Path effect on a polished surface always matches tool motions and manifests as mid-spatial frequency (MSF) errors in magnetorheological jet polishing processing. To control the path effect, extended methods and part-constrained paths are presented in this paper. The extended methods, Zernike extension and Neighbor-Gerchberg extension, are developed for building an extended surface with a weak edge effect in simulation. Under the constraint of the pitch principle, the unicursal part-constrained path is presented to enhance the randomness of the tool path, including path turns and dwell-point positions. Experiments are executed to validate the effectiveness of these measures for diminishing MSF errors. The peak to valley and root mean square of the surface are improved from 0.220 lambda and 0.047 lambda (lambda = 632.8 nm) to 0.064 lambda and 0.007 lambda, respectively, while simultaneously restricting the path effect. (C) 2016 Optical Society of America
展开▼
