Rolling-wheel method is an effective way of measuring big diameter. After amending the temperature error and pressure
error, the uncertainty of measurement can not be φ =5um/m stably because of the influence of skid. The traditional
method of identifying skid loses sight of the influences of the unstable motor speed, the appearance form error and the
eccentric of installation of the big axis and rolling wheel and so on, so the method has its limitation. In this paper, a new
method of multiple identification and repair is introduced, namely n diameters are measured and Chauvenet standard is
used for identifying the anomalous measurements one by one, and then the average value of the remaining data is used
for repairing identified anomalous measurements, and the next round identification and repair is carried out until the
accuracy requirement of the measurement is satisfied. The result of experiments indicates that the method can identify
anomalous measurements whose offsets caused by the skid are greater than 0.2φ , and the uncertainty of measurement
has improved substantially.
|