基于非线性轴位控制的单轴机床弹性摩擦精度控制研究  

Research on Control of Elastic Friction Accuracy of Single Axis Machine Tool Based on Nonlinear Axial Position Control

作　　者：李锐[1] 孟亮[2] LI Rui;MENG Liang(School of Innovation and Entrepreneurship,Changzhou Vocational Institute of Engineering,Changzhou Jiangsu 213164,China;College of Engineering,Huazhong Agricultural University,Wuhan Hubei 430070,China)

机构地区：[1]常州工程职业技术学院创新创业学院,江苏常州213164 [2]华中农业大学工学院,湖北武汉430070

出　　处：《机床与液压》2021年第24期78-82,共5页Machine Tool & Hydraulics

基　　金：江苏高校“青蓝工程”项目资助。

摘　　要：由于机床轴摩擦参数改变会导致系统性能下降,使其精度控制具有较大的困难。构建了由机床轴和等效双质量振荡器组成的单轴机床系统,实现单轴机床的弹性摩擦精度控制。将转矩指令通过电机转矩常数转换为正交电流参考信号,从而对单轴系统的动力学进行数学建模。采用位置-速度级联结构,提出基于滑模和非线性控制的STSMC-NAC非线性轴位控制算法,并与传统的P-PI级联控制进行对比分析。仿真结果表明:相比于传统的P-PI控制,STSMC-NAC控制在0.1、0.5、1 Hz的频率下对库仑摩擦估计值更接近实际参数值,且在保证最大绝对误差和功率控制分别降低约50%和33.3%的情况下,系统的复杂度也没有增加。说明STSMC-NAC方法对库仑摩擦进行了良好的精度估计,提高了单轴机床弹性摩擦控制精度以及控制效率。Because the change of machine tool shaft friction parameters will lead to the system performance decline,so that its precision control has a great difficulty.A single-axis machine tool system composed of a machine shaft and an equivalent dual-mass oscillator was constructed to control the elastic friction precision of the single-axis machine tool.The dynamics of the uniaxial system was mathematically modeled by converting the torque instruction into the orthogonal current reference signal by the torque constant of the motor.The STSMC-NAC nonlinear axial position control algorithm based on sliding mode and nonlinear control was proposed by using the position-velocity cascade structure,and the experimental comparison with the traditional P-PI cascade control was made.The simulation results show that compared with the traditional P-PI control,the Coulomb friction estimated by STSMC-NAC control at the frequencies of 0.1,0.5,1 Hz is closer to the actual parameter,and the complexity of the system does not increase while the max⁃imum absolute error and power control are reduced by about 50%and 33.3%,respectively.The results show that the STSMC-NAC method can be used to estimate the Coulomb friction well,and the control precision and efficiency of the elastic friction of single-axis machine tools are improved.

关 键 词：单轴机床系统 摩擦精度控制 P-PI级联控制 STSMC-NAC非线性轴位控制 

分 类 号：TH161.21[机械工程—机械制造及自动化]