Abstract: Embodiments are directed to obtaining data from at least one sensor, the data pertaining to rotor loads and motion, processing, by a device comprising a processor, the data to obtain an estimate of at least one of gross weight (GW) and center of gravity (CG) for a rotorcraft, and outputting the estimate.

Abstract: Methods and systems are provided that enable accurate driving behavior data (e.g., vehicle acceleration data) to be obtained by a mobile device, despite the reference frames of the mobile device and the vehicle occasionally moving relative to each other. Accordingly, a user does not have to maintain a mobile device stationary relative to a vehicle in order to have a high likelihood that accurate driving data is collected.

Abstract: Methods and systems are provided herein for measuring 3D apparatus (e.g., manual tool or tool accessory) orientation. Example implementations use an auto-nulling algorithm that incorporates a quaternion-based unscented Kalman filter. Example implementations use a miniature inertial measurement unit endowed with a tri-axis gyro and a tri-axis accelerometer. The auto-nulling algorithm serves as an in-line calibration procedure to compensate for the gyro drift, which has been verified to significantly improve the estimation accuracy in three-dimensions, especially in the heading estimation.

Abstract: The gravity control apparatus (1) comprises: a first rotating body (10) that rotates along a first shaft (11a) as a result of being driven by a first driving device; a second rotating body (20) that rotates along a second shaft that is orthogonal to the first shaft (11a) within the region of rotation of the first rotating body (10) as a result of being driven by a second driving device; an accelerometer (40) that is set at any position on the second rotating body (20) and detects acceleration; and a control device (50) that controls driving by the first driving device and the second driving device. The control device (50) controls driving by the first driving device and the second driving device on the basis of acceleration data detected by the accelerometer (40).

Abstract: Methods and systems for azimuth measurements using a gyroscope unit are disclosed. The method includes acquiring a ratio value between two earth rate components orthogonal to each other by using the gyroscope unit at a measuring position; acquiring three gravity vector components orthogonal to each other at the measuring position; and determining an azimuth with respect to a reference axis predetermined in the gyroscope unit, based on the ratio value, the three gravity vector components and a geodetic latitude of the measuring position.

Abstract: The invention relates to a method and system for determining vehicle wheel alignment, and namely, camber angles, total and individual toe and front wheel steering axis caster and tilt angles (caster and kingpin inclination), by measuring changes in wheel sensor angles from a predetermined position. Changes are measured using gyroscopic sensors or MEMS angular rate sensors (MEMS gyroscopes).

Abstract: There is provided a flexible display capable of improving an angle-measuring accuracy using different kinds of sensors and a method of measuring an angle thereof. The flexible display includes a first sensor unit disposed in a first region and including different kinds of sensors, a second sensor unit disposed in a second region adjacent to the first region and including different kinds of sensors, and an angle-measuring unit measuring a folding angle between the first region and the second region in response to sensing signals outputted from the first sensor unit and the second sensor unit.

Abstract: A human-portable MEMS azimuth sensing unit and method that determines the azimuth of a target. There is a spinning support structure, with at least a gyroscope carried by the support structure. The gyroscope has an input axis and an output signal. There is an angle resolver that measures the spin angle of the support structure relative to a reference direction and that has an output signal. Circuitry determines the target azimuth based on the phase difference between the output signals of the gyroscope and the angle resolver. The phase difference can be based on the time between zero crossings of the sinusoidal gyro and angle resolver signals. An accelerometer can also be carried by the support structure, in which case its output can be used to level the unit.

Abstract: A device includes: a gyroscope adapted to be mounted to a goniometer, wherein a sensitivity axis of the gyroscope is substantially perpendicular to a rotation axis of the goniometer, wherein the goniometer is adapted to provide at least a first goniometer azimuth reading (A1) at a first azimuthal direction and a second goniometer azimuth reading (A2) at a second azimuthal direction, wherein the gyroscope is adapted to provide at least a first gyroscope angular rate reading (?1) at the first azimuthal direction and a second gyroscope angular rate reading (?2) at the second azimuthal direction, wherein the device enables measurement of a tilt angle.

Abstract: An apparatus for azimuth measurements is provided. The apparatus comprises a housing and a plurality of gyro sensors aligned in the housing. Each of the plurality of gyro sensors has an input axis for angular velocity measurements. There is provided a drive unit for rotating each of the plurality of gyro sensors about a rotation axis. Each of the plurality of gyro sensors changes orientation of the input axis with the drive unit.

Abstract: A stride monitoring device that can be used particularly for sports applications and that includes a pair of shoes, one of which includes at least one magnetic mass, and the other includes at least a measurement device to make at least one measurement, and a processor for processing of the measurement. The measurement device includes at least one accelerometer and at least one magnetometer capable of outputting signals that can be processed to determine stride parameters.

Abstract: A device includes: a gyroscope adapted to be mounted to a goniometer, wherein a sensitivity axis of the gyroscope is substantially perpendicular to a rotation axis of the goniometer, wherein the goniometer is adapted to provide at least a first goniometer azimuth reading (A1) at a first azimuthal direction and a second goniometer azimuth reading (A2) at a second azimuthal direction, wherein the gyroscope is adapted to provide at least a first gyroscope angular rate reading (?1) at the first azimuthal direction and a second gyroscope angular rate reading (?2) at the second azimuthal direction, wherein the device enables measurement of a tilt angle.

Abstract: An apparatus for azimuth measurements comprises an elongated housing, a plurality of gyro sensors, each of the gyro sensors having an input axis for angular velocity measurements, spherical sensor holders arranged along the longitudinal direction of the housing, at least one motor for driving the sensor holders, a transmission mechanism for transmitting a rotation force from the motor to each of the sensor holders and a controller for controlling a rotation of the motor. Each of the sensor holders has one of the gyro sensors and is rotatable about a rotation axis so as to change the orientation of the input axis of the gyro sensor.

Abstract: A gyroscope assembly is mounted within a sports instrument swing aid. A motor is connected to a rotor within the gyroscope assembly. A power source drives the motor to rotate the rotor. During a forward swing of the swing aid, an angular momentum of the rapidly spinning rotor tends to maintain the swing aid parallel to a plane of the swing. A reaction torque from the gyroscope assembly may be sensed by a player if a player's wrists are rotated in a release, and may also be sensed if a parallel relationship of the swing aid to a plane of the swing is not maintained. The swing aid may be in the form of a bat or racket.

Abstract: Provided is a method and apparatus for controlling the precision of the rotation angle of a rotation of a dynamic apparatus, including the step of determining a conversion factor of a gyroscope installed in the dynamic apparatus to control the rotary movement to be a first conversion factor; a first step of measuring an output angular velocity in the case of applying a predetermined test operation to the gyroscope; a second step of measuring a second conversion factor based on the test operation and the output angular velocity corresponding to the test operation; a third step of computing an error between the first conversion factor and the second conversion factor; and a fourth step of updating the first conversion factor of the gyroscope by the second conversion factor in the case the error is more than a predetermined standard value, wherein in the case the dynamic apparatus is on standby or an operation command with respect to a predetermined operation is inputted, the first through fourth steps are perfo

Abstract: A sensor system and method for determining a relative direction to true north is provided. The system comprises at least one angular rate sensor, such as a MEMS sensor, which has an input axis and a rotation axis. The sensor comprises a motor drive structure, a motor signal output from the motor drive structure, a gyroscope, and a sensor rate output from the gyroscope for a sensor rate signal. A frequency divider is in operative communication with the motor signal output, and a spinning device is coupled to the angular rate sensor. A spinning device motor is coupled to the spinning device and is in operative communication with the frequency divider. The spinning device motor has an axis of rotation that is substantially perpendicular to the input axis of the sensor. The spinning device motor is configured to be driven by a periodic signal from the sensor. A position of the spinning device is synchronized to the periodic signal to generate a spinning device position signal.

Abstract: An activity monitor is provided that corrects for the effects of motion external to the entity being monitored. For example, the activity monitor can overcome the effects of vehicular travel.

Abstract: The portable self-contained horizontal and vertical level, angle and distance measuring device is suitable for indicating whether or when two or more points are level with each other and for measuring distances and angles between two or more points, a point and a line or a point and a plane. Moreover, the measuring device is capable of displaying such measurements to a user in real time. The measuring device includes a measuring point (3) for identifying from where measurements are to be calculated, a user actuated trigger (11) and a display (9) for displaying measurements to the user either in real time or in memory mode. The measuring device is compact and light-weight making it particularly convenient and portable. It is also very versatile and is capable of replacing a multiplicity of measuring devices commonly employed in DIY, engineering, and in trade in general.

Abstract: In a method for determining the zero-point error of a Coriolis gyro, the resonator of the Coriolis gyro has a disturbance force applied to it such that a change in the stimulation oscillation of the resonator is brought about. A change in the read oscillation of the resonator, caused by a partial component of the disturbance force, is extracted from a read signal which represents the read oscillation of the resonator as a measure of the zero-point error.

Abstract: A method for determination of the zero error of a Coriolis gyro. Appropriate disturbance forces are applied to the resonator of the Coriolis gyro such that at least one natural oscillation of the resonator is stimulated that differs from the stimulating and read oscillations. A change in a read signal which represents the read oscillation and results from the stimulation of the at least one natural oscillation is determined as a measure of the zero error.

Abstract: A gyroscopic system for translating parallel and non-parallel lines between a reference line and a device to be aligned with respect to the reference line is provided. The system includes a first inertial sensor configured to be substantially stationary, the first inertial sensor comprising a first three-axis gyroscopic sensor configured to produce an output signal and a reflector. A second inertial sensor is configured to be portable so as to be positionable adjacent to the first inertial sensor and comprises a gimbal restricted to two physical axes, a gimbal drive system, an electromagnetic energy beam generator, a second three-axis gyroscopic sensor configured to generate an output signal, and a collimator. The collimator is operable to determine an angle between a beam projected by the beam generator and a beam reflected from the reflector and to generate an output signal indicative of the determined angle.

Abstract: An ergonomically equipped and interference signal-reducing position measurement probe for mutual alignment of bodies has a speech input device and/or a speech output device. The probe is wirelessly linked to an external control or a higher-level supervisory computer either by an infrared interface or a radio link which operates at an extremely high frequency. Error-reducing measured value acquisition is effected by averaging. The average represents several individual measured value. In the acquisition of the individual measured values, it is watched that the times of measured value recording and the time peaks of a solid-borne sound oscillation on the measurement object are essentially asynchronous to one another.

Abstract: A process for determining the alignment of a cylindrical body with respect to a reference direction by means of a measurement device which has a first and a second attachment area and a position measurement probe which is calibrated to the reference direction and is made for detecting a first angle of rotation of the probe around a first axis fixed in space and a second angle of rotation of the probe around a second axis fixed in space. A first measurement and a second measurement is carried out at different areas of the body, the probe being swung in contact with the peripheral surface of the body relative to the first attachment area to measure a characteristic of the first and the second angle of rotation. A comparison of the characteristic of measurements is used to determine the alignment of the body with respect to the reference direction.

Abstract: A system is disclosed for using camera attitude sensors with a camera. A camera assembly includes a tripod base, a tripod head interface mounted on the tripod base, a tripod head mounted on the tripod head interface and a camera mounted on the tripod head. The tripod head enables the camera to pan and tilt. The system also includes a first optical encoder for detecting the amount that the camera has been panned and a second optical encoder for detecting the amount that the camera has been tilted. Two inclinometers are mounted on the tripod head interface to measure attitude of the tripod head. Two gyroscopes (“gyros”) are mounted on the camera assembly. Data from the encoders, gyros and inclinometers are packaged and sent to graphics production equipment to be used for enhancing video captured by the camera.

Abstract: The invention concerns a compass having an electro magnetic half-shell transformer energy transmission and opto electronic data transmission. To avoid a slipring connection during the transfer of supply voltage at least one winding on the primary half-shell is connected to a controllable input voltage source via a H-bridge circuit, and at least one secondary winding having taps is provided at the other half-shell coil.

Abstract: An inclinometer for measuring the angle between a reference angular position and an angularly adjustable surface, such as on the control surfaces of a model aircraft. In one form, the inclinometer has a beam and a pair of opposed arms attached to the beam with centering faces to attach the inclinometer to the leading and trailing edges of the adjustable surface. In another form, the inclinometer has opposed gripping faces to attach to opposite sides of the adjustable surface. A pair of accelerometers sense the earth's gravitational vector and supply output signals to a data processor. The data processor determines a first reference position and a second angular position of the adjustable surface to determine the angle of the adjustable surface. A display receives information from the data processor to display the angle. Related methods are also disclosed.

Abstract: A laser plumb includes a laser, and a mass that is rotatable about a spin axis to stabilize the laser. The mass is mounted to a support to be pivotable about at least one axis, and preferably two axes. The two axes are perpendicular to each other and the spin axis. The laser is mounted to the mass to maintain its orientation relative to the support, as the mass rotates about the spin axis. A weight below the tilt axes aligns the spin axis with the gravitational axis. Preferably, the mass and laser are mounted to the support by a gimballed mount. The plumb optionally includes markings on its base to measure a deflection of the laser from the support, thereby allowing measurement of the angle of inclination of a surface supporting the base.

Abstract: A calculation system for calculating the control signals which are designed to perform a frequency-dependent weighting of the angular velocity signals and the angular position signals. The angular velocity indicators are preferably used for stabilization in a high frequency band while the angular position indicators are suitable for stabilization in a low frequency band. A further calculation system which is designed to perform the frequency-dependent weighting such that the control signals for frequencies below a certain frequency are substantially determined by the angular position signals and the control signals for higher frequencies are substantially determined by the angular velocity signals.

Abstract: Using an inertial master box mounted on a carrier for measuring its movements with respect to a geographic frame of reference of fixed directions along three axes Xg, Yg, Zg, a measuring method provides for continuously measuring an orientation of a frame of reference Xm, Ym, Zm tied to the inertial master box. Positioning is provided by applying a sequence of cycles of eight inversions of the inertial master box while keeping the axis Ym in a direction parallel to the axis Yg. A first motor causes a gimbal to pivot on a first axle secured to the carrier, while a second motor causes the inertial master box to pivot about a second perpendicular axle secured to the gimbal. A processor calculates three attitude angles by running a first inertial navigation program of the strapdown type and controls the first and second motors by running a second program.

Abstract: Using an inertial master box (3) mounted on a carrier for measuring its movements with respect to a geographic frame of reference of fixed directions along three axes Xg, Yg, Zg, the method comprises measuring actions which consist in constantly measuring an orientation of a frame of reference tied to the inertial master box Xm, Ym, Zm by using the inertial master box (3) in the geographic frame of reference, positioning actions which consist in applying a sequence of cycles of eight turnings-over of the inertial master box (3) each of which keeps the axis Ym in a direction parallel to the axis Yg, a succession of two turnings-over about the axis Xm being preceded and followed by a turning-over about the axis Zm, a succession of two turnings-over about the axis Zm being preceded and followed by a turning-over about the axis Xm.

Abstract: An orientation measuring device with a plurality of precision tooled grooves, indentations or the like. Two precision tooled adaptor bodies, preferably of cylindrical shape, are removably mountable in the indentations, where appropriate, for a given measuring task. The adaptor bodies are held in place by, e.g., magnets. The device is capable of determining the spatial orientation of rolls, bars, hollow or solid cylinders, ranging from small to large diameters by appropriately selecting in which of the grooves or indentations the adaptor bodies are mounted.

Abstract: A calculation system for calculating the control signals which are designed to perform a frequency-dependent weighting of the angular velocity signals and the angular position signals. The angular velocity indicators are preferably used for stabilization in a high frequency band while the angular position indicators are suitable for stabilization in a low frequency band. A further calculation system which is designed to perform the frequency-dependent weighting such that the control signals for frequencies below a certain frequency are substantially determined by the angular position signals and the control signals for higher frequencies are substantially determined by the angular velocity signals.

Abstract: A sensor includes a plurality of weight portions which swivel, support parts each of which supports at one end a corresponding one of the plurality of weight portions in the same direction, and a driving part which supplies driving power to the support parts to swivel the plurality of weight portions. The driving part swivels at least one weight portion of the plurality of weight portions in a first direction and a remaining weight portion in a second direction opposite to the first direction so that the angular velocity about an axis parallel to a predetermined swivel locus of the at least one weight portion, excluding an acceleration component in the direction of the axis, can be detected from the difference between a deviation of a swivel locus of the at least one weight portion from the predetermined swivel locus and a deviation of a swivel locus of the remaining weight portion from a predetermined swivel locus thereof.

Abstract: A three-dimensional homologous surveying instrument includes a base with an outer spherical shell mounted thereon for receiving therein a ring-shaped shell holder, an intermediate spherical shell and an inner spherical shell with respective zero references at in a homologous relationship with each other. The inner spherical shell rotates within the intermediate spherical shell about X-axis. The intermediate spherical shell rotates within the ring-shaped shell holder about Y-axis. The outer spherical shell is positioned in the base to serve as the X-axis. The inner spherical shell and the intermediate spherical shell each have a pendulum at the bottom. The outer spherical shell, the ring-shaped shell holder, the inner spherical shell and the intermediate spherical shell form a gyroscopic device for three dimensional surveying through X-axis, Y-axis and Z-axis concomitantly. The pendulum of the inner spherical shell is mounted with a compass for indicating the direction of the angle of slope being surveyed.

Abstract: A navigation unit having a gyro sensor mounted thereon. The unit includes a mounting mechanism for changing the mounting direction of the gyro sensor so that the rotation detecting axis of the gyro sensor may be vertical, i.e. normal to a vehicle. In one embodiment, the navigation unit includes a support device for supporting the gyro sensor rotatably with respect to a casing. The gyro sensor may be supported in a rocking manner in the casing, and mounted to be changed between a first mounting direction and a second mounting direction perpendicular to the first mounting direction. In the preferred construction, the gyro sensor has a first pin and a second pin, and the casing has a first guide groove for receiving and guiding the first pin, and a second guide groove extending perpendicular to the first guide groove for receiving and guiding the second pin. The second guide groove provides a rocking center for the gyro sensor.

Abstract: An inertial sensor unit for determining north, has a housing and a positioning gimbal rotatably mounted in this housing about a substantially vertical axis. A releasable, cooperating detent mechanism defines three fixed angular detent positions of the positioning gimbal about the substantially vertical axis relative to the housing. The positioning gimbal is successively rotated into the three detent positions. A fiber optical gyro is mounted on the positioning gimbal. The input axis forms an acute angle with a substantially horizontal axis orthogonal to the above mentioned substantially vertical axis. A signal processing system is provided, to which the signals generated by the fiber optical gyro in the three detent positions are applied. The signal processing system provides, therefrom, the angle between a reference direction and north.

Abstract: The present invention provides a method and apparatus for utilizing spin valve magnetoresistance devices for the measurement of weak magnetic fields. The magnetoresistive element consists of a pinned ferromagnetic layer and a soft ferromagnetic layer separated by a thin spacer layer. The pinned layer may be pinned by high intrinsic coercivity, or by a neighboring antiferromagnet or high coercivity ferromagnet layer. An oscillating magnetic field is applied to the device. The amplitude of the excitation field is large enough to reverse the magnetization of the soft layer during each cycle, but small enough that the magnetization direction of the pinned layer is not much affected. In one embodiment, the applied field is applied using a current strip deposited onto the top of the other layers, so that the entire device can be produced on a single chip.

Abstract: An offset-drift correcting device is designed for a gyro-sensor mounted on an object and outputting a signal representing an angular speed of the object. The device includes a first section for detecting whether or not the object is rotating. A second section connected to the gyro-sensor is operative for smoothing the angular speed represented by the output signal of the gyro-sensor, and deriving an average angular speed of the object from the angular speed represented by the output signal of the gyro-sensor. A third section connected to the first section and the second section is operative for estimating an offset level of the output signal of the gyro-sensor in response to the average angular speed derived by the second section in cases where the first section detects that the object is not rotating. The third section includes an adaptive filter processing an output signal of the second section which represents the derived average angular speed.

Abstract: The present invention relates to a method and a device for correcting measurement errors of a magnetometer mounted on a vehicle. According to the method, a theoretical corrective model is defined in accordance with the following equation: ##EQU1## where ?A!, ?C!i and Hp are elements to be determined, Hm is the measured field, H the effective field, and ?M! is a transformation matrix, and in which a vector error is defined in accordance with the following equation: ##EQU2## where the square of the error thus defined is determined and the coefficients of the model which minimize the sum of the squares of the error moduli for all the measurements taken are identified.

Abstract: The system includes for planar angular measurements a gyro--preferably a laser gyro--and an angle encoder mounted with their sensitive axes coaxially on a turntable shaft, which is rotatably mounted in a case and driven at constant speed with respect to said case. The angular rate should be high enough to operate the laser gyro above the lock-in rate. For spatial angular measurements and navigation three gyros are mounted with their sensitive axes spatially arranged with respect to the turntable shaft to sense the same component of its angular rate. For avaraging errors due to gyro scalefactor and drift, the turntable is mounted on a second shaft with is axis perpendicular to the turntable. The second shaft is provided with a second an coder and a motor rotating the second shaft. The processing of the signal readout of the gyro(s) and encoder(s) allows to increase the accuracy, resolution and bandwidth of angular measurements with respect to a locally fixed basis or to inertial space.

Abstract: A support base of an angular velocity sensor is supported rotatably at one end, and the support base is vibrated by a piezoelectric element. By this vibration, a known rotational angular velocity is applied to the angular velocity sensor. For example, a difference of two output signals of the angular velocity sensor is measured. This difference of the output signals is detected in synchronism with phases which differ from each other by 180.degree., in two synchronous detection circuits. The detected signal is smoothed in smoothing circuits, and further, amplified in amplifying circuits. An output signal of the amplifying circuit is composed in a variable resistor as a composite circuit. Meanwhile, from the output signal of the amplifying circuit, the output signal of the variable resistor and a signal corresponding to the known rotational angular velocity are subtracted.

Abstract: The calibration of time-depending measurement uncertainties of gyros and inertial systems by the differences of angular and/or velocity and/or positional measurements which are carried out and repetitiously executed with a view to undetermined reference directions and/or fixed locations varying with time. The differentiation allows to forego precise reference data. Measurement uncertainties can be corrected through calibration subsequently to the measurement process. For the measurement of spatial angles a three-axis gyro measurement package comprising a computer and the possibility of feeding or automaticly reading-in of reference data characterizing the reference directions. The reference data can be a number, a marker of the measurement point or in the case of positional measurements a terrestrial aiming point. When measuring angular characteristics, i.e. the interdependence of angles and external forces or moments, the latter are considered as references.

Abstract: An angular rate sensor system preferably comprising closely spaced vibrating drive and sensing elements in a paired tuning fork configuration mounted to rotate about a rotational axis oriented perpendicular to the sensitive axes. The rotational drive assembly includes an encoder to modulate sensing element orientation, and coupling means to transmit drive and output signals to and from the rotating elements. Each pair of sense and drive elements are disposed in non-aligned parallel side-by-side opposition across the axis of rotation. The elements may be carried on torsional masses including a resilient coupling therebetween. The angular rate sensor system may be utilized as a north-seeking gyroscope in applications such as mining, surveying, or artillery. The phase of the sinusoidal sensor output signal corresponds to the orientation between the sensitive axis of the sensing elements and the earth's angular rate vector to produce a reference to geographic north.

Abstract: A gyrocompassing system intended for land based equipment requiring north reference information includes a novel gyrocompass implementation which enables utilization of high grade inertial sensors while achieving the desired goal of moderate cost. The north finding system is designed to provide high accuracy with fast reaction time over a wide temperature range without the aid of heaters and other auxiliary equipment. The arrangement is specifically configured to tolerate settling and/or oscillatory base motion without additional reaction time or degradation of gyrocompassing accuracy. The input axis of a gyroscope used in the system is skewed, so it can measure a component of gimbal rotation, thereby eliminating the need for independently measuring the relative gimbal angle. Absolute position alignment between the gimbal and the system case as is required is accomplished by an appropriate stop arrangement, which is an easier task than measuring the relative gimbal angle as aforenoted.

Abstract: A sensor may be scanned relative to any arbitrarily selected reference coordinate system by the use of a system including an attitude determination unit, attitude control unit, inertial measurement unit, navigation unit, and a scan generation unit. Methods are also employed, in this system, for reducing errors and increasing the accuracy of the scan of the sensor. These methods include the use of gyroscopes having no cross axis coupling or inherent limit on their angular speed, a Kalman filter to reduce system errors, continually estimating solutions to the strapdown equation, and a dual loop control system utilizing both rate and position signals which issues motion control commands to the sensor.

Abstract: A gyrocompassing system intended for land based equipment requiring north reference information includes a novel gyrocompass implementation which enables utilization of high grade inertial sensors while achieving the desired goal of moderate cost. The north finding system is designed to provide high accuracy with fast reaction time over a wide temperature range without the aid of heaters and other auxilliary equipment. The arrangement is specifically configured to tolerate settling and/or oscillatory base motion without additional reaction time or degradation of gyrocompassing accuracy.

Abstract: An apparatus for detecting deflection of the spin axis of a gimbal supported spinning mass relative to the gimbal axis comprises four equally spaced linear arrays of detector elements mounted around the gimbal axis and extending parallel to that axis. Four light sources are provided, each one in alignment with a respective one of the arrays, and a reflective surface is provided on the spinning mass for reflecting light onto the respective detector arrays. Deflection of the spin axis will be registered by displacement of a reflected light spot in one or more of the arrays.

Abstract: A method for aligning pieces of equipment on board a vehicle, particularly on board an aircraft is disclosed. The method assumes the use of at least one computer on board the vehicle working in connection with the pieces of equipment.

Abstract: The north direction shall be determined by a carrier fixed two-axis rate gyro having a substantially vertical spin axis from the two components of the horizontal component of the rotary speed of the earth. Deviations of the position of the rate gyro from an exact vertical alignment of the spin axis are detected by two accelerometers which provide acceleration signals. The ratio of acceleration signals and acceleration due to gravity provide values of the angles of inclination. Correction signals are formed out of the accelerometer signals and are subtracted from the signals obtained by the rate gyro. One of the correction signals compensates for the component of the vertical component of the rotary speed of the earth falling into the direction of the input axes of the rate gyro. Another signal compensates the rotary speed of the carrier relative to the earth and thus rotatory interferences. The tangent of the true azimuth angle is obtained by forming quotients of the rate gyro signals corrected in this way.

Abstract: A gyro apparatus includes a support in a base table for supporting one end of a vibrating member which has a circular cross-section and which is driven by a drive apparatus mounted on the base table to vibrate it in the longitudinal or axial direction. The vibrating member may be light conducting and a light source sends light through it which is projected onto a light detector so as to detect vibrations perpendicular to the axis direction of the vibrating member.