| Five-axis hybrid machining robot is a new type of Computer Numerical Control(CNC)machine tool,which has the advantages of high accuracy,high stiffness,large load capacity,good flexibility,and large working space.It is used for milling carbon fiber composite material,drilling on curved surface and polishing parts.Developing Five-axis hybrid machining robot is of great significance in improving China’s advanced manufacturing capabilities and developing intelligent manufacturing equipment.The motion control technology of five-axis hybrid machining robots is studied by designing and building an open and modular CNC system.And new trajectory planning methods of five-axis hybrid machining robot is proposed for smoothing movement and reducing acceleration shock and vibration.The CNC system is mainly composed of industrial computer and servo drivers.Based on open motion control platform,the CNC system is developed.The core modules in CNC system,including G code compilation,path smoothing,speed planning,interpolation,etc.are studied and developed,thus achieving the key five-axis machining function.In order to get more smoothing trajectory of each driving axis,velocity planning algorithms,which are Hot Area Optimization(HAO)method and Dynamic Adjustment(DA)method,are proposed.Both algorithms are tested by line path and complex curved path,and results show that both proposed methods successfully get the feed rate curves that meet the constraints.The HAO method has better motion smoothness,and the DA method can make better use of the robot’s capability.The CNC system is tested through trajectory tracking experiment,which verifies the system’s basic properties,and also implies that the proposed velocity planning method has positive effect on reducing trajectory contour errors. |
