Investigation of a 2-D planar motor based machine tool motion system

A new 2-D planar motion system for precision machining operations is investigated. Characteristics of the 2-D planar motor system are studied to gain better understanding of its capabilities, limitations and interactions with machining processes. The planar motor system is applied to an end milling process, where experimental data on cutting force and surface finish are in agreement with simulation results. Of further interest is that the motor's fast response and ability to perform simultaneous motion in two directions potentially provides a simpler means to compensate for errors such as runouts. Issues associated with such compensation motions to improve surface finish are discussed.     

铁电电容的特理模型研究

用一种物理方法解释了非理想铁电电容器的电路行为。在该方法中反分立的铁电电容假设为堆积状的介电层结构,包括铁电层和非开关介电层。通过这种方法改进了Sawyer-Tower电路并测量了其电特性。用该模型较准确地测量了由于输入信号频率变化而引起的电滞回线的畸变,并且输入信号幅度的影响与实验结果比较吻合。     

一种Sawyer马达驱动二维运动平台测量和控制系统设计

介绍一种使用Sawyer马达驱动的平台和表面编码器组成的精密定位系统．该平台包括一个台板和若干线性脉冲马达推动器．台板由防腐钢板制成，在其表面加工了齿牙．线性脉冲马达推动器靠空气支承悬浮在台板上，用以驱动平台．每一驱动器均由一个永久磁铁和两个驱动线圈组成，用以产生X向和Y向的平台驱动力．设计了一种表面编码器用以测量和控制平台的运动．一个正弦格栅装在台板上，一个传感组件装在平台驱动器上．在该传感组件中有三个光学传感器，用以测量三个分离点上的X和Y方向的位置，平台的θz向位置可以从传感器输出求得．开发了一种反馈控制系统用以控制平台运动．测量和反馈控制实验证明了该精密系统的可行性．