Cutting Path Planning for Complex Optical Surface Using Hermite Interpolation

Abstract

The cutting path planning is discussed in order to solve the difficulties of processing complex optical surfaces.Cutter location point(CL) planning is designed,cutting contact point(CC) discretization and cutting tool compensation are analyzed based on slow tool servo.Based on programmable multi-axis controller(PMAC),Hermite segment interpolation is analyzed which is used by trajectory interpolation,and three position velocity time(PVT) entrance parameters algorithms are putted forward,the constant speed method,the area method and the three points method.The simulation of cutting path of off-axis parabolic,toric and sinusoidal surfaces shows that the design of CL can be used to complex surfaces processing.Meanwhile,the analysis of z axis motion characteristics shows that area method(c = 2/3) and three points method both can meet the requirements of smooth velocity of z axis when z axis reciprocating frequency is similar to C axis rotary frequency.And three points method is better than area method in the change of acceleration when z axis reciprocating frequency is significantly greater than C axis rotary frequency.The proposed method affords benefit for practical manufacturing of complex optical surfaces.