Abstract: A system and process are provided for determining the concentration of a first component of a mixture wherein the first component includes at least 3 materials. The process includes directing 2 beams of x-rays into the mixture and receiving portions of the beams which are transmitted through the mixture. The concentration of the first component is determined based upon the beams transmitted through the mixture.

Abstract: The present invention relates generally to the control of processes which include relatively long time delays, yet which are susceptible to transient external disturbances, such as high-speed sheetmaking processes. Exemplary embodiments include a control system architecture that combines internal model-based control with state feedback in a manner which provides robust control, yet provides rapid rejection of external transient disturbances even in processes including relatively long time delays.

Abstract: Disclosed is an apparatus for measuring on-line the color and color-related properties of a moving sheet. Contrast ratio reflectance measurements are made for providing opacity corrections substantially in real time for a full color spectrum. An optical color sensor in accordance with the invention includes a pair of synchronized spectrometers, the first spectrometer being aligned to view a region of the sheet backed with a highly reflective ("white") material and the second spectrometer being aligned to view a region of the sheet backed with a highly absorptive ("black") material. The use of two spectrometers permits substantially simultaneous "black" and "white" measurements for a full color spectrum. The optical color sensing system further includes two light sources, a flashlamp and a continuously energized tungsten filament lamp. Light beams from the two sources are combined to form a sheet-illuminating third beam approximating the D65 standard source.

Abstract: A control system regulates a controlled process. A first controller receives at least a first input variable and a second input variable and produces at least a first control variable and a second control variable. A delay unifier associated with the first controller introduces a first delay to one of the first and second control variables, the first delay being determined as a function of a second delay associated with another of the first and second control variables, and outputs first and second control variables with unified delay. A processor models effects of the controlled process. The processor receives the delayed first and second control variables output by the first controller and produces estimated process output variables. A second controller processes a difference between measured process output variables and the estimated process output variables to correct for disturbances.

Abstract: A system and process are provided for determining the concentration of a first component of a mixture wherein the first component includes at least 3 materials. The process includes directing 2 beams of x-rays into the mixture and receiving portions of the beams which are transmitted through the mixture. The concentration of the first component is determined based upon the beams transmitted through the mixture.

Abstract: In a scanner used in a paper-making process to measure basis weight and other parameters of the fabricated paper sheet, variations in the separation of an opposed pair of sensing heads due to temperature induced deflections of upper and lower beams on which the heads are movably mounted as well as deflections and/or expansions of other portions of the support structure for the sensor are dynamically measured and compensated for. Temperature sensors mounted on carriages for the sensing heads measure the temperatures at different locations within the sensor support structure so that temperature differentials can be determined. The temperature differentials, which provide a measure of beam deflection at any given position of the head carrying carriage, are applied in accordance with a linearizing algorithm to correct the values provided by the sensing heads.