Abstract: A detection system in an aircraft includes an optical fiber arranged along a structure of the aircraft and affixed to the structure with clamps that are spaced apart along the structure. The optical fiber includes two or more sets of fiber Bragg gratings (FBGs). The system also includes a light source to generate light with two or more wavelengths for injection into the optical fiber, and processing circuitry to identify an overheat condition and monitor vibration experienced by the optical fiber based on reflected signals generated by the two or more sets of FBGs. Integrity of the clamps is indicated by monitoring the vibration.

Abstract: Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

Abstract: A fire protection system includes two or more fire extinguishers. Each fire extinguisher includes a housing, the housing including an extinguisher outlet and a burst disk. The burst disk is configured to retain a volume of fire suppressant material in the housing. A firing cartridge is operably connected to the housing and includes an output charge, and an ignition charge that, when detonated, causes release of the output charge to rupture the burst disk and release the volume of fire suppressant material through the extinguisher outlet. An optical fiber is configured to transmit a light signal toward the ignition charge to heat and detonate the ignition charge. A light source is operably connected to the optical fiber to selectably transmit a first light signal to selectably activate a first fire extinguisher or a second fire extinguisher of the two or more fire extinguishers.

Abstract: A fire protection system includes a fire extinguisher including a housing. The housing includes an extinguisher outlet and a burst disk. The burst disk configured to retain a volume of fire suppressant material in the housing. A firing cartridge is operably connected to the housing. The firing cartridge includes an output charge, and an ignition charge that, when detonated, causes release of the output charge to rupture the burst disk and release the volume of fire suppressant material through the extinguisher outlet. An optical fiber is configured to transmit a light signal toward the ignition charge to heat and detonate the ignition charge. A light source is operably connected to the optical fiber to transmit the light signal along the optical fiber.

Abstract: A compressed fluid source assembly may comprise: a pressure cylinder configured to receive a compressed fluid source therein; and a surface acoustic wave (SAW) sensor coupled to an external surface of the pressure cylinder.

Abstract: A flow angle sensor includes a sensing element, a background component connected to and movable with the sensing element, the background component having a marker, a lens adjacent the disk, an image sensor axially aligned with the lens, a light source positioned to illuminate the disk, and an image processing system connected to the image sensor. The image processing system provides an angle of attack output based on a location of the marker sensed by the image sensor.

Abstract: A method includes receiving wavelength domain data for a time step, performing a Discrete Fourier Transform (DFT) to transform the wavelength domain data for the time step into frequency domain data for the time step only for the limited set of frequency bins associated with a frequency of interest, calculating pressure based on the frequency domain data for the time step, and updating the frequency of interest and the limited set of frequency bins. The method includes repeating receiving wavelength data for subsequent time steps, performing a DFT to transform the wavelength data for the respective subsequent time steps, calculating pressure for each subsequent time step, and updating the frequency of interest and limited set of frequency bins for each subsequent time step. The method includes outputting pressure data based on calculating pressure for the subsequent time steps.

Abstract: A system and method for monitoring the health of a heater connected to a power supply by first and second power leads which conduct an inlet and outlet current, respectively. The system includes an injection transformer with a number of primary turns that are inductively coupled to the first power lead, a signal generator configured to generate and supply a time-varying injection signal to the primary turns thereby imposing the time-varying injection signal on the inlet current, and a signal reader configured to receive a diagnostic signal from the heater, filter the diagnostic signal to pass a frequency associated with the time-varying injection signal, and produce a heater capacitance signal that is indicative of a capacitance value of the heater, where the heater capacitance signal is indicative of the health of the heater.

Abstract: A method for coordinating Wireless Avionics Intra-Communication (WAIC) communications with a radio altimeter signal includes monitoring a frequency band and recording a sequence of time stamps, each time stamp of the sequence of time stamps corresponding to a time at which a strength of the radio altimeter signal exceeds a threshold signal strength in the frequency band. The method further includes calculating time stamp intervals between successive time stamps to produce a sequence of time stamp intervals, and identifying a pattern of time stamp intervals in the sequence of time stamp intervals. The method further includes coordinating the WAIC communications with the pattern of time stamp intervals to avoid interference with the radio altimeter signal.

Abstract: A detection system in an aircraft includes an optical fiber arranged along a structure of the aircraft and affixed to the structure with clamps that are spaced apart along the structure. The optical fiber includes two or more sets of fiber Bragg gratings (FBGs). The system also includes a light source to generate light with two or more wavelengths for injection into the optical fiber, and processing circuitry to identify an overheat condition and monitor vibration experienced by the optical fiber based on reflected signals generated by the two or more sets of FBGs. Integrity of the clamps is indicated by monitoring the vibration.

Abstract: Apparatus and associated methods relate to health-monitoring of a magnetic speed probe. An inductive coil of the magnetic speed probe is used for two purposes: i) to sense a changing magnetic field caused by rotation of a rotating member; and ii) to radiatively transmit radio-frequency signals for determining the health of the magnetic speed probe. A signal generator coupled to the inductive coil of the magnetic speed probe generates the radio-frequency signals that, when conducted by the inductive coil, causes an inductive coil to act as a radio transmitter by radiatively transmitting the radio-frequency signals. The radio-frequency signals transmitted by the inductive coil are detected by a radio receiver. The radio-frequency signals received are indicative of health of the magnetic speed probe.

Abstract: Apparatus and associated methods relate to monitoring health of a system for sensing rotational frequency of a rotatable member. A plurality of magnetic speed probes, each of which is configured to sense the rotational frequency of the rotatable member, are arranged in transmissive proximity with one another. A transmitter-configured one of the plurality of magnetic speed probes includes a signal coupler that couples an electrical signal generated by a radio-frequency signal generator into the inductive coil of the transmitter-configured magnetic speed probe, thereby radiatively transmitting an electromagnetic signal. A speed-probe monitor electrically coupled to each of the plurality of magnetic speed probes determines, based on the coil current sensed by each of the plurality of magnetic speed probes in response to the electromagnetic signal radiatively transmitted, health of the system.

Abstract: Apparatus and associated methods relate to optically determining rotation frequency of a rotatable member using a Fabry-Perot cavity formed between a mirror and a movable reflective mirror. A cavity dimension between the mirror and a movable reflective mirror changes in response to movement of the movable reflective mirror. The movable reflective mirror is bonded to a magneto-strictive material having a thickness dimension that changes in response to changes in a magnetic field. A magnet generates the magnetic field, which changes in response to rotation of the rotatable member.

Abstract: Apparatus and associated methods relate to health-monitoring of a magnetic speed probe. An inductive coil of the magnetic speed probe is used for two purposes: i) to sense a changing magnetic field caused by rotation of a rotating member; and ii) to radiatively transmit radio-frequency signals for determining the health of the magnetic speed probe. A signal generator coupled to the inductive coil of the magnetic speed probe generates the radio-frequency signals that, when conducted by the inductive coil, causes an inductive coil to act as a radio transmitter by radiatively transmitting the radio-frequency signals. The radio-frequency signals transmitted by the inductive coil are detected by a radio receiver. The radio-frequency signals received are indicative of health of the magnetic speed probe.

Abstract: A method for coordinating Wireless Avionics Intra-Communication (WAIC) communications with a radio altimeter signal includes monitoring a frequency band and recording a sequence of time stamps, each time stamp of the sequence of time stamps corresponding to a time at which a strength of the radio altimeter signal exceeds a threshold signal strength in the frequency band. The method further includes calculating time stamp intervals between successive time stamps to produce a sequence of time stamp intervals, and identifying a pattern of time stamp intervals in the sequence of time stamp intervals. The method further includes coordinating the WAIC communications with the pattern of time stamp intervals to avoid interference with the radio altimeter signal.

Abstract: A system and method for monitoring the health of a heater connected to a power supply by first and second power leads which conduct an inlet and outlet current, respectively. The system includes an injection transformer with a number of primary turns that are inductively coupled to the first power lead, a signal generator configured to generate and supply a time-varying injection signal to the primary turns thereby imposing the time-varying injection signal on the inlet current, and a signal reader configured to receive a diagnostic signal from the heater, filter the diagnostic signal to pass a frequency associated with the time-varying injection signal, and produce a heater capacitance signal that is indicative of a capacitance value of the heater, where the heater capacitance signal is indicative of the health of the heater.

Abstract: A sensor to sense pressure in a pressure bottle and a method of assembling the sensor involve two or more fiber Bragg gratings (FBGs) affixed to a different radial location of a diaphragm seal of the pressure bottle. The sensor includes a light source to provide incident light to the two or more FBGs, and a photodetector to detect reflected light resulting from the two or more FBGs. Processing circuitry determines a pressure change in the pressure bottle based on the reflected light resulting from each of the two or more FBGs.

Abstract: A windshield wiper system includes a wiper arm, a wiper blade attached to the wiper arm, an output shaft attached to an end of the wiper arm, an actuator attached to the output shaft, a controller, a first sensor, a second sensor, and a third sensor. The controller is configured to activate the actuator, causing the output shaft to rotate and thus driving the wiper arm with the attached wiper blade in a sweeping motion across a windshield. The controller is also configured to receive signals from the first, second, and third sensors indicating the position of the wiper arm and the wiper blade.

Abstract: A gauge device is provided and includes an analog display to signify a measured valued, a motor and worm gear arrangement which is configured to retain a current state of the analog display when de-energized or to change the analog display when energized and a control system. The control system is configured to normally de-energize the motor and worm gear arrangement and to energize the motor and worm gear arrangement only in accordance with a calculated state of the analog display differing from the current state by at least a threshold level.