Radial Error Motion Measurement and Its Uncertainty Estimation of Ultra Precision Axes of Rotation with Nanometer Level Precision

Abstract

The radial error is the key performance indicator of ultra-precision axis. In order to measure and evaluate the radial error of ultra-precision axis with nanometer accuracy, a measurement system with an accuracy of nanometer based on capacitive displacement probes and standard spheres is developed. The nonlinearity error of capacitive displacement probes, misalignment error of the probes, eccentric error of standard spheres, error caused by environment temperature change, environment vibration and error separation methods are analyzed and the effects of the above factors are obtained; Multiple measurement examples carried out with the measurement system this paaper constructed indicate the repeatability of the measurement system reaches 10.5 nm and the roundness error of artifact separated is less than 4.03 nm. In order to evaluate the measurement dispersion of the ultra-precision axis radial error, the major uncertainty components and the complete process of the comprehensive evaluation of the measurement uncertainty are proposed. The combined uncertainty of radial error motion measurement of the ultra-precision axis with Donaldson reversal is 31.64 nm (k = 2).

In Situ Measurement of Spindle Radial Error for Ultra-Precision Machining Based on Three-Point Method

“…The proposal of error separation technology is a major breakthrough in the field of spindle radial error measurement [ 7 ], promoting the development of spindle metrology. Several error separation techniques were then developed, including the multi-point method [ 7 ], multi-step method [ 8 , 9 ] and the Donaldson reversal method [ 10 , 11 ]. The multi-step method is rarely used in the field of ultra-precision measurement because of its complex operation steps.…”

“…Gao et al [ 22 , 23 ] proposed several new multi-probe methods, which can effectively separate the roundness of the measured workpiece from the spindle radial error, thereby avoiding the problem of harmonic suppression. In addition, some scholars have also systematically studied the three-point method [ 11 , 24 , 25 ], but most of them have only carried out theoretical research and verified it in the laboratory environment. To sum up, many scholars have conducted in-depth research on the three-point method, but there are still few practical applications of the three-point method in ultra-precision machining measurement.…”