大功率全电动折弯机伺服同步控制系统研究与设计

发布时间：2018-09-17 10:14

【摘要】：随着复杂精密折弯工艺要求的不断提高、劳动力成本与劳动者对工作环境要求的日益提升，在钣金制造业中应用具有响应速度快、智能化与网络化程度高、控制精度优良、节能环保等特点的全电动折弯机已成为发展趋势。某些特殊行业加工的钣金件尺寸较大、板材较厚以及精度要求高，，对全电动折弯机的研制提出了更苛刻的要求，不仅须具备强劲的折弯压力，还须有优越的多轴同步性能。而大吨位折弯压力的输出一般需多台电机同步并行驱动来实现，因此研究大吨位高精度全电动折弯机伺服同步控制系统及关键技术为发展新一代具有我国自主知识产权的全电动折弯机产业打下坚实基础。本文通过综合分析市场发展需求和国内外全电动折弯机研究现状，提出一种基于LinuxCNC2.5开放式数控平台的大功率全电动折弯机伺服同步控制系统总体设计方案。重点对电气控制系统硬件、数控系统软件以及折弯控制工艺作出详细设计与研究。该方案通过实时EtherCAT总线将工业PC与伺服驱动器联接起来，实现了硬件结构的最优精简。数控软件采用LinuxCNC2.5数控平台具有良好的稳健性、扩展性及控制性能。本文首先在分析全电动折弯机传动结构与运行原理的基础上提出了两种设计方案，一种是基于DSP和FPGA的嵌入式平台，形成专用于折弯工艺的特制数控系统。另一种为基于工业PC和LinuxCNC2.5的开放式控制系统，借助PC强大的运算能力和实时Linux操作系统以实现功能更强、精度更高的控制。经多方面比较，本文选取后者展开设计。其次，针对选定的方案进行详尽系统硬件选型，包括伺服驱动器和电机、位置检测传感器、工业PC等，并利用各个设备组建起一个完整稳定的硬件平台。再次，进行数控软件设计及关键技术研究，在分析实时Linux系统和LinuxCNC2.5架构的基础上实现EtherCAT主站模块的设计、S型加减速控制算法的改进以及面向折弯机工艺的HAL配置。在深入剖析四轴同步控制难点的基础上，创造性提出一种基于偏差耦合与动态力矩控制技术融合的同步驱动策略，样机测试充分表明该策略有效可行。最后，采用PyQt与OpenGL技术实现功能完备的人机界面与3D图形化编程，并重点研究了利用数据库技术与最小二乘法原理来设计自学习型折弯进深补偿算法。样机试验表明上述设计切实可行，具有满意的同步性能和加工精度，为大功率全电动折弯机提供了一种合理、可靠、高效的控制方法。
[Abstract]:With the development of complex precision bending process and the increasing demand of labor cost and working environment, the application in sheet metal manufacturing industry has fast response speed, high degree of intelligence and networking, and good control precision. Energy-saving and environmental-friendly all-electric bending machine has become a trend of development. The sheet metal parts processed in some special industries are larger in size, thicker in plate and higher in precision, so the development of all-electric bending machine is required to be more stringent. It must not only have strong bending pressure, but also have superior multi-axis synchronous performance. The output of large tonnage bending pressure usually requires synchronous and parallel drive of multiple motors. Therefore, the research on servo synchronous control system of large-tonnage and high-precision all-electric bending machine and its key technologies lay a solid foundation for the development of a new generation of all-electric bending machine industry with independent intellectual property rights in China. Based on the comprehensive analysis of the market development requirements and the research status of all-electric bending machines at home and abroad, this paper presents an overall design scheme of servo synchronous control system for high-power all-electric bending machines based on LinuxCNC2.5 open CNC platform. Focus on the electrical control system hardware, numerical control system software and bending control technology to make a detailed design and research. This scheme connects industrial PC with servo driver by real-time EtherCAT bus, and realizes the optimal reduction of hardware structure. Numerical control software using LinuxCNC2.5 CNC platform has good robustness, expansibility and control performance. In this paper, based on the analysis of transmission structure and operation principle of all-electric bending machine, two design schemes are put forward. One is embedded platform based on DSP and FPGA to form a special CNC system for bending process. The other is an open control system based on industrial PC and LinuxCNC2.5. With the help of the powerful computing power of PC and the real-time Linux operating system, the control system with stronger function and higher precision can be realized. After many aspects of comparison, this paper selects the latter to expand the design. Secondly, the hardware selection of the selected system is carried out in detail, including servo driver and motor, position detection sensor, industrial PC and so on, and a complete and stable hardware platform is constructed by using each equipment. Thirdly, the numerical control software design and the key technology are studied. Based on the analysis of the real-time Linux system and the LinuxCNC2.5 architecture, the design of the EtherCAT master station module and the improvement of the S-type acceleration and deceleration control algorithm and the HAL configuration oriented to the bending machine process are realized. On the basis of deeply analyzing the difficulties of four-axis synchronous control, a synchronous drive strategy based on the combination of deviation coupling and dynamic torque control is proposed. The prototype test shows that the strategy is effective and feasible. Finally, PyQt and OpenGL are used to realize the fully functional man-machine interface and 3D graphical programming, and the algorithm of self-learning bending depth compensation is designed by using database technology and least square method. The prototype test shows that the design is feasible, has satisfactory synchronous performance and machining precision, and provides a reasonable, reliable and efficient control method for the high-power all-electric bending machine.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP273

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