菜单
  

    . The difference of RP0
    and RP1
    is the diagonal
    error . With the sequential step diagonal measurement
    method, first, collect the diagonal displacement RP0
    of point
    P0, and then move Dx along the X-axis direction to the
    middle measurement point M1 and acquire the diagonal
    displacement RM1
    , and next move Dy along the Y-axis
    direction to the second middle measurement point M2 and
    also acquire the diagonal displacement RM2
    , finally move
    Dz along the Z-axis direction to the point P1 and also
    acquire the diagonal displacement RP1
    . As there are four
    displacement values, three sets of diagonal errors can be
    calculated with the differences of the values one and
    another, which means three times more data are obtained
    than in the conventional diagonal measurement.
    For a machine working volume, there are four body
    diagonals directions shown in Fig. 4.Here, p means
    positive direction while n means negative direction and
    the sequence of the three letters is ordered by X-, Y-, and Z-
    axis. Thus, 12 sets of measurement results can be identified
    if these four diagonals are measured; the same variable
    number in Eq. 2 given in the above section. With the
    analysis, the relationship between the variables or the nine 4 Measurement of volumetric positioning error
    4.1 Measurement setup
    The measurements were performed on a vertical machining
    center [19]. The machine configuration is shown in Fig. 2.
    The machine is equipped with linear motor drives, a cross
    bed with two driven axes X, Y and a vertically oriented
    spindle (Z-axis) form the structure of the machine. The
    measurements were performed on the machining center
    over a working volume of X=500 mm, Y=400 mm, and
    Z=320 mm. All measurements were performed using
    Optodyne laser system and there were four setups, one on
    each of the four body diagonal directions. To reduce the
    alignment time, two laser systems were aligned in the
    directions ppp and nnp as shown in Fig. 5.
    In addition, 12 thermocouple temperature sensors were
    placed at different locations within the machine frame to
    measure the thermal variation of the machine tool. Table 1
    gives the number of temperature sensors and their locations.
    As the temperature of the machine changes slowly in a
    normal condition, some operations were done to warm the
    machine warm. The duty cycle consists of a continuous
    spindle ran at maximal speed at 15,000 rpm and X-, Y-, and
    Z-axes motion at maximum stroke in the ppp diagonal
    direction at 50% maximum rapid feed rate. The 12
    temperature sensors readings were recorded at 2-min
    interval starting before the measurement and ending after
    the measurement during the day, shown in Fig. 6.
    4.2 Measurement results
    During a measurement day, measurement was performed six
    times and then six sets of positioning error data are obtained.
    For X-axis, the linear displacement errors Ex(x), vertical
    straightness errors Ey(x), and horizontal straightness errors
    Ez(x) are plotted in Fig. 7a–c, respectively. For the linear displacement errors Ex(x), the maximal error increased from
    6.5 to 12 μmat X=500 mm with 3 μm variation due to the
    thermal effect; for Ey(x), the maximal error increased from
    6.5 to 12 μmat X=100 mm with 3 μm variation; for Ez(x),
    the maximal error increased from 9 to 10 μmat X=150 mm
    with only 1-μm variation. For the X-axis positioning errors,the change of straightness errors were relatively small over
    the temperature range compared with the linear displace-
    ment errors.
    For Y-axis, as shown in Fig. 8a–c, the maximal error of
    linear displacement errors Ey(y), increased from 4 to 8.5 μm摘要:几何定位误差的测量与补偿常常应用于显著提高机床的精度。本文中,一种分布对角线测量介绍了短时间内测量9个立体定位误差。在各种热条件下的测量预制成理解立体定位误差和机械温度场及变化之间的关系。基于径向基函数的神经网络被用于预测在所有位置基于机器分布温度的立体定位误差。补偿实验得到实现以此来验证测量的性能和预测方法。测试结果显示机床的立体误差精度通过误差补偿得到了显著的提高。
  1. 上一篇:自动化控制系统英文文献和中文翻译
  2. 下一篇:定位器旋转气缸英文文献和中文翻译
  1. 汽车乘员舱的声振耦合英文文献和中文翻译

  2. 立体光照成型的注塑模具...

  3. 数控机床英文文献和中文翻译

  4. 工业机械手英文文献和中文翻译

  5. 低频振动的铁路车轴的状...

  6. 接头的形状对沥青塞接头...

  7. 数控加工技术英文文献和中文翻译

  8. java+mysql车辆管理系统的设计+源代码

  9. 当代大学生慈善意识研究+文献综述

  10. 大众媒体对公共政策制定的影响

  11. 电站锅炉暖风器设计任务书

  12. 乳业同业并购式全产业链...

  13. 十二层带中心支撑钢结构...

  14. 中考体育项目与体育教学合理结合的研究

  15. 河岸冲刷和泥沙淤积的监测国内外研究现状

  16. 酸性水汽提装置总汽提塔设计+CAD图纸

  17. 杂拟谷盗体内共生菌沃尔...

  

About

751论文网手机版...

主页:http://www.751com.cn

关闭返回