Research On Prediction Algorithm And Simulation For Surface Morphology Of Optical Free Surface

Freeform optical surface is a kind of aspheric surface of Non rotationalsymmetry and irregular. In the optical system, it could simplify structure, improveperformance and reduce the complexity of system debugging. Based on theseadvantages, freeform optical surfaces are widely used in industry and national defensefields. Now, in the processing optical surface methods, the most commonly used isdiamond turning based on FTS (Fast Tool Servo). In recent years, the study of FTShas made some progress both at home and abroad. Because of the surface accuracyand surface quality decide to the using performance, so how to improve the surfaceaccuracy and surface quality is very important and is a hot spot for research. Surfacetopography is the important index to measure the surface accuracy and surface quality,so prediction and simulation of surface topography has certain guiding significance tothe actual processing. This article is mainly on the prediction of the surfacemorphology research.Based on the diamond turning of FTS to machine freeform optical surface, thisarticle discussed how to choose the blade shape and geometric parameters of tools.According to the FTS device of two axes linear and using the tool path planning ofconstant radial feed, two kinds of tool path generation algorithm are obtained. Andaccording to the algorithm, has obtained the respective tool path trajectory.By analyzing the generation mechanism of surface topography, residual areaheight is an important factor to affect the information of surface topography. Byanalyzing three curved surface (concave surface, convex curved surface and plane)when machining freeform optical surface, established the mathematical model ofperfect residual area height. Due to the processing of freeform optical surface belongto the category of ultra-precision machining, and considering the influence of theminimum cutting thickness in practical machining, established the mathematicalmodel of the actual maximum residual height. Combined actual residual area heightwith tool path planning, a new prediction algorithm of surface topography is proposed.And based on the prediction algorithm, simulated the surface topography of ring surface by Visual Studio software and MATLAB software.Through to describe the method of measurement and evaluation about surfacetopography, choosing the commonly used evaluation parameter named PV (Peak toValley) to evaluate surface topography. Put the spindle speed, feed speed and cornerradius as influencing factors, analyze and calculate the surface PV. And based on theresult, obtained the curve of influence rule.Based on the research work, when do the actual processing, choosing the rightalgorithm of tool path, improve the machining efficiency. Combined surfacemorphology prediction algorithm with tool path, simulated the better morphologypicture. Through to calculate the data, obtained the influence curve. By the analysisresult, it can provide a theoretical basis about how to choose the cutting technologyparameters for actual machining. Based on the actual machining, it can improve thegood surface when elected the higher spindle speed, the smaller feed rate and thelarger arc radius.