Error separation technique of "two-point and two-setting method" and application in contactless automatic measurement

Abstract

Combining with the characteristics of contactiess sensor and according to the Donaldson principle , the paper puts forward the error separation technique of "two points and two setting method". This technique can not only realize the separation for roundness error of intermediary from rotating error movement of spindle , but also reduce the time of a measuring period and avoid the "drift" error which is brought by measuring system. Besides , according to above error separation technique , the authous of the paper develop a error separation system which can be used in ultra-high--precision contactless roundness measuring instrument. The maximal "drift"value of the system is less than 10 nm.

Automated setup for non-tactile high-precision measurements of roundness and cylindricity using two laser interferometers

“…In [11] two diametrically opposed radial roundness deviations r(ϕ) and r(ϕ+180 • ) are measured simultaneously with capacitance probes. Those signals are used to separate the radial roundness profile from the spindle error based on the Donaldson reversal but without the need of reversing the probes.…”

“…Thus, it becomes obvious that high-precision measurements of roundness are very time consuming. On the other hand, the prolonged measurement time due to the use of reversal methods can lead to serious drifting of the measurements and might counteract the benefit of the error separation [11].…”