Web measurement system monitors properties of a web during manufacture without chopping measuring radiation during web measurement. A single chop is performed at each sheet edge or every n th sheet edge to measure edge temperature and edge thermal radiation for correction for Planckian radiation. Correction factors (R, W, F) including Planckian radiation correction factors, are derived for each point in a web profile. The measuring system also enables derivation of correction factors during operation in a single point and similar machine operating modes.
th sheet edge to measure edge temperature and edge thermal radiation for correction for Planckian radiation. Correction factors, including Planckian radiation correction factors, are derived for each point in a web profile. The measuring system also enables derivation of correction factors during operation in a single point and similar machine operating modes.
A method and apparatus for generating a comprehensive response model for a sheet forming machine are provided. A finite number of critical points and a response type are used to create a continuous response profile for each actuator zone. The continuous response profile for each actuator zone is discretized into a discrete response profile based on the resolution appropriate for an application. A multi-zone response model for each pair of actuator set and sheet property profile is created from the discretized response profile of the actuator zones in the actuator set. The comprehensive response model for a multivariable sheet-forming machine is created from a collection of multi-zone response models for multiple pairs of actuator sets and sheet property profiles.
G06F 19/00 - Digital computing or data processing equipment or methods, specially adapted for specific applications (specially adapted for specific functions G06F 17/00;data processing systems or methods specially adapted for administrative, commercial, financial, managerial, supervisory or forecasting purposes G06Q;healthcare informatics G16H)
7.
A METHOD AND APPARATUS FOR CREATING A COMPREHENSIVE RESPONSE MODEL FOR A SHEET FORMING MACHINE
A method and apparatus for generating a comprehensive response model for a sheet forming machine are provided. A finite number of critical points and a response type are used to create a continuous response profile for each actuator zone. The continuous response profile for each actuator zone is discretized into a discrete response profile based on the resolution appropriate for an application. A multi-zone response model for each pair of actuator set and sheet property profile is created from the discretized response profile of the actuator zones in the actuator set. The comprehensive response model for a multivariable sheet-forming machine is created from a collection of multi-zone response models for multiple pairs of actuator sets and sheet property profiles.
A method and apparatus for creating a generalized response model for a sheet forming machine are provided. Sheet property profiles are measured while the setpoint of an actuator is changed. A response (or change) profile of the sheet property resulting from a setpoint change is calculated. A finite set of critical points are selected from the property response profile. Using the selected critical points, the property response profile is classified in one of a finite number of response types. Under each of the response types, the property response profile is fitted with a plurality of continuous functions associated therewith. These continuous functions are combined to form the response model that minimizes the deviation between the property response and the fitted combination of continuous functions.
A method and apparatus for creating a generalized response model for a sheet forming machine are provided. Sheet property profiles are measured while the setpoint of an actuator is changed. A response (or change) profile of the sheet property resulting from a setpoint change is calculated. A finite set of critical points are selected from the property response profile. Using the selected critical points, the property response profile is classified in one of a finite number of response types. Under each of the response types, the property response profile is fitted with a plurality of continuous functions associated therewith. These continuous functions are combined to form the response model that minimizes the deviation between the property response and the fitted combination of continuous functions.
A single-sided web stabilizer for stabilizing a continuous moving web for making various web property measurements. The arrangement is characterized by a nozzle having a central structure, which may be a protrusion, surrounded by an annular opening through which air is emitted to generate a suction proximate the nozzle. The nozzle may be a Coanda nozzle, or may generate suction via a vortex flow. Two nozzle arrangements are provided, one sheet-contacting, where the sheet is drawn against the protrusion, and another sheet non-contacting, where an air bearing is provided between the protrusion end surface and the moving web to space the sheet from the protrusion. To provide a central air bearing the protrusion may be provided with an aperture or apertures through which air is expelled.
There is described a method and apparatus for tracking the location of web features through a converting process, one application of which can involve tracking paper defects from a paper machine (10) as detected by a camera system(12), to a winder where the sheet is wound to rolls (16) so that the web defects (14) can be repaired in the winder before making the rolls. The method to track web features is based on pattern identification of inherent sheet variability or defects. The apparatus involves two or more sheet property or defect monitoring web sensors arranged at the same cross directional location at different stages of the converting operation, augmented by tachometers and / or roll diameter sensors. A full automation system for drive control on the winder based on this information is preferably added to make maximum advantage of this information.
B65H 26/02 - Warning or safety devices, e.g. automatic fault detectors, stop-motions, for web-advancing mechanisms responsive to presence of irregularities in running webs
A sensor is provided that measures web caliper using optical as well as magnetic or inductive measuring devices. The optical measuring devices may employ a confocal chromatic aberration method to accurately determine the distance to the moving web and the magnetic devices may be ferrite core coil and target. Means of stabilizing a moving web are included for improving dynamic measurement accuracy.
A sensor is provided that measures web caliper using optical and magnetic measuring devices. The optical measuring devices may employ a confocal chromatic aberration method to accurately determine the distance to the moving web and the magnetic devices may be ferrite core coil and target. Means of stabilizing a moving web are included for improving dynamic measurement accuracy.
A sensor is provided that measures web caliper using optical and magnetic measuring devices. The optical measuring devices may employ a confocal chromatic aberration method to accurately determine the distance to the moving web and the magnetic devices may be ferrite core coil and target. Means of stabilizing a moving web are included for improving dynamic measurement accuracy.
A method for measuring both caliper and tension of a web such as paper wound into a roll. The method may include a standard caliper sensor whose air supply is selectively modified to allow for both the measurement of caliper and tension of the web. In another embodiment two similar or identical measurement devices are installed in tandem where one device measures tension without pinching the sheet and the other device measures caliper. The sensor may include two sheet guides for providing support for tension measurement or one or both sheet guides can be eliminated by support from machinery rolls.
A dual sided sheet surface property sensor has the capability to simultaneously measure both sides of a moving sheet at the same location of the sheet on the top and bottom surfaces of the sheet. The energy directed to each side of the sheet may include UV, visible light, infrared, radio frequency, microwave, broadband, or X-ray. The sensor has a source and associated detector on each side of the moving sheet and each source provides energy at a different modulation frequency and the associated detector is responsive only to that frequency.
Fast cross direction caliper control recovery time in a sheet making machine during startup of the machine after a sheet break is achieved provided that a preselected time duration measured from the occurrence of the sheet break to the clearing, of sheet break has elapsed. One or more of three operations, namely, open loop calender stack conditioning, a conditioning of a measurement from a sensor for measuring caliper of the sheet and a closed loop change in a set of control tuning parameters of a PI controller for providing feedback caliper control of actuators associated with, the calender stack can be selectably performed. The operations have an order of precedence. The first and second can be performed concurrently if the selected time duration for both are identical, the first is performed before the third if both are selected and the second is performed before the third if both are selected.
Fast cross direction caliper control recovery time in a sheet making machine during startup of the machine after a sheet break is achieved provided that a preselected time duration measured from the occurrence of the sheet break to the clearing of sheet break has elapsed. One or both of calender stack conditioning and conditioning of a measurement from a sensor for measuring caliper of the sheet, both with feedback CD control suspended, can be selectably performed. These operations can be performed concurrently if the selected time duration for both are identical. A closed loop change in a set of control tuning parameters of a PI controller providing feedback caliper control of actuators associated with the calender stack can be performed after either or both of the other operations are performed.
G06F 7/66 - Digital differential analysers, i.e. computing devices for differentiation, integration or solving differential or integral equations, using pulses representing incrementsOther incremental computing devices for solving difference equations wherein pulses represent unitary increments only
