Showing papers on "Gyroscope published in 1969"

Angular rate coordinate transformer

Abstract: Apparatus for converting signals representing rates of change of the angular position of a body with respect to its own axes to Euler angle rates of change utilizing three resolvers and two feedback paths so as to avoid practical difficulties equivalent to the ''''gimbal-lock'''' problem in the gyroscope art.

Experimental strapdown redundant sensor inertial navigation system

Abstract: Strapdown redundant experimental sensor inertial navigation package containing gyros and accelerometers, discussing signal real time processing by digital computer

A gyroscopic seismometer: Measurements during the borrego earthquake

Abstract: The gyro seismometer, consisting of two counter-rotating pendulous Nordsieck gyroscopes, permits separation of tilts from horizontal motion. Sensitivity is limited by the accuracy with which the gyro orientation can be measured, ∼1 arcsecond rms in a 0.5 Hz bandwidth. This instrumental noise level is equivalent to ground tilts of ∼1 arcsecond and ground velocities of ∼0.1 cm/sec. Peak values in the instrumental pass band (0 to 0.5 Hz ) of the tilt and horizontal velocity during the Borrego Mountain, California, earthquake of April 9, 1968, were 1 cm/sec and 10 arcseconds respectively. In La Jolla, 115 km from the epicenter, the static displacement and tilt were less than 1 cm and 0.1 arcsecond (5 × 10−7 radian).

A linearization tool for use with matrix formalisms of rotational dynamics.

Abstract: Rotational dynamics equations in linearized matrix form applied to satellite librations in circular orbit and gyroscope motion

Target locating system

Abstract: A receiving system including a mirror mounted on a pair of gimbals to direct light to a stationary detector, wherein the inner gimbal is driven from a drive shaft which rotates at twice the speed as the mirror and in the same direction. Gyroscopes and position transducers are mounted on the drive shaft.

Submersible water bicycle

Abstract: A submersible water bicycle is provided for use by scuba divers, and others, so that they may propel themselves easily and comfortably beneath the surface of the water at any desired depth The vehicle includes an inertial wheel which may be brought up to speed to provide a measure of momentum to the vehicle and a gyroscope effect to maintain the vehicle in a desired angular position with respect to its longitudinal axis

Effect of the earth's quadrupole moment on the precession of a gyroscope

Abstract: It is shown that there is a contribution to the precession of a gyroscope due to the quadrupole moment of the Earth. The magnitude of this additional precession is a maximum for a gyroscope in a satellite in equatorial orbit around the Earth at a moderate altitude, and exceeds the experimental error for observations which cover a span of about one year or greater.

Hydrostatically supported gyroscope, a combined centrifugal and viscous shear rotary pump

Abstract: A combination in a hydrostatically supported gyroscope of a centrifugal and viscous shear rotary pump of a disc impeller type with extremely shallow spiral grooves fabricated in both sides of the disk and in close proximity to smooth stator surfaces so as to cause a high viscous shear in a low-viscosity fluid to effect an improved pressure rise in the spiral grooves as the disk rotates in a sense aiding in a centrifugal pumping action of the impeller disk. In operation, the disk floats hydrodynamically between the stator faces and on a center journal bearing so that there are no wear points during operation of the rotary pump which is particularly adapted for use in an arrangement for supplying fluid pressure to hydrostatically supported bearings of the gyroscope.

Minimizing frequency locking in ring laser gyroscopes

Abstract: A ring laser gyroscope utilizes a pair of oppositely rotating beams which are given a difference frequency in accordance with the rotation rate of their optical paths. A plurality of frequency modulated bias signals are imposed upon the beams, the modulation indices of these frequency modulation signals being chosen to minimize the effects of frequency locking at low rotation rates.

Stability characteristics of gyroscopes with hydrodynamic-grooved rotor bearings

Abstract: Stability characteristics of two degree of freedom gyroscope having hydrodynamic grooved journal rotor bearings, discussing frequency of self excited oscillation

Two-resolver, strapped-down inertial reference system

Abstract: The strapped-down reference system attains the equivalence of a three- and four-gimbal, inertial reference system by using a forward resolver chain, which can be of relatively low accuracy, to derive gimbal angle values, and high-accuracy feedback resolvers to derive signals to cage the gyroscopes. The gyroscopes are caged by pulse torque techniques and integration of angular rates is performed in an essentially digital fashion by pulse generators and stepping motors.

Motion in a Schwarzschild Field I. Precession of a Moving Gyroscope

Abstract: A simple hypothesis is used to obtain, in lowest order, the precessional angular velocity of a slowly moving gyroscope in a Schwarzschild gravitational field. The hypothesis is that, at least to first approximation, the motion of the spin vector in a small displacement is the sum of two effects: (1) the motion the spin would have if it moved by parallel transfer in the curved 3-space, and (2) the motion of the spin as calculated directly from the principle of equivalence, treating the gravitational field in the vicinity of the gyroscope as though it were uniform. The precessional angular velocity obtained is in agreement with the general relativistic result. In another paper it will be shown that the same hypothesis also leads to the general relativistic result for the lowest order deflection of light by the central mass. These derivations are useful because they help to show how the motion of the spin vector can be understood from a 3 + 1 dimensional viewpoint.

Magnetically-tuned resonant gyroscope

Abstract: A ''''tuned'''' gyroscope having spring restraints, which is tuned to resonance by a restoring torque produced by hysteresis motor windings which also spin the gyro rotor.

Stop assembly for a gyroscope

Abstract: A STOP ASSEMBLY FOR A GYROSCOPE HAVING A UNITARY MASS MEMBER ROTATED BY MEANS OF A DRIVE SHAFT AND CONNECTED TO THE SHAFT BY MEANS OF A FLEXIBLE CONNECTION MEMBER TO PERMIT UNIVERSAL TILTING MOVEMENT BETWEEN THE MASS MEMBER AND THE SHAFT MEMBER. A STOP MEANS IS MOUNTED WITH RESPECT TO A LEAST ONE OF THE MEMBERS AND IS ADAPTED TO ENGAGE ANOTHER OF THE MEMBERS TO STOP THE TILTING MOVEMENT AFTER A PREDETERMINED AMOUNT THEREOF.

Erection cutoff system for plural gyroscopes

Abstract: A system for ensuring that the long term erection sensors of a plurality of gyroscopes installed in the same aircraft and providing substantially identical attitude reference information are cut off simultaneously to thereby reduce discrepancies in the information supplied by each of the gyroscopes due to tolerances in the cutoff thresholds of the long term reference sensors of each gyroscope.

Liquid armature induction pump for an electrically conductive liquid to support a gimbal element of a gyroscope in a hydrostatic bearing

Abstract: A liquid armature induction pump including a stator, liquid armature tube and magnetic shunt for pumping electrically conductive liquid such as mercury so as to hydrostatically support a gimbal element of a gyroscope in a hydrostatic bearing.

Analysis and evaluation of a novel inertial navigation system

Abstract: sensors. The theory of the system mechanization is develop ed from first principles and methods for calculation of the system loop gains are presented. First, a single-axis system is considered and then the analysis is generalized to a three-axis system. The analyses performed indicate that error propagation for the novel system and the conven tional system are identical for identical error sources. It is also shown that the RAMP base motion isolation syste provides a better gyro environment than that used in a con ventional system since the level gyros are not required in the gimbal servo loops. Reports of flight tests of this system corroborate these conclusions. SUMMARY A novel inertial navigation system referred to in the literature as the RAMP inertial navigator is analyzed and then compared to a conventional local vertical navigation system. The main attraction of this system is that it is capable of indicating the vertical using only gyros as sensors, The theory of the system mechanization is developed from first principles and methods for calculation of the system loop gains are presented. First, a single-axis system is considered and then the analysis is generalized to a three-axis system. The analyses performed indicate that error propagation for the novel system and the conventional system are identical for identical error sources. It is also shown that the RAMP base motion isolation system provides a better gyro environment than that used in a conventional system since the level gyros are not required in the gimbal servo loops. Reports of flight tests of this system corroborate these conclusions. fulfillment of the requirements for the degree of Master of Science.

Designing differentiating and integrating gyroscopes and accelerometers

Abstract: : The book covers the fundamentals of analysis and designing of differentiating and integrating gyroscopes and accelerometers and an analysis of their errors under different operating conditions is given. Simple calculation formulas for determination of the basic parameters of these instruments and also their instrumental and methodical errors are given. Depending upon the assignment of the instrument, requirements for static, dynamic, and accuracy characteristics are shown. Much attention is given description of the physical essence and causes of appearance of the examined errors. (Author)

Stabilized direction sighting device

Abstract: A SIGHTING DEVICE FOR MAINTAINING THE IMAGE OF A POINT AT INFINITY IN A FIXED POSITION ON THE RETICLE OF A TELESCOPE DESPITE MOVEMENTS OF A VEHICLE ON WHICH THE SIGHTING DEVICE IS MOUNTED. IT COMPRISES A GYROSCOPE THE AXIS OF WHOSE ROTOR REMAINS DIRECTED TOWARD THE POINT AT INFINITY, AN INNER FRAME WHICH IS MOUNTED FOR VERTICAL SWINGING MOVEMENT ABOUT A HORIZONTAL AXIS THAT PASSES THROUGH THE AXIS OF ROTATION OF THE ROTOR AND WHICH CARRIES THE ROTOR, AN OUTER FRAME WHICH CARRIES THE INNER FRAME AND WHICH IS MOUNTED FOR ROTATION ABOUT A VERTICAL AXIS THAT PASSES THROUGH THE AXIS OF ROTATION OF THE ROTOR AND THE HORIZONTAL ROTATIVE AXIS OF THE INNER FRAME. AT LEAST ONE REFLECTIVE SURFACE IS CONNECTED TO AT LEAST ONE OF THE FRAMES OF THE GYROSCOPE IN SUCH A WAY THAT THE REFLECTIVE SURFACE SENDS LIGHT FROM SAID POINT TO THE OBJECTIVE OF THE TELESCOPE IN WHICH THE RETICLE IS FIXED, ALONG A LINE PARALLEL TO SAID VERTICAL AXIS.

In a hydrostatically supported gyroscope a flexible tube pump providing fluid circulation to hydrostatic bearings of the gyroscope

Abstract: A combination in a hydrostatically supported gyroscope of a flexible tube pump of a Bourdon tube type in an assembly including a motor means or electrically controlled solenoid to actuate the flexible tube in an arrangement in which the tube functions as a low power input pump which may be utilized to supply a liquid pressure medium to hydrostatically support bearings of the gyroscope.

Flight aid systems

Abstract: A flight aid system is provided for an aircraft having a control system in which two parallel control rods move together in the same or in opposite directions to control movement of the aircraft about a first or a second control axis respectively. The system includes, for each control rod, a closed-loop autostabilizer including a rate gyroscope. The two rate gyroscopes are mounted with their sensitive axes coplanar with the two control axes and displaced by equal and opposite angles about the second control axis.

Transducer pick-up mechanism

Abstract: AN IMPROVED PICK-OFF MECHANISM FOR A TRANSDUCER SUCH AS AN ACCELEROMETER OR GYROSCOPE COMPRISING A FLEXIBLE CANTILEVERED SHAFT MOUNTED ON A SUPPORT, A FLLOWER ON THE UNSUPPORTED END OF THE SHAFT, A SENSIN DEVICE FOR SENSING MOVEMENT OF THE FOLLOWER UPON FLEXING OF THE SHAFT, AND CONNECTING MEANS FOR FIXING THE SENSING DEVICE TO THE SUPPORT INDEPENDENTLY OF OTHER STRUCTURE.

Design of Strapdown Gyroscopes for a Dynamic Environment Interim Scientific Report II

Abstract: Error analysis for single degree of freedom integrating gyro, and figure of merit relating gyro errors to orientation error of strapdown inertial reference system

Strapdown Miniature Electrostatic Gyro /SDMEG/ development and evaluation Final report, 1 Jun. 1965 - 28 Mar. 1969

Abstract: Feasibility study for strapdown electrically suspended gyroscope in attitude reference system for spacecraft

Air-driven gyroscope erection system with seal-free gimbal connections

Abstract: AN ERECTING SYSTEM FOR A VERTICAL GYROSCOPE USEFUL IN AIRCRAFT ATTITUDE-INDICATING INSTRUMENTS AND THE LIKE. A GIMBAL-SUPPORTED HOUSING IN THE GYRO ENCLOSES A GYRO ROTOR, AND IS SUPPLIED WITH AIR WHICH DRIVES THE ROTOR. AIR IS EXHAUSTED FROM THE HOUSING THROUGH FOUR DOWNWARDLY DIRECTED OUTLET PORTS AT THE CORNERS OF THE HOUSING UNDERSURFACE. CONTROL VANES ARE PENDULOUSLY SUPPORTED ON THE HOUSING AND EXTEND BENEATH THE OUTLET PORTS TO INTERCEPT THE EXHAUST AIR STREAMS AND THEREBY IMPART TORQUES TO THE GYROSCOPE TENDING TO ERECT THE ROTOR SPIN AXIS A SUBSTANTIALLY VERTICAL POSITION. AIR PASSAGES THROUGH OUTER AND INNER GIMBALS SUPPLY AIR TO THE HOUSING, AND THE PASSAGES ARE CONFIGURED SO A PRESSURE DIFFERENTIAL EXISTS ACROSS A ROTARY CONNECTION BETWEEN THE INNER AND OUTER GIMBALS. A PRESSURE DROP OCCURS GOING FROM THE OUTER GIMBAL TO THE INNER GIMBAL OR ROTOR HOUSING, WHEREBY AIR DELIVERED TO THE ROTOR DOES NOT TEND TO LEAK OUTWARDLY THROUGH THE ROTARY CONNECTION AND THE NEED FOR BULKY AND FRICTIONPRODUCING SEALS IS ELIMINATED.

Some aspects of gyroscope stability and dynamic response

Abstract: The thesis describes the results of some investigations into the causes of instability in free gimbal-mounted gyroscopes. Considerable use has been made of analogue and digital computation to isolate the effects of various types of reaction forces which may occur in the spin axis bearings, and the effect of rotor asymmetry is also considered. Rotor asymmetry and variation of radial stiffness in the spin axis bearings were both found to give rise to I inear differential equations with periodic coefficients, and an analytical procedure of general applicability has been developed for obtaining the width of the unstable zones and the degree of instability at the parametric resonances. This procedure gives excellent agreement with the results of direct computer solution of the equations of motion. Slackness in the spin axis bearings of a gyroscope did not appear, per se, to produce instability. It may do so, however, as a secondary effect since forces which otherwise would be negligible become significant when other restraints on shaft displacement are removed. Tangential forces in the spin axis bearings in either direction were found to produce instability but different modes of vibration were excited according to the direction of the forces. The effect of cage accelerations in the spin axis bearings has been considered and has been shown to be small. Likewise, transverse couples which arise due to non uniformity of the motor magnetic field when the rotor tilts relative to the stator, have been shown to be negligible. Shaft and bearing compliance has also been considered, mainly from the point of view of natural frequency and frequency response to externally applied torques. Bearing eccentricity has been shown to cause a forced nutation at the frequency of rotation of the ball cage, giving rise to a simple resonance if this frequency should coincide with a natural frequency of the gyro. Experimental work has been carried out with a view to establishing the nature of the dynamic forces and deflections in the spin axis bearings. Because these are of such small amplitude and of such a complex waveform, analysis of the experimental results has proved difficult. Sinusoidal forcing of a casing containing a gyro rotor in order to obtain the frequency response of the shaft and bearing deflections was moderately successful while the rotor was stationary but no readings were possible with the rotor running because of a seemingly random variation in the response.