Abstract: A proximity sensor for determining a position of an object. The proximity sensor includes a SAW device having a load end and an input end for receiving an input pulse. A sensing section connects to the load end of the SAW device. When the object is in a first position, the sensing section provides a first response indicative of the first position and, when the object is in a second position, the sensing section provides a second response indicative of the second position such that the position of the object can be determined based upon the response to the input pulse.

Abstract: A method of assembling an inductive proximity sensor maintains inductive coil wound bobbins in fixed relation to an inductive core within a housing. The method includes configuring two inductive coil wound bobbins with an integral ledge cantilevered from an inside surface thereof for forming a pocket under the integral ledge at a bottom of each bobbin; disposing each inductive coil wound bobbin around a corresponding leg of the inductive core; containing a foot of each core leg into the pocket of the corresponding bobbin; inserting each of two legs of a thruster element into a corresponding bobbin so that each leg rests upon the ledge of the corresponding bobbin; disposing the inductive core, inductive coil wound bobbins, and thruster element into the housing; disposing a spring element on a top surface of the thruster element; and compressing the spring element against the top surface of the thruster element.

Abstract: A first measured value is determined which is associated with the proximity of a target to an inductive sensor. A first voltage signal having a first amplitude is generated. The first voltage signal is provided as a driving signal to the inductive sensor. A sensor current signal is received as a return signal output from the inductive sensor. The sensor current signal has an amplitude proportional to a proximity of the target to the inductive sensor. The sensor current signal is converted to a corresponding second voltage signal having a second amplitude. A differential measuring technique is used to determine the first measured value in accordance with relative amplitudes of said first voltage signal and said second voltage signal.

Abstract: A proximity sensor assembly includes a multilayer printed wiring board proximity sensor, the proximity sensor being operable as either a variable-reluctance sensor or an eddy current loss sensor. The proximity sensor includes a plurality of layers configured to form at least one wound coil disposed about at least a portion of a core. The coils are electrically driven to generate an alternating magnetic field such that the inductance of the coils changes when a permeable or conductive object is moved in relation to the magnetic field. The change in inductance is recognized and used to detect the proximity and presence of an object relative to the sensor.

Abstract: A float switch system for limiting to desirable levels current and energy entering a tank of combustible liquid comprises: a float switch disposed within the tank; an interface circuit external to the tank and coupled through wiring to the float switch; a passive transient suppression circuit coupled to the wiring external and in proximity to the tank, and operative to limit current and energy entering the tank over the wiring to the desirable levels; and a control circuit coupled to the float switch through the transient suppression circuit and to the interface circuit, the control circuit operative to monitor the status of the float switch with current within the desirable current level and to energize the interface circuit based on the switch status.

Abstract: Detecting video phenomena, such as fire in an aircraft cargo bay, includes receiving a plurality of video images from a plurality of sources, compensating the images to provide enhanced images, extracting features from the enhanced images, and combining the features from the plurality of sources to detect the video phenomena. The plurality of sources may include cameras having a sensitivity of between 400 nm and 1000 nm and/or may include cameras having a sensitivity of between 7 and 14 micrometers. Extracting features may include determining an energy indicator for each of a subset of the plurality of frames. Detecting video phenomena may also include comparing energy indicators for each of the subset of the plurality of frames to a reference frame.

Abstract: Described are systems and methods for determining the gross weight of an aircraft. A flight regime is determined based on one or more inputs. A neural net is selected based on a flight regime. The neural net inputs may include derived values. A first estimate of the gross weight is produced by the selected neural net. The first estimate is used, along with other inputs, with a Kalman filter to produce a final gross weight estimate. The Kalman filter blends or fuses together its inputs to produce the final gross weight estimate.

Abstract: Detecting video phenomena, such as fire in an aircraft cargo bay, includes receiving a plurality of video images from a plurality of sources, compensating the images to provide enhanced images, extracting features from the enhanced images, and combining the features from the plurality of sources to detect the video phenomena. The plurality of sources may include cameras having a sensitivity of between 400 nm and 1000 nm and/or may include cameras having a sensitivity of between 7 and 14 micrometers. Extracting features may include determining an energy indicator for each of a subset of the plurality of frames. Detecting video phenomena may also include comparing energy indicators for each of the subset of the plurality of frames to a reference frame.

Abstract: Determining a shaft balance adjustment includes measuring an initial vibration of the shaft, determining if the initial vibration is greater than a predetermined value, and, if the initial vibration is greater than the predetermined value, determining an adjustment by choosing a best adjustment for each possible location for adjustments. Choosing the best adjustment may include choosing an adjustment that causes a lower amount of vibration than adjustments not chosen. Measuring an initial vibration may include using an accelerometer. Measuring an initial vibration may include using conditioning electronics in connection with the accelerometer. The predetermined value may be 0.01 ips.

Abstract: A method of fabricating a multilayer wiring board proximity sensor includes forming a laminate, and fabricating a plurality of through-conductors through the layers of the laminate. The laminate has a plurality of layers including one or more core layers and a plurality of coil layers. Each core layer includes a core pattern formed of a permeable material, and each coil layer comprises at least one coil trace formed of a conducting material. Thus, the through-conductors may be fabricated through the layers of the laminate such that the coil traces are interconnected by the through-conductors to thereby form one or more coils disposed about at least a portion of the core patterns of the core layers.

Abstract: An inductive proximity sensor for sensing the presence of target based on a change of inductance in the sensor. The sensor includes a coil and a core formed of a permeable material so as to form an electromagnetic field when the coil is electrically driven. The core has a base, a central post, an outer wall, and at least one slot. The central post extends distally from the base and through the coil and defines a distal end. The outer wall extends distally from the base and around the coil and also defines a distal end. The slot or slots are for enhancing the performance of the sensor by reducing eddy current losses in the core. Each slot extends at least partially along a path defined from the distal end of the outer wall to the base and from the base to the distal end of the central post.

Abstract: Detecting a fire, such as a fire in an aircraft cargo bay, includes receiving a plurality of frames of video information, determining an energy indicator for each of a subset of the plurality of frames, and detecting the presence of fire in response to the energy indicator for each of the subset of the plurality of frames corresponding to a predetermined pattern as a function of time. Detecting a fire may also include comparing energy indicators for each of the subset of the plurality of frames to a reference frame. The reference frame may correspond to a video frame taken when no fire is present or a video frame immediately preceding each of the subset of the plurality of frames. At least some of the subset of the plurality of frames may be provided by a camera having a sensitivity of between 400 nm and 1000 nm that may generates 640×480 pixels per frame. At least some of the subset of the plurality of frames may be provided by a CCD camera or a CMOS camera.

Abstract: A multiplexing system is provided for a plurality of sensors disposed in a tank containing a potentially explosive environment and excited from a common excitation circuit outside of the tank through a corresponding plurality of signal lines that penetrate the tank. The multiplexing system comprises: a multiplexer switch for each sensor, each multiplexer switch disposed outside of the tank in series with the corresponding signal line between the common excitation circuit and the corresponding sensor in the tank.

Abstract: Detecting fire and non-fire conditions includes receiving a plurality of frames of video information, determining an energy indicator for each of a subset of the plurality of frames, detecting a fire condition in response to the energy indicator for each of the subset of the plurality of frames forming a pattern as a function of time corresponding to a fire condition, and detecting a non-fire condition in response to the energy indicator for each of the subset of the plurality of frames forming a pattern as a function of time corresponding to a non-fire condition. Detecting fire and non-fire conditions may also include comparing energy indicators for each of the subset of the plurality of frames to a reference frame. The reference frame may correspond to a video frame taken when no fire is present, a video frame immediately preceding each of the subset of the plurality of frames, or a video frame immediately preceding a frame that is immediately preceding each of the subset of the plurality of frames.

Abstract: Interpolation techniques are described for use with data that may not be uniform and may be characterized as scattered. Such data may be obtained in instances where data acquisition may not be easily controlled such as in obtaining experimental data for use with models. Data interpolation techniques may be used in connection with the experimental data to produce a more complete and accurate data set representative of a variety of conditions using as input the non-uniform or scattered data. Such data sets may be used in a variety of applications including providing a realistic and complete set of data for training and verifying neural networks.

Abstract: A transient suppression device for limiting to desirable levels current and energy entering a fuel tank of an aircraft over interface wiring that penetrates a wall of the fuel tank comprises: an elongated, hollow, conductive housing capped at one end and open at another end, the housing being disposed external and in proximity to the fuel tank, and supported physically from a structure of the aircraft; a transient suppression circuit disposed within the housing and connected in series with the interface wiring; and a shield braid of conductive material disposed over the open end of the housing and covering the interface wiring over the distance between the housing and tank wall, the shield braid electrically coupling the housing to the tank wall. A method of packaging the transient suppression device is also disclosed.

Abstract: An inductive proximity sensor comprises: a housing including an opening on one side; an inductive core including two legs, each core leg including a foot portion; an inductive coil wound bobbin disposed about each leg of the core, each bobbin including an integral ledge cantilevered from an inside surface of the bobbin for forming a pocket under the integral ledge at a bottom of the bobbin for containing the foot portion of the corresponding core leg; a thruster element including a top surface and two legs, each thruster leg disposed into a respective bobbin resting on the integral ledge thereof, the core, wound bobbins and thruster element disposed in the housing; a spring element disposed on the top surface of the thruster element at the housing opening; and a housing cover disposed over the housing opening for compressing the spring element against the thruster element which renders the core and wound bobbins in a fixed relationship to each other in the housing.

Abstract: A proximity sensor assembly includes a multilayer printed wiring board proximity sensor, the proximity sensor being operable as either a variable-reluctance sensor or an eddy current loss sensor. The proximity sensor includes a plurality of layers configured to form at least one wound coil disposed about at least a portion of a core. The coils are electrically driven to generate an alternating magnetic field such that the inductance of the coils changes when a permeable or conductive object is moved in relation to the magnetic field. The change in inductance is recognized and used to detect the proximity and presence of an object relative to the sensor.

Abstract: Classifying a portion of an electrical signal propagating through a conductor includes digitizing the electrical signal to provide a digitized signal, providing a plurality of stored digitized signals, wherein each stored digitized signal corresponds to a type of fault for the conductor, comparing the digitized signal to each of the stored digitized signals to determine a score therefore, if the score is less than a predetermined value for a particular one of the stored digitized signals, classifying the portion of the electrical signal as a fault corresponding to the particular one of the stored digitized signals, and, if none of the scores are less than the predetermined value, classifying the portion of the electrical signal as having no fault. Classifying a portion of an electrical signal may also include converting the digitized electrical signal to reflection coefficients.

Abstract: Disclosed are techniques used in connection with determining a health indicator (HI) of a component, such as that of an aircraft component. The HI is determined using condition indicators (CIs) which parameterize characteristics about a component minimizing possibility of a false alarm. Different algorithms are disclosed which may be used in determining one or more CIs. The HI may be determined using a normalized CI value. Techniques are also described in connection with selecting particular CIs that provide for maximizing separation between HI classifications. Given a particular HI at a point in time for a component, techniques are described for predicting a future state or health of the component using the Kalmán filter. Techniques are described for estimating data values as an alternative to performing data acquisitions, as may be used when there is no pre-existing data.