Patent application number | Description | Published |
20080264591 | Apparatus and method for controlling product grade changes in a paper machine or other machine - A paper machine includes equipment for processing or producing a product in a continuous manner, such as a paper sheet. A grade change occurs when the equipment transitions from producing or processing a product having a first grade to producing or processing a product having a second grade. To support the grade change, a target for at least one controlled variable and a target for at least one manipulated variable are identified. The at least one manipulated variable and the at least one controlled variable are associated with the production of the product. A trajectory for the at least one manipulated variable and a corresponding trajectory for the at least one controlled variable are identified using the targets. The grade change is implemented using the trajectories so as to transition from production of the product having the first grade to production of the product having the second grade. | 10-30-2008 |
20080294419 | Apparatus and method for simulating multi-dimensional non-linear multivariable processes - A process simulator is provided for simulating the behavior of multi-dimensional non-linear multivariable processes. A multi-dimensional non-linear multivariable model of a process can be generated, such as by using smaller building blocks. One or more inputs are provided to the model, a behavior of the process is simulated in real-time using the model, and one or more outputs of the model are provided. The model could represent a two-dimensional non-linear multivariable model, and the one or more inputs to the model and/or the one or more outputs of the model could be array-based. The process simulator could be formed from multiple components, such as a regulatory loop simulator object, a process model object, a disturbance generator object, and a scanner simulator object. The arrangement of the objects can be flexible and configurable, such as by designing the objects in an object-oriented manner utilizing a sink/source architecture. | 11-27-2008 |
20110295390 | APPARATUS AND METHOD FOR MODELING AND CONTROL OF CROSS-DIRECTION FIBER ORIENTATION PROCESSES - A method includes generating a model associated with cross-directional fiber orientation of a web, which includes identifying spatial frequency characteristics of a fiber orientation (FO) process. The method also includes providing the model for control of the FO process. Generating the model could include performing a spatial impulse test of the FO process, and long wavelength responses of the FO process can be identified by performing a spatial long wavelength test of the FO process or by retrieving information from a historical database. Actuator edge padding can be applied to the model in order to generate a controller model. A controller can be used to control the process based on the controller model. At least one parameter of the controller model can be dynamically adjusted during operation of the controller. The controller can change average fiber orientation angle profiles and twist profiles by only adjusting slice lip actuators in a headbox. | 12-01-2011 |
20120173023 | APPARATUS AND METHOD FOR CONTROLLING AUTOTROPH CULTIVATION - A method includes receiving at least one measurement of a dissolved carbon dioxide concentration of a mixture of fluid containing an autotrophic organism. The method also includes determining an adjustment to one or more manipulated variables using the at least one measurement. The method further includes generating one or more signals to modify the one or more manipulated variables based on the determined adjustment. The one or more manipulated variables could include a carbon dioxide flow rate, an air flow rate, a water temperature, and an agitation level for the mixture. At least one model relates the dissolved carbon dioxide concentration to one or more manipulated variables, and the adjustment could be determined by using the at least one model to drive the dissolved carbon dioxide concentration to at least one target that optimize a goal function. The goal function could be to optimize biomass growth rate, nutrient removal and/or lipid production. | 07-05-2012 |
20130325148 | EFFICIENT QUADRATIC PROGRAMMING (QP) SOLVER FOR PROCESS CONTROL AND OPTIMIZATION - A method includes identifying an initial solution to a quadratic programming (QP) problem associated with a process. The method also includes performing an iterative procedure having one or more iterations. Each iteration includes determining whether any constraint associated with the process is violated in the solution. Each iteration also includes selecting a violated constraint, determining a step direction and a step length associated with the selected violated constraint, and updating the solution based on the step direction and the step length. Determining the step direction and the step length includes using a Schur complement based on an active set of constraints associated with the solution. The Schur complement is nonsingular during all iterations of the iterative procedure except when the active set is empty. | 12-05-2013 |
20140358254 | TECHNIQUE FOR CONVERTING A MODEL PREDICTIVE CONTROL (MPC) SYSTEM INTO AN EXPLICIT TWO-DEGREES OF FREEDOM (2DOF) CONTROL SYSTEM - A method includes obtaining a reference tracking performance ratio and a disturbance rejection performance ratio associated with a model predictive control (MPC) controller. The method also includes filtering an output target signal for the controller using a first filter based on the reference tracking performance ratio. The method further includes filtering a feedback signal for the controller using a second filter based on the disturbance rejection performance ratio. The filters can provide two degrees of freedom for tuning reference tracking and disturbance rejection operations of the controller. The reference tracking operation of the controller and the disturbance rejection operation of the controller can be independently tunable. The reference tracking performance ratio can control how aggressively the controller responds to a change in the output target signal. The disturbance rejection performance ratio can control how aggressively the controller responds to a disturbance in the feedback signal. | 12-04-2014 |
20150081046 | APPARATUS AND METHOD FOR MODELING AND CONTROL OF CROSS-DIRECTION FIBER ORIENTATION PROCESSES - A method includes generating a model associated with cross-directional fiber orientation of a web, which includes identifying spatial frequency characteristics of a fiber orientation (FO) process. The method also includes providing the model for control of the FO process. Generating the model could include performing a spatial impulse test of the FO process, and long wavelength responses of the FO process can be identified by performing a spatial long wavelength test of the FO process or by retrieving information from a historical database. Actuator edge padding can be applied to the model in order to generate a controller model. A controller can be used to control the process based on the controller model. At least one parameter of the controller model can be dynamically adjusted during operation of the controller. The controller can change average fiber orientation angle profiles and twist profiles by only adjusting slice lip actuators in a headbox. | 03-19-2015 |
20150268645 | METHOD AND APPARATUS FOR SPECIFYING AND VISUALIZING ROBUST TUNING OF MODEL-BASED CONTROLLERS - A method includes obtaining information identifying uncertainties associated with multiple parameters of a model for an industrial model-based controller. The method also includes obtaining information identifying multiple tuning parameters for the controller. The method further includes generating a graphical display identifying (i) one or more expected step responses of an industrial process that are based on the tuning parameters of the controller and (ii) an envelope around the one or more expected step responses that is based on the uncertainties associated with the parameters of the model. The parameters could include a process gain, a time constant, and a time delay associated with the model. The uncertainties associated with the parameters of the model could include, for each parameter of the model, an uncertainty expressed in the time domain. The information identifying the tuning parameters could include a settling time and an overshoot associated with the controller. | 09-24-2015 |