Sensitivity analysis of relationship between error motions and machined shape errors in five-axis machining center - Peripheral milling using square-end mill as test case -

Abstract

Five-axis machine tools, consisting of three translational axes and two rotary axes, are increasingly being used for complex surface machining. This paper proposes a new sensitivity analysis method to elucidate the relationship between the tool trajectory error and the error motions of the feed axes. Based on the free-curve trajectory during simultaneous five-axis machining, a surface coordinate system is created for each tool center point, to define the tool trajectory and the trajectory errors. Then, a novel sensitivity coefficient is defined to investigate the relationship between the trajectory error and the error motions. It is shown that the proposed sensitivity analysis method can successfully determine whether the trajectory is sensitive to the error motions, based on sensitivity analyses performed during conic frustum machining and S-shaped machining tests. Moreover, the sensitivity analysis method can also predict the effects of the error motion source, such as the reversal errors. In the future, we intend to study other types of machining processes, such as ball-end milling, as well.