Research And Implementation Of Motion Planner For Complex Curve In CNC Systems

In recent years, accompanying with the rapid development of manufacturing,user requirements for the machining of workpieces with complex surface enlarge increasingly, the study of complex curve motion planning method comes to one of the primary missions of NC technique development. At present whether it has complex curve motion planning method ,comes to be an important guideline of judging of high performance of NC system.This thesis describes using motion planning methods to machine workpieces with complex surface in existence, it always appears some problems such as speeding up or slowing down frequently,machining inefficiently,roughness of surface,and data hungry, wherefore it makes a study of complex curve motion planning method and practises the researching findings to the actual maching.This thesis first introduces the structure of open numerical control,and researches some related methods about motion planning.On the basis of researches about motion planning method at the basis of S-shape acceleration and deceleration method, this thesis aimed at the problem in tapical micro-segment method for machining complex curve in existence presently,it gives out segments-chain active motion planning method,this method can carry out fast and smooth machining for complex curve by processing the segments chain made of many micro-segments processes unified motion planning. A motion planer which uses the method above is designed and implemented in the environment of LT-NC210. The actual machining test in LT-NC210 system indicates that when machining complex curve fitted by micro-segments by new method, electromotor runs calmly, high efficiently,and machining surface smoothly.Besides,as spline method applys to complex curve with high precision and small NC file,it can efficiently avoid the data hungry made by micro-segment method in the actual machining and other excellences,this thesis also studys the motion planning method for spline curve and gives out cubic parameterization spline curve motion planning method.Emulate test shows that, parameterization cubic spline motion planning method realizing the motion planning of cubic spline curve,can carry out in LT-210 system.