| Although our country is one of the largest global machine tool industry consumer market,but still mainly imported high-grade machine tools,with the CNC(Computer Numerical Control)of abroad FANUC,SIEMENS.And our country independent production of CNC machine tools for low-end consumer market.Entry barriers to reduce domestic CNC system,severe industry follow suit,lead to a vicious competition,industry growing share of the low-end market,technology to a fundamental breakthrough.Because the CNC machine tool function unceasingly strengthens,composite technology is more widely used,can the user wants to use the machine a variety of process of machine tool,makes the original processing a single process of machine tool demand.See domestic users of high-grade compound CNC machine tool and CNC system market demand,based on the development of lathe composite grinding CNC system as the goal,in view of the CNC system interpolation and deceleration research work,some key technologies such as NURBS spline curve interpolation algorithm is mainly studied,eccentric circular grinding,NURBS spline curve interpolation algorithm in the application of camshaft grinding to the transition and experimental research,to develop the lathe composite grinding high-grade CNC system to the market.The paper firstly introduces the overall design of EtherCAT bus CNC system based on industrial PC.Then the current CNC system commonly used linear interpolation,arc interpolation algorithm,NURBS spline curve interpolation algorithm and so on has carried on the brief introduction,deeply analyzes the theory of NURBS curve and its the nature and characteristics.In this paper,the acceleration and deceleration control of the trajectory interpolation is carried out by the linear and S-shaped curves.The calculation of the target speed and the length of deceleration zone and the new acceleration or acceleration are analyzed.The "tail" phenomenon of the remaining displacement is solved by solving the minimum velocity.For eccentric circle machining,designs an eccentric circle interpolation functions of specific methods,according to the grinding wheel radius,eccentric circle radius,use their geometric relations,and the motion law of eccentric circle grinding are analyzed in detail,that intuitive and easy to control equations of motion,X and C axes linkage.Finally,the proposed interpolation algorithm and the deceleration control method are used in the CNC lathe machine to carry out the eccentricity circle and the camshaft grinding experiment on the CNC grinding machine.The experimental results show that the proposed interpolation algorithm and the deceleration control method can realize the processing of the outer circle,eccentric circle and camshaft,and the machining accuracy is high and the performance is stable and reliable. |
