Development of nanometer-order ultra-precision machine for realizing six-degree-of-freedom perfect relative motion between workpiece and tool

开发纳米级超精密机床实现工件与刀具完美六自由度相对运动

基本信息

批准号：
16360078
负责人：
OIWA Takaaki
金额：
$ 8.26万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

To realize ultra precise machining or measurement, a machine system generating accurately relative motion between its tool and the workpiece is required as well as the accuracy improvements of each element of the machine. This research proposes a machine system using a measurement device for six-degree-of-freedom (6-DOF) motion errors between the tool and the workpiece. A hexapod-type parallel kinematics mechanism installed between the tool spindle and the surface plate is passively actuated by a conventional machine. Then, the hexapod measures the 6-DOF motions regardless with temperature fluctuation and external forces because the mechanism has a compensation device with Super-Invar rods for elastic and thermal errors of the joints and the links. Therefore, the measured 6-DOF errors compensate the tool position and orientation. First, an extensible connecting chain (strut) consisting of spherical joints and a prismatic joint with a linear scale unit has been designed and experimental … More ly manufactured. The spherical joint has been improved to eliminate thermal deformation of its ball shanks. Moreover, a compensation device with Super-Invar rods has been installed in the strut, and tested for investigating effects of the gravity and temperature change. As a result, the gravity and the temperature change have little effect on length measurement accuracy of the strut. Second, a conventional Cartesian-coordinate-geometry mechanism has been. The mechanism employs three ball-screw-driven linear positioning stages equipped with AC servomotors and rotary encoders. Positioning errors and motion errors between the surface plate and the tool spindle have been measured by using a laser interferometer length measurement system. Finally, a calibration method with a redundant passive connecting chain has been investigated for identifying 37 kinematics parameters for the hexapod mechanism. Length changes measured by the scale unit and changes calculated by the kinematics derive seven length errors of strut when the hexapod mechanism moves in its workspace. The least square method using Jacobian matrix corrects the 37 parameters and repeated so that the length errors are minimized. As a result, obtained parameters decreased positioning errors of the mechanism. Less

为了实现超精确的机械或测量，需要在其工具和工作场所之间准确地产生相对运动的机器系统以及机器每个元素的准确性改进。这项研究建议使用测量设备在工具和工作场所之间使用测量设备进行六度（6-DOF）运动误差的机器系统。刀具主轴和表面板之间安装的六型型平行运动学机制被传统的机器被动地激活。然后，Hexapod无论温度波动和外力如何测量6-DOF运动，因为该机理具有带有超级红色杆的补偿装置，可用于弹性和热误差和链接的弹性和热误差。因此，测量的6-DOF误差可以补偿工具位置和方向。首先，已经设计和实验性地制造了一个由球形接头和具有线性尺度单元的棱镜关节组成的广泛连接链（支柱）。球形接头已得到改进，以消除其球柄的热变形。此外，已经在支柱中安装了带有超级气棒的补偿装置，并测试了重力和温度变化的效果。结果，重力和温度变化对支撑杆的长度测量精度几乎没有影响。其次，传统的笛卡尔坐标几何形状机制。机构员工三个配备了AC伺服电机和旋转编码的球螺钉驱动的线性定位阶段。通过使用激光干涉仪长度测量系统来测量表面板和工具主轴之间的定位误差和运动误差。最后，已经研究了一种具有冗余无源连接链的校准方法，用于识别37个运动学参数的六型机制。长度变化由刻度单元测量和通过运动学计算得出的变化在六足动物机构移动其工作空间时会导致七个长度误差。使用Jacobian矩阵的最小平方方法纠正了37个参数并重复，以使长度误差最小化。结果，获得的参数减少了机制的定位误差。较少的