轴瓦拉削加工机床电气控制系统研制

发布时间：2018-08-28 06:48

【摘要】：本文基于当前拉床行业在误差补偿技术上关于动态误差补偿方面的技术空白，提出了一种基于贝叶斯网络PID(BNPID)的误差补偿控制策略，并基于该策略，研制了轴瓦拉削加工机床电气控制系统，最后进行了实验研究，实际运行结果表明，应用了本文研制的电气控制系统的轴瓦拉床对比传统轴瓦拉床有更高的加工精度。本文针对轴瓦拉床闭环控制系统，首先介绍了轴瓦拉床的机械系统和电液驱动系统，完成了拉床电气控制系统硬件部分的设计；接着，基于拉床的机械系统，根据空间定位误差，推导出了拉床多误差综合数学模型；然后，在贝叶斯网络的基础上，设计了BNPID控制器；最后进行了相应的软件设计以及实验研究。第1章介绍了有关拉床误差补偿的背景和意义及其相关关键技术的国内外研究现状。第2章介绍了轴瓦拉削加工机床闭环控制系统及其性能指标，讲解了机床的整体机械结构，，重点说明了电气系统的硬件设计，主要包括电源供配电设计(380v电源供配电设计、220v电源供配电设计)，PLC模块选型，元器件选型。第3章中，采用了传统的齐次坐标变换方法，基于第2章中介绍的轴瓦拉床的机械系统，分别在轴瓦拉床的底座上建立了基坐标系，在轴瓦拉床横向以及纵向运动轴上建立了子坐标系，然后通过在拉床底座、床身、主溜板、刀具各个部分之间建立其坐标变换矩阵，建立刀具到拉床底座这条运动链的坐标变换矩阵，同理再建立工件到拉床底座之间运动链的坐标变换矩阵，最后基于以上两条运动链，建立轴瓦拉削加工机床的多误差综合数学模型。同时本章中也引入了阀控缸的数学模型，架构了由阀芯位移到液压缸位移的数学模型。第4章以PID理论作为运动控制方法，并基于第3章的多误差综合模型，运用贝叶斯网络计算各误差源的热误差，同时考虑几何误差，提出了一种新型的BNPID控制策略。BNPID控制策略汲取了当今流行的误差补偿方法，并在此基础上推陈出新，以多误差（几何误差、热误差）综合数学模型为基础，并将热误差分为3个相对独立的分量，与8个热敏点一一对应，运用贝叶斯网络分别计算3个热误差分量，同时在运动控制上借鉴了传统PID控制简单且有效的优点。第5章主要完成了轴瓦拉削加工机床软件部分的设计及其实验部分的研究。软件部分的设计包括了基于西门子CPU315的PLC程序设计和基于研华工控机的上位机监控程序设计；实验部分则主要研究了BNPID控制策略在轴瓦拉削加工机床上的控制效果。第6章中，对本文的工作内容进行了分析总结，并对今后轴瓦拉削加工机床电气控制系统的研究方向进行了展望。
[Abstract]:In this paper, a new error compensation control strategy based on Bayesian network (PID (BNPID) is proposed based on the technical blank of dynamic error compensation in broaching machine industry, and based on this strategy, an error compensation control strategy based on Bayesian network (PID (BNPID) is proposed. The electrical control system of the machine tool for the broaching of the bearing bush is developed. At last, the experimental research is carried out. The actual operation results show that the bearing broaching machine with the electrical control system developed in this paper has higher machining accuracy than the traditional broaching machine of the bearing bush. Aiming at the closed-loop control system of the bearing broaching machine, this paper first introduces the mechanical system and the electro-hydraulic drive system of the bearing broaching machine, and completes the hardware design of the electrical control system of the broaching machine, and then, the mechanical system based on the broaching machine, According to the spatial positioning error, the multi-error comprehensive mathematical model of broaching machine is derived. Then, based on Bayesian network, the BNPID controller is designed. Finally, the corresponding software design and experimental research are carried out. Chapter 1 introduces the background and significance of error compensation of broaching machine and the research status of related key technologies at home and abroad. In chapter 2, the closed-loop control system and its performance index are introduced, the overall mechanical structure of the machine tool is explained, and the hardware design of the electrical system is emphasized. It mainly includes power supply and distribution design (380v power supply and distribution design) PLC module selection and components selection. In Chapter 3, the traditional homogeneous coordinate transformation method is used. Based on the mechanical system of the bearing broaching machine introduced in Chapter 2, the basic coordinate system is established on the base of the bearing broach respectively. The sub-coordinate system is established on the horizontal and longitudinal moving axis of the bearing broaching machine, and then the coordinate transformation matrix is established between the broach base, the bed, the main slide plate and the cutting tool. The coordinate transformation matrix of the motion chain from the tool to the broach base is established, and the coordinate transformation matrix of the motion chain between the workpiece and the broach base is also established. Finally, based on the above two motion chains, A comprehensive mathematical model of multi-error for broaching machine tool for bearing bush is established. At the same time, the mathematical model of valve control cylinder is introduced in this chapter, and the mathematical model from valve core displacement to hydraulic cylinder displacement is constructed. In chapter 4, the PID theory is used as the motion control method, and based on the multi-error synthesis model in chapter 3, the thermal error of each error source is calculated by using Bayesian network, and the geometric error is considered at the same time. In this paper, a new BNPID control strategy .BNPID control strategy is proposed, which draws on the popular error compensation method, and on this basis, it is based on the comprehensive mathematical model of multi-error (geometric error, thermal error). The thermal error is divided into three relatively independent components, corresponding to eight heat sensitive points, and three thermal error components are calculated by using Bayesian network, and the advantages of traditional PID control are used for reference in motion control. In chapter 5, the design and experimental research of the machine tool software for bearing broaching are completed. The software design includes the design of PLC program based on Siemens CPU315 and the design of monitor program of upper computer based on CPU315. The experiment part mainly studies the control effect of BNPID control strategy on the broaching machine tool of axle bush. In Chapter 6, the work of this paper is analyzed and summarized, and the research direction of the electrical control system of the machine tool for bearing broaching is prospected in the future.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG57;TP273

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