Abstract: Methods and systems to minimize energy cost in response to time-varying energy prices are presented for a variety of different pricing scenarios. A cascaded model predictive control system is disclosed comprising an inner controller and an outer controller. The inner controller controls power use using a derivative of a temperature setpoint and the outer controller controls temperature via a power setpoint or power deferral. An optimization procedure is used to minimize a cost function within a time horizon subject to temperature constraints, equality constraints, and demand charge constraints. Equality constraints are formulated using system model information and system state information whereas demand charge constraints are formulated using system state information and pricing information. A masking procedure is used to invalidate demand charge constraints for inactive pricing periods including peak, partial-peak, off-peak, critical-peak, and real-time.

Abstract: A controller is configured to use an energy cost function to predict a total cost of energy purchased from an energy provider as a function of one or more setpoints provided by the controller. The energy cost function includes a demand charge term defining a cost per unit of power corresponding to a maximum power usage of the building system. The controller is configured to linearize the demand charge term by imposing demand charge constraints and to mask each of the demand charge constraints that applies to an inactive pricing period. The controller is configured to determine optimal values of the one or more setpoints by performing an optimization procedure that minimizes the total cost of energy subject to the demand charge constraints and to provide the optimal values of the one or more setpoints to equipment of the building system that operate to affect the maximum power usage.

Abstract: A controller for a building system receives training data that includes input data and output data. The output data measures a state of the building system affected by both the input data and an extraneous disturbance. The controller performs a two-stage optimization process to identify system parameters and Kalman gain parameters of a dynamic model for the building system. During the first stage, the controller filters the training data to remove an effect of the extraneous disturbance from the output data and uses the filtered training data to identify the system parameters. During the second stage, the controller uses the non-filtered training data to identify the Kalman gain parameters. The controller uses the dynamic model with the identified system parameters and Kalman gain parameters to generate a setpoint for the building system. The building system uses the setpoint to affect the state measured by the output data.

Abstract: Methods for system identification are presented using model predictive control to frame a gray-box parameterized state space model. System parameters are identified using an optimization procedure to minimize a first error cost function within a range of filtered training data. Disturbances are accounted for using an implicit integrator within the system model, as well as a parameterized Kalman gain. Kalman gain parameters are identified using an optimization procedure to minimize a second error cost function within a range of non-filtered training data. Recursive identification methods are presented to provide model adaptability using an extended Kalman filter to estimate model parameters and a Kalman gain to estimate system states.

Abstract: A refrigeration system includes a compressor, a condenser, an expansion device, an evaporator, and an additional refrigerant vessel connected in a closed refrigerant loop. The additional refrigerant vessel is connected to the condenser at the high pressure side by a first valve and to the evaporator at a low pressure side by a second valve. A controller controls operation of the first valve and the second valve. Only one of the first valve and the second valve may be open at the same time. Refrigerant from the additional refrigerant vessel may be added to the closed refrigerant loop when the controller receives a low refrigerant level indication of in the evaporator. Refrigerant may also be removed from the closed refrigerant loop when the controller receives a high refrigerant level indication in the evaporator.

Abstract: An optimization system for a central plant includes a processing circuit configured to receive load prediction data indicating building energy loads and utility rate data indicating a price of one or more resources consumed by equipment of the central plant to serve the building energy loads. The optimization system includes a high level optimization module configured to generate an objective function that expresses a total monetary cost of operating the central plant over an optimization period as a function of the utility rate data and an amount of the one or more resources consumed by the central plant equipment. The high level optimization module is configured to optimize the objective function over the optimization period subject to load equality constraints and capacity constraints on the central plant equipment to determine an optimal distribution of the building energy loads over multiple groups of the central plant equipment.

Abstract: Systems and methods for low level central plant optimization are provided. A controller for the central plant uses binary optimization to determine one or more feasible on/off configurations for equipment of the central plant that satisfy operating constraints and meet a thermal energy load setpoint. The controller determines optimum operating setpoints for each feasible on/off configuration and generates operating parameters including at least one of the feasible on/off configurations and the optimum operating setpoints. The operating parameters optimize an amount of energy consumed by the central plant equipment. The controller outputs the generated operating parameters via a communications interface for use in controlling the central plant equipment.

Abstract: An optimization system for a central plant includes a processing circuit configured to receive load prediction data indicating building energy loads and utility rate data indicating a price of one or more resources consumed by equipment of the central plant to serve the building energy loads. The optimization system includes a high level optimization module configured to generate an objective function that expresses a total monetary cost of operating the central plant over the optimization period as a function of the utility rate data and an amount of the one or more resources consumed by multiple groups of the central plant equipment. The optimization system includes a load change penalty module configured to modify the objective function to account for a load change penalty resulting from a change in an amount of the building energy loads assigned to one or more of the groups of central plant equipment.

Abstract: A controller for a chiller includes processing electronics configured to detect a plurality of surge events. The processing electronics create a surge map by calculating and plotting a point for each detected surge event in an at least two dimensional coordinate system. The surge map is displayed through the use of an electronic display system. The surge map describes at least three conditions of the chiller when the surge event was detected through the use of axis and non-axis representations. The processing electronics are further configured to control at least one setpoint for the chiller using the calculated surge map.

Abstract: A method for detecting and responding to disturbances in a HVAC system using a noisy measurement signal and a signal filter is provided. The method includes detecting a deviation in the noisy measurement signal, resetting the filter in response to a detected deviation exceeding a noise threshold, filtering the noisy measurement signal using the signal filter to determine an estimated state value, and determining that a disturbance has occurred in response to the estimated state value crossing a disturbance threshold. In some embodiments, the method further includes performing one or more control actions in response to the detection of a disturbance.

Abstract: A controller for a chiller includes processing electronics configured to detect a plurality of surge events. The processing electronics calculate a point for each detected surge event in at least a three dimensional coordinate system. The three dimensional coordinate system describes at least three conditions of the chiller when the surge event was detected. The processing electronics are configured to calculate a surface map for the at least three dimensional coordinate system using the calculated points. The processing electronics are further configured to control at least one setpoint for the chiller using the calculated surface map.

Abstract: A controller for a chiller includes processing electronics configured to detect a plurality of surge events. The processing electronics create a surge map by calculating and plotting a point for each detected surge event in an at least two dimensional coordinate system. The surge map is displayed through the use of an electronic display system. The surge map describes at least three conditions of the chiller when the surge event was detected through the use of axis and non-axis representations. The processing electronics are further configured to control at least one setpoint for the chiller using the calculated surge map.

Abstract: A refrigeration system includes a compressor, a condenser, an expansion device, an evaporator, and an additional refrigerant vessel connected in a closed refrigerant loop. The additional refrigerant vessel is connected to the condenser at the high pressure side by a first valve and to the evaporator at a low pressure side by a second valve. A controller controls operation of the first valve and the second valve. Only one of the first valve and the second valve may be open at the same time. Refrigerant from the additional refrigerant vessel may be added to the closed refrigerant loop when the controller receives a low refrigerant level indication of in the evaporator. Refrigerant may also be removed from the closed refrigerant loop when the controller receives a high refrigerant level indication in the evaporator.

Abstract: A data structure and method of use thereof for encoding video information are described. Macroblock parameters are initialized, and it is determined whether an operating point is selected. If the operating point is selected, then the following occurs: each quad of nodes of a first node level are obtained and a check for merger is done on them; each quad of nodes of a second node level is obtained and a check for merger is done on them; nodes of a third node level are obtained and check for merger is done on them; nodes of a fourth node level are obtained and a check for merger is done on them; and modes are assigned responsive to cost of combinations of encoding modes associated with possible mergers.

Abstract: Method and apparatus for processing scalable content having a base layer and at least one enhancement layer is described. In one example, static logic having decoder logic and system monitor logic is provided. Programmable logic having a plurality of reconfigurable slots is also provided. The decoder logic includes a base layer processor for processing the base layer of the scalable content. The system monitor logic is configured to dynamically reconfigure at least one of the plurality of reconfigurable slots with at least one enhancement block for processing the at least one enhancement layer of the scalable content.

Abstract: A controller for a chiller includes processing electronics configured to detect a plurality of surge events. The processing electronics calculate a point for each detected surge event in at least a three dimensional coordinate system. The three dimensional coordinate system describes at least three conditions of the chiller when the surge event was detected. The processing electronics are configured to calculate a surface map for the at least three dimensional coordinate system using the calculated points. The processing electronics are further configured to control at least one setpoint for the chiller using the calculated surface map.

Abstract: Method and apparatus for communication between hardware blocks configured in a programmable logic device (PLD) and a computation device external to the PLD is described. A bus controller is provided for receiving words from the computation device. Each of the words includes an address component and a data component. A first-in-first-out buffer (FIFO) is configured for communication with the bus controller to store the words. A processing engine is provided having a memory space associated with the hardware blocks and being configured to receive a word at a top of the FIFO. An address decoder is provided for decoding the address component of the word at the top of the FIFO to obtain an address of a memory location in the memory space. A strobe generator is provided for coupling a strobe signal to the processing engine. The strobe signal is configured to store the word in the memory location.

Abstract: Various approaches for embedding identifier information in a configuration bitstream for a programmable logic device (PLD) are disclosed. In various embodiments, the bits in the configuration bitstream that are unused in implementing a the design are identified. The identifier information is encrypted, and a subset of the unused bits are selected using a pseudo-random function. The encrypted identifier information is placed in the selected subset of unused bits. Decryption is accomplished by reversing the encryption approach.

Abstract: An aspect of the invention relates to communication between a first processing element and a second processing element. A first-in-first-out circuit (FIFO) includes a data input port, a data output port, an object-sent port, an object-end port, a memory, and control logic. The data input port is coupled to the first processing element. The data output port is coupled to the second processing element. The object-sent port is configured to receive an object-sent signal from the first processing element. The object-end port is configured to send an object-end signal to the second processing element. The memory is configured to store objects, each of the objects include a plurality of data words. The control logic is configured to control reading and writing to the memory, processing the object sent signal, and generating the object end signal.

Abstract: Circuit arrangements and methods for real-time image resizing and image rotation. Line buffers are used for storage of lines of pixel values for both resizing and rotation. A first one of the line buffers receives input pixel values, and the line buffers are coupled in a chain such that line buffer i receives pixel values from line buffer i−1. The lines of pixel values are moved from line buffer i to line buffer i+1 as the pixel values are processed for resizing or rotation.