The Exploitation Of Real-Time Compensation Controller Based On ARM11 For CNC Thermal Error

With the advancement of modernization, machining accuracy of industry is highly required. As the main tools in machining, machine tool’s precision determines the level of industry. Many factors affect the accuracy of CNC machine tool, thermal error is one of the largest sources of errors that affect machining accuracy. Error compensation is the more common method of controlling errors. Although error compensation technology has made some progress, the thermal error modeling achieves accurately and convenient thermal error compensation is difficult to come true. The embedded technology, neural network and Matlab simulation modeling are combined and applied to the thermal error compensation of machine tool in this paper. The major works of exploitation for thermal error compensation controller are as follows:Firstly, the applied widely and more mature BP neural network model and stronger generalization performance, robustness support vector machine are used to mathematical modeling, their principle and algorithm are introduced respectively. The temperature sensors are used to collect critical point temperature of the machine, and collected series experiments data sets. These data are used as the source data to establish thermal error compensation model. Compared two different modeling methods, the two models are used to simulation using MATLAB; the effectiveness of the thermal error compensation model is verified.Secondly, real-time thermal error compensation of machine tool controller is exploited. Human-computer interaction interface is designed by QT Creator software. The platform of software and hardware developing environment is established. The real-time thermal error compensation controller is divided into three modules:the module of temperature acquiring, the module of further development for thermal error modeling and real-time compensation module. The hardware and software of the real-time thermal error compensation controller are introduced too.Finally, the thermal error compensation experiments of machine’s spindle are conducted. The sensors sample the temperatures real-time, the model is established offline and the parameters are saved, and on this basis the secondary development model is embedded in ARM1 ILinux development board. This embedded controller is exploited which is get rid of the PC computer and compensates the CNC thermal error online.The real-time thermal error compensation of CNC machine tool is primarily achieved, some simulations and researches have done in SIEMENS machine tool and FANUC machine tools, and it has some theoretical significance and practical value for improve the machine tools’accuracy and construct the finally thermal error compensation controller.