , the other is all PIGEs and PDGEs particular to rotary axis of horizontal boring machine tool are determinated accurately. The measurement and identify strategy is demonstrated by experimental comparison on a four-axis precision horizontal boring machine tool, the minimum compensation rate of each precision index of test specimen is 40.0%, the average compensation rate is 52.7%, and the maximum compensation rate is 62.5%. under the actual condition of machine tool.