Abstract: To solve problems of too large non-linear error and damages to the workpiece, the cutter and the machine tool caused by drastic motion of the rotational axis in singular area, an algorithm that optimizes the tool path of five-axis machining in singular area is proposed. Consider a table-tilting type machine tool with two rotational axes A and C. The initial optimization for C angle based on the periodicity of sine function and cosine function proceeds. Based on judging whether the tool passes the singular point, there are two ways to decrease too large rotation of C axis further. The one is setting the value of C angle at the singular point. The other is modifying the direction of tool axis near the singular point. The intervals whose non-linear errors still exceed the allowed range are interpolated recursively. The experiment is performed to test that the rapid motion of axis in singular area is effectively prevented and the non-linear error is largely reduced by such method. Simultaneously, compared with the method just using linear interpolation, the number of interpolated points is fewer and the processing speed is faster via such method.

Key words: Five-axis machining, Motion control, Singular area, Tool path optimization