A method/structure for calibrating a product fluid flow device having one or more apertures with aggregate area A.sub.o, where fluid flows along a fluid flow path therethrough in response to pressure differentials ΔP across the apertures. Calibration is effected relative to a calibration fluid flow device having a geometry and operational parameters corresponding to those of the product fluid flow device. A piecewise curved calibration controller establishes calibration conditions and generates a discrete point calibration flow rate (dpCFR) Function by measuring at a sparse set of points in a range of interest and determining a piecewise curved mathematical representation of fluid flow through the calibration fluid flow device. Data representative of the CFR function is transferred to a product blade controller, which processes the mathematical representation, and controls fluid flow through product fluid flow device based on values extracted from the received dpCFR Function.

An intelligent self-balancing downstream device that can obtain accurate flow measurements (e.g., flow of a liquid or gas through a tube) that can perform the self-balancing in situ and during operation to satisfy a set point and without k factors or the use of TAB balancers. The downstream device may be controllable by a single software system or network. The downstream device can operate in a single zone or be coupled with multiple like apparatuses. It has a high turndown ratio and self-balances, which can allow for continuous commissioning with built-in fault diagnostic systems. A fluid metering device can include control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

A fluid distribution apparatus that can serve as a fluid metering device that is operable on a single platform by building automation systems. The building automation system may be controllable by a single software system or network accessible locally on site or remotely off site. The fluid distribution apparatus can operate independently or coupled with multiple like apparatuses for system operation. It is a high turndown, self-balancing system which allows for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply system, exhaust system, or a combination thereof. The fluid distribution apparatus includes fluid metering devices that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

According to one aspect, a control system for providing stable balance control may include an H.sup.∞ controller, a state-feedback circuit, a first feedback loop, and a second feedback loop. The control system may be implemented in a robot as a controller for the robot. The H.sup.∞ controller may receive an input signal and generate a control effort signal. The state-feedback circuit may receive the control effort signal as an input and generate an output signal. The feedback loop may include the H.sup.∞ controller and the state-feedback circuit and may transfer the output signal of the state-feedback circuit back to the input of the H.sup.∞ controller and input a tracking error input signal to the H.sup.∞ controller. The tracking error input signal may be the difference between the output signal of the state-feedback circuit and the input signal.

An intelligent self-balancing downstream device (e.g., air fixture or diffuser) that can obtain accurate flow measurements that can be used to perform the self-balancing in situ and during operation to satisfy a set point and without k factors or the use of TAB balancers. The downstream device may be controllable by a single software system or network accessible locally on site or remotely off site. The downstream device can operate in a single zone or be coupled with multiple like apparatuses for multi-zone operation. It is a high turndown ratio and self-balances, which can allow for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply, return, or exhaust system, or a combination thereof. The downstream device can include multi-stage airflow control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

A self-balancing system that can obtain accurate flow measurements that can be used to perform the self-balancing in situ and during operation to satisfy a set point and without k factors or the use of TAB balancers. The building automation system may be controllable by a single software system or network accessible locally on site or remotely off site. The air distribution apparatus can operate in a single zone or coupled with multiple like apparatuses for multi-zone operation. It is a high turndown, self-balancing system which allows for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply, return, or exhaust system, or a combination thereof. The air distribution apparatus can include multi-stage airflow control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

A method for calibrating a product fluid flow valve disposed along a flow path in a site duct, and including damper blades, an actuator coupled thereto, a differential pressure sensor, and a blade controller adapted to define adjustable product flow apertures, comprising the steps: with a calibration fluid flow valve in a calibration duct remote from the product fluid flow valve, and characterized by a geometric shape and operational parameters corresponding to those of the product fluid flow valve, and with a calibration controller, establishing a plurality of calibration conditions including pressure drop across the calibration blades and area of the calibration apertures, determining a calibration flow rate (CFM) function, transferring the CFM function to the product blade controller and adjusting the adjustable product flow apertures so that a parameter set point is attained. In a form, fluid flowing through the product flow apertures forms a vena contracta.

A variable aperture orifice plate assembly for controlling and/or measuring fluid flow therethrough, from an upstream end to a downstream end. The orifice plate assembly includes a damper assembly having an array of adjustable cross-section apertures having an aggregate aperture area, upstream and downstream pressure sensors on opposite sides of the damper assembly, an actuator assembly for adjustably controlling the aggregate area of the apertures, and a processor configured for feedback operation in a closed-loop, to effect operation as an orifice plate. The processor is responsive to differential pressure across the damper assembly, and the aggregate area of the respective apertures normal to the flow paths of fluid flowing therethrough, to control the differential pressure and/or the aggregate area in a closed-loop manner so that fluid flowing between the array of apertures and the downstream end, is characterized by a corresponding array of vena contractae.

A method/structure for remotely calibrating a product fluid flow device having one or more apertures with aggregate area A.sub.o, where fluid flows along a fluid flow path therethrough in response to pressure differentials P across the apertures. Calibration can occur on a calibration device to determine a fluid flow profile for a product device. In response to a determination that the product device is installed according to a different arrangement than used during calibration, the flow profile can be updated according to the different arrangement and provided to the product device in situ.

A self-balancing system that can obtain accurate flow measurements that can be used to perform the self-balancing in situ and during operation to satisfy a set point and without k factors or the use of TAB balancers. The building automation system may be controllable by a single software system or network accessible locally on site or remotely off site. The air distribution apparatus can operate in a single zone or coupled with multiple like apparatuses for multi-zone operation. It is a high turndown, self-balancing system which allows for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply, return, or exhaust system, or a combination thereof. The air distribution apparatus can include multi-stage airflow control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.