To meet the requirements of high performances of linear guideway, an aerostatic lubrication model (ALM) with orifice restriction is put forward with finite difference method based on the bearing of slider block. With the combination of flux-error feedback and grids parameter optimization, the model is solved and the static behaviors of the bearing are obtained, and the bearing configurations, such as the diameter, number and position of the orifice are optimized. Finally, the performance test of the linear guideway is carried out, and the theoretical results have a good agreement with the experimental data. The actual stiffness and linearity of the system are 59N/μm and 0.3μm/255mm respectively. The conclusions are useful for the design and analysis of high precision aerostatic equipment.
Traditional methods of measuring out-of-squareness of ultra-precision motion stage have many limitations, especially the
errors caused by inaccuracy of standard specimens, such as bare L-square and optical pentaprism. And generally, the
accurate of out-of-squareness measurement is lower than the accurate of interior angles of standard specimens. Based on
the error separation, this paper presents a novel method of out-of-squareness measurement with a polygon artifact. The
angles bounded with the guideways and the edges of polygon artifact are measured, and the out-of-squareness distraction
is achieved by the principle that the sum of internal the angles of a convex polygon artifact is (n-2)π. A out-of-squareness
metrical experiment is carried out on the profilometer by using an optical square brick with the out-of-squareness of
interior angles at about 1140.2 arcsec. The results show that the measurement accuracy of three out-of-squareness of the
profilometer is not affected by the internal angles. The measurementwith the method can be applied to measure the
machine error more accurate and calibrate the out-of-squareness of machine.