Development of Simultaneous 3-axis control ultraprecision machine tool based on principle of Walking Drive

基于步进驱动原理，研制了一种三轴联动超精密XYrheta工作台，并对其基本特性进行了研究。主要研究成果如下：1.高刚度超精密XYrheta工作台的研制三轴控制XYrheta工作台是根据研究者提出的步进驱动原理研制的。该装置由一个平板台和三套驱动装置组成，每套驱动装置装有两对驱动块。一个驱动块具有三个压电（PZT）致动器以在两个方向上夹紧和进给工作台，使得工作台可以通过同时控制致动器的运动而在X、Y和rheta方向上被驱动。由于工作台直接由PZT驱动器支撑，因此在X和Y方向上都具有25 kgf/um的高刚度。虽然PZT致动器本身的冲程为3.5 μ m/35 V，但工作台可以在X、Y和rheta方向分别驱动<plus-minus>50 mm、<plus-minus>20 mm和<plus-minus>10 μ m的冲程。XYrheta工作台实时运动控制器的研制针对压电陶瓷驱动器的复杂运动，研制了一种实时运动控制器。该控制器的设计使X轴、Y轴和十字轴的进给速度指令自动处理，控制压电陶瓷驱动器的运动。采用重复学习控制策略，实现了纳米级的高运动精度.基于XYrheta控制的超精密车床的开发研制了一台超精密车床，该车床主要由超精密空气主轴和开发的XYrheta工作台组成。对无氧铜镜面进行了金刚石车削试验。

A simultaneous 3-axis control ultraprecision XYrheta table has been developed based on the principle of Walking Drive, and its fundamental characteristics are investigated. The major research results are summarized as follows ;1. Development of high stiffness ultraprecision XYrheta tableThree-axis control XYrheta table was newly developed, which is based on the principal of Walking Drive proposed by the investigators. The device consists of a flat plate table and three sets of driving units, each of which is equipped with two pairs of driving blocks. One driving block has three piezoelectric (PZT) actuators to clamp and feed the table in two directions so that the table can be driven in X,Y and rheta directions by simultaneously controlling the motion of the actuators. Since the table is supported by PZT actuator directly, it has high stiffness of 25kgf/um in both X and Y directions. Although the stroke of the PZT actuator itself is 3.5 mum/35V, the table can be driven for the storkes of <plus-minus>50mm, <plus-minus>20mm and <plus-minus>10ﾟ in X,Y and rheta directions respect2. Development of realtime motion controller for XYrheta tableA realtime motion controleer was developed to control complicated motion of PZT actuators. The controller is so designed that the motion command of feed rates of X,Y and rheta axs is automatically processed to control the motion of PZT actuators. High motion accurcy of nm order was achived by applying the repetitive learning control scheme.3. Development of ultraprecision turning machine with XYrheta controlAn ultraprecision turning machine was developed, which basically consists of an ultraprecision air spindle and the XYrheta table developed. Some diamond turning tests were carried out to finish the mirror surfaces of oxygeon free copper.