Abstract: A system for an aircraft includes a first fluid circuit extending from a first end to a second end, and a network comprising a plurality of networked heater assemblies disposed along the first fluid circuit between the first end and the second end. Each of the networked heater assemblies includes at least one temperature sensor, a heater element, and a local controller. The at least one temperature sensor is in communication with the first fluid circuit for periodically measuring a temperature in the first fluid circuit and generating a corresponding local temperature signal. The heater assembly selectively applies heat to the first fluid circuit based on the local temperature signal or another temperature signal on the network. The local controller receives the local temperature signal or another networked temperature signal and operates the heater assembly in response thereto to maintain the local temperature signal above a predetermined threshold.

Abstract: At least one baseline structural interrogation of a physical structure is performed in one or more corresponding baseline conditions of the structure. The one or more baseline conditions are stored, and one or more current conditions are sensed. It is determined whether a difference between the one or more current conditions and the one or more baseline conditions satisfies at least one threshold deviation criterion. A current structural interrogation of the structure is performed in response to determining that the difference between the one or more current conditions and the one or more baseline conditions satisfies the least one threshold deviation criterion. An indication that the at least one threshold deviation criterion is not satisfied is output in response to determining that that the difference between the one or more current conditions and the one or more baseline conditions does not satisfy the at least one threshold deviation criterion.

Abstract: A method of fuel gauging includes the use of limited physical probes and a number of virtual probes that are mathematically represented despite having no physical representation. Each probe determines the volume of fuel in a particular section of the fuel tank. The calculation method includes using the attitude of the fuel tank to calculate the rotation of each physical probe, using this information to determine the height of the fuel at each physical probe, and extrapolating the physical height information to determine the position of each virtual probe. Once the information on each physical and virtual probe is obtained, a total fuel volume can be calculated.

Abstract: Apparatus and associated methods relate to determining a measure of collision risk between a taxiing aircraft and an object external to the taxiing aircraft. The measure of collision risk is determined using the dynamics of both the taxiing aircraft and the external object. The taxiing aircraft's dynamics can be determined based on collected position, heading, and ground-speed data. The external object's dynamics can be determined based on location data tracked by an object tracking system, for example. A measure of collision risk is calculated, based on the determined dynamics of both the taxiing aircraft and the external object. In some embodiments, image data of an area external to and including the taxiing aircraft is formed. The image data can be annotated with the calculated collision risks and/or indicia of regions of the taxiing aircraft and/or the external objects associated with the collision risks.

Abstract: A method is provided of generating a course-correction signal for a spin-stabilized projectile. The method includes capturing a time-sequence of images of a scene at a frame rate, comparing respective current images of the time-sequence of images to a corresponding previous image of the time-sequence of images, determining a rotation angle between the current and previous images, rotating the images using the rotation angle, identifying a target in the rotated images, generating target bearing angles to cause the projectile to correct its course toward the target using the target bearing angles, and adjusting the target bearing angles to compensate for the rotation of the images.

Abstract: A method of aircraft fuel distribution includes selecting a longitudinal center of gravity and predicting a rate of change of the center of gravity during flight. Fuel is located in a tail fin tank of a vertical tail fin of the aircraft, and is transferred from the tail fin tank forward at a predetermined transfer rate to counteract the predicted rate of change thereby maintaining the selected center of gravity. An aircraft fuel distribution system includes a center main fuel tank, a tail fin tank and a tail fin fuel pump to pump fuel between the tail fin tank and the center main fuel tank. An electronic controller operates the tail fin fuel pump such that fuel is flowed between the tail fin tank and the center main fuel tank at a predetermined transfer rate to maintain automatically an optimal position of a longitudinal center of gravity of the aircraft.

Abstract: A computer implemented method includes transmitting a transmit command to a first data concentrator to send out a predetermined signal of predetermined characteristics according to a transmission setting, receiving a received signal from at least one second data concentrator, and determining if there are any signal transmission effects between the first data concentrator and the second data concentrator based on a comparison of the predetermined signal and the received signal.

Abstract: A liquid measurement system for determining a quantity of a liquid within a tank includes a pressurized air supply, a valve connected to the pressurized air supply with the valve able to introduce a known mass of air into the tank, a pressure sensor able to measure the change in air pressure within the tank, and a processor operatively connected to the valve and the pressure sensor. The processor is able to determine the volume of the liquid within the tank from the known mass of air introduced into the tank and the change in air pressure within the tank.

Abstract: A system and method includes a structural body, a plurality of structural health monitoring (SHM) sensors, and first and second computer systems. The structural body includes a plurality of structures. The SHM sensors are configured to sense structural health data for a plurality of zones of the structures. The first computer system is configured to collect the structural health data from the SHM sensors. The second computer system includes a display and is configured to receive the structural health data from the first computer system and groups the zones into a plurality of structural regions, and groups the plurality of structural regions into at least one structural area. The display is configured to provide a visual representation of a structural region health of a first one of the plurality of structural regions based on the structural data for respective ones of the zones within the first one of the plurality of structural regions.

Abstract: A brake monitoring and adjustment control system includes an electromechanical brake actuator controller (EBAC) and at least one sensor operatively connected to the EBAC. The sensor is configured to sense a characteristic of a brake and provide a feedback signal to the EBAC. The system includes a switch for turning power to the sensor on and off to reduce the duration with voltage applied to the sensor. Reducing the duration in which voltage is applied to the sensor reduces power consumption and assists with mitigating electro-migration growth.

Abstract: A method for obtaining a baseline for detecting rotating stall using localized information already included within the frequency spectrum. Namely, ratiometric measures, i.e., quadratic coefficients obtained from weighted quadratic regression of sub-synchronous spectrum and/or information obtained through peak detections, are used to detect rotating stall. These ratiometric measures are configured to isolate changes caused by rotating stall from those caused by other operational conditions. As a result, new baseline information can be established to more reliably characterize a system, such as a system with associated turbines or compressors. Empirical or statistical approaches can be combined to automate the process of obtaining a new baseline and to detect rotating stall.

Abstract: A method for fault detection and accommodation for a controller and actuator system is provided. The method includes receiving, from a controller, a flag at an actuator in response to an excitation voltage and current falling below a threshold value, engaging a sensor in the actuator in response to receiving the flag, receiving, using the sensor a first load cell signal and a second load cell signal in response to the sensor being engaged, determining how actuator is operating brake based on the received flag, first load cell signal, and second load cell signal, adjusting a state of the actuator based on the determination, and reporting the state of the actuator by transmitting a report signal to the controller.

Abstract: A method can include generating reference image data representing a field of view of an interior of a fuel tank, and generating active image data representing the field of view of the interior of the fuel tank when the fuel tank contains fuel. The method can further include producing, by a processing device, a fuel measurement value representing an amount of fuel contained in the fuel tank based on the reference image data and the active image data, and outputting, by the processing device, an indication of the fuel measurement value.

Abstract: Apparatus and associated methods relate to generating a trigger signal in response to detection of a triggering acoustic event sensed by one of a distributed network of optical acoustic sensors mechanically coupled to an aircraft structure. Each of the optical acoustic sensors is configured to generate an optical response signal indicative of an acoustic condition detected by the optical acoustic sensor. A controller receives the optical response signals and generates, if a triggering one of the optical response signals is indicative of a triggering acoustic event, a trigger signal. The controller also determines a location of the specific one of the distributed network of optical acoustic sensors that generated the triggering one of the optical response signals. In some embodiments, the trigger signal is sent to a Health & Usage Monitoring System configured to perform a health scan, in response to receiving the trigger signal, of the aircraft structure.

Abstract: A system and method includes an arbitrating data bus and a plurality of sensing nodes connected to communicate on the arbitrating data bus. The plurality of sensing nodes are configured to digitize and monitor a first amount of data during a listening mode of an event monitoring mode and detect an event based upon the first amount of data. The plurality of sensing nodes are further configured to output an event message to the arbitrating data bus upon detection of the event. The plurality of sensing nodes are further configured to digitize and retain a second amount of data following detection of the event message on the arbitrating data bus.

Abstract: An inductive sensor includes a core body, a coil wound on the core body, a cavity having a fixed volume within the core body, and an epoxy mixture filling a controlled portion of the fixed volume. The controlled portion of the fixed volume filled with the epoxy mixture controls an inductance of the sensor.

Abstract: A method for estimating rotational speed of a system includes receiving vibrational data from a sensor, estimating a speed from the vibrational data to create estimated speed data, and filtering the estimated speed data through an adaptively weighted filter to minimize incorrect speed estimation.

Abstract: Redundant wireless sensor networks include a plurality of wireless sensors and a wireless data concentrator. The plurality of wireless sensors sense a parameter and transmit sensor signals representative of the parameter sensed. The wireless data concentrator receives the sensor signals and adjusts the transmission schedules of at least one of the plurality of wireless sensors based on a change in operating status of one or more of the plurality of wireless sensors.

Abstract: A multi-level network system of an aircraft includes at least one equipment area network and a wide area network. The equipment area network includes equipment of the aircraft, at least one wireless device, and at least one equipment area network coordinator. The at least one wireless device is configured to transmit and receive data using a first wireless link. The at least one equipment area network coordinator is configured to transmit to and receive data from the at least one wireless device using the first wireless link and to transmit data to and receive data from the wide area network using a second wireless link, the first wireless link using lower power than the second wireless link. The wide area network includes a wide area network coordinator that is configured to transmit and receive data from the at least one equipment area network coordinator using the second wireless link.

Abstract: A method can include illuminating an interior of a fuel tank with one or more light pulses, and receiving reflected returns of the one or more light pulses at a light sensor array. The method can further include producing, by a processing device, three-dimensional image data of the interior of the fuel tank based on the received reflected returns, producing, by the processing device, a fuel measurement value representing an amount of fuel contained in the fuel tank based on the three-dimensional image data, and outputting, by the processing device, an indication of the fuel measurement value.