KINEMATIC COUPLING INTERCHANGEABILITY（运动学耦合可交换性）.PDFVIP

KINEMATIC COUPLING INTERCHANGEABILITY A. John Hart (ajhart@mit.edu), Alexander H. Slocum Precision Engineering Research Group Massachusetts Institute of Technology, Cambridge, MA I. INT RODU CTION To achieve greater load capacity yet maintain Traditional studies of kinematic couplings, such repeatability, the “canoe ball” shape (named as such because it looks like the bottom of a canoe) evolved as those by Slocum, Mullenheld, and Poovey to include an integrated tooling ball for calibration [1,2,3], have focused on the need for high interface repeatability; however, modular machines and as shown in Figure 1. The “canoe”, made by preci- sion contour grinding, emulates the contact region instruments require rapid, accurate interchangeabil- of a ball as large as one meter in diameter in an ele- ity. Interchangeability of a kinematic coupling is the tendency of the centroidal frame of the top half of ment as small as twenty-five millimeters across. the interface to return to the same position and ori- entation relative to the centroidal frames of differ- ent bottom halves when switched between them [4,5]. ~1m When a kinematic coupling is used to mount a