Abstract: A controller controls precession of a gyroscope that oscillates about a precession axis perpendicular to a spin axis and a roll axis of the gyroscope. To do so, the controller detects a deviation of a center of the oscillation away from a nominal center. The precession is caused by roll of the gyroscope about the roll axis and imposes decreasing amounts of damping upon the roll as the precession moves away from the nominal center. The controller reduces the deviation of the center of the oscillation by applying an asymmetric amount of braking to the precession when the precession and the deviation are in a same direction relative to when the precession and the deviation are in opposing directions.

Abstract: Embodiments may be used to evaluate completed inspection jobs using updated pipe segment data obtained by inspecting a rehabilitated pipe after completion of a project. One embodiment provides a method of generating an infrastructure project summary, including: collecting, using one or more sensors of an inspection robot, pipe segment data relating to the one or more pipe segments; the second pipe segment data comprising one or more of laser condition assessment data and sonar condition assessment data; generating infrastructure summary data for at least a part of the network using the pipe segment data, comparing, using a processor, first and second infrastructure summary data; generating, using the processor, a parameter of the infrastructure project summary based on the comparing; and including the parameter of the infrastructure project summary in a project summary report. Other embodiments are disclosed and claimed.

Abstract: Techniques are disclosed for disseminating network service-specific mapping information across administrative domains. In one example, a network device receives an indication of a route target and one or more underlay tunnels configured to support a service route. The service route is configured to transport network traffic associated with a first network service of a plurality of network services. The network device defines, based on the indication, a first transport class of a plurality of transport classes. The network device receives a service route for the first network service and stores a correspondence between the service route and the first transport class. The network device receives network traffic associated with the first network service and forwards, based on the correspondence, the network traffic along the underlay tunnels specified by the first transport class.

Abstract: Method for operation of a strap-down ship's gyro compass for optimal calculation of position and course angle on a ship, with three rotational rate sensors each mutually aligned to each other at a right angle, and two nominally horizontally aligned orthogonal acceleration sensors, without required specification of the geographic latitude and/or of the speed of the ship, characterized by the steps: a. Preparation of a set of dynamic equations based on the angular velocity components detected by the rotational rate sensor, b. Preparation of a measured data equation based on the force components detected by the acceleration sensors, c. Determination of the properties of the lever arm between the strap-down ship's gyro compass and the point of rotation of the ship, and d.

Abstract: An angle measurement system includes a first component group, a second component group, and bearing elements arranged between the component groups. A gap extends at an axial extension between a first component and a second component so that the components are disposed along both sides of the gap relative to each other without coming into contact. An annular first body is mounted on the first component, which is disposed without contact in relation to the second component group. The second component includes a section, which is separated by a radial gap and is located radially outside and across from a region of the first body that extends in the axial direction, and the first body is situated radially outside and circumferentially about the axis in relation to the bearing elements. The first body is able to hold lubricant. Alternatively or additionally, a corresponding annular second body is fixed in place on the second component.

Abstract: An inertial sensor system according to one embodiment having a platform with an x axis and a y axis, a rotational table that is free to rotate about the x axis, a rotational table gyroscope mounted onto the rotational table to measure p, q, and r rotation rates referenced to the rotational table and at least one platform gyroscope mounted off the rotational table, wherein the rotational table gyroscope and the platform gyroscope provide sense rotation used to process gyroscope biases that are used to correct measurements for the inertial sensing system.

Abstract: In one aspect, a device includes at least one gyroscope, a processor, and a memory accessible to the processor. The memory bears instructions executable by the processor to identify a force-related parameter to apply at the device, and actuate the gyroscope to apply the force based at least in part on the identification.

Abstract: A payload including a gimbal assembly and gyro assembly that includes a gyro assembly control associated with the gyro assembly and operable to trigger the gyro assembly to obtain deviation measurements and process the measurements in a first dynamic range for stabilizing the payload utilizing the gimbal assembly. The gyro assembly control is operable to trigger the gyro assembly to obtain instantaneous measurements and process the measurements in a second dynamic range having different sensitivity than the first dynamic range, for finding deviation of the payload from the magnetic north of the earth.

Abstract: A true north heading is determined by using gyroscopes of differing accuracy and orienting a gyroscope of a higher accuracy to a direction that is more sensitive to azimuth change (e.g., an east/west direction). A gyroscope with a lower accuracy is placed perpendicular to the gyroscope with a higher accuracy and can be oriented towards a north or south direction. The gyroscopes may be placed on a rotatable platform to properly orient the gyroscopes. The higher-accuracy gyroscope may be implemented by using multiple gyroscopes oriented in the same direction.

Abstract: The six direction directing device includes a shaft, a rotation member, a driving source, and a guide member. The shaft extends in an X axis direction. The rotation member is rotatable around an inclined axis inclined at ? deg with respect to the shaft. The rotation member has an xyz rectangular coordinate system. The rotation member further includes a spherical surface and an orbit portion formed around an x axis of the spherical surface. The guide member is fixed to an XYZ rectangular coordinate system. The orbit portion has such a shape that the y axis of the rotation member is sequentially directed in + and ? directions on the U, V, and W axes that cross one another at intervals of 60 deg around the X axis when the rotation member is rotated in contact with the guide member by the rotation of the shaft.

Abstract: A method of determining a heading by means of an inertial device (1) providing measurements by means of at least one vibratory gyro (3), the method comprising the steps of: •positioning the inertial device in such a manner that the gyro extends close to a plane that is substantially horizontal; •orienting the inertial device successively in a predetermined number of orientations about a vertical axis, the predetermined number being greater than one; •for each orientation, adjusting the electric angle of the vibratory gyro to a predetermined value, the predetermined value of the electric angle being the same for all of the orientations of the inertial device, and taking a measurement; and •determining the heading from the measurements and an angle between the orientations.

Abstract: The invention relates to an orientation device comprising: a true north finder including a rate-gyroscope-type member, as well as sensors that can be used to measure the inclination of the device in relation to the horizontal, and associated calculation means for determining the orientation of the true north used on information provided by the rate gyroscope-type member and the sensors. According to the invention, the device also includes three feet that are used to support the device when it is placed on a support, at least one of said feet including a built-in sensor that changes state when the device is resting on a support by means of the feet, and means for automatically triggering the determination of the orientation of the north when the device is sufficiently horizontal and when the sensor indicates that it is placed on a support.

Abstract: The six direction directing device includes a shaft, a rotation member, a driving source, and a guide member. The shaft extends in an X axis direction. The rotation member is rotatable around an inclined axis inclined at ? deg with respect to the shaft. The rotation member has an xyz rectangular coordinate system. The rotation member further includes a spherical surface and an orbit portion formed around an x axis of the spherical surface. The guide member is fixed to an XYZ rectangular coordinate system. The orbit portion has such a shape that the y axis of the rotation member is sequentially directed in + and ? directions on the U, V, and W axes that cross one another at intervals of 60 deg around the X axis when the rotation member is rotated in contact with the guide member by the rotation of the shaft.

Abstract: A six-direction indicator is provided in an XYZ rectangular coordinate system and includes a shaft on an X axis, a rotation member rotatable around an axis inclined with respect to a rotation axis, guide pins provided upright on the rotation member, and a guide member provided around the X-axis to surround the rotation member. The guide member has a zigzag slit track bent alternately in a mountain-like shape and a valley-like shape in the X direction at intervals of 60° around the X-axis. The guide pins are inserted in the slit track and move around on the slit track by rotation of the shaft. The device indicates one of the positive and negative directions on the U, V, and W axes crossing one another at intervals of 60° around the X-axis.

Abstract: The invention relates to a compass or direction determination device comprising one or more rotation sensitive sensors and means for rotating the one or more rotation sensitive sensors, wherein the means for rotating is configured to produce two or more rotation speeds of the one or more rotation sensitive sensors during a single direction determination operation.

Abstract: A method of determining a heading by means of an inertial device (1) providing measurements by means of at least one vibratory gyro (3), the method comprising the steps of: • positioning the inertial device in such a manner that the gyro extends close to a plane that is substantially horizontal; • orienting the inertial device successively in a predetermined number of orientations about a vertical axis, the predetermined number being greater than one; • for each orientation, adjusting the electric angle of the vibratory gyro to a predetermined value, the predetermined value of the electric angle being the same for all of the orientations of the inertial device, and taking a measurement; and • determining the heading from the measurements and an angle between the orientations.

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 azimuth determination system has a platform. A plurality of gimbals is attached to the platform to allow the platform to rotate about multiple axes. A pair of gryos is attached to the platform. A leveling device is attached to the platform to indicate when the platform is at a desired position. A control device attached to the plurality of gimbals to move the platform to the desired position indicated by the leveling device. An electronics system is to provide power to the azimuth determination system and to determine azimuth by positioning the gyros in a first position with an input axis of the gyros in the horizontal plane and orthogonal to the Earth Rate vector to calculate a first output and rotating the gyros 180° about the vertical to a second position to calculate a second output, the platform is then inverted and an additional set of two readings is taken. The four outputs are combined to produce the azimuth value and a gyro induced bias error.

Abstract: A jig for selecting a valve part number or a joint part number representing respective selected conditions required for selecting a valve or a joint comprising: a substantially rectangular base plate defining an inner space, and several sliding gauges laterally arranged in the inner space to slide in a longitudinal direction of the base plate, each of the sliding gauges comprising a condition description area including several conditions thereon from which the selected condition is determined, and a symbol description area including several symbols thereon, both the conditions and the symbols arranged in the sliding direction, several condition selecting windows laterally arranged, each of the condition selecting window being configured to expose one of the selected conditions, several symbol selecting windows laterally arranged, each of the symbol selecting window being configured to expose one of the selected symbols.

Abstract: A six-direction indicator is provided in an XYZ rectangular coordinate system and includes a shaft on an X axis, a rotation member rotatable around an axis inclined with respect to a rotation axis, guide pins provided upright on the rotation member, and a guide member provided around the X-axis to surround the rotation member. The guide member has a zigzag slit track bent alternately in a mountain-like shape and a valley-like shape in the X direction at intervals of 60° around the X-axis. The guide pins are inserted in the slit track and move around on the slit track by rotation of the shaft. The device indicates one of the positive and negative directions on the U, V, and W axes crossing one another at intervals of 60° around the X-axis.

Abstract: A system and method for generating an image appended with extra landscape information are disclosed. An image recorder is provided, and having a global-positioning system, an electronic compass, a gyro sensor, and an accelerometer for determining the space information as capturing an image. Under the determination, the space information can include a view angle, a direction, an elevation angle, and a coordinate. The information is used to compare with the content of a database, in order to obtain the landscape information of the image. After that, an image appended with the landscape information is generated. Thereby, the image appended with the landscape information may be used for generating a space map and be a liveview of the recorder.

Abstract: An apparatus and method for compensation of the effects of various bias errors encountered by inertial rate gyroscopes, particularly vibrating element gyroscopes, configured to detect heading relative to true north. Certain embodiments are suitable for reducing rotational dynamic errors associated with rotating gyroscopes. Other embodiments may include compensation of biases not related to rotational dynamics, such as thermal drift. The various methods disclosed may also account for the bias by sampling the rotational vector of the earth at an arbitrary heading, and at a heading that is 180° offset from the arbitrary heading. The sequence may be repeated numerous times to compensate for bias drift. The bias drift may be constant with respect to time (linear) or changing over time (non-linear) during the data acquisition sequence. Some embodiments include methods that utilize data from accelerometers to infer the bank and elevation angles as well as earth latitude location relative to the equator.

Abstract: The present technical solution provided allows it to determine true meridian of any movable object. This solution is based on determining true meridian by zero value of linear acceleration induced created by changing the projection of the vector of linear velocity, caused by rotating any heavenly body, in particular, the terrestrial globe. The determination is implemented in compact variant only by the devices located on the movable object without any necessity of using induced radiations, quickly and accurately without any necessity of knowing the coordinates of location and the speed of movement irrespective of weather conditions, transverse accelerations, temperature changes and external magnetic fields influence.

Abstract: The technical solution provided enables it to determine true meridian of an unmovable object on the Earth, and when moving at constant velocity true track angle. This solution is based on fixation of true meridian by zero value of linear acceleration with induced rotating points of determining pressure around the vertical. Said determinations are implemented quickly and accurately, irrespective of the disturbing factors influence, in particular, electromagnetic and magnetic fields, weather conditions, vibrations, cross accelerations, temperature and others.

Abstract: A method and system for azimuth measurements using one or more gyro sensors is disclosed. The method includes acquiring a first data from each of the gyro sensors with an input axis aligned to a first angular orientation and acquiring a second data from each of the gyro sensors with the input axis flipped to a second angular orientation opposite to the first angular orientation. An earth rate component at the first angular orientations is determined based on a difference between the first data and the second data to cancel out bias of each of the gyro sensors. The method may include acquiring a third data of the gyro sensor with the input axis aligned to the same angular orientation as the first angular orientation. An average of the first data and the third data may be used instead of the first data for determining the earth rate component.

Abstract: An apparatus and method for compensation of the effects of various bias errors encountered by inertial rate gyroscopes, particularly vibrating element gyroscopes, configured to detect heading relative to true north. Certain embodiments are suitable for reducing rotational dynamic errors associated with rotating gyroscopes. Other embodiments may include compensation of biases not related to rotational dynamics, such as thermal drift. The various methods disclosed may also account for the bias by sampling the rotational vector of the earth at an arbitrary heading, and at a heading that is 180° offset from the arbitrary heading. The sequence may be repeated numerous times to compensate for bias drift. The bias drift may be constant with respect to time (linear) or changing over time (non-linear) during the data acquisition sequence. Some embodiments include methods that utilize data from accelerometers to infer the bank and elevation angles as well as earth latitude location relative to the equator.

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: The technical solution provided enables it to determine true meridian of an unmovable object on the Earth, and when moving at constant velocity true track angle. This solution is based on fixation of true meridian by zero value of linear acceleration with induced rotating points of determining pressure around the vertical. Said determinations are implemented quickly and accurately, irrespective of the disturbing factors influence, in particular, electromagnetic and magnetic fields, weather conditions, vibrations, cross accelerations, temperature and others.

Abstract: A gyrocompass has a gyrosphere which incorporates a rotor and floats in a liquid tank filled with an electrolyte, and a plurality of electrodes which are disposed in the gyrosphere and the liquid tank, and are respectively opposed through the electrolyte, wherein at least one circuit which supplies electric power to the rotor involves the electrodes, and the plurality of the electrodes includes a first belt-shaped electrode disposed in an equatorial portion of the gyrosphere, the first belt-shaped electrode is formed of a metal which is corrosion-resistant and is a good conductor, and an insulating film is formed on a portion of a surface of the first belt-shaped electrode.

Abstract: A gyrocompass has a liquid tank containing a supporting liquid therein, a gyrosphere floating in the liquid tank by the supporting liquid and whose central portion is rotatably supported by a center pin provided in an upper portion of the liquid tank, a gyro rotor incorporated in the gyrosphere, two dish-shaped electrodes disposed at a lower portion of the liquid tank and a lower portion of the gyrosphere, and opposed through the supporting liquid, and a pair of follow-up electrodes disposed in a vicinity of a equator of the liquid tank and opposed to be apart by 180°, and two belt-shaped electrodes disposed in vicinities of equators of the liquid tank and the gyrosphere in a state that the follow-up electrodes are located therebetween, and opposed through the supporting liquid, wherein electricity is fed to the gyro rotor through the dish-shaped electrodes and the belt-shaped electrodes.

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: 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: A device, method and computer program for generating and displaying graphical displays symbolic of current and available operational modes of instrument systems, such as navigation and autopilot systems. Accordingly, the method of the invention includes receiving a signal representative of a current mode of operation of one or more instrument systems, interpreting the current mode of operation signal to determine the current mode of operation, outputting a control signal informing a pictographic representation symbolic of the current mode of operation, and displaying the pictographic representation of the current mode of operation on a display device, such as a cockpit panel display.

Abstract: An improved method, system, and device for a compass combining an electronic magnetic compass and an angular velocity sensing gyroscope. One aspect of the invention integrates an angular velocity output signal from an angular velocity sensor or rate gyroscope to determine the angle of motion. An initial magnetic heading is obtained from a geomagnetic sensor and used as a reference for the integrated angular velocity signal. A geomagnetic heading signal is blended with the angular velocity output signal at an adaptive time interval. The adaptive time interval is increased if the reliability of the magnetic field improves and decreased if the reliability of the magnetic field degenerates. Additionally, dynamic calibration of the angular velocity sensor may be performed to correct for gyroscope bias (zero offset), and/or gyroscope scale factor or gain.

Abstract: A survival device for use in an emergency situation includes a battery, a lamp, and a detection circuit for detecting an occurrence of the emergency situation and for switching the lamp to be powered by the battery when such an occurrence is detected. In one form, the detection circuit detects a presence of water along a surface of the device, with safety tools for escaping from an submerged vehicle being provided. In another form, the detection circuit detects a failure of electrical service within a building, with safety tools for escaping a fire being provided.

Abstract: Wellbore survey methods and apparatus for wireline and measurement-while-drilling operations are disclosed which include a gyroscope, wherein the gyroscope has a spin axis, aligned with the instrument axis, and further having two sensitive axis orthogonally related to the spin axis and to each other. In addition, the wellbore survey apparatus contains a drive means, functionally connected with the gyroscope, to rotate the gyro about the instrument axis. The wellbore survey apparatus also contains a set of accelerometers, wherein the sensitive axis are aligned orthogonally to each other, and said drive means is functionally connected to the accelerometers to rotate the accelerometers about the instrument axis. Sensors determine the azimuthal direction of inclination of the wellbore at a first location therein and while traversing from said first location.

Abstract: An angle detection device with a data transmission path on an n·360° bearing assembly with at least one scanning disk (21) arranged on one of two components at right angles to the axis of rotation, and with electro-optical illumination and detection means on the respective components held together by the bearing assembly, for scanning the instantaneous angle of the scanning disk (21), wherein electro-optical data transmission means are provided on said scanning disk (21) and on a surface opposite said scanning disk (21).

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: A gyrocompass having a capsule, mounted to float in an air-tight fashion, for at least one electrically driven gyro. The capsule is produced from two mutually adapted shells which are sealed with respect to one another and consist of a high-strength, corrosion-resistant material which is a good electrical conductor. A steel alloy, titanium alloy, or a high-strength conducting plastic material is suitable. The device avoids electrically insulated bushings on the bottom and edge sides, substantially simplifying the configuration of an equatorial azimuthal tap. The mechanical stability of the capsule is conspicuously improved, and the official HSC requirements for fast ships are readily met.

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: To provide a gyro compass for the use of a high speed ship, in a gyro compass of the type having north-seeking means which is applied to support a gyro sphere or gyro case immersed in a liquid in a tank, a substantially first-order lag filter is provided in an azimuth follow-up loop or a damping loop, the substantially first-order lag filter having a time constant T.sub.F which is approximately equal to a ratio C/k.sub.T of the viscosity torque coefficient C to the twisting torque coefficient k.sub.T of the torque produced between the tank and the gyro case. A speed error correcting means has a substantially first-order lag filter having a time constant which is approximately equal to that of the north-seeking means, and is applied to correct the output of azimuth indicator by a speed error correcting angle through the substantially first-order lag filter.

Abstract: A method of installing a compass system includes the steps of mounting the electronic compass in a vehicle, coupling the electronic compass to a power source of the vehicle, downloading precalibration data into the electronic compass after the electronic compass has been mounted in the vehicle, and initiating a precalibration routine in the vehicle that is headed in a predetermined direction. The method may further include the steps of identifying characteristics of the vehicle and selecting precalibration data corresponding to the identified vehicle characteristics. The precalibration data selected corresponds to a make and model of the vehicle in which the compass may be installed and further may correspond to sets of vehicle options that may affect vehicular magnetism. If the electronic compass is provided as part of a trip computer, the precalibration data is preferably downloaded at the same time that the fuel tank size is downloaded into the trip computer.

Abstract: An engineering drawing plotter includes a feed roller for moving paper lengthwise bidirectionally with respect to one or more plotting pens. A counter installed on the plotter includes a pulse switch for measuring absolute lengthwise paper displacement, a direction transducer for determining paper movement direction, and a counter responsive to the measuring device and direction indicating device, for determining and displaying cumulative net paper displacement.

Abstract: An inertial sensor arrangement comprises a fiber gyro which responds to the horizontal component of the angular rate of the earth. A fiber coil of the fiber gyro is arranged at a positioning frame which is supported for rotation about a vertical axis relative to a housing. The positioning frame can be rotatably adjusted and mechanically locked into three fixed positions. Signals obtained thereby provide a measured value of the angle formed between a reference direction and north. Inclination sensors are provided for determining the inclination of the inertial sensor arrangement. The fiber coil inclusive of the positioning frame and two inclination sensors are mounted at a rigid sensor block which is connected to the housing in heat insulating manner.

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: A process and algorithms to determine and correct for the error in azimuth alignment and the errors in "North" and "East" Gyro Drift Rates in an inertial navigator which has been aligned via gyrocompassing, or via the "Stored Heading" technique, with the system "at rest". The process and algorithms may be implemented as an automatic sequence within the system computer to determine and correct the system errors thus determined. These actions make the inertial navigator more accurately represented by the model of an ideal navigation system with a pure and singular initial azimuth misalignment error. Thus the inertial navigator's inital azimuth misalignment error can be more accurately determined and corrected by the model.

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: A first liquid container has therein a level control including a float valve, a storage tank or second container and a third container having therein a liquid which is maintained at a fixed liquid level. The third container is connected to the liquid in the first container by the float valve, and is replenished by the liquid in the storage tank. Preferably the storage tank is designed as an evaporator, with a condensate separator plate or surface arranged above the third container which also has an overflow to the storage tank. A temperature stabilizer keeps the liquid in the first liquid container at a temperature above ambient, and the storage tank is in contact with the liquid in the first container to be warmed thereby, and the condensate separator is cooled by ambient air.

Abstract: In a ribbon suspended meridian gyroscope in which the gyroscope restoring moment is compensated by a compensating moment, which compensating moment is measured, a North reference angle is determined from a number of different measurements taken in various azimuthal positions. In order to shorten the total measurement time required, for each current individual measurement, the degree of accuracy required for this current individual measurement is determined from the measurement results of the previous measurements in accordance with the magnitude of the effects caused by an error of the individual measurement upon the error in determining the direction of North. The current individual measurement is then carried out to this degree of accuracy. In this manner, each individual measurement is only carried out to the degree of accuracy which corresponds to the weight of this individual measurement in the total error-budget for the North-determination for the respective North reference angle.

Abstract: A gyro compass having a gyro case housing therein a gyro and supported with freedom of three axes, functions for outputting a signal corresponding to an inclined angle of the gyro spin axis relative to the horizontal plane, and a function for applying a torque around a vertical axis of the gyro case in proportion to an input signal. A controller is supplied with a signal corresponding to the inclined angle and a latitude value at which the gyro compass is located, and a constant relative to the input latitude value is determined by the controller after the gyro compass is energized. A signal, resulting from differentiating the signal corresponding to the inclined angle during a predetermined time, is added to the product of the signal corresponding to the inclined angle and the constant. This added signal functions as the input signal for the gyro, whereby a constant optimum north-seeking movement is carried out regardless of the change of the latitude value.