Robust on-machine profile measurement using a parallel mechanism with small touching force scanning motion

研制了一种采用无冗余和冗余驱动平移并联机构的三自由度主动扫描探头。为了提高定位精度和控制小力，研制了一种低摩擦关节的小平行四边形机构。为了评价并联机构的精度，我们研制了立体摄像机三维测量系统。在边长为1.6 mm的立方工作范围内，冗余驱动机构的位置分辨率为0.5μm。通过机械参数标定，将并联机构的绝对位置精度提高到2.4μm，并实现了基于阻抗控制的稳定扫描运动。

A 3-dof active scanning probes using non-redundantly and redundantly actuated translational parallel mechanisms are developed. In order to improve the positioning accuracy and controlling small forces, a small parallelogram linkage with low friction joint is developed. We have developed 3D measurement system by stereo cameras for evaluating the accuracy of the parallel mechanisms. The positional resolution of the redundantly actuated mechanism becomes 0.5μm in a cubic working range with side length of 1.6 mm. By applying mechanical parameters calibration, the accuracy of the absolute position of the parallel mechanism has been improved to 2.4μm. A stable scanning motion based on the impedance control is also developed.