Abstract: A selective catalytic reduction system includes a catalyst, a device to measure an amount of nitrogen oxide (NO), a device to measure an amount of nitrogen dioxide (NO2), a device to add an ammonia source, and a control unit to calculate the amount of ammonia source to add as a function of a ratio of an amount of nitrogen oxide and an amount of nitrogen dioxide or an absolute amount of nitrogen oxide and an absolute amount of nitrogen dioxide.

Abstract: A selective catalytic reduction system includes a catalyst, a device to measure an amount of nitrogen oxide (NO), a device to measure an amount of nitrogen dioxide (NO2), a device to add an ammonia source, and a control unit to calculate the amount of ammonia source to add as a function of a ratio of an amount of nitrogen oxide and an amount of nitrogen dioxide or an absolute amount of nitrogen oxide and an absolute amount of nitrogen dioxide.

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 system for controlling nonlinear plants which may be effected with gain scheduled feedback controllers. Several linear sub-controllers having various gains may be put together as one unit. The overall controller may be changed by switching from one sub-controller to another according to an exogenous or endogenous parameter. The signal to the switch may reflect operational ranges of the plant occurring at certain times and indicate the gain desired from the system relative to the output and input signals of the plant at those times. The advantages of the present approach may include a guarantee of nominal and robust stability both global and local, a permitting of the use of control structures that are familiar to industrial practitioners, and no requirement of advanced mathematical techniques for its implementation.

Abstract: Methods and systems for using a measure of fueling rate in the air side control of an engine. By using a measure of the fueling rate, the air side control may, for example, anticipate the future air side needs of the engine, and adjust one or more air side parameters to meet the anticipated future air side needs of the engine. This may improve the responsiveness, performance and emissions of the engine.

Abstract: A fast and reliable technique for tuning multivariable model predictive controllers (MPCs) that accounts for performance and robustness is provided. Specifically, the technique automatically yields tuning weights for the MPC based on performance and robustness requirements. The tuning weights are parameters of closed-loop transfer functions which are directly linked to performance and robustness requirements. Automatically searching the tuning parameters in their proper ranges assures that the controller is optimal and robust. This technique will deliver the traditional requirements of stability, performance and robustness, while at the same time enabling users to design their closed-loop behavior in terms of the physical domain. The method permits the user to favor one measurement over another, or to use one actuator more than another.

Abstract: A controller design for switching between m linear multivariable controllers each of whom stabilizes a linear plant has been presented. A Youla-Kucera factorization was exploited in the interest of obtaining a closed-loop system that is exponentially stable for any switching signal ?(t) in the absence of plant model uncertainty. Robustness to practical model uncertainty was also considered and lower and upper bounds on the tolerable magnitude of unstructured additive plant uncertainty were presented. Numerical example demonstrated that the two controller degrees of freedom in the proposed controller design could be used to separately modify the closed-loop steady-state (with respect to ?(t)) performance and the switching transients.

Abstract: A reverse bump test, for identifying the alignment of a sheetmaking system while the system remains in closed-loop control, includes the following steps: (a) leaving the control system in closed-loop, (b) artificially inserting a step signal on top of the measurement (or setpoint) profile from the scanner, (c) recording the data as the control system moves the actuators to remove the perceived disturbance (or setpoint change), and (d) refining or developing a model from the artificial measurement disturbance (or setpoint change) to the actuator profile. The technique supplies the probing/perturbation signal to the scanner measurement, which is equivalent to supplying the probing/perturbation signal to the setpoint target) rather than inserting bumps via the actuator set points as has been practiced traditionally.

Abstract: Systems and methods for controlling automotive powertrains using a distributed control architecture are disclosed. A distributed control system may include a supervisory control unit for controlling one or more powertrain subsystems, and one or more subsystem control units in communication with the supervisory control unit. The supervisory control unit can be configured to execute a central optimization algorithm that computes variables from across multiple powertrain subsystems, and then outputs a number of globally approximated command values to each associated subsystem control unit. In some embodiments, the central optimization algorithm can be configured to solve a global cost function or optimization routine. One or more of the subsystem control units can be configured to execute a lower-level algorithm or routine, which can comprise a higher-fidelity model than that used by the central optimization algorithm.

Abstract: Systems and methods for using pedal position and/or pedal change rate in the fuel side and/or air side control of an engine. By knowing the pedal position and/or pedal rate, an engine controller may anticipate future fuel and/or air needs of the engine, and adjust the fuel profile and/or air profile to meet those anticipated needs. This may help improve the responsiveness, performance and emissions of the engine.

Abstract: A reverse bump test, for identifying the alignment of a sheetmaking system while the system remains in closed-loop control, includes the following steps: (a) leaving the control system in closed-loop, (b) artificially inserting a step signal on top of the measurement (or setpoint) profile from the scanner, (c) recording the data as the control system moves the actuators to remove the perceived disturbance (or setpoint change), and (d) refining or developing a model from the artificial measurement disturbance (or setpoint change) to the actuator profile. The technique supplies the probing/perturbation signal to the scanner measurement, which is equivalent to supplying the probing/perturbation signal to the setpoint target) rather than inserting bumps via the actuator set points as has been practiced traditionally.

Abstract: A system for controlling fuel to an engine to minimize emissions in an exhaust of the engine. There may be a controller connected to an actuator, for example a fuel control actuator, of the engine and to emissions sensors, such as an NOx and/or PM sensor, proximate to an exhaust output of the engine. The controller, for example a speed controller, may have an input connected to an output of a pedal or desired speed setting mechanism. A speed sensor at a power output of the engine may be connected to an input of the controller.

Abstract: A system for automatic multivariable calibration of an engine controller. The system may take inputs which include actuator setpoints, sensor measurements, performance requirements, and so forth. There may be an algorithm to compute engine calibration parameters for the controller. Each of the actuators may be separately stepped through to experimentally obtain actuator input and sensor output data. Algorithmic processing of the experimentally obtained data may be performed to calculate parameters of a model of an engine. A model based control design algorithm may then be invoked to obtain the calibration parameters for a controller. The calibrated controller may be tested with real or simulated engine conditions. The performance related to the parameters may be analyzed and determination of the acceptability of the data be made. If not acceptable, the parameters may be reprocessed. If acceptable, the calibration parameters may be downloaded to the engine controller for application and use.

Abstract: A system for controlling fuel to an engine to minimize emissions in an exhaust of the engine. There may be a controller connected to an actuator, for example a fuel control actuator, of the engine and to emissions sensors, such as an NOx and/or PM sensor, proximate to an exhaust output of the engine. The controller, for example a speed controller, may have an input connected to an output of a pedal or desired speed setting mechanism. A speed sensor at a power output of the engine may be connected to an input of the controller.

Abstract: A system for controlling nonlinear plants which may be effected with gain scheduled feedback controllers. Several linear sub-controllers having various gains may be put together as one unit. The overall controller may be changed by switching from one sub-controller to another according to an exogenous or endogenous parameter. The signal to the switch may reflect operational ranges of the plant occurring at certain times and indicate the gain desired from the system relative to the output and input signals of the plant at those times. The advantages of the present approach may include a guarantee of nominal and robust stability both global and local, a permitting of the use of control structures that are familiar to industrial practitioners, and no requirement of advanced mathematical techniques for its implementation.

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 multivariable controller that models the interaction between groups of sensors and groups of actuators during the operation of an engine. By accounting for the interactive effects that a group of actuators has on a sensor or group of sensors, improved system performance may be achieved. When emission sensors are used, such as NOX and/or PM sensors, the multivariable controller may help control the various engine actuators to reduce emissions of the engine.

Abstract: A fast and reliable technique for tuning multivariable model predictive controllers (MPCs) that accounts for performance and robustness is provided. Specifically, the technique automatically yields tuning weights for the MPC based on performance and robustness requirements. The tuning weights are parameters of closed-loop transfer functions which are directly linked to performance and robustness requirements. Automatically searching the tuning parameters in their proper ranges assures that the controller is optimal and robust. This technique will deliver the traditional requirements of stability, performance and robustness, while at the same time enabling users to design their closed-loop behavior in terms of the physical domain. The method permits the user to favor one measurement over another, or to use one actuator more than another.

Abstract: Methods and systems for controlling a diesel engine using a combined fuel and air-side controller are disclosed. An illustrative method may include the steps of providing a combined fuel and air-side controller adapted to coordinate both the fuel and air-side control of an engine, sensing one or more parameters, and outputting a fuel profile signal and one or more air-side control signals for controlling at least a part of the fuel-side and at least a part of the air-side of the engine. By centrally coordinating both the fuel and air-side control of the engine, the system can be configured to anticipate future fuel and/or air-side needs of the engine, thus improving system response, performance, and/or emissions.

Abstract: The invention concerns turbochargers, or more particularly to multivariable dual stage series turbochargers having two degrees of freedom. A multistage series turbocharger apparatus has a low pressure turbocharger comprising a low pressure compressor and a low pressure turbine; a high pressure turbocharger comprising a high pressure compressor and a high pressure turbine, and a exhaust gas recirculation device. A controller controls the operation of at least two of the low pressure compressor, high pressure compressor, low pressure turbine, high pressure turbine, and exhaust gas recirculation device such that at least one operating parameter is maintained at about a selected value.