Abstract: Optical components with complex surfaces or microstructure array are more and more widely applied, but it is very difficult to satisfy the requirements of surface accuracy and machining efficiency by using traditional mechanical fabricating methods. Ultraprecision fast tool servo (FTS) system can manufacture these complex surfaces efficiently and accurately. The relative position between the tool and workpiece surface will vary continuously in the FTS machining process, owing to the height change of workpiece profile, and this will worsen the cutting conditions, debase the machining accuracy, and even produce the phenomenon of tool interference and over-cut. In view of the situation, the varying rules of cutting angle are studied in the FTS machining process of complex workpieces, as well as the influences on rake angle and back angle of the tool. The algorithms for identifying tool interference and the selection basis of machining parameters are given. In order to realize rational route planning, the analysis and algorithm design of tool compensation are accomplished in the machining process of typical complex optical surface. On the basis of the above work, a kind of representative complex workpiece, radial sinusoidal workpiece, is manufactured by using the FTS system. The measuring results indicate that accuracy of machined surface can reach PV 0.17 μm, and the over-cut and tool interference do not occur.

Key words: Complex surface, Cutting angle, Fast tool servo, Route planning, Tool interference