Abstract: A method of controlling signal transmission in a building control system including measuring a number of signal values associated with an environmental variable using a sensor of a wireless device, dynamically determining, by the wireless device, a noise threshold based on the number of signal values, combining a first signal value and a second signal value of the number of signal values using a mathematical relationship to determine a result associated with the first signal value and the second signal value, and periodically transmitting the first signal value from the wireless measurement device to a controller in response to the result exceeding the noise threshold.

Abstract: A method for performing extremum-seeking control of a plant includes determining multiple values of a correlation coefficient that relates a control input provided as an input to the plant to a performance variable that characterizes a performance of the plant in response to the control input. The performance variable includes a noise-free portion and an amount of noise. The method includes determining an adjusted correlation coefficient by scaling a first value of the correlation coefficient selected from the multiple values relative to a second value of the correlation coefficient selected from the multiple values. The adjusted correlation coefficient relates the noise-free portion of the performance variable to the control input. The method includes using the adjusted correlation coefficient to modulate the control input provided as an input to the plant.

Abstract: A method of controlling signal transmission in a building control system including measuring a number of signal values associated with an environmental variable using a sensor of a wireless device, dynamically determining, by the wireless device, a noise threshold based on the number of signal values, combining a first signal value and a second signal value of the number of signal values using a mathematical relationship to determine a result associated with the first signal value and the second signal value, and periodically transmitting the first signal value from the wireless measurement device to a controller in response to the result exceeding the noise threshold.

Abstract: A thermostat is disclosed. The thermostat can include one or more temperature sensors configured to measure one or more temperature values. The thermostat can include a processing circuit. The processing circuit can receive the one or more temperature values from the one or more temperature sensors. The processing circuit can receive one or more central processing unit (CPU) usage values, wherein the one or more CPU usage values indicate computing usage of the processing circuit. The processing circuit can determine, based on an empirical model comprising one or more gain values and one or more filters and based on one or more signals, a temperature of the building. The one or more signals comprise the one or more temperature values and the one or more CPU usage values. The empirical model accounts for dynamics of heat generated by the processing circuit and airflow acting on the thermostat.

Abstract: An adaptive flow limit controller for controlling a flow rate of a fluid through a heat exchanger includes a processing circuit. The processing circuit is configured to use an adaptive model to determine a threshold flow rate of the fluid through the heat exchanger at which a gradient of a temperature difference of the fluid across the heat exchanger with respect to the flow rate of the fluid through the heat exchanger has a threshold gradient value. The processing circuit is configured to operate a flow control device to maintain the flow rate of the fluid of through the heat exchanger at less than or equal to the threshold flow rate.

Abstract: A self-perturbing extremum-seeking controller for a plant that includes at least a static portion includes a processing circuit. The processing circuit is configured to obtain a value of a performance variable characterizing a performance of the plant. The processing circuit is configured to determine a sign of a gradient of the performance variable with respect to an input to the static portion of the plant. The processing circuit is configured to adjust a control input for the plant using the sign of the gradient, and provide the control input to the plant to affect the performance variable.

Abstract: An extremum seeking controller includes a processing circuit configured to modulate a manipulated variable provided as an input to a plant using an extremum-seeking control technique to drive a gradient of an objective function with respect to the manipulated variable toward an extremum. The objective function includes a performance variable characterizing a performance of the plant responsive to the manipulated variable. The objective function also includes a saturation adjustment term that becomes active as the plant approaches a saturation point and remains active as the plant operates within a saturated region past the saturation point. The saturation adjustment term causes the processing circuit to adjust the manipulated variable toward a value of the manipulated variable that returns the plant from the saturated region to a non-saturated region.

Abstract: A controller for HVAC equipment of a plant includes a processing circuit configured to predict an impact of a time delay of the plant on a performance variable received as feedback from the plant. The processing circuit is configured to artificially increase or decrease a value of the performance variable using an adjustable time delay parameter to at least partially negate the impact of the time delay on the performance variable. The processing circuit is configured to use the artificially increased or decreased value of the performance variable in on-off feedback control to operate the HVAC equipment.

Abstract: An on-off control system includes on-off equipment configured to operate in either an on state or an off state, an on-off controller configured to cause the equipment to transition between the on state and the off state based on a setpoint value and a deadband value to drive a control variable toward the setpoint value, and a deadband controller, according to some embodiments. In some embodiments, the deadband controller is configured to generate the deadband value used by the on-off controller. In some embodiments, the deadband controller is configured to generate the deadband value by obtaining a cost function that defines a cost based on at least a set of control values and the deadband value and selecting the deadband value that results in an optimal value of the cost function over a range of possible deadband values, the selected deadband value defining an optimal deadband value.

Abstract: A space controller and method for determining energy savings of the space controller are provided. The method includes estimating, by one or more processing circuits, a steady state gain of a controlled variable of a heating, ventilation, and air conditioning (HVAC) system; determining, by the one or more processing circuits, an actual runtime that HVAC equipment of the HVAC system is in an on state based on a first setpoint or schedule; predicting, by the one or more processing circuits, a reduction of runtime that the HVAC equipment is in the on state for a second setpoint or schedule based on the actual runtime and the steady state gain; and adjusting, by the one or more processing circuits, the first setpoint or schedule to the second setpoint or schedule based on the reduction of runtime.

Abstract: A self-configuring controller includes one or more processors and one or more non-transitory machine readable media storing instructions. When executed by the one or more processors, the instructions cause the one or more processors to receive an output signal from a controlled system or device representative of an operation of the controlled system or device in response to a first perturbed control input perturbed using a first dither signal, estimate a bandwidth of the controlled system or device based on the output signal and the first dither signal, perturb a second control input using a second dither signal based on the bandwidth of the controlled system or device to generate a second perturbed control input, and transmit the second perturbed control input to the controlled system or device.

Abstract: A method for controlling flow in a heating, ventilation, and air conditioning (HVAC) system that imposes an upper limit on the flow of fluid through a heating or cooling coil. Imposing this limit on the flow rate ensures that a temperature change across the coil remains above a minimum threshold and can significantly reduce energy waste. The method includes receiving a first temperature measurement associated with an inlet of the coil, receiving a second temperature measurement associated with an outlet of the coil, and receiving a flow measurement associated with the valve, applying the first temperature measurement, the second temperature measurement, and the flow measurement as input to a model, determining a maximum flow rate that ensures that a difference between the first temperature measurement and the second temperature measurement is above a threshold using the model, and operating the valve in accordance with the maximum flow rate.

Abstract: An adaptive flow limit controller for controlling a flow rate of a fluid through a heat exchanger includes a processing circuit. The processing circuit is configured to use an adaptive model to determine a threshold flow rate of the fluid through the heat exchanger at which a gradient of a temperature difference of the fluid across the heat exchanger with respect to the flow rate of the fluid through the heat exchanger has a threshold gradient value. The processing circuit is configured to operate a flow control device to maintain the flow rate of the fluid of through the heat exchanger at less than or equal to the threshold flow rate.

Abstract: An extremum seeking controller includes a processing circuit configured to modulate a manipulated variable provided as an input to a plant using an extremum-seeking control technique to drive a gradient of an objective function with respect to the manipulated variable toward an extremum. The objective function includes a performance variable characterizing a performance of the plant responsive to the manipulated variable. The objective function also includes a saturation adjustment term that becomes active as the plant approaches a saturation point and remains active as the plant operates within a saturated region past the saturation point. The saturation adjustment term causes the processing circuit to adjust the manipulated variable toward a value of the manipulated variable that returns the plant from the saturated region to a non-saturated region.

Abstract: A method of controlling signal transmission in a building control system including measuring a number of signal values associated with an environmental variable using a sensor of a wireless device, dynamically determining, by the wireless device, a noise threshold based on the number of signal values, combining a first signal value and a second signal value of the number of signal values using a mathematical relationship to determine a result associated with the first signal value and the second signal value, and periodically transmitting the first signal value from the wireless measurement device to a controller in response to the result exceeding the noise threshold.

Abstract: A self-perturbing extremum-seeking controller for a plant that includes at least a static portion includes a processing circuit. The processing circuit is configured to obtain a value of a performance variable characterizing a performance of the plant. The processing circuit is configured to determine a sign of a gradient of the performance variable with respect to an input to the static portion of the plant. The processing circuit is configured to adjust a control input for the plant using the sign of the gradient, and provide the control input to the plant to affect the performance variable.

Abstract: A building management system includes building equipment configured to operate in accordance with an input to alter a variable state or condition of a building as a process function of the input while incurring a cost of operating the equipment as a cost function of the input. The building management system also includes a controller configured to calculate a value of a self-optimizing control variable as a function of a measured state of the building equipment and drive the value of the self-optimizing control variable towards a setpoint value by generating the input based on the self-optimizing control variable and providing the input to the building equipment. The function comprises multiplying the measured state by a matrix and adding an offset vector. Values of elements of the matrix and the offset vector are determined using a non-optimal reference.

Abstract: A building management system includes building equipment configured to operate in accordance with an input to alter a variable state or condition of a building, a feedback controller configured to generate the input as a function of a measured state of the building equipment, and an analytics circuit. The analytics circuit is configured to obtain and store a dataset comprising the measured state and the input for a plurality of time steps, determine, based on at least a portion of the dataset, a self-optimizing control function that defines a self-optimizing control variable as a function of the measured state, calculate a value of the self-optimizing control variable using the self-optimizing control function and the measured state, monitor the value of the self-optimizing control variable over time, and generate an indication of performance of the building equipment relative to optimal performance based on the value of the self-optimizing control variable.

Abstract: Disclosed is a system to control a climate of a space via a first control loop and a second control loop interacting with the first control loop. The system includes a first controller of the first control loop to generate a first control signal based on a first modified set point and a first feedback signal. The system further includes a second controller of the second control loop to generate a second control signal based on a second modified set point and a second feedback signal. The system further includes a decoupler configured to predict a first effect of the first control signal on the second control loop and a second effect of the second control signal on the first control loop, and generate the first modified set point and the second modified set point to reduce the first effect and the second effect.

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.