Abstract: A system has a first temperature sensor located at a first location. A second temperature sensor is located at a second location. A control is configured to determine a difference between voltages indicated of a temperature sensed by each of the first and second sensors. A method is also disclosed.

Abstract: A system has a first temperature sensor located at a first location. A second temperature sensor is located at a second location. A control is configured to determine a difference between voltages indicated of a temperature sensed by each of the first and second sensors. A method is also disclosed.

Abstract: A system has a first temperature sensor located at a first location. A second temperature sensor is located at a second location. A control is configured to determine a difference between voltages indicated of a temperature sensed by each of the first and second sensors. A method is also disclosed.

Abstract: A method of determining density of a fluid within a system includes actuating a piston of a hydraulic cylinder at a target velocity. Additionally, the method includes determining differential pressure and volumetric flow rate of the fluid flowing through an orifice under actuation of the piston. The density of the fluid is determined based on the first differential pressure and the volumetric flow rate of the fluid, which is used by the system to regulate a mass flow rate of fluid within the system.

Abstract: A ducting system has a first upstream location is to be connected to a first source of air. A downstream location in the duct is to be connected to a second source of air. The upstream location has a first valve, and the downstream location has a second valve. An end location of the duct is to be connected to a sink. A control for the valves achieves a desired pressure and temperature of air at the end location. The first temperature sensor is located at a position intermediate the upstream location and the downstream location. A second temperature sensor is located at a position intermediate the downstream location and the end location. A control is programmed to determine the health of the first and second valves based upon a difference between temperatures sensed by the first and second sensors. An air use system and a method are also disclosed.

Abstract: Disclosed is an aircraft sensor fault detection system. The system includes a sensor system having a sensing apparatus to measure a parameter of an environment and a measurement circuit coupled to the sensing apparatus. The system includes a source of alternating current connected to the sensor system. The system further includes an alternating current measurement system that measures alternating current passing through the sensor system and indicates an error when a threshold based on a change in impedance of the sensing apparatus is exceeded.

Abstract: Disclosed is a short detection system for an aircraft. The system includes a pair of alternating current sources defined by respective frequencies being offset by a predetermined value. The system includes a pair of sensor systems including respective measurement circuits coupled to respective sensor apparatuses to measure at least one parameter of an environment. The system includes an alternating current measurement system that includes a low pass filter having a cutoff frequency greater than the predetermined value such that a beat indicative of a difference between the respective frequencies passed through the pair of sensor systems is isolated by the low pass filter. The system indicates a short among the pair of sensor systems when the beat is present.

Abstract: A system has a first temperature sensor located at a first location. A second temperature sensor is located at a second location. A control is configured to determine a difference between voltages indicated of a temperature sensed by each of the first and second sensors. A method is also disclosed.

Abstract: A ducting system has a first upstream location is to be connected to a first source of air. A downstream location in the duct is to be connected to a second source of air. The upstream location has a first valve, and the downstream location has a second valve. An end location of the duct is to be connected to a sink. A control for the valves achieves a desired pressure and temperature of air at the end location. The first temperature sensor is located at a position intermediate the upstream location and the downstream location. A second temperature sensor is located at a position intermediate the downstream location and the end location. A control is programmed to determine the health of the first and second valves based upon a difference between temperatures sensed by the first and second sensors. An air use system and a method are also disclosed.

Abstract: A filter assembly for a fluid flow system includes a filter housing, a housing inlet to allow the fluid flow into the filter housing and a housing outlet to allow the fluid flow to exit the filter housing. A filter element is located in the filter housing to collect contaminants from the fluid flow. A pressure sensor is located to measure a pressure drop across the filter element. The pressure sensor includes at least one sense line extending into an interior volume of the filter housing. A method of monitoring a filter assembly for a fluid flow system includes positioning a pressure sensor at a filter assembly, extending at least one sense line from the pressure sensor into an internal volume of a filter housing of the filter assembly, and measuring a pressure drop across a filter element of the filter assembly via the pressure sensor.

Abstract: Disclosed is an aircraft sensor fault detection system. The system includes a sensor system having a sensing apparatus to measure a parameter of an environment and a measurement circuit coupled to the sensing apparatus. The system includes a source of alternating current connected to the sensor system. The system further includes an alternating current measurement system that measures alternating current passing through the sensor system and indicates an error when a threshold based on a change in impedance of the sensing apparatus is exceeded.

Abstract: Disclosed is a short detection system for an aircraft. The system includes a pair of alternating current sources defined by respective frequencies being offset by a predetermined value. The system includes a pair of sensor systems including respective measurement circuits coupled to respective sensor apparatuses to measure at least one parameter of an environment. The system includes an alternating current measurement system that includes a low pass filter having a cutoff frequency greater than the predetermined value such that a beat indicative of a difference between the respective frequencies passed through the pair of sensor systems is isolated by the low pass filter. The system indicates a short among the pair of sensor systems when the beat is present.

Abstract: Embodiments of the invention include systems and techniques for implementing voltage differential transducer (VDT) fault detection. Embodiments include a computing resource electrically coupled to an AC power supply, a VDT including a primary winding and a set of secondary windings, wherein the VDT is electrically coupled to the AC power supply. Embodiments also include a current sensing circuit electrically coupled to the AC power supply and the VDT, and a signal processor electrically coupled to an output of the VDT and the computing resource, the signal processor providing a signal indicative of a voltage differential of the set of secondary windings of the VDT, that is used by the computing resource to make an error determination.

Abstract: A method and system providing a pressurized fluid includes a pump having a pump inlet and a pump outlet, the pump to provide a fluid flow, a bypass path to direct the fluid flow from the pump outlet to the pump inlet, a load path having a load path pressure, the load path including: a fluid accumulator to accumulate a fluid volume, and at least one load device, a bypass regulator valve in fluid communication with the pump outlet, the bypass path, and the load path, and a controller to direct the fluid flow to the load path in response to the load path pressure being less than a low load path threshold pressure via the bypass regulator valve and to direct the fluid flow to the bypass path in response to the load path pressure being greater than a high load path threshold pressure via the bypass regulator valve.

Abstract: A fluid system has a fluid actuator that receives a fluid to cause movement of a component. A valve selectively controls the flow of fluid to the fluid actuator. A motor for the valve is provided with an electric voltage or current. A control applies a pulse width modulation variation to the supplied voltage or current. The control is operable to vary the pulse width modulation of the voltage or the current based upon conditions of the system. A mechanical system and a method are also disclosed.

Abstract: Embodiments of the invention include systems and techniques for implementing voltage differential transducer (VDT) fault detection. Embodiments include a computing resource electrically coupled to an AC power supply, a VDT including a primary winding and a set of secondary windings, wherein the VDT is electrically coupled to the AC power supply. Embodiments also include a current sensing circuit electrically coupled to the AC power supply and the VDT, and a signal processor electrically coupled to an output of the VDT and the computing resource, the signal processor providing a signal indicative of a voltage differential of the set of secondary windings of the VDT, that is used by the computing resource to make an error determination.

Abstract: Distributed fuel control system and methods are disclosed. A distributed fuel control system may comprise a controller, a fuel delivery system, and fuel delivery system sensors and combustion sensors. The controller may output a control signal in response to at least one of the fuel delivery system sensor or the combustion sensors. In response, the fuel flow to individual multiplex fuel delivery unit may be controlled according to various methods. One such method includes determining a desired fuel pressure differential, directing a torque motor to set a pressure regulator to a position corresponding to the desired fuel pressure differential, determining a sensed fuel pressure differential, and adjusting the torque motor in response to a difference between the sensed fuel pressure differential and the desired fuel pressure differential.

Abstract: An in-line shutoff valve includes a valve body with an inlet chamber, an outlet chamber, and a poppet seat disposed between the inlet and outlet chambers. A poppet is movably disposed within the valve body and has an open and closed position. The poppet seats against the poppet seat in the closed position, fluidly separating the inlet chamber from the outlet chamber. The poppet is unseated from the poppet seat in the open position, fluidly coupling the inlet and outlet chambers. A manifold with a servo port and a vent port is disposed within the valve body between the inlet and outlet chambers, the vent port being in fluid communication with the servo port to cool valve internal structures when the poppet is in the closed position.

Abstract: A method for accurately determining a density of a fuel includes obtaining dielectric constant versus density characteristics of the fuel at a first location and measuring a dielectric constant of the fuel at a second location. The environmental conditions at the second location differ from environmental conditions at the first location. Density of the fuel at the second location is inferred using the dielectric constant of the fuel at the second location and the dielectric constant versus density characteristics of the fuel at the first location.

Abstract: A tip clearance measurement system (TCMS) includes a probe and sensing circuitry. The probe directs microwave signals toward a turbine blade and receives microwave signals reflected by the turbine blade. The sensing circuitry includes a switch having a first state in which a main frequency is provided at an output of the switch and a second state in which a reference frequency is provided at an output of the switch. The sensing circuitry further includes a first conditioning circuit that receives a frequency provided at the output of the switch and provides a conditioned frequency to the probe and a second conditioning circuit that receives both the conditioned frequency provided by the first conditioning circuit and a reflected frequency received by the probe, and provides a conditioned output based on the conditioned frequency and reflected frequency.