Abstract: A building management system includes connected equipment and a predictive diagnostics system. The connected equipment is configured to measure a plurality of monitored variables. The predictive diagnostics system includes a communications interface, a steady state detector, a controller. The communications interface is configured to receive samples of the monitored variables from the connected equipment. The steady state detector is configured to recursively update a mean and a variance of the samples each time a new sample is received, identify whether each of the samples reflects a steady state or a transient state of operation of the connected equipment using the mean and the variance, and associate each of the samples to the steady state or the transient state as identified. The controller is configured to adjust an operation of the connected equipment based on the steady state or the transient state as identified.

Abstract: A building management system includes sensors configured to measure a plurality of monitored variables and fault detection and diagnosis (FDD) system configured to identify an operating state associated with the monitored variables. The FDD system includes a communications interface configured to receive samples of the monitored variables from the plurality of sensors. The FDD system includes a direction extractor configured to use locations, in a multidimensional modeling space, of a plurality of stored operating states to extract a direction from each of the stored operating states to each of the other stored operating states. The FDD system includes a fault diagnoser configured to use the extracted directions in a voting-based diagnosis to determine an operating state for each of the samples of the monitored variables.

Abstract: An asynchronous wireless data transmission system includes a wireless sensor and a data recipient device. The wireless sensor includes a measurement device configured to collect a plurality of samples of a measured variable at a plurality of different sampling times, a transmission generator configured to generate a compressed data object containing the plurality of samples of the measured variable, and a wireless radio configured to transmit the compressed data object at a transmission time asynchronous with at least one of the sampling times. The data recipient device includes an object decompressor configured to extract the plurality of samples of the measured variable from the compressed data object.

Abstract: A building management system includes sensors configured to measure a plurality of monitored variables and fault detection and diagnosis (FDD) system configured to identify an operating state associated with the monitored variables. The FDD system includes a communications interface configured to receive samples of the monitored variables from the plurality of sensors. The FDD system includes a direction extractor configured to use locations, in a multidimensional modeling space, of a plurality of stored operating states to extract a direction from each of the stored operating states to each of the other stored operating states. The FDD system includes a fault diagnoser configured to use the extracted directions in a voting-based diagnosis to determine an operating state for each of the samples of the monitored variables.

Abstract: A system for monitoring and controlling flow rate of a fluid through a valve, the system including a flow rate sensor configured to measure the flow rate of the fluid through the valve, and a controller in communication with the flow rate sensor. The controller is configured to receive the measured flow rate from the flow rate sensor and determine if the measured flow rate is equal to a predetermined flow rate value. In response to determining equality, the controller is configured to determine a minimum valve position threshold (xmin), and determine a minimum flow rate threshold (ymin) corresponding to xmin. The controller is further configured to calculate a corrected flow rate (?f) using xmin, ymin, and an indication of valve position (v). Additionally, the controller is configured to control a valve operation using the corrected flow rate (?f).

Abstract: A system for monitoring and controlling flow rate of a fluid through a valve is disclosed. The system includes a flow rate sensor to measure the flow rate of the fluid through the valve, and a controller. The controller is configured to receive the measured flow rate from the flow rate sensor, and determine if the measured flow rate is equal to a predetermined flow rate value. The controller is further configured to, in response to a determination that the measured flow rate is equal to the predetermined flow rate value, determine a minimum valve position threshold (xmin). Additionally, the controller is configured to determine a minimum flow rate threshold (ymin) corresponding to xmin, and configured to generate a PWM signal and calculate a corrected flow rate (?f) using the PWM signal. The controller controls a valve operation using ?f. The PWM signal switches between zero and ymin.

Abstract: A control system with asynchronous wireless data transmission includes a wireless sensor and a controller. The wireless sensor includes a measurement device configured to collect a plurality of samples of a measured variable at a plurality of different sampling times, a transmission generator configured to generate a compressed data object containing the plurality of samples of the measured variable, and a wireless radio configured to transmit the compressed data object at a transmission time asynchronous with at least one of the sampling times. The controller includes an object decompressor configured to extract the plurality of samples of the measured variable from the compressed data object and a feedback controller configured to use one or more of the extracted samples of the measured variable to modulate a control signal for a plant that operates to affect the measured variable.

Abstract: A control system for a plant includes a controller and a sensor. The controller is configured to estimate a response time of the plant and adjust a sampling rate based on the estimated response time. The response time is a parameter that characterizes a response of the plant to a disturbance. The sensor is configured to receive the adjusted sampling rate from the controller, collect samples of a measured variable from the plant at the adjusted sampling rate, and provide the samples of the measured variable to the controller.

Abstract: A control system for a plant includes a controller configured to detect a disturbance in the control system. In response to detecting the disturbance, the controller is configured to evaluate a signal affected by the disturbance to estimate a response time of a plant. The response time is a parameter that characterizes a response of the plant to the disturbance. The controller is configured to adjust an operating parameter used by the control system based on the estimated response time. The controller is configured to use the adjusted operating parameter to generate and provide an input to the plant.

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: A plant includes equipment that operate to affect a variable state or condition of the plant in response to a control signal. A feedback controller monitors a process variable received via a feedback signal from the plant and uses an error signal representing a setpoint error between the process variable and a setpoint to generate the control signal for the plant. An exponentially-weighted moving average (EWMA) calculator generates EWMA values based on the setpoint error. A normalized index generator uses the EWMA values to calculate a normalized performance index. A threshold generator generates a threshold based on a first alarm parameter ? representing a normalized magnitude of the setpoint error and a second alarm parameter ? representing a normalized duration that the setpoint error has persisted. An alarm manager generates an alarm in response to the normalized performance index crossing the threshold.

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: A setpoint alarming system includes a feedback controller that monitors a process variable provided as a feedback signal from a plant and uses an error signal representing a difference between the process variable and a setpoint to generate a control signal for the plant. The plant uses the control signal to affect the process variable. The system includes a normalized index generator that uses the error signal to generate a normalized performance index for the plant. The system includes an expected value estimator that estimates a value of the normalized performance index expected to occur when a setpoint error of a predetermined magnitude has persisted for a predetermined duration. The system includes an alarm manager that compares the normalized performance index to the expected value and generates an alarm in response to the normalized performance index dropping below the expected value.

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: A thermostat for transmitting data wirelessly to a controller in a building includes a temperature sensor, a processing circuit, and a wireless radio. The processing circuit is configured to receive a measured temperature value from the temperature sensor, determine a current temperature error based on the current measured temperature value and a setpoint temperature, and determine whether a difference between the current temperature error and a previous temperature error is greater than an error threshold. The processing circuit is configured to determine whether a minimum amount of time has passed since transmitting a previous measured temperature value and transmit the current measured temperature value to the controller via the wireless transmitter in response to determining that both the difference between the current temperature error and the previous temperature error is greater than the error threshold and the minimum amount of time has passed since transmitting a temperature value.

Abstract: A control system with asynchronous wireless data transmission includes a wireless sensor and a controller. The wireless sensor includes a measurement device configured to collect a plurality of samples of a measured variable at a plurality of different sampling times, a transmission generator configured to generate a compressed data object containing the plurality of samples of the measured variable, and a wireless radio configured to transmit the compressed data object at a transmission time asynchronous with at least one of the sampling times. The controller includes an object decompressor configured to extract the plurality of samples of the measured variable from the compressed data object and a feedback controller configured to use one or more of the extracted samples of the measured variable to modulate a control signal for a plant that operates to affect the measured variable.

Abstract: A control system is configured to operate a multiple-input system to achieve an optimal value for a performance variable of the multiple-input system. The control system includes a mapper configured to generate a mapping from a first number of manipulated variables to a second number of latent variables. The second number is smaller than the first number and each of the latent variables includes a linear combination of the manipulated variables. The control system also includes an extremum-seeking controller configured to receive the performance variable from the multiple-input system as a feedback and modulate values of the second number of latent variables to drive the performance variable to the optimal value. The mapper is further configured to use the mapping to translate modulated values of the second number of latent variables to modulated values of the first number of manipulated variables and provide the modulated values of the first number of manipulated variables to the multiple-input system.

Abstract: A building management system includes connected equipment and a predictive diagnostics system. The connected equipment is configured to measure a plurality of monitored variables. The predictive diagnostics system includes a communications interface, a principal component analysis (PCA) modeler, a controller. The communications interface is configured to receive samples of the monitored variables from the connected equipment. The PCA modeler is configured to automatically assign each of the samples of the monitored variables to one of a plurality of operating states of the connected equipment and to construct a PCA model for each operating state using the samples assigned to the operating state. The controller is configured to use the PCA models to adjust an operation of the connected equipment.

Abstract: A building management system includes connected equipment and a predictive diagnostics system. The connected equipment is configured to measure a plurality of monitored variables. The predictive diagnostics system includes a communications interface, a steady state detector, a controller. The communications interface is configured to receive samples of the monitored variables from the connected equipment. The steady state detector is configured to recursively update a mean and a variance of the samples each time a new sample is received, identify whether each of the samples reflects a steady state or a transient state of operation of the connected equipment using the mean and the variance, and associate each of the samples to the steady state or the transient state as identified. The controller is configured to adjust an operation of the connected equipment based on the steady state or the transient state as identified.

Abstract: A building management system includes connected equipment and a predictive diagnostics system. The connected equipment is configured to measure a plurality of monitored variables. The predictive diagnostics system includes a communications interface, a principal component analysis (PCA) modeler, and a fault predictor. The communications interface is configured to receive samples of the monitored variables from the connected equipment. The PCA modeler is configured to construct PCA models for a plurality of operating states of the connected equipment using the samples of the monitored variables. Each PCA model defines a location of one of the operating states in a multidimensional modeling space. The fault predictor is configured to determine a proximity of a new sample of the monitored variables to one or more of the operating states using the PCA models and to predict a fault occurrence based on the proximity.