一种数控滚齿机工作台动态特性建模方法及实验分析

发布时间：2018-04-01 19:42

本文选题：数控滚齿机　切入点：动态特性　出处：《西安交通大学学报》2017年12期

【摘要】：为了研究数控滚齿加工中滚刀轴转速波动引起的工件轴速度波动的动态响应特性,对数控滚齿机旋转工作台即工件轴的伺服控制问题进行了分析。首先根据电机学原理和机械动力学原理对伺服控制系统组成的各个环节进行了建模和分析,推导出旋转工作台的整体伺服控制系统模型,并考虑到伺服控制环节在动态响应过程中的摩擦因素,引入了非线性Stribeck黏性摩擦结构;然后利用Simulink建立了滚齿机旋转工作台的伺服系统仿真模型,并研究了不同的位置和速度指令频率变化对工件轴伺服动态响应影响效果;最后通过数控滚齿机工作台控制实验来验证工件轴的动态响应特性。仿真结果表明:旋转工作台伺服系统在低速运行时,位置跟踪存在"平顶"现象,速度跟踪存在"死区"现象;旋转工作台伺服系统位置和速度的跟随率随着指令频率的增大而减小,当指令频率增大到31Hz时,速度跟随率不足10%。在和仿真相同的指令频率变化条件下,进行滚齿机工件轴的转速控制实验,工件轴的响应曲线与仿真响应曲线基本吻合,验证了模型的有效性和可靠性。该模型可为数控回转工作台伺服进给系统设计、伺服控制方法研究及故障诊断等工作提供理论依据。
[Abstract]:In order to study the dynamic response characteristics of the speed fluctuation of the workpiece shaft caused by the fluctuation of the rotational speed of the hob shaft in NC hobbing machining, The servo control problem of the rotary table of NC gear hobbing machine that is workpiece shaft is analyzed. Firstly, every link of servo control system is modeled and analyzed according to the principle of motor and mechanical dynamics. The whole servo control system model of the rotary table is deduced, and the nonlinear Stribeck viscous friction structure is introduced considering the friction factor of the servo control link in the dynamic response process. Then the servo system simulation model of the rotary table of the hobbing machine is established by using Simulink, and the effect of different position and speed command frequency on the dynamic response of the workpiece shaft is studied. Finally, the dynamic response characteristics of the workpiece shaft are verified by the control experiment of the worktable of the CNC gear hobbing machine. The simulation results show that when the servo system of the rotary table is running at low speed, the "flat-top" phenomenon exists in the position tracking. There is a "dead zone" phenomenon in velocity tracking, and the position and velocity follow rate of the rotary table servo system decreases with the increase of instruction frequency, when the instruction frequency increases to 31Hz, The speed following rate is less than 10. Under the same command frequency change condition as simulation, the speed control experiment of the workpiece shaft of the hobbing machine is carried out. The response curve of the workpiece shaft basically coincides with the simulation response curve. The validity and reliability of the model are verified. The model can provide theoretical basis for the design of servo feed system of NC rotary table, the research of servo control method and fault diagnosis.
【作者单位】：西安交通大学机械工程学院;西安交通大学机械制造系统工程国家重点实验室;
【基金】：国家科技重大专项资助项目(2015ZX04005001)
【分类号】：TG612

【相似文献】