Filtering method research on laser thickness measuring for thin plates

Sub-filtering is a dynamic collecting method that point to establish a decision rule. Through feature analysis of actually measured data of thin plate sample, and divided them into edge drop zone, mid-continental region and overlap parts. the analysis shows that variation of plank width and thickness has the similar change to marginal thickness reduction, which means Cc and Ce increase along with plank width and thickness value increase. However, width variation influence is far smaller than that of thickness variation. On the basis of total samples medial-filter pretreatment, 6 exponent polynomial fit was carried on edge-drop-zone data, and 26-point recursive process mid-continental-region data, normalize process and quadratic fit the recursive data of overlap part from edge drop zone and mid-continental region, contrast of the wave filtering under different parameter condition shows this method has achieved the desired effect of filtering, so that the measurement accuracy reached micron-level.