Process for controlling a parameter based upon filtered data

Claim 2

A process for controlling a parameter of a sheet material which is being manufactured, comprising: (a) causing the sheet material to travel; (b) moving a scanning means across the sheet a plurality of times, i; (c) measuring a parameter of the sheet with the scanning means in a plurality of zones, j, which are disposed side-by-side across the sheet to produce a plurality of data; (d) filtering the data using a filter factor which is calculated based upon the data; (e) controlling the parameter based upon the filtered data.

Claim 3

A process according to claim 1 wherein the filter factor is calculated based upon the relative long-term variation in the data.

Claim 4

A process according to claim 2 wherein β(i,j)=α+{[ABS[L(i,j)]/Nom]/M}[U-α] where α, U, M and Nom are predetermined constants and if X(i,j)-Y(i-1,j)≧0, then L(i,j)=Min X(i,j)-Y(i-1,j); T(i-1,j) or if X(i,j)-Y(i-1,j)<0, then L(i,j)=0.0, where T(i-1,j)=U[D(i-1),j)]+[1-U]T(i-2,j); U is a constant; D(i-1,j)=X(i-1,j)-Y(i-1,j); Y(i-1,j) is filtered data; and X(i,j) is the data measured by the scanning means.

Claim 5

A process according to claim 1 wherein the data measured by the scanning means is identified as X(i,j) and the filter factor is identified as β(i,j).

Claim 6

A process according to claim 4 wherein a second filter factor Γ(i,j) is calculated and the data is repeatedly filtered using the two filter factors β(i,j) and Γ(i,j).

Claim 7

A process according to claim 5 wherein Γ(i,j) is calculated based upon the relative short-term variation of X(i,j).

Claim 8

A process according to claim 6 wherein Γ(i,j)=α-{[ABS[S(i,j)]/Nom]/M}[α-F], where α, F, M and Nom are predetermined constants and S(i,j)=[X(i,j)-Y(i-1,j)]-L(i,j), wherein Y(i-1,j) is filtered data and L(i,j) is long-term machine direction variation.

Claim 9

A process for controlling a parameter of a sheet material which is being manufactured, comprising: (a) causing the sheet material to travel; (b) moving a scanning means across the sheet a plurality of times, i; (c) measuring a parameter of the sheet with the scanning means in a plurality of zones, j, which are disposed side-by-side across the sheet to produce a plurality of data; (d) filtering the data using a filter factor which is recalculated after the scanning means has been moved across the sheet; (e) controlling the parameter based upon the filtered data.

Claim 10

A process for controlling a parameter of a sheet material which is being manufactured, comprising: (a) causing the sheet material to travel; (b) moving a scanning means across the sheet a plurality of times, i; (c) measuring a parameter of the sheet with the scanning means in a plurality of zones, j, which are disposed side-by-side across the sheet to produce a plurality of data; (d) filtering the data using a filter factor which is recalculated after the scanning means has been moved across the sheet; (e) controlling the parameter based upon the filtered data.

Claim 11

A process according to claim 8 wherein the filter factor is recalculated each time the scanning means has been moved across the sheet.