Abstract: A system and methods are provided for controlling turboshaft engines. In one embodiment, a method includes receiving input signals for a collective lever angle (CLA) command and real-time power turbine speed (NP) of an engine, determining system data for engine effectors by the control unit based on the input signals for the collective lever angle (CLA) command and the real-time power turbine speed (NP) based on an integrated model for the turboshaft engine including a model of a gas generator section of the turboshaft engine and a model of a power turbine and rotor load section of the turboshaft engine. The method may also include determining control output based on model-based multi-variable control including optimization formulation and a constrained optimization solver. The method may also include outputting one or more control signals for control of the turboshaft engine.

Abstract: A fuel system for a gas turbine engine includes, among other things, a plurality of components defining a plurality of localized nodes at distinct locations relative to a fuel flow path, each of the plurality of localized nodes characterized by a distinct set of failure parameters. One or more fuel sensors are configured to measure at least one fuel condition relating to flow through the fuel flow path. A fuel observation assembly is coupled to one or more engine sensors configured to measure at least one engine condition.

Abstract: A control system for a gas turbine engine, a method for controlling a gas turbine engine, and a gas turbine engine are disclosed. The control system may include a nozzle scheduler for determining an exhaust nozzle position goal based on a nozzle schedule of exhaust nozzle positions related to flight conditions. The control system may further include a control module for determining a control command for the gas turbine engine. The control command may include, at least, a fuel flow command and an exhaust nozzle position command and the control command may be based on, at least, the exhaust nozzle position goal and an estimated thrust value. The control system may further include an actuator for controlling the gas turbine engine based on the control command.

Abstract: A control system for a gas turbine engine is disclosed. The control system may include a computer processor. The control system may also include an outer loop control module programmed into the computer processor to determine a torque request based at least in part on a real-time collective lever angle command. The control system may also include an inner loop control module programmed into the computer processor to receive the torque request from the outer loop control module, to determine fuel flow and inlet guide vane schedules based at least in part on the received torque request, and to send signals to a gas generator of the gas turbine engine in order to control the gas generator according to the determined fuel flow and inlet guide vane schedules.

Abstract: A method for controlling a gas turbine engine having a constrained model based control (CMBC) system. The method including obtaining information about a current and previous states of the engine, updating model data information in the CMBC and a parameter estimation system based on the obtained information, and identifying trends in the data based on the information. The method also includes diagnosing the engine, based on the identified trends, determining at least one of a new constraint, objective, initial condition, model characteristic, prediction horizon, and control horizon for the control system based on the diagnosing step if the diagnosing step identified a fault condition, and adapting the CMBC system based on the at least one new constraint, objective, initial condition, model characteristic, prediction and control horizon. The method further includes generating at least on control command based on the adapting and commanding an actuator based on the control command.

Abstract: A method and control system for an aircraft using a gas turbine engine is provided. The control system includes a controller that includes a load and engine control modules and communicates control signals to a plant that includes a gas generator and a rotor load, an engine estimation module that receives engine state measurements and effector feedback/command signals from the controller and communicates a power turbine torque estimate, and a load estimation module that receives signals including the power turbine torque estimate, a first power turbine speed value, a first power turbine torque value, a second power turbine speed value, a second power turbine torque value, and a rotor speed value. The load estimation module generates one or more of a power turbine speed estimate, a power turbine torque estimate, and a rotor load estimate based on the received signals.

Abstract: A method and control system for an aircraft using a gas turbine engine is provided. The control system includes a controller that includes a load and engine control modules and communicates control signals to a plant that includes a gas generator and a rotor load, an engine estimation module that receives engine state measurements and effector feedback/command signals from the controller and communicates a power turbine torque estimate, and a load estimation module that receives signals including the power turbine torque estimate, a first power turbine speed value, a first power turbine torque value, a second power turbine speed value, a second power turbine torque value, and a rotor speed value. The load estimation module generates one or more of a power turbine speed estimate, a power turbine torque estimate, and a rotor load estimate based on the received signals.

Abstract: Systems and methods for use with a variable pressure actuator control system for a gas turbine engine are provided. A variable pressure actuator control system for a gas turbine engine may comprise a controller, a pressure regulating electro-hydraulic servo valve assembly (P-EHSV), including a variable restriction flow path, in electronic communication with the controller, a position regulating electro-hydraulic servo valve assembly (X-EHSV), including a network of flow paths, in electronic communication with the controller, a bypass regulator (BPR) in fluid communication with at least one of a pump, the P-EHSV, or the X-EHSV, the BPR configured to be controlled by the P-EHSV via a bypass pressure to vary an available pressure, and an actuator comprising an actuator piston. The variable pressure actuator control system may minimize pressure when possible to increase mission capability for a gas turbine engine.

Abstract: A multivariable fuel control and estimator (MFCE) of a gas turbine engine for preventing combustor blowout is provided. The MFCE includes a first input port that receives controller requests and provide system usage commands, a second input port that receives measured disturbance values, a third input that receives system and component limits, a fourth input port that receives sensed parameters, a fuel system model of the fuel system of the gas turbine engine and an engine model of the engine system that includes the combustor of the gas turbine engine, a processor that generates a control signal for controlling the fuel valve and generates a control signal for controlling the actuator using the fuel system and engine model based on the controller requests, the measured disturbance values, the system and component limits, and the sensed parameters, and an output port that transmits the control signals to the fuel system.

Abstract: A fuel system for a gas turbine engine includes, among other things, a plurality of components defining a plurality of localized nodes at distinct locations relative to a fuel flow path, each of the plurality of localized nodes characterized by a distinct set of failure parameters. One or more fuel sensors are configured to measure at least one fuel condition relating to flow through the fuel flow path. A fuel observation assembly is coupled to one or more engine sensors configured to measure at least one engine condition.

Abstract: According to an aspect, a method includes generating, by a computer processor, thermo-fluid parameter estimates of a thermal management system (TMS) of an engine based on sensed parameters and monitoring for TMS component failures based on the thermo-fluid parameter estimates and the sensed parameters. Thermo-mechanical parameter estimates are generated based on selected thermo-fluid parameters. Life usage estimates and life usage rate estimates are generated based on the selected thermo-fluid parameters and the thermo-mechanical parameter estimates. Life usage rate targets are generated based on external commands and the life usage estimates. Limits and goals are modified based on the life usage rate estimates, failure flags, and the life usage rate targets. A model predictive control is applied to command one or more TMS control components based on thermo-mechanical model parameters, the failure flags, and the limits and goals.

Abstract: Systems and methods for use with a variable pressure actuator control system for a gas turbine engine are provided. A variable pressure actuator control system for a gas turbine engine may comprise a controller, a pressure regulating electro-hydraulic servo valve assembly (P-EHSV), including a variable restriction flow path, in electronic communication with the controller, a position regulating electro-hydraulic servo valve assembly (X-EHSV), including a network of flow paths, in electronic communication with the controller, a bypass regulator (BPR) in fluid communication with at least one of a pump, the P-EHSV, or the X-EHSV, the BPR configured to be controlled by the P-EHSV via a bypass pressure to vary an available pressure, and an actuator comprising an actuator piston. The variable pressure actuator control system may minimize pressure when possible to increase mission capability for a gas turbine engine.

Abstract: A load power sharing control system for a twin-engine rotorcraft having a first gas turbine engine and a second gas turbine engine is provided.

Abstract: A control system for a gas turbine engine, a method for controlling a gas turbine engine, and a gas turbine engine are disclosed. The control system may include a nozzle scheduler for determining an exhaust nozzle position goal based on a nozzle schedule of exhaust nozzle positions related to flight conditions. The control system may further include a control module for determining a control command for the gas turbine engine. The control command may include, at least, a fuel flow command and an exhaust nozzle position command and the control command may be based on, at least, the exhaust nozzle position goal and an estimated thrust value. The control system may further include an actuator for controlling the gas turbine engine based on the control command.

Abstract: A system and methods are provided for controlling turboshaft engines. In one embodiment, a method includes receiving input signals for a collective lever angle (CLA) command and real-time power turbine speed (NP) of an engine, determining system data for engine effectors by the control unit based on the input signals for the collective lever angle (CLA) command and the real-time power turbine speed (NP) based on an integrated model for the turboshaft engine including a model of a gas generator section of the turboshaft engine and a model of a power turbine and rotor load section of the turboshaft engine. The method may also include determining control output based on model-based multi-variable control including optimization formulation and a constrained optimization solver. The method may also include outputting one or more control signals for control of the turboshaft engine.

Abstract: A control system for a gas turbine engine is disclosed. The control system may include a computer processor. The control system may also include an outer loop control module programmed into the computer processor to determine a torque request based at least in part on a real-time collective lever angle command. The control system may also include an inner loop control module programmed into the computer processor to receive the torque request from the outer loop control module, to determine fuel flow and inlet guide vane schedules based at least in part on the received torque request, and to send signals to a gas generator of the gas turbine engine in order to control the gas generator according to the determined fuel flow and inlet guide vane schedules.

Abstract: Liquefied petroleum gas (propane), natural gas, hydrogen gas, or the like, is continuously injected at substantially constant pressure into the air intake manifold, or air induction system, of a conventional internal combustion engine, the engine being electronically, or mechanically, controlled to adjust the air to liquid fuel mixture to a optimum value. The engine may use liquid gasoline, methanol, diesel, or any other, primary fuel. When retrofitted to a conventional 2 or 4 stroke, spark or compression ignited engine, the gaseous fuel preferable is supplied from a reservoir where it is stored in liquefied or compressed form through an appropriate pressure control valve to a pipe T installed in the crankcase ventilation pipe. The supply of gaseous fuel is controlled by an ON-OFF solenoid valves which are only operated when the alternator or generator of the engine is running and the engine has attained a predetermined temperature.

Abstract: A slicer generally resembling a hand held wood planing tool sits atop a block of food to be sliced or shaved, such as cheese. The slicer has a main platform or base which supports a carriage slidable on a guide groove formed in the base. The carriage supports a shaft rotatably mounted therein, from which shaft depends a pair of arms holding a cutting wire between them. The arms are pivotally and adjustably mounted to the shaft. The arms are fixed in place at a desired cutting depth by a screw. A stop located on the underside of the base counteracts the tendency of the block of food to be pushed by the cutting wire. A curved handle disposed upon the carriage enables the same to be moved, thus slicing the food, with one palm bearing thereagainst.