【作者】 方称生；

【导师】 高伟强；

【作者基本信息】 广东工业大学 ， 机械制造及其自动化， 2012， 硕士

【摘要】 随着科学技术的发展,数控技术正朝着高精化、高速化、柔性化、智能化等方向发展。传统的封闭式数控系统因其缺乏开放性而无法适应灵活多变的市场需求。开放式数控系统的硬件和软件都具备可置换、可扩展和可互操作等灵活多变的特性,因而受到越来越多的关注。本文针对于多个著名开放式控制系统项目进行研究,提出了切合实际的基于现场总线的开放式数控系统的设想并设计了软硬件架构。在基于现场总线的开放式数控系统中,主站控制器与从站运动模块之间的通信不仅要满足底层运动模块的柔性扩展而且还需要满足运动控制的实时性和同步性,因此其通信方式的研究相当重要。另外在采用COM组件的方式对数控软件进行模块化设计的过程中,运动控制模块的设计应是考虑的重点。其中曲线插补技术将有助于数控系统性能的提高,它能够使系统直接进行曲线加工,从而提高系统的加工精度和加工效率。因此本文将重点对基于现场总线的开放式数控系统的通信方式和曲线插补技术两个关键性技术进行深入细致的研究。在通信方式的研究过程中,比较了多种实时以太网在通信速率、同步性和实时性方面的优缺点及适用性,确定了既能满足开放性要求又能满足实时性、同步性要求的EtherCAT实时以太网作为通信方式。EtherCAT实时以太网具有高传输速率、良好同步性,高实时性,具备开放性标准等特点能够克服传统脉冲和模拟量传输方式的传输速率慢、通信质量差和缺乏开放性等弊端。本文将对EtherCAT通信协议、工作原理以及数据帧结构进行研究,为后续主站控制软件的设计提供理论基础。数控系统如果采用直线插补技术进行曲线加工,将使加工速度和加工精度受限。如果数控系统能够采用曲线插补技术,将有益于提高曲线加工时的加工速度和加工精度。本文在对恒定参数增量、泰勒一阶、泰勒二阶插补算法的研究基础上提出了基于插补弦长的自适应多段均匀有理B样条曲线插补算法。该算法能够根据曲线的曲率和插补弦长的情况,在弦弓高误差的控制下实现速度的自适应控制。该算法可以使数控系统获得更高的加工速度和更高的加工精度。本文在上述关键技术研究的基础上搭建了基于EtherCAT实时以太网的开放式数控系统平台,设计了基于EtherCAT实时以太网的主站控制软件。通过对平台的实时性、同步性和多轴联动性能以及主站控制软件的功能进行测试。测试结果表明该数控系统平台符合开放式数控系统的设计目标。更多还原

【Abstract】 With the development of science and technology, CNC technology is moving towards to the direction of high-precision, high-speed, efficient, flexible, intelligent and integration. Closed CNC system is impossible to adapt flexibly to be fit for the changing market requirements because of its lack of openness. Open CNC system with replaceable hardware and software, scalable and interoperable, flexible features receive widespread attention. In open CNC system based on field bus, the communication between the master controller and the slave movement module not only make the module flexibly expand also need to meet the real-time and motion control synchronicity. So the research on the methods of communication is very important. In addition in the software design process, it need analysis the NC system function module and use the COM components to realize the modular design. And motion control module is the core of the control software, the study on motion control module will to improve the performance of the CNC system. The curve interpolation technology research will be able to make the system directly process curve, so as to improve the machining precision and processing efficiency. This article will focus on communication mode and curve interpolation technology.In the study course of communication, through compared the advantages and disadvantages of the variety of real-time Ethernet in the communication rate, the real time and synchrony, real-time Ethernet EtherCAT with the international standard which meet openness requirements, real-time and synchronicity requirements is decided as the communication mode of the open CNC system. EtherCAT with characteristic of the open standards has high real-time transmission rate and high Ethernet good synchronicities. Its high real time capability can over come the slow transmission rate, the poor communication quality and the lack of openness in traditional pulse and analogue transmission way. It is suitable for open CNC system. At the same time through research to communication protocol, working principle and data frame structure of the EtherCAT in order to lay the foundation for the design of the control software.In the research process of the curve interpolation technology, through compared the quality between the linear interpolation and the curve interpolation in the curve process, this paper puts forward directly curve interpolation technology. Through research on parameters increment, the Taylor first order and the Taylor second order interpolation algorithm, put forward on the adaptive b-spline interpolation algorithm. This algorithm can control adaptable speed by high error, according to the curvature of the curve and interpolation length. The algorithm not only can improve more interpolation precision but also change the interpolation speed smoothly.the open NC system based on real-time Ethernet EtherCAT is built with the study on the key technology and design the control software based on the EtherCAT. At end, test the platform of multi axises linkage and test host control software function, The results show that the numerical control system platform with open CNC system design goal, master station control software is feasible.更多还原