Research Of Trajectory Control Method About CNC System For A Novel Five-axis Hybrid Machine Tool

This thesis deals with some key issues in the development of CNC system of a novel five-axis hybrid machine tool based on a 3-DOF parallel spindle head,including interpolation,velocity control strategy,post-processing,The following achievements have been obtained.Considering the structural characteristics of A3,a two-step interpolation strategy is proposed.The disadvantage of traditional interpolation is considered.The CL file is processed by tool orientation interpolation algorithm in work space and by modified three B-spline fine interpolation algorithm in joint space,which verifies the tool path control algorithm can reduce the CL point position error and cutter swept surface space contour error.On the basis of the two-step interpolation strategy,the velocity control strategy of five-axis hybrid machine tool is put forward.The five stages of S curve velocity control algorithm can ensure the continuous speed and acceleration and can improve the flexibility of the system.Moreover,in order to improve the processing efficiency of CNC system,a velocity transition method for the adjacent program is adopted without decrease the contour accuracy.According to the characteristics of parallel mechanism,the post processing module is developed based on Labview software.The post processing function is implemented to converse the cutter location files to five-axis NC codes automatically.Finally,the programming and machining experiment of a specimen with S shape was completed successfully,which verifies that the performance of the developed module is expected.