The Design And Implement Of Acceleration/Deceleration Algorithm For CNC System

With the rapid development of science and technology in our country,the requirements of manufacturing industry for numerical control processing technology are becoming higher and higher.To realize high speed and high precision machining,excellent acceleration and deceleration control algorithm is indispensable.The acceleration and deceleration control algorithm controls the physical variables(jerk,acceleration,speed and displacement)of the machining path,so that the numerical control system has better acceleration and deceleration performance.However,sudden changes in jerk or acceleration speed during machining will lead to a decrease in the running stability of the numerical control system,thus affecting the machining accuracy and surface quality.There is a contradiction between the processing efficiency and the operation stability of the machine tool.Improving the processing efficiency will inevitably lead to the reduction of the operation stability,and vice versa.How to make the balance between the two and make the numerical control system meet the acceleration and deceleration characteristics of high-speed and high-precision machining are the research difficulties.In view of the above situation,thesis proposes a sine S-curve acceleration and deceleration algorithm based on trigonometric function.First of all,the basic principles and parameter expressions of several existing acceleration and deceleration control algorithms are studied,the change laws of acceleration and acceleration speed curves are analyzed,and the acceleration and deceleration characteristics of these algorithms are compared and analyzed.On the basis of comparison and analysis,their advantages are learned,and their disadvantages are improved,so that the improved acceleration and deceleration change laws are deduced,and a new acceleration and deceleration control algorithm is designed.Secondly,a sine S-type flexible acceleration and deceleration algorithm based on trigonometric function is proposed,and the corresponding calculation expressions of jerk,acceleration,velocity and displacement are given.Considering various situations that may occur in the actual machining process,the speed planning is carried out by using the optimization theory,and the numerical control machining is carried out at the optimal average speed.Finally,the acceleration and deceleration algorithms of cubic S-curve,five S-curve acceleration and deceleration based on arc,S-shape acceleration and deceleration,sine S-shape curve acceleration and deceleration are simulated and analyzed.The simulation results show that the sine S curve acceleration and deceleration control algorithm can ensure the smooth change of jerk and acceleration speed in the machining process and improve the motion stability of the numerical control system.The addition speed is maintained around themaximum value for most of the time,thus improving the processing efficiency and ensuring the running stability.