数控车床静压气体轴系回转误差补偿及控制方法的研究

发布时间：2019-04-26 07:46

【摘要】：随着科学技术的飞速发展,人们对数控车床轴系精度的要求越来越高,因此为了满足不断增长的高精度要求,要找到经济合理、技术可行的解决方案。针对提高数控车床主轴回转精度的问题,本文提出在采用的静压气体轴承上引入主动磁轴承,利用静压气体轴承作为主要承载元件,磁轴承作为辅助元件来修正主轴的回转误差。这样的结构具有回转精度高、承载力大、刚度大及可控性好等优点。本文中数控车床的主轴系统包括两个静压气体轴承和两个主动磁轴承、一个止推轴承。首先对静压气体轴承和磁轴承进行结构的设计和参数的确定；通过对主轴系统的研究分析,对静压气体轴承进行静特性分析、磁轴承进行电磁力分析以及建立并分析系统单自由度和五自由度动力学模型；然后对主轴回转误差进行测量并进行去谐波分离,得出精确的回转误差图像；最后对控制系统进行设计：该系统是一个带有反馈的闭合系统,在主轴的前后端分别安装三个电涡流位移传感器,采集到的数值作为系统的输入,该数值经过A/D变换,转换成数字信号传入作为硬件CPU的数字信号处理器(DSP)中,得到磁轴承的控制律,把信号经D/A转换加载到磁轴承上,修正主轴的回转误差。本文采用模糊自整定PID控制方法,针对系统的控制要求搭建系统仿真的平台,通过仿真验证在模糊自适应PID控制作用下主轴的回转精度能否得到大幅度的提高,验证控制系统的可行性与实用性,达到提高主轴回转精度的目的。设计基于TMS320LF2407A DSP的数控车床静压气体轴承轴系的控制系统,并对系统中的硬件部分和软件部分进行设计。
[Abstract]:With the rapid development of science and technology, the accuracy of CNC lathe shafting becomes more and more demanding. Therefore, in order to meet the increasing requirement of high precision, it is necessary to find an economical, reasonable and technically feasible solution. In order to improve the rotary accuracy of the spindle of CNC lathe, this paper presents the introduction of active magnetic bearing on the hydrostatic gas bearing used, and the use of the hydrostatic gas bearing as the main bearing element. The magnetic bearing is used as an auxiliary element to correct the rotation error of the spindle. This kind of structure has the advantages of high rotation precision, large bearing capacity, large stiffness and good controllability. The spindle system of CNC lathe consists of two hydrostatic gas bearings, two active magnetic bearings and one thrust bearing. Firstly, the structure design and parameter determination of hydrostatic gas bearing and magnetic bearing are carried out. Through the study and analysis of the spindle system, the static characteristics of the hydrostatic gas bearing, the electromagnetic force of the magnetic bearing and the dynamic models of the single degree of freedom and five degrees of freedom of the system are established and analyzed. Then the rotation error of the spindle is measured and the harmonic removal is carried out to obtain the accurate image of the rotation error. Finally, the control system is designed: the system is a closed system with feedback. Three eddy current displacement sensors are installed on the front and back ends of the spindle, and the collected values are used as the input of the system. The digital signal is transferred into the digital signal processor (DSP), which is used as the hardware CPU. The control law of the magnetic bearing is obtained, and the signal is loaded into the magnetic bearing through the D / A conversion to correct the rotation error of the spindle. In this paper, the fuzzy self-tuning PID control method is used to build the system simulation platform according to the control requirements of the system. The simulation verifies whether the rotation accuracy of the spindle can be greatly improved under the action of fuzzy adaptive PID control. The feasibility and practicability of the control system are verified to improve the precision of spindle rotation. The control system of hydrostatic gas bearing shafting of NC lathe based on TMS320LF2407A DSP is designed, and the hardware and software parts of the system are designed.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG519.1

【参考文献】