Abstract: The present invention relates to a method for self-testing an angle-of-attack probe comprising the steps of controlling an angular excitation of a rotary element that is rotatable about its equilibrium position according to known excitation characteristics; acquiring angular measurements relating to the rotation of the rotary element, determining a parasitic torque applied to the rotary element on the basis of the angular measurements and of the excitation characteristics; comparing at least one component of the parasitic torque with at least one predetermined threshold and detecting an operating fault in the probe when said component exceeds the predetermined threshold.

Abstract: Systems, methods, and computer-readable media storing instructions for determining cross-track error of an aircraft on a taxiway are disclosed herein. The disclosed techniques capture electronic images of a portion of the taxiway using cameras or other electronic imaging devices mounted on the aircraft, pre-process the electronic images to generate regularized image data, apply a trained multichannel neural network model to the regularized image data to generate a preliminary estimate of cross-track error relative to the centerline of the taxiway, and post-process the preliminary estimate to generate an estimate of cross-track error of the aircraft. Further embodiments adjust a GPS-based location estimate of the aircraft using the estimate of cross-track error or adjust the heading of the aircraft based upon the estimate of cross-track error.

Abstract: A system and method of augmenting an existing air data system includes a multi-function probe (MFP) having a portion extending into an oncoming airflow about an exterior of an aircraft. A plurality of pressure sensing ports in the portion includes at least first and second static pressure ports. A first electronics channel of the MFP includes pressure sensors communicating with the first and second static pressure ports and is configured to determine first and second altitude values based on sensed static pressures at the first and second static pressure ports, respectively, that are independent of the existing air data system.

Abstract: A method for calibrating aircraft tri-axial balance include steps of: receiving a first indicator signal; tumbling an aircraft by 360 degrees by specified times according to the first indicator signal; collecting and recording first geomagnetic data; receiving a second indicator signal; rotating the aircraft laterally by 360 degrees by the specified times according to the second indicator signal; collecting and recording second geomagnetic data; receiving a third indicator signal; rotating the aircraft horizontally by 360 degrees by the specified times according to the third indicator signal; collecting and recording third geomagnetic data; and obtaining a calibrated geomagnetic curve according to the first geomagnetic data, the second geomagnetic data and the third geomagnetic data.

Abstract: A precision calibration method of attitude measuring systems is provided. The precision calibration method of attitude measuring systems includes the following steps: calibrating a zero-deviation, a scale coefficient, and a non-orthogonal angle between axes of an accelerometer to the attitude measuring system via an ellipsoid fitting model (S1); compensating original data of the accelerometer using a calculated ellipsoid parameter (S2); calibrating an electronic compass via the ellipsoid fitting model according to compensated accelerometer data (S3); compensating original electronic compass data by the calculated ellipsoid parameter (S4); calculating an attitude according to the compensated data of the accelerometer and compensated data of the electronic compass (S5). The above steps of the method have a reliable calibration result and a high precision with a less time consumption of calibration.

Abstract: A system and method is disclosed herein for measuring anterior-posterior slope of a bone to set a cutting jig coupled to the muscular-skeletal system. The system comprises a sensored module that can be placed within a prosthetic component to measure anterior-posterior slope. The system further includes a remote system for receiving, processing, and displaying quantitative measurements from the sensors. A first bone and a second bone are placed in extension. A sensored module is referenced to a bone landmark of the first bone. The sensored module includes a three-axis accelerometer that is configured to measure position, tilt, and rotation. A bone cutting jig is coupled to the first bone. The sensored insert is coupled to the bone cutting jig. The accelerometer in the sensored insert is used to measure the anterior-posterior slope. The bone cutting jig is then adjusted to a predetermined anterior-posterior slope as measured by the sensored insert.

Abstract: A method for harmonizing a frame of reference of an angular positioner to receive a moving body relative to the terrestrial frame of reference, the angular positioner carrying a measurement device for taking inertial measurements of the moving body, the method includes obtaining, using inertial measurements taken by a measurement device on-board the angular positioner during at least one predetermined operating period, values representative of a local magnitude of gravity as perceived by the measurement device and/or of a speed of rotation of the earth, the angular positioner being held stationary during the at least one operating period; evaluating, using the obtained values, at least one angular bias affecting the frame of reference of the positioner; and harmonizing the frame of reference of the positioner relative to the terrestrial frame of reference by compensating for the at least one angular bias as evaluated in this way.

Abstract: A method and apparatus for identifying a position of a surface on an aircraft. Image data for an image of the surface on the aircraft is received. The image data is processed to determine whether the position of the surface on the aircraft is a desired position. A surface position identification report comprising information identifying whether the position of the surface on the aircraft is the desired position is generated.

Abstract: A device is provided for checking a flow pressure measurement probe as well as a probe comprising the device. The probe includes an internal volume and at least one orifice for communication with the outside of the volume. The device includes: an acoustic transmitter and an acoustic receiver that are intended to be connected to the internal volume so that the transmitter transmits an acoustic signal that propagates in the internal volume and so that the receiver picks up an observed acoustic signal; and, means for comparing the observed signal with a reference signal. The device may be a stand-alone device or may be integrated into the probe.

Abstract: Techniques and architecture are disclosed for performing alignment harmonization of a collection of electro-optical and/or gimbaled componentry that is to operate within a common coordinate frame. In some cases, the techniques and architecture can provide a cost- and time-efficient approach to achieving alignment harmonization that is compatible, for example, with field-test and/or operational environments. In some instances, the techniques and architecture can be used in concert with error calibration techniques to further improve the accuracy of the alignment harmonization. The techniques and architecture can be utilized with a wide range of components (e.g., sensors, armaments, targeting systems, weapons systems, countermeasure systems, navigational systems, surveillance systems, etc.) on a wide variety of platforms. Numerous configurations and variations will be apparent in light of this disclosure.

Abstract: A porous composite substrate that includes reinforcement material disposed within a resin matrix. The resin matrix includes a first matrix region with a first density, and a second matrix region with a second density that is different than the first density. The first matrix region includes a plurality of pores that are formed by pore forming material.

Abstract: A method and apparatus for bearing thrust monitoring allows measurable detection of tilt of a support bearing a roller which rotatably supports a rotating body. A tilt meter adapted to measurably detect a tilt of the support bearing is coupled to the support bearing, where the tilt is defined as an angular difference in bearing orientation between a first bearing position and a second subsequent bearing position that is cause by an axial thrust on the rotary body. Once tilt is detected, the bearing orientation of the support bearing can be adjusted to return the support bearing to substantially the first bearing position.

Abstract: A method for independent alignment of an inertial measurement unit for a stand-by instrument in an aircraft includes: determining a status of the aircraft, that is to say whether or not the aircraft is in flight, and in the case where the aircraft is detected as being in flight, carrying out a flight alignment, and in the case where the aircraft is not detected as being in flight, determining a stability of the aircraft, that is to say whether the aircraft is on the ground or at sea, and in the case where the aircraft is detected as being on the ground, carrying out a ground alignment, and in the case where the aircraft is detected as being at sea, carrying out a sea alignment.

Abstract: A system and method for the determination for automated initiation of onboard aircraft weight and balance measurement systems. The system is used in monitoring, measuring, computing and displaying the weight and balance of aircraft utilizing telescopic landing gear struts. Pressure sensors, axle deflection sensors, and/or linkage rotation sensors are mounted in relation to each of the landing gear struts to monitor, measure and record strut and aircraft movement and rates of said movement experienced by landing gear struts, as the aircraft proceeds through typical ground and flight operations. Also, acceleration sensors and GPS can be used to monitor aircraft movements and positions during ground and flight operations. The system and method identify the position of the aircraft as related to airport ground operations to determine the optimum time to initiate an aircraft weight and balance measurement.

Abstract: A system and method for more accurately and robustly determining the heading of a vehicle by taking measurements of angle rates using rate sensors mounted on a movable mechanical assembly. In a quasi-static state of the vehicle, the mechanical assembly is rotated around axes perpendicular to the tangent plane of the Earth, and angle rates are measured by the rate sensors at different rotational angles of the mechanical assembly. The measurements of the angle rates are then computed to determine the initial heading of the vehicle relative to the true north of the Earth in the quasi-static state of the vehicle. After determining the initial heading, navigation state propagation is performed to determine the heading of the vehicle in non-quasi-static state of the vehicle. By taking measurements of the rate sensors at different rotation angles and performing computation, the heading of the vehicle relative to the Earth's true north can be determined using less accurate angle sensors.

Abstract: A method for harmonizing a frame of reference of an angular positioner to receive a moving body relative to the terrestrial frame of reference, the angular positioner carrying a measurement device for taking inertial measurements of the moving body, the method includes obtaining, using inertial measurements taken by a measurement device on-board the angular positioner during at least one predetermined operating period, values representative of a local magnitude of gravity as perceived by the measurement device and/or of a speed of rotation of the earth, the angular positioner being held stationary during the at least one operating period; evaluating, using the obtained values, at least one angular bias affecting the frame of reference of the positioner; and harmonizing the frame of reference of the positioner relative to the terrestrial frame of reference by compensating for the at least one angular bias as evaluated in this way.

Abstract: A method and apparatus for bearing thrust monitoring allows measurable detection of tilt of a support bearing a roller which rotatably supports a rotating body. A tilt meter adapted to measurably detect a tilt of the support bearing is coupled to the support bearing, where the tilt is defined as an angular difference in bearing orientation between a first bearing position and a second subsequent bearing position that is cause by an axial thrust on the rotary body. Once tilt is detected, the bearing orientation of the support bearing can be adjusted to return the support bearing to substantially the first bearing position.

Abstract: An apparatus and method for detecting whether a mobile device is in flight based on sensor measurements from a 3-dimensional accelerometer are presented. For example, embodiments estimate a direction of gravity and non-gravity acceleration, separate this non-gravity acceleration into a vertical and horizontal components, then test the estimated accelerations to determine whether the mobile device is experiencing sufficient vertical acceleration to warrant an in-flight determination.

Abstract: A calibration tool for an air data sensor of a vehicle comprises a target surface which is disposable on the vehicle. The calibration tool may further comprise a light pointer which is mountable on the air data sensor and which is operative to project a beam of light toward the target surface. The air data sensor may be configured as a flow direction sensor which may include at least one of an alpha vane for measuring angle of attack or a beta vane for measuring sideslip. The flow direction sensor may be mountable in spaced relation to the vehicle via a standoff. The flow direction sensor may include a hollow pivot arm having a laser pointer mounted therewithin for projecting a beam of laser light onto the target surface.

Abstract: The effects of IMU gyro and accelerometer bias errors are significantly reduced in accordance with the present teachings by a system or method for commanding an IMU or vehicle through a series of preprogrammed maneuvers. The maneuvers can be designed to minimize the effects of other gyro errors including scale factor errors, nonlinearities, cross coupling/misalignment, and scale factor asymmetries. A sample maneuver is provided which demonstrates performance based on a sequence of roll and yaw maneuvers resulting in zero build up of error at the end of a maneuver cycle period as a result of these errors. Modification of the system involves the addition of control logic to determine the maneuver period, maneuver rate, and vehicle orientation. No additional hardware beyond possible fuel required to perform the maneuver is required.

Abstract: A method and apparatus for bearing thrust monitoring allows measurable detection of tilt of a support bearing (52 or 56) for a roller (34 or 36) which rotatably supports a rotating body (22). A tilt meter (75 or 77) adapted to measurably detect a tilt of the support bearing is coupled to the support bearing (52 or 56), where the tilt is defined as an angular difference in bearing orientation between a first bearing position and a second subsequent bearing position that is cause by an axial thrust on the rotary body (22). Once tilt is detected, the bearing orientation of the support bearing (52 or 56) can be adjusted to return the support bearing (52 or 56) to substantially the first bearing position.

Abstract: A method for independent alignment of an inertial measurement unit for a stand-by instrument in an aircraft determining a status of the aircraft, that is to say whether or not the aircraft is in flight, and in the case where the aircraft is detected as being in flight, carrying out a flight alignment, and in the case where the aircraft is not detected as being in flight, determining a stability of the aircraft, that is to say whether the aircraft is on the ground or at sea, and in the case where the aircraft is detected as being on the ground, carrying out a ground alignment, and in the case where the aircraft is detected as being at sea, carrying out a sea alignment.

Abstract: The Field Testing Instrument (FTI) is designed for use in the regular maintenance and installation of airport Precision Approach Path Indicator (PAPI). The FTI is a self-contained and portable instrument that accurately measures the most important PAPI parameters, such as vertical aiming angle, transition angle, and light intensity. In addition to working with the current incandescent PAPIs, the FTI also measures parameters specific to the next generation LED PAPI. The FTI uses modern, efficient technology to reduce the life-cycle cost of approach lighting systems. The FTI improves on traditional PAPI testing methods by directly measuring the PAPI light beam focused to a target plate, as if seen from the pilot perspective. Due to significantly improvements in measurement accuracy and reliability, the FTI may supplement and even replace costly flight checks for PAPI maintenance with ground based operation.

Abstract: An inertial navigation system is provided. The system includes a sensor block, an outer shell that substantially surrounds the sensor block and a plurality of gas pads connected to the outer shell that float the sensor block in gas creating a near frictionless environment to allow the sensor block to rotate in all directions. Each of the plurality of gas pads is adapted to receive pressurized gas. The outer shell and the sensor block are separated by a gap created by the pressurized gas at each pad.

Abstract: An accelerometer has an acceleration transducer producing uncorrected analog acceleration signals representing vertical, lateral, and longitudinal components of acceleration. An error correction system is connected to the acceleration transducer for receiving the uncorrected analog acceleration signals. The error correction system includes a system controller for generating a plurality of correction coefficients, an analog to digital converter which converts the uncorrected analog acceleration signals to uncorrected digital acceleration signals, a filter for filtering the uncorrected digital acceleration signals, an error compensation circuit receiving the correction coefficients to compensate the uncorrected digital acceleration signals, and a digital to analog converter which converts the corrected digital acceleration signals to corrected analog acceleration signals. The error compensation circuit corrects for bias offset, cross-axis alignment errors, scaling errors, and thermal offset.

Abstract: The invention relates to a method of correcting the effects of aging of a measurement sensor upon turning on the sensor. It also relates to a device delivering measurements corrected for the effects of aging of the device. According to the invention, the method of correcting the effects of aging of a sensor starts by on turning on the processing unit. The absolute time information is transmitted from a satellite positioning receiver to a processing unit. The age of the sensor is determined by comparison of the date of manufacture of the sensor and the absolute time information. Corrections to be made to a sensor measurement, based on the age of the sensor and on the degradation law, are determined. The corrections are applied to the sensor measurement.

Abstract: A method to detect if an aircraft is airborne or on the ground may include detecting at least one of a truck tilt of each main landing gear and a strut compression of each main landing gear. The method may also include detecting the aircraft being airborne or substantially on the ground in response to at least one of the truck tilt of each main landing gear and the strut compression of each main landing gear.

Abstract: The present invention provides the stress detection method for force sensor device with multiple axis sensor device and force sensor device employing this method, whose installation angle is arbitrary. The stress detection method includes, first and second force sensors whose detection axes are orthogonal to each other. When the detection axis of first force sensor forms angle ? with direction of detected stress Ax, and the stress component of direction perpendicular to direction of the detected stress Ax is Az, output Apx of the axis direction of first force sensor is found as Apx=?x (Ax×cos ?+Az×sin ?), and output Apz of the axis direction of the second force sensor is found as Apz=?z (Ax×sin ?+Az×cos ?), and, when ?x and ?z are detection sensitivity coefficients of first and second force sensors respectively, the detection sensitivity coefficient ?z of second force sensor is set as ?z=?x tan ?, and the detected stress Ax is found as Ax=(Apx?Apz)/?x(cos ??tan ?×sin ?).

Abstract: An inertial measurement unit is provided. The inertial measurement unit comprises two rotational axes, wherein a first of the two rotational axes is aligned nominally along a thrust axis and a second of the two rotational axes is aligned substantially perpendicular to a plane formed by a local gravity vector and a thrust vector, and one or more sensors which rotate about the second rotational axis.

Abstract: An array of three-axis magnetometers used for dynamic magnetic anomaly compensation are located at the corners of a parallelopiped, with pairs of magnetometer outputs used to derive a magnetic anomaly gradient vector used to compensate a compass and/or the output of a gyroscope in an inertial management unit. The system may be used in a neutrally buoyant remotely operated vehicle to permit ascertaining of course and position in the absence of surface control signals.

Abstract: A method for providing dynamic disturbance compensation to an inertial system is described. The method includes determining estimated correction factors based on received acceleration components, and dynamically determining filter coefficients for a filter configured to receive velocity and position signals and output a prediction error. The method further includes combining the estimated correction factors and the prediction error into adjustment factors, where the prediction error is configured to be a feedback control signal, and applying the adjustment factors to compensate the inertial system such that effects of the dynamic disturbance are removed.

Abstract: This invention concerns a method of making airborne geophysical measurements. Such measurements may be made from fixed or moving wing airplanes or dirigibles. The method comprises the following steps: taking first real time measurements from one, or more, geophysical instruments mounted in an aircraft to produce geophysical data related to the ground below that instrument. Taking second real time measurements from navigation and mapping instruments associated with or carried by the aircraft. Computing a background response of each geophysical instrument using the second real time measurements to take account of its time varying altitude, and the time varying topography of the ground below it. Adjusting an operating or data processing condition of each geophysical instrument using the respective background response and the instrument's attitude to enhance the performance of that instrument.

Abstract: A method for producing inertial measurement data is provided. The method comprises receiving raw inertial measurement data from one or more inertial sensors; receiving raw position data based on signals from a global navigation satellite system; processing the raw inertial measurement data and the raw position data with a filter to generate state variable estimates; and calculating enhanced inertial measurement data based on the raw inertial measurement data and the state variable estimates from the filter.

Abstract: The present invention provides the stress detection method for force sensor device with multiple axis sensor device and force sensor device employing this method, whose installation angle is arbitrary. The stress detection method includes, first and second force sensors whose detection axes are orthogonal to each other. When the detection axis of first force sensor forms angle ? with direction of detected stress Ax, and the stress component of direction perpendicular to direction of the detected stress Ax is Az, output Apx of the axis direction of first force sensor is found as Apx=?x (Ax×cos ?+Az×sin ?), and output Apz of the axis direction of the second force sensor is found as Apz=?z (Ax×sin ?+Az×cos ?), and, when ?x and ?z are detection sensitivity coefficients of first and second force sensors respectively, the detection sensitivity coefficient ?z of second force sensor is set as ?z=?x tan ?, and the detected stress Ax is found as Ax=(Apx?Apz)/?x(cos ??tan ?×sin ?).

Abstract: An inertia control system includes an integrated inertial measurement unit coupled to an inertial platform. The integrated inertial measurement unit includes three accelerometer gimbals/axes (first, second, and third) respectively, each including a pair of flexure plate accelerometers. First and second accelerometers are coupled to the first gimbal, third and fourth accelerometers are coupled to the second gimbal, and fifth and sixth accelerometers are coupled to the third gimbal. The system further includes a processor utilizing outputs from the inertial measurement unit in three processor modes, including a leveling mode, a compass mode, and an operational mode.

Abstract: A method and apparatus for recording data concerning a system is provided. The apparatus comprises a memory card, such as a COMPACTFLASH card, and a processor unit, such as a T2CAS processor unit. The memory card includes a supplemental file that contains instructions as to what data is to be recorded and when the recording should start and stop. To conserve space the supplemental file is written as a sequence of hexadecimal characters whose position in the sequence and binary bit value indicates which data is to be recorded and when. A lookup table can be used to interpret the supplemental file. The processor unit includes or is coupled to a memory card reader/writer.

Abstract: A portable system (20) for testing an electro-optical guidance assembly (22) includes an electro-optical test unit (40) with at least two sources of electromagnetic energy at different wavelengths for selectively illuminating the guidance assembly. The electro-optical test unit (40) is mounted within a frame (56) that can be part of a wheeled cart (50). The system (20) further includes one or more of: an adjustable fixture (84) for supporting a guidance assembly (22) for testing, a processor unit (42) for controlling the electro-optical test unit (40), a power supply unit (44) for providing electrical power to the electro-optical test unit (40) and the guidance assembly (22), and a leak test unit (46) for generating a vacuum in the guidance assembly (22) or for pressurizing the guidance assembly (22) with an inert gas to test for leaks.

Abstract: The present invention describes a method to calibrate an angular measurement device using acceleration measurement device. The angular rate measurement device includes at least one angular measurement sensor, wherein the acceleration measurement device is able to distinguish the direction and strength of gravity. By performing the calibration method the scale factor(s) of the angular measurement device and the strength and direction of gravity can be obtained and/or corrected. An embodiment according to the method of the present invention describes optional use of a communication network to perform necessary evaluation and calculation steps at a remote device.

Abstract: The method according to the invention allows to determine the yaw angle of a satellite from the reading of two different sensors measuring the roll and/or pitch angles, provided that the reference point of the two sensors are not identical. A description is given basically for geostationary satellites but the method can be applied directly to satellites which are stationary with respect to any star. The method can be employed for circular and non-circular orbits.

Abstract: A system for testing inertial measurement devices on a multi-axis rate table without having to utilize slip rings to transfer signals between the inertial measurement devices and remote processors by incorporating a processor internal to the inertial measurement devices and transferring the signals directly to the processors for determining and storing the calibration coefficients of the inertial measurement devices internally so that they are self calibrating.

Abstract: A method of detecting errors in air data sensing systems having multi-function probes being used in combinations to define probe systems includes a step (A) of, for each probe system, making a first prediction of an aircraft parameter as a function of local angles of attack at two member probes of the particular system, and making a second prediction of the aircraft parameter as a function of local pressure ratios at the two member probes of the particular system. A step (B) is performed in which, for each of the probe systems, the first and second predictions of the aircraft parameter are compared to determine whether the first and second predictions are within a predetermined threshold of each other. Then, a step (C) is performed in which, for each of the probe systems, if the first and second predictions of the aircraft parameter are not within the predetermined threshold of each other, then the particular probe system is identified as having a malfunctioning member probe.

Abstract: The invention is a method and apparatus for improving the accuracy of an inertial navigation system. The method comprises (1) obtaining a measure of the angular velocity of a body frame of reference having a first axis, a second axis, and a third axis, (2) obtaining a measure of the acceleration of a first reference point in the direction of the first axis, a second reference point in the direction of the second axis, and a third reference point in the direction of the third axis, the first, second, and third reference points being fixed in the body frame, and (3) determining compensated acceleration values. A compensated acceleration value is the difference of the measure of acceleration of a reference point and a compensation quantity. A compensation quantity is an estimate of the portion of the acceleration of the reference point resulting from the rotation of the body frame. The method further comprises establishing the optimum navigation center based on a criterion of goodness.

Abstract: In an aircraft conventionally-including a redundant pair of independent primary altitude determination systems of accuracy certified for RVSM operations, an initially loosely calibrated backup altimeter receives independent static pressure data for use in calculating altitude. During normal flight of the aircraft, the current altitude determinations of the primary altimeters and, using a recursive filter, the static source error correction (SSEC) of the backup altimeter is recursively adjusted until the SSEC attains a steady-state value with which the calculated altitude determinations by the backup altimeter accurately conform to the altitude determinations of the primary altimeters. Through this self-correction functionality the backup altimeter is rendered sufficiently accurate for permitted use in RVSM airspace in the event of a failure of one of the primary altitude determination systems.

Abstract: A calibrating device is composed of a movable portion having a degree of freedom movable in three axis directions orthogonal to each other, a displacement detector for detecting displacement of said movable portion as per degree of freedom, a universal joint having a three-axis rotating degree of freedom, which is attached to the tip end portion of said movable portion, a fixture attached to a free end of the universal joint, which is capable of being easily connected to the tip end portion of the wrist of the robot. The calibrating device measures displacement of the wrist tip end portion. That is, the invention provides a comparatively simple calibrating device and a calibrating method, in which automation is easy without requiring any complicated operations, using the calibrating device.