宏宏双驱动微量进给伺服系统动态特性研究

发布时间：2018-04-15 02:14

本文选题：双驱动微量进给 + 运动学分析　；参考：《山东大学》2016年博士论文

【摘要】：实现超精密加工的关键技术瓶颈之一是如何在加工过程中使工具或工件得到准确、稳定可靠的微量位移,即精密定位技术。精密定位系统对于精密测量、精密加工等各种精密设备都起着至关重要的作用。由于机电系统自身固有属性导致的低速爬行现象的影响,常规结构形式和工作方式的机电传动系统,因低速非线性蠕动爬行现象的影响,很难实现精确、均匀的微小位移的进给控制,不能满足当前高精度制造装备及加工的迫切需求,因而研究微位移技术是实现超精密加工的重要途径。针对高精度加工技术的迫切需求,宏微双驱动技术是目前实现大行程、高精度运动控制的一种有效策略,具有极高的分辨率、定位精度和动态响应速度以及较大的进给刚度,但也存在着明显的缺点,如刚度小、非线性、迟滞、蠕变等,尤其是迟滞非线性,使其定位精度大打折扣,因此基于运动合成原理和现代伺服驱动技术,本文提出了“宏宏双驱动微量进给伺服系统”,通过“一个伺服电机驱动滚珠丝杠”和“一个伺服电机驱动滚珠螺母”的两个准相等(瞬时速度大小近乎相等,转向相同)宏观运动叠加,从而避开了因传统机电伺服系统结构自身固有属性导致的不可回避的、低速非线性爬行现象的影响,从而实现高精度微量进给。本文基于赫兹接触理论,滚道接触控制理论,多体动、静力学分析,摩擦学及热力学等理论,借助于Pro/E、ABAQUS、MATLAB等分析计算软件,构建了运动学模型、动力学模型以及热力耦合模型,对双驱动微量进给机构的动态特性进行了研究,主要内容包括：(1)利用微分几何学原理分析工作滚珠的运动状态,计算接触点处的摩擦力,建立力和力矩平衡方程式,研究丝杠和螺母在不同转速下对滚珠运动学参数的影响,以及在不同驱动方式下滚珠运动状态的差别,并计算双驱动滚珠丝杠副机构的机械效率,理论分析的结果为该微量进给机构的设计计算及动力学分析奠定了基础。(2)利用弹性力学中的赫兹接触理论,分析计算丝杠轴的轴向及扭转刚度、螺母组件的轴向刚度以及支撑滚动轴承的轴向刚度,采用集中质量法建立双驱动传动系统的动力学模型,由拉格朗日万程和状态空间向量对系统的频响特性进行计算,最后通过数值分析得出双驱动系统频响特性并比较分析与单驱动系统的差异；以及预紧力、扭转刚度和工作台总质量的变化对双驱动系统频率响应特性的影响,建模及仿真结果可作为双驱动进给系统结构设计和控制器设计的重要参考。(3)由于非线性摩擦及机械系统固有的弹性及阻尼特性会导致系统的爬行、振荡等不稳定行为,因此建立了考虑摩擦的双驱动微量进给系统动力学模型。利用传递函数框图表示双驱动伺服微量进给系统的运动关系,通过Simulink仿真分析在匀速进给时不同驱动方式下,工作台输出速度波动的差异以及两电机不同速度组合对工作台输出速度的影响；在变速输入时不同驱动方式下工作台输出速度变化情况。(4)基于传热学理论建立了系统各部件的传导和对流换热热阻模型,通过热节点的热平衡分析,利用热阻网络法建立了该进给系统的热平衡方程组,采用Newton Raphson法求解热平衡方程组,获得进给系统的温度场分布模型；结合机械热变形理论,用所建立的温度场模型预测双驱动滚珠丝杠的轴向热误差。分别对单/双驱动工况下的热动态特性进行了数值分析,结果表明,在相同进给速度且不同驱动方式下,单/双驱动系统的温度场分布及热误差是不同的,对比分析还显示了不同进给速度下双驱动系统热动态特性的变化规律。(5)立足现代传感检测、信号处理与计算机现代数控技术,自主开发研制了双驱动微量进给特性综合实验台。在所搭建的实验台上进行动态特性实验研究,包括频率响应测试实验、工作台在不同驱动方式下的临界爬行速度测试实验、系统温升及热伸长测量实验。通过实验验证了所建立的理论模型,实验与仿真结果基本一致,说明对双驱动进给系统的理论计算及分析结果是正确的。
[Abstract]:One of the key technologies to realize the bottleneck of ultra precision machining is how to make the tool or workpiece accurately in the machining process, micro displacement is stable and reliable, the precision positioning technology. Precision positioning system for precision measurement, precision machining and other precision equipment plays an important role. Because of low speed creeping phenomenon of electromechanical system inherent properties cause the electrical drive system of conventional structure and working mode, due to the impact of low-speed nonlinear creeping phenomenon, it is difficult to achieve precise micro displacement, uniform feed control, can not meet the urgent needs of the current manufacturing equipment and high precision machining, so the study of micro displacement technology is an important way to realize the ultra precision machining. Aiming at the urgent need of high precision machining technology, macro micro dual drive technology is the realization of the trip, an effective strategy for high precision motion control That has a very high resolution, the positioning accuracy and dynamic response speed and larger feed stiffness, but there are obvious shortcomings, such as stiffness, nonlinear, hysteresis, creep, especially the hysteresis nonlinearity, the positioning accuracy is greatly reduced, so the motion synthesis principle and modern servo drive technology based on this the "macro Hongshuang drive servo system trace", "by a servo motor to drive the two quasi equal ball screw and a servo motor driven ball nut" (instantaneous speed of nearly equal size, the same direction) macro motion superposition, so as to avoid the traditional electromechanical servo system structure inherent attribute to can not be avoided, effects of low-speed nonlinear creeping phenomenon, in order to achieve high precision micro feed. Based on Hertz contact theory, contact raceway control theory, multi body dynamic and static credit Analysis of tribology and thermodynamics theory, with the help of Pro/E, ABAQUS, MATLAB and other software analysis, construct the kinematics model, kinetics model and thermodynamic coupling model of the dual drive micro feed mechanism of the dynamic characteristics of the main contents include: (1) motion analysis of ball using the principle of differential geometry, calculation the friction force at the contact point, the establishment of force and torque balance equation, influence of ball screw and nut on kinematic parameters under different rotational speeds, and the difference in different driving conditions of ball movement, and the calculation of double ball screw drive mechanism of the mechanical efficiency, the results of theoretical analysis have laid the foundation for the design and calculation of dynamics analysis of the micro feed mechanism. (2) by using Hertz contact theory in elastic mechanics, the calculation and analysis of torsional stiffness of the axial screw shaft and nut assembly The axial stiffness and axial supporting stiffness of rolling bearing, dynamic model of dual drive transmission system using the lumped mass method, calculated by the Lagrange equation and the state space vector frequency response characteristics of the system, and finally through the numerical analysis of double drive frequency response characteristics and compare with the single drive system; and the pre tightening force, torsion stiffness change and total quality table of the dual drive system frequency response characteristics, modeling and simulation results can be used as a double feed drive system structure design and controller design is an important reference. (3) the elastic and damping characteristics of nonlinear friction and mechanical system will cause the system to crawl, oscillation the unstable behavior, so the establishment of a double drive dynamic micro feed system model considering friction. Using the transfer function block diagram of dual drive servo trace into To the motion relationship of the system, through the Simulink simulation analysis of driving in different uniform feeding mode, difference table output speed fluctuation and two different motor speed combinations on the worktable output speed; speed input in different driving mode table output speed changes. (4) established the conduction heat transfer theory all parts of the system and the convection heat transfer thermal resistance model based on the heat balance heat node analysis, using thermal network method to establish the feed system of the heat balance equations of heat balance equations using Newton Raphson method to obtain temperature distribution model of the feed system; combined with the mechanical thermal deformation theory, the axial thermal error prediction double ball screw driven by temperature field model. Two single / double drive dynamic thermal performance under the condition of the numerical analysis results show that in the same. Drive to speed and different, single / dual drive system of the distribution of temperature field and thermal error is different, comparative analysis also shows the variation of thermal dynamic characteristics of the system driven by two different feed speeds. (5) based on modern sensor detection, signal processing and computer modern CNC technology, developed a double the driving characteristics of Taiwan. Comprehensive experimental micro feeding experiments were carried out to study the dynamic characteristics of the built experimental platform, including the frequency response test bench in different driving conditions of the critical creeping speed test system, temperature rise and thermal elongation measurement experiment. The model is verified by experiment, the experimental and simulation results basically the same, indicating the theoretical calculation and analysis result of the double feed drive system is correct.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG659

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