Abstract: A method and apparatus are set forth for modeling a coloring process in moving web manufacturing through dye response gain adaptation using measured sheet color spectrum; and dye response shape adaptation using measured color spectrum of the production sheet. The adaptation of colorant (dye) response gain uses the measured sheet color spectrum value at the value of maximum light absorbance of the dye. The adaptation of dye response spectrum uses the measured sheet color reflectance spectrum and sample sheet color spectrum with a corresponding response shape calculated using a formula to adapt the current sheet condition dye response shape using the dye response from the sample sheet on the assumption of a constant ratio of absorption change to dye concentration change.

Abstract: A method and apparatus are set forth for controlling and actuator in a moving web manufacturing process. The method includes: (1) measuring a plurality of actuator profiles and in response generating nominal response models thereof; (2) generating a multivariable profile prediction based on the nominal response models; (3) generating a multivariable control target based at least one of the actuator profile; and (4) adjusting control of the actuator by minimizing error between the multivariable control target and the multivariable profile prediction.

Abstract: A method and apparatus are set forth for modeling a coloring process in moving web manufacturing through dye response gain adaptation using measured sheet color spectrum; and dye response shape adaptation using measured color spectrum of the production sheet. The adaptation of colorant (dye) response gain uses the measured sheet color spectrum value at the value of maximum light absorbance of the dye. The adaptation of dye response spectrum uses the measured sheet color reflectance spectrum and sample sheet color spectrum with a corresponding response shape calculated using a formula to adapt the current sheet condition dye response shape using the dye response from the sample sheet on the assumption of a constant ratio of absorption change to dye concentration change.

Abstract: A method and apparatus are set forth for controlling an actuator in a moving web manufacturing process, comprising measuring a plurality of actuator profiles and in response generating nominal response models thereof; generating a multivariable profile prediction based on the nominal response models; generating a multivariate control target based at least one of the actuator profiles; and adjusting control of the actuator by minimizing error between the multivariate control target and said multivariate profile prediction.

Abstract: A multivariable analysis tool is provided wherein an orthogonal decomposition method such as a Partial Least Squares algorithm is applied to a disturbance model, which relates the known loop disturbances to the loop model residue. The tool according to the invention first extracts the most dominant correlation to the loop model residue and then uses the residue to search for secondary dominant correlation in an orthogonal space, and repeats this process until no further output variation can be significantly attributed by the next dominant correlation. In this way, the analysis tool of the present invention is able to estimate the performance potential of each control loop under different disturbance conditions and provide a control performance index by comparing the achieved performance to the performance potential in a multi-variable environment. This index indicates whether or not a given loop is under optimal operation and shows variance of the loop from the best achievable loop performance.

Abstract: A multivariable analysis tool is provided wherein an orthogonal decomposition method such as a Partial Least Squares algorithm is applied to a disturbance model, which relates the known loop disturbances to the loop model residue. The tool according to the invention first extracts the most dominant correlation to the loop model residue and then uses the residue to search for secondary dominant correlation in an orthogonal space, and repeats this process until no further output variation can be significantly attributed by the next dominant correlation. In this way, the analysis tool of the present invention is able to estimate the performance potential of each control loop under different disturbance conditions and provide a control performance index by comparing the achieved performance to the performance potential in a multi-variable environment. This index indicates whether or not a given loop is under optimal operation and shows variance of the loop from the best achievable loop performance.

Abstract: A method and apparatus for controlling the color of an article such as a paper web includes performing a comparison between target and measured reflectance values in numerous wavelength bands spanning the visible spectrum. The comparison quantifies correspondingly numerous errors that are modified by a non-linear operation, such as squaring, and then added together. The resulting sum is minimized by individually adjusting the application of a number of colorants to the article. The number of wavelength bands is greater than the number of colorants. This avoids metameric effects which are common in conventional systems that rely on three color space coordinates such as Hunter Laboratories L, a, b; C.I.E. L*, a*, b*; chromaticity x, y, z; and tristimulus X, Y, Z. Colorant response simulators enable the effects of changes in application of colorants to be tested while the actual application of colorants to the article is unchanged.