Measurex Devron Inc.

Honeywell Measurex Devron Inc.

Edwin Michael Heaven

Robert Bucher

Christopher B Lynch

Par O Hallman

Scott B Crumpacker

Dimitry M Gorinevsky

John King

Ron I Powell

Robert N Vyse

Apparatus and method for controlling the size of a gap through which material is metered. The gap is defined by a rigid surface and a flexible surface connected to at least one actuator for deforming the flexible surface. A plurality of sensors are positioned along the rigid or flexible surfaces to detect the other of the surfaces and generate signals indicating its position. A computing unit in communication with the plurality of sensors processes the signals to generate a continuous gap measurement profile. The computing system also stores a pre-determined desired gap measurement profile. A control system in communication with the computing unit actuates the actuators to deform the flexible surface to adjust the gap measurement profile to correct any deviation from the desired gap measurement profile.

Intelligent gap control for improved paper machine profile control

A method for controlling the properties of a sheet of material to be manufactured on a sheet making machine using a network of intelligent actuators distributed across and down the length of the paper machine. The method includes the steps of measuring and acquiring properties data about the sheet of material and communicating the measured properties data as the data becomes available to the actuators that control the properties of the sheet of material. A control action for each actuator is calculated and implemented using a control model of each actuator's influence on the properties of the sheet so as to minimize the variation of the measured properties data from a desired target. The control action made at an actuator and the predicted changes in the measured properties based on the control model are also communicated to all the actuators. The control actions of all actuators are co-ordinated such that the actuators co-operate to minimize the variation of the measured properties data sheet from desired targets.

Coordinated control of sheet properties by receiving a measured and

A process for determining shrinkage and alignment of the web in a sheetmaking machine having a plurality of actuators for controlling web parameters in the cross-direction. The process involves the steps of applying excitation to the actuators, collecting data regarding the change in cross-direction web properties due to the excitation of the actuators to determine a measured actuator response profile. A modeled actuator response profile is established and a best fit of the modeled actuator response profile to the measured actuator response profile is established to allow for determination of alignment and shrinkage parameters of the web based on the best fit modeled actuator response profile. The foregoing approach permits reliable identification of alignment and shrinkage within 10-20 data scans of the web, despite process noise, with improved accuracy when compared with conventional 'bump' tests.

Automated identification of web shrinkage and alignment parameters in

A method for determining the cross-machine shrinkage or expansion profile of a travelling sheet produced in a sheetmaking machine between an upstream location and a downstream location. The method involves marking the sheet at the upstream location with an array of marks at measured, predetermined intervals in the cross-machine direction. The sheet is inspected in the cross-machine direction at the downstream location to measure the spacing of the array of marks. A shrinkage or expansion profile of the travelling sheet is developed based on the changes in the spacing between the array of marks at the downstream location. Apparatus for carrying out the method is also disclosed. The method and apparatus of the present invention permit rapid and precise determination of the sheet shrinkage or expansion profile to allow for better control of property variation across the sheet.

Apparatus and method of determining sheet shrinkage or expansion

A process for transforming a plurality of data points n defining a high resolution profile for a parameter of a sheet material being manufactured into a low resolution profile for control of the parameter is disclosed. The process involves filtering the data points of the high resolution profile using an anti-aliasing filter function to create an intermediate profile and reducing the number of datapoints of the intermediate profile by an integer factor to create the low resolution profile to be used to control the parameter.

Process for transforming a high resolution profile to a control profile

A caliper profile control system for a paper machine provides reduced start up times after sheet breaks to bring the caliper profile across the sheet to within the desired limits. The method comprises the steps of scanning at predetermined intervals across the width of the paper sheet to monitor thickness error of the sheet from predetermined limits and change in the thickness error between the intervals, in each of a plurality of zones across the sheet. A control change signal is determined for each of the zones based on the error and the change in error using an exponential function of the magnitude of the error to maximize the change in the error and reduce integral action when the error is large. The control signal is used to reduce the error in each zone and the integral action is increased as the error decreases until the predetermined limits are met.

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Vancouver, Canada

Edwin Michael Heaven