Patent application number | Description | Published |
20090143872 | On-Line Adaptive Model Predictive Control in a Process Control System - A method of creating and using an adaptive DMC type or other MPC controller includes using a model switching technique to periodically determine a process model, such as a parameterized process model, for a process loop on-line during operation of the process. The method then uses the process model to generate an MPC control model and creates and downloads an MPC controller algorithm to an MPC controller based on the new control model while the MPC controller is operating on-line. This technique, which is generally applicable to single-loop MPC controllers and is particularly useful in MPC controllers with a control horizon of one or two, enables an MPC controller to be adapted during the normal operation of the process, so as to change the process model on which the MPC controller is based to thereby account for process changes. The adaptive MPC controller is not computationally expensive and can therefore be easily implemented within a distributed controller of a process control system, while providing the same or in some cases better control than a PID controller, especially in dead time dominant process loops, and in process loops that are subject to process model mismatch within the process time to steady state. | 06-04-2009 |
20090198350 | ROBUST ADAPTIVE MODEL PREDICTIVE CONTROLLER WITH TUNING TO COMPENSATE FOR MODEL MISMATCH - An MPC adaptation and tuning technique integrates feedback control performance better than methods commonly used today in MPC type controllers, resulting in an MPC adaptation/tuning technique that performs better than traditional MPC techniques in the presence of process model mismatch. The MPC controller performance is enhanced by adding a controller adaptation/tuning unit to an MPC controller, which adaptation/tuning unit implements an optimization routine to determine the best or most optimal set of controller design and/or tuning parameters to use within the MPC controller during on-line process control in the presence of a specific amount of model mismatch or a range of model mismatch. The adaptation/tuning unit determines one or more MPC controller tuning and design parameters, including for example, an MPC form, penalty factors for either or both of an MPC controller and an observer and a controller model for use in the MPC controller, based on a previously determined process model and either a known or an expected process model mismatch or process model mismatch range. A closed loop adaptation cycle may be implemented by performing an autocorrelation analysis on the prediction error or the control error to determine when significant process model mismatch exists or to determine an increase or a decrease in process model mismatch over time. | 08-06-2009 |
20100204808 | MODEL PREDICTIVE CONTROLLER WITH TUNABLE INTEGRAL COMPONENT TO COMPENSATE FOR MODEL MISMATCH - An MPC controller technique integrates feedback control performance better than methods commonly used today in MPC type controllers, resulting in an MPC controller that performs better than traditional MPC techniques in the presence of process model mismatch. In particular, MPC controller performance is enhanced by adding a tunable integration block to the MPC controller that develops an integral component indicative of the prediction or other control error, and adds this component to the output of an MPC controller algorithm to provide for faster or better control in the presence of model mismatch, which is the ultimate reason for the prediction error in the first place. This technique enables the MPC controller to react more quickly and to provide better set point change and load disturbance performance in the presence of model mismatch, without decreasing the robustness of the MPC controller. | 08-12-2010 |
20120046764 | METHODS, APPARATUS AND ARTICLES OF MANUFACTURE TO TEST PROCESS CONTROL SYSTEMS - Example methods, apparatus and articles of manufacture to test process control systems are disclosed. A disclosed example method includes obtaining user inputs to a first process control system, obtaining process inputs and first process outputs of the first process control system, providing the user inputs and the process inputs to a second process control system to operate the second process control system, obtaining second process outputs of the second process control system operated with the user inputs and the process inputs, and comparing the first and second process outputs to determine whether the second process control system is implemented as intended. | 02-23-2012 |
20120209557 | METHODS, APPARATUS AND ARTICLES OF MANUFACTURE TO TEST BATCH CONFIGURATIONS - Example methods, apparatus and articles to test batch configurations are disclosed. A disclosed example method includes identifying, using a processor, an execution path through a batch configuration of a process control system, generating a test plan for the execution path, stimulating the process control system to execute the test plan, and recording a result of the test plan. | 08-16-2012 |
20120221124 | USING AUTOCORRELATION TO DETECT MODEL MISMATCH IN A PROCESS CONTROLLER - A process controller adaptation and tuning technique uses a closed loop adaptation cycle that performs an autocorrelation analysis on the prediction error or the control error of a process control system to determine if significant process model mismatch exists or to determine an increase or a decrease in process model mismatch over time. The adaptation and tuning technique may perform a controller tuning cycle when the determined model mismatch raises above a predetermined level. | 08-30-2012 |
20150095692 | PROCESS CONTROL SYSTEMS AND METHODS - Process control system and methods are disclosed. An example method includes operating a first cluster including first virtual machines and first servers and operating a second cluster including second virtual machines and second servers. The example method also includes storing first data from the first virtual machines at a first data store of the first cluster and storing a replica of the first data at a second data store of the second cluster. The example method also includes storing second data from the second virtual machines at the second data store and storing a replica of the second data at the first data store and identifying a failure of the first cluster. The method also includes, in response to the failure, restarting the first virtual machines using the second servers and the replica of the first data at the second data store. | 04-02-2015 |
20150095788 | SYSTEMS AND METHODS FOR AUTOMATED COMMISSIONING OF VIRTUALIZED DISTRIBUTED CONTROL SYSTEMS - Systems and methods for automated commissioning of virtualized distributed control systems are disclosed. An example method includes accessing a data structure including a list of configuration names for network cards associated with first and second host servers of a virtual process control environment. The first and second host servers implement virtual machines corresponding to workstations for a process control system. The example method also includes when configuring the first host server, assigning a first name to a first one of the network cards associated with the first host server. The example method further includes when configuring the second host server, assigning the first name to a second one of the network cards associated with the second host server based on a user selection of the first name from the list of configuration names. The second host server is configured after the first host server. | 04-02-2015 |