Research And Implementation Of Acceleration/Deceleration Control And Smoothing Algorithm During The NC Machining

With rapid development of economy,the precise instrument,aerospace and other industries have more and more high requirement of high speed and high precision CNC system motion control technology.Common acceleration and deceleration control algorithm is used for planning physical parameters such as jerk,acceleration,velocity and displacement of processing path.The discontinuity of jerk and acceleration will greatly reduce the flexibility and stability of CNC system.In order to prevent above situation,this paper study the acceleration and deceleration control algorithm and the smooth switching algorithm of current CNC system,then an five-segment S-curve acceleration and deceleration algorithm based on the transition of arc is proposed.First of all,study the acceleration and deceleration control algorithm in small continuous segment.Study the principle of algorithms and parameters of expression of several existing acceleration and deceleration control algorithms and then compare and analysis the advantages and disadvantages of these algorithms.Secondly,study the constraint factors of smooth switching algorithm of tiny straight line segments: the limit of feed speed,acceleration,processing error and the mechanical properties of machine tool.Study the direct transition algorithm,the curve-fitting algorithm and the circular arc transition algorithm of the small line segments.In order to realize high speed smooth connection between the small line segments,compare and analyze the advantages and disadvantages of these algorithms,choose the appropriate algorithm according to the requirement during the processing of the smooth transfer.Once again,to realize high speed and high flexibility processing,this paper puts forward an five-segment S-curve acceleration and deceleration algorithm.This paper provides expressions of jerk,acceleration,velocity and displacement.In view of the situations that may occur during processing,this paper plans speed in the processing according to the principle of optimal control.Finally,do the simulation of above algorithms.The simulation results show that the five-segment S-curve acceleration and deceleration algorithm is able to improve the flexibility of system,effectively improve the smooth transfer speed between segments.