Research On Constant Power Adaptive Control Method Based On SINUMERIK 840D CNC System

With the development of aerospace and other industries in our country, intelligent manufacturing is an inevitable trend in the development of manufacturing industry. The cutting process is highly nonlinear and uncertain, and the NC machine tool has a limited ability of identfying the uncertainty in the process of machining. Therefore, the lower cutting paramaters was taken in the actual machining and the machining efficiency is restricted. As one of the key technologies in intelligent machining, the adaptive control with constraints for the CNC machine processing has important research value. The previous studies of adaptive control has a disadvantage of high cost and complicated installation using the external sensor. To solve this problem, a constant power adaptive control system was developed using the inner sensor and controller based on the SINUMERIK 840 D.The total solution of the constant power adaptive control system for open-architecture CNC machine was analyzed, taken three types of CNC system for example. A fuzzy controller was designed to ensure the intelligent control of the machining process. The fuzzy processing、fuzzy control rule and fuzzy inference was discussed and the fuzzy interrogation table was made using MATLAB. The SINUMERIK 840 D was taken as the research object and the real time collection of the spindle power based on OPC(OLE for Process Control) was studied. The control method of feed rate based on the DDE and PLC was developed. The friendly human-machine interface was developed based on the rules of OEM method of SINUMERIK 840 D. The configuration method of the control file and the DLL documents was introduced.Finally, a group of cutting experiments was designed based on whether using the constant power adaptive control system or not. The spindle power and the feed rate was analyzed and the result showed that: the developed constant power adaptive control system for open-architecture CNC machine had a good control effect. The machining efficiency was significantly improved with a good protection of the machine tools.