Research And Implementation Of Embedded Reconfigurable CNC System

The reconfigurable manufacturing system (RMS) is a new trend of the futuremanufacturing system, and the reconfigurable computer numerical control (CNC) system is akey technology in the reconfigurable manufacturing systems. The reconfigurable technologycan improve the flexibility of the CNC system, respond quickly to the machining processrequirement, configure reasonably system resources and save the cost of manufacturing.Additionally, with the development of microelectronics and the field-programmable logicdevices, embedded numerical control system will be an important direction of developmentin the future. From a macro perspective, the research of embedded reconfigurable CNCsystem, not only keep with the national policy, but also meet with the needs of the machiningmarket.At present, there are few researches of CNC system based on the embedded architecture.In structural design, system reconfigurability is often ignored. Moreover, the logicalextension is not strong, and the system is less universal. In addition, there have been manyresearchers working on NURBS interpolation algorithm, but most of them did not considershort spline curve interpolation, which resulted in the algorithms lacking versatility. Forthese reasons, this paper proposed the architecture of an embedded reconfigurable CNCsystem, then on the base of which, NURBS interpolation algorithm and reconfigurable servoalgorithm have been studied. Finally, an embedded reconfigurable CNC system, whoseperformance was confirmed by experiment and project applications, was developed and built.The major research works and contributions of the thesis are introduced as follows:1. By analyzing the limitations of the PC-based CNC system and the present embeddedCNC system, a modular, reconfigurable embedded CNC system architecture was proposed,which combined the functional requirements of the opening numerical control system. Thesystem was improved from the traditional embedded system architecture which was based onthe ARM+DSP+FPGA architecture, and expanded the industrial Ethernet function module. Then, the reconfigurability and network capabilities of the system were analyzed from theperspective of hardware and software.2. Based on the research and analysis of the servo operating mode and thecorresponding control method, and combined with the advantages and disadvantages of thepresent commercial motion controller on the market, a reconfigurable servo controlalgorithm model was proposed. Meanwhile, the reconfigurability was analyzed based on theproposed algorithm, and the implementation of the proposed algorithm was introduced byfocusing on the implementation of digital PID controller and notch filters.3. A novel and accurate real-time NURBS interpolation algorithm was proposed, whichovercame the deficiencies of the existing NURBS curve interpolation algorithm. An S-curveacceleration/deceleration (Acc/Dec) control was adopted, and the look-ahead process wasoptimized. Meanwhile, it improved machining efficiency by adding the circular buffer andpre-interpolation (non-off-line) and enhanced the real-time performance by reasonablearrangement of the interpolation tasks.4. According to the proposed embedded reconfigurable CNC system architecture, amodular, reconfigurable embedded CNC system with industrial Ethernet function wasdesigned and implemented. Then the composition of system key hardware module andinterface circuit design was presented. Finally, the software implementation of theapplication layer and the hardware driver layer was given.5. Based on designed reconfigurable embedded CNC hardware platform and theproposed algorithms, an embedded reconfigurable CNC system controller, whoseperformance was confirmed by experiment and project applications, was developed andbuilt.