Uncertainty Propagation in Calibration of Parallel Kinematic Machines; Precision Engineering, American Society for Precision Engineering (ASPE)

摘要

Uncertainty Propagation in Calibration of Parallel Kinematic Machines joint center locations and distances be rather large in size, the kinematic parameters (joint center locations, and initial strut lengths) for determining all of the kinematic parameters of an assembled parallel kinematic device. This and Y circle center coordinates, radii and circularities were calculated over all of the iterations. show that the correct kinematic parameters were identified, although a great improvement machine frame (M), (2) identifying the joint center locations, (3) determining the spindle nose location and centerline orientation, and (4) determining the initial strut lengths. single fixed coordinate reference frame (R) to which all future coordinate measurements collected in other floating reference frame; will be transformed (Figure 2.1). Utilizing a spatial coordinate strut rotates about the base joint center. fixed length strut rotates about the platform spindle and rotated slowly by hand. .at approximately 30-40 different locations, the motion is coordinates of the center of the circle projected along the positive direction of the normal vector by the offset distance of the fixture and tool holder are the coordinates of the center of the spindle Propagation of strut length and measurement uncertainties to the recovered kinematic 10000 iterations. First, the reverse kinematic solver calculated the nominal strut lengths for the Finally, the joint center locations and initial strut lengths were determined from the perturbed gage point locations.