摇篮式五坐标加工中心C轴转台旋转故障原因分析与处理

针对HS664RT,摇篮式五坐标加工中心力矩电动机驱动的C轴转台故障,介绍了故障排查、处理方法和力矩电动机相位角同步设置步骤。     

Current Control Method of Achieving Wide‐Range Power Driving for Linear Synchronous Motor with Half‐Wave‐Rectified Self‐Excitation

In a previous paper, we proposed a novel linear synchronous motor with half‐wave‐rectified self‐excitation. A long‐stator‐type linear synchronous motor was built and its performance was verified by experiments. This paper presents a new current control method for the linear synchronous motor in order to achieve a wide range of speeds and high‐power operations. First, we propose a current control method for high‐thrust operation in the constant‐thrust region. This operation is realized by using the reluctance thrust resulting from the saliency of the linear synchronous motor. We also propose a control method that maximizes the ratio of the thrust to the voltage; this method can be used to expand the operating range. Wide‐range‐speed operation can be achieved by applying this new control method along with field‐weakening control. The thrust and operating characteristics of the proposed control methods are estimated by performing experiments and coupled electric and magnetic analysis.     

A Restart Control Method for Position Sensorless PMSM Drive Systems Without Potential Transformer for Railway Vehicle Traction

This paper proposes a restart control method for position sensorless PMSM drive systems without a potential transformer for railway vehicle traction. This method can estimate the initial rotor speed and position under coasting conditions over the entire speed range. The method can also be used when the back‐EMF voltage is higher than the inverter DC link voltage. The proposed method is verified by experiments using a 200‐kW PMSM.     

基于优化粒子数和分段权值的粒子群直线电机PID整定

以工程中直线电机伺服系统为研究对象,提出一种优化粒子数量加分段式惯性权重递减的粒子群PID控制器参数优化算法。优化粒子数量的方法可降低函数调用次数,通过对近两代的全局最优值进行比较,得到的误差值如果大于设定值,认为是在初始寻优阶段,保持粒子数量,否则在最终优化阶段,减少粒子数量,所减少的粒子特征是最接近最佳粒子的粒子,以保证在欧氏距离内实现粒子的分散性。最后再结合指数衰减曲线加线性递减曲线构成的分段式惯性权重递减策略提升算法的全局寻优和局部寻优能力。经数值验证分析,该优化算法在保证遍历性的同时,在一定程度上提高了算法的运行速度和寻优精度。实验仿真结果表明,该算法对PID控制器进行参数优化,直线电机系统响应速度快,超调量小,调节时间短。     

一种基于施密特触发器原理的直流电机位置控制及消抖算法

有刷直流电机的位置控制是一种常用的工作场景，对系统的响应速度、调节速度和控制精度等都有一定要求。经典的有刷直流电机位置控制算法一般都较理论，算法编写和调试较为复杂。基于现实应用需求，提出了一种新型的控制算法。该算法基于电子电路中施密特触发器的工作原理，实测具有响应速度快、控制精度较高、无抖动、适用范围广和编程简易等特点，可供相关技术人员参考借鉴。     

Reinvestigation of the photostrictive effect in lanthanum-modified lead zirconate titanate ferroelectrics

Photostriction of lanthanum-modified lead zirconate titanate (PLZT) was commonly attributed to the combination of anomalous photovoltaic effect and inverse piezoelectric response. Herein, distinct photostrictions are detected in both poled and unpoled PLZT ceramics under 405 and 520 nm laser illuminations. The maximum photostriction around 0.09% is obtained in unpoled PLZT under 405 nm illumination, which is nine times of previously reported value that deduced from poled PLZT. The photoelectric and photovoltaic characterizations of poled/unpoled PLZT further evidence that the detected photostriction shows no direct association with the photovoltage-induced inverse piezoresponse. The light-induced microstructure changes observed by in situ piezoelectric force microscopy are revealed by domain evolutions along the boundaries. The possible photostriction mechanism of PLZT is attributed to the strong photo-induced electron-lattice coupling, which is suggested by the light-induced changes of the Zr/Ti-O-Zr/Ti bonds reflected by the power-dependent Raman spectra. This study extends the photostriction of PLZT to visible light range and will also stimulate reappraisal of the underlying mechanism of photostrictive effect involving ferroelectrics.     

施工期富水路基的地质雷达探测研究

以江西省赣县区境内S219省道韩坊~安远段道路工程为依托,考虑采用地质雷达对施工期路基内部的富水情况进行探测分析。基于地形地貌、地表水文等信息,以地质调查为基本手段对路基的富水状况进行初步调查和分类;在此基础上,以地质雷达探测为具体手段,对路基内部的富水情况进行探测分析。工程实践表明:采用地质雷达对路基内部的富水情况进行探测是可行的。     

煤矿地面轨道运输矿车自动避障技术研究

介绍了煤矿地面轨道运输矿车自动避障技术。首先介绍了基于雷达的矿车前方障碍物检测技术及其相关算法,然后详细介绍了基于机器视觉的矿车前方障碍物检测系统和常用的图像处理方法以及相关的算法,最后介绍了雷达和机器视觉融合的障碍物检测技术在煤矿地面轨道运输矿车自动避障过程中的应用。     

综合物探方法在天然气高瓦斯隧道超前地质预报中的应用

天然气高瓦斯隧道中的瓦斯不可预见性很大。施工过程中，在遇到隧道洞身段局部岩体节理裂隙发育、围岩破损带、断层处，均可能发生瓦斯逸出甚至瓦斯突涌现象，现场存在很大的瓦斯安全隐患。主要研究了TSP探测、地质雷达、超前钻探等方法在瓦斯隧道施工中的应用情况，多种物探手段与钻探相结合对不良地质体进行综合预测，取得了较好的预报效果，有力保障了现场施工安全。     

用于嵌入系统的超声电机驱动设计

为了在嵌入式控制系统中充分利用超声电机特有功能,对超声电机的驱动原理进行了研究,在分析了超声电机的驱动控制原理的基础上,提出了一种基于单片机控制超声电机的软硬件控制实现方法。利用单片机输出数字量作为控制信号,通过串行输入并行输出芯片扩展后,输出到超声电机驱动器,实现超声电机启动/停止/正反转的功能;通过扩展单片机数模转换,将单片机控制超声电机速度的数字信号转换为电压信号,实现超声电机的速度控制功能;利用运行脉冲宽度控制实现超声电机的位置控制功能,并将光电编码器实现超声电机的反馈,最后通过试验验证了单片机系统实现超声电机驱动设计。