Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method includes predicting measurements or states to be used by a controller to control a process. The predicted measurements or states are generated using a model of the process. The method also includes providing the predicted measurements or states to the controller such that the controller uses the predicted measurements or states at a sampling rate of the controller. In addition, the method includes updating at least some of the predicted measurements or states using measurements associated with a characteristic of an item from a sensor. The model may represent a discrete time model, and the method may also include generating the discrete time model using a continuous time model of the process. The measurements could be received from a plurality of sensors, where at least two of the sensors have different sampling times.

Abstract: A method includes determining one or more setpoint changes for one or more actuators in a process control system. Determining the one or more setpoint changes includes making larger or more frequent setpoint changes when operating in a first mode and making smaller or less frequent setpoint changes when operating in a second mode. The method also includes outputting the one or more setpoint changes to the one or more actuators. The method could further include entering the first mode after a paper sheet has broken and been rethreaded through a paper machine. The method could also include entering the second mode (i) after a specified amount of time has elapsed since entering the first mode or (ii) after the first mode has been entered and a caliper profile of the paper sheet is within a specified threshold of a desired caliper profile.

Abstract: A method includes receiving measurement data from at least one sensor at a first controller. The measurement data is associated with a process. The method also includes receiving a first output signal at the first controller. The first output signal is generated by a second controller and affects the process. The method further includes determining how to control at least a portion of the process using the measurement data and the first output signal. In addition, the method includes providing a second output signal, where the second output signal is operable to control at least the portion of the process. The second controller may be operable to use the second output signal to generate the first output signal.

Abstract: 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.

Abstract: 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.

Abstract: A method includes determining one or more setpoint changes for one or more actuators in a process control system. Determining the one or more setpoint changes includes making larger or more frequent setpoint changes when operating in a first mode and making smaller or less frequent setpoint changes when operating in a second mode. The method also includes outputting the one or more setpoint changes to the one or more actuators. The method could further include entering the first mode after a paper sheet has broken and been rethreaded through a paper machine. The method could also include entering the second mode (i) after a specified amount of time has elapsed since entering the first mode or (ii) after the first mode has been entered and a caliper profile of the paper sheet is within a specified threshold of a desired caliper profile.

Abstract: A process for coordinated control of machine direction MD and cross direction CD actuators in a sheetmaking machine for manufacturing a sheet of material is disclosed. The process involves measuring a plurality of sheet properties at regular intervals to collect sheet measurement data. The sheet measurement data is manipulated to establish a plurality of sheet property measurement arrays, which are then mapped to a common resolution. The common resolution sheet property measurement arrays are concatenated into one larger one-dimensional common resolution measurement array. The common resolution measurement array and an array of past changes in actuator set point are used as inputs to a paper machine process model state observer to generate the estimated current internal state of the sheet manufacturing process. A plurality of future sheet property target arrays are concatenated into one target array.

Abstract: A process for coordinated control of machine direction MD and cross direction CD actuators in a sheetmaking machine for manufacturing a sheet of material is disclosed. The process involves measuring a plurality of sheet properties at regular intervals to collect sheet measurement data. The sheet measurement data is manipulated to establish a plurality of sheet property measurement arrays, which are then mapped to a common resolution. The common resolution sheet property measurement arrays are concatenated into one larger one-dimensional common resolution measurement array. The common resolution measurement array and an array of past changes in actuator set point are used as inputs to a paper machine process model state observer to generate the estimated current internal state of the sheet manufacturing process. A plurality of future-sheet property target arrays are concatenated into one target array.