Abstract: Systems and methods for estimating a time to cool down or warm up a building zone from a temperature setback condition are provided. A described method includes determining, by a controller for the building zone, at least one of a cooling demand for the building zone and a heating demand for the building zone for a time period corresponding to the temperature setback condition. The method further includes estimating a return time using at least one of the cooling demand and the heating demand. The return time is the time to cool down or warm up the building zone from the temperature setback condition.

Abstract: A system for detecting a control loop interaction between two or more control loops. The system includes a processing circuit configured to store a history of detected loop disturbances for a plurality of control loops. The processing circuit is also configured to compute a measure of interaction between control loops using the history of detected loop disturbances. The processing circuit is further configured to determine whether a loop interaction exists based on the computed measure of interaction.

Abstract: A dither switching extremum seeking controller includes a communications interface configured to receive an output signal from a plant and provide a plurality of control inputs to the plant. The controller includes a demodulation module configured to extract, from the output signal, a performance gradient for a variable of interest affected by the plant for each of the control inputs. The controller includes a stabilization module configured to stabilize the extracted performance gradients using a history of previous values for the extracted performance gradients and an integration module configured to generate values for the control inputs. The generated values drive the stabilized performance gradients toward zero. The controller includes a dither signal module configured to perturb the control inputs by adding a dither signal to each control input. The perturbed control inputs are provided to the plant via the communications interface.

Abstract: Systems and methods for estimating a time to cool down or warm up a building zone from a temperature setback condition are provided. A described method includes determining, by a controller for the building zone, at least one of a cooling demand for the building zone and a heating demand for the building zone for a time period corresponding to the temperature setback condition. The method further includes estimating a return time using at least one of the cooling demand and the heating demand. The return time is the time to cool down or warm up the building zone from the temperature setback condition.

Abstract: A system for operating a process includes a processing circuit that uses a self-optimizing control strategy to learn a steady-state relationship between an input and an output. The processing circuit is configured to switch from using the self-optimizing control strategy to using a different control strategy that operates based on the learned steady-state relationship.

Abstract: A system for controlling start-up of a feedback controller includes a memory device and a processing circuit. The processing circuit is configured to receive a gain parameter from the feedback controller and to store the gain parameter in the memory device. The processing circuit is further configured to multiply the stored gain parameter and to cause the feedback controller to use the multiplied gain parameter in response to a determination that the feedback controller has restarted.

Abstract: An extremum seeking control method optimizes a control process for a plant such as an air handling unit. The method improves the performance of an extremum seeking control strategy by limiting, removing or preventing the effects of an actuator saturation condition, particularly as the extremum seeking control strategy relates to HVAC applications.

Abstract: An extremum seeking control method optimizes a control process for a plant such as an air handling unit. The method compensates for abrupt changes in the operation of the plant by resetting the extremum seeking control strategy in response to a detection of the abrupt change.

Abstract: A method for controlling turbines in a wind farm turbine array is shown and described. The method includes using a cascade of self-optimizing controllers to in an attempt to maximize the power generated by at least a portion of the wind farm turbine array, wherein at least one of the self-optimizing controllers for an upstream turbine is configured to control the upstream turbine in an attempt to maximize the combined total of (a) the power output of the upstream turbine and (b) the power output of at least one downstream turbine.

Abstract: Systems and methods for regulating the amount of outdoor air that is introduced into a building are shown and described. These systems and methods utilize extremum seeking control logic to vary the flow of outdoor air into the building in response to cooling load determinations.

Abstract: A system for detecting a control loop interaction between two or more control loops. The system includes a processing circuit configured to store a history of detected loop disturbances for a plurality of control loops. The processing circuit is also configured to compute a measure of interaction between control loops using the history of detected loop disturbances. The processing circuit is further configured to determine whether a loop interaction exists based on the computed measure of interaction.

Abstract: A computerized method for operating a process includes using at least one sensor to determine when to transition a state machine between a first operating state wherein the process is operated using extremum seeking control and a second operating state wherein the process is operated without extremum seeking control. The method further includes, in response to the determination, automatically transitioning from the first operating state to the second operating state.

Abstract: A fault detection system for detecting a fault in a process system includes a first circuit configured to modify an input of the process system with a modifying signal. The fault detection system further includes a second circuit configured to receive an output from the process system and configured to determine whether the fault exists based on at least one of a reduction of a signal component and an unexpected transformation of the signal component, wherein the signal component corresponds to a function of the modifying signal.

Abstract: A system for controlling a cooling tower that cools condenser fluid for a condenser of a chiller includes a cooling tower fan system that controllably varies a speed of at least one fan motor. The system further includes an extremum seeking controller that receives inputs of power expended by the cooling tower fan system and of power expended by the chiller. The extremum seeking controller provides an output to the cooling tower fan system that controls the speed of the at least one fan motor. The extremum seeking controller determines the output by searching for a speed of the at least one fan motor that minimizes the sum of the power expended by the cooling tower fan system and the power expended by the chiller.

Abstract: A system for operating a process includes a processing circuit that uses a self-optimizing control strategy to learn a steady-state relationship between an input and an output. The processing circuit is configured to switch from using the self-optimizing control strategy to using a different control strategy that operates based on the learned steady-state relationship.

Abstract: An extremum seeking control method optimizes a control process for a plant such as an air handling unit. The method improves the performance of an extremum seeking control strategy by limiting, removing or preventing the effects of an actuator saturation condition, particularly as the extremum seeking control strategy relates to HVAC applications.

Abstract: An extremum seeking control method optimizes a control process for a plant such as an air handling unit. The method compensates for abrupt changes in the operation of the plant by resetting the extremum seeking control strategy in response to a detection of the abrupt change.

Abstract: A system is disclosed for detecting faults in an environmental control system for a building zone. The system includes a circuit configured to determine that a fault exists based on a comparison of the current value for the climate condition in a heating state and the estimate of the climate condition at which a transmission from the heating state to the no heating state is expected to be caused by a finite state machine of the system.

Abstract: An extremum seeking control method optimizes a control process for a plant such as an air handling unit. The method improves the performance of an extremum seeking control strategy by limiting, removing or preventing the effects of an actuator saturation condition, particularly as the extremum seeking control strategy relates to HVAC applications.

Abstract: Systems and methods for estimating a time to cool down or warm up a building zone from a temperature setback condition are provided. A described method includes determining, by a controller for the building zone, at least one of a cooling demand for the building zone and a heating demand for the building zone for a time period corresponding to the temperature setback condition. The method further includes estimating a return time using at least one of the cooling demand and the heating demand. The return time is the time to cool down or warm up the building zone from the temperature setback condition.