【作者】 袭著燕；

【导师】 路长厚；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2006， 博士

【摘要】 工作台进给系统广泛用于机械制造和加工过程中。该系统中存在的多种非线性特性，如摩擦、间隙、磁滞效应、饱和、未建模动态特性和外部扰动等，给系统的性能带来很大影响，其中非线性摩擦对系统运动控制性能的影响最为明显。在消除了滚珠丝杠螺距误差和间隙以后，高精度工作台伺服进给系统中存在的摩擦就成为影响运动控制精度的主要原因，如何有效的消除摩擦的影响已成为研究的关键问题。通过控制摩擦影响，实现期望的运行性能是机电伺服控制系统中一个具有重大科学意义和实际应用价值的研究课题。 本文以滚珠丝杠与直线滚动导轨组成的交流伺服驱动工作台进给系统为研究对象，进行摩擦测量、识别、建模和补偿技术的研究，从理论和实践上尝试给出利用多信号耦合特征的摩擦分析、建模以及补偿控制的方法。 首先利用激光多普勒仪对滚珠丝杠的螺距误差进行了测量与分析。基于测量结果的分析和补偿方法的理论分析，采用软硬结合的方法对不同性质的误差进行了分类补偿。通过采用加装原点开关和改进原点捕捉方法，有效提高了系统的重复定位精度；对于系统的周期性误差和偶然性误差，采用了一种误差前馈补偿控制方法；接着分析了其控制精度的改善和算法实现。在XY实验台上的补偿实验结果验证了补偿方法的有效性与理论分析的正确性，从而在不提高成本的情况下较好的改善了数控工作台定位精度。 详细分析了数控交流工作台进给系统的各个环节，建立了系统动力学模型，进行了系统参数辨识。利用交流伺服驱动器提供的力矩监控信号，测量出摩擦力(矩)和稳态速度之间的关系，根据实验测量数据建立了一个简化的Stribeck摩擦力模型，进行了交流伺服工作台进给系统摩擦特性建模仿真研究，证明了摩擦仿真模型的有效性，为摩擦补偿控制研究打下了必要的基础。 提出了利用小波分析提取交流伺服电流中摩擦影响的信息特征的方法，该方法能识别出从静摩擦力到动摩擦力转变过程中的信息特征，通过和位移输出信号变化对比分析说明伺服电流里包含摩擦力矩的变化信息，特别是它能提供静动摩擦力发生突变的时间位置；同时，从静摩擦力到动摩擦力转变过程中伺服电流存在突变，并且伺服电流中的突变总是提前于工作台的宏观运动时刻。接着，继续引入工作台的加速度信号，通过实际测试实验验证了工作台从静止到宏观运动的过渡时间与零速度时刻对应的加速度平方根的倒数成正比的定量关系，并且它不受负载变化影响。 从工程实用性的角度探索摩擦补偿方法，提出了带有摩擦前馈补偿的伺服控更多还原

【Abstract】 A table feed system is widely used in machine building and machining process. Several nonlinearities of the system, such as friction, backlash, hysteresis, saturation, non-model dynamics and external disturbance etc. bring big influences on system performance, among which nonlinear friction has the most evident impact on the performance of system motion control. After pitch error of ball-screw and backlash eliminated, friction will be the dominate factor influencing precision of motion control of a high-precision table servo feed system. So how to eliminate effectively influences of friction has been a key problem of study. To realize the expected operating performance by controlling influences of friction is a research task of significance and practical application value.A subject investigated in this dissertation is an AC servo driven table feed system consisting of ball-screw and linear rolling guide, on which friction measurement, diagnosis, modeling and compensation technologies are studied. From view of theory and practice, the methods of analysis, modeling and compensation of friction based on the feature of multi-signals are attempted to be presented.Firstly, pitch error of ball-screw is measured and analyzed by a laser Doppler displacement meter. Based on analysis of measuring results and theoretical analysis of compensation methods, different errors are classified and respectively compensated with the software and hardware method. Installation of an origin switch and improvement of the method of origin trapping effectively enhance repetitive positioning precision of the system. An error feed-forward compensation control means is employed in terms of periodical error and casual error of the system, and its amelioration of control precision and algorithm implementation. Compensation experimental results on the XY worktable verify effectiveness of the compensation method and correctness of theoretical analysis so that positioning precision of the computer-controlled table is improved well without addition of cost.Secondly, each section of the CNC AC servo table feed system is investigated in detail, then a dynamical model of the system is built and system parameter identification is carried out. By utilizing torque monitoring signal provided by the AC servo driver, the relationship between friction and steady velocity is determined. A simplified Stribeck friction model is established based on these experimental data.更多还原