Advances in Gyroscope Technologies

BASIC CONCEPTS OF FLIGHT MECHANICS.

Advances in Gyroscope TechnologiesMr. PRUTHVIRAJ A1BI14MMD081st Semester M. Tech in Machine Design

Guided byDr. B. N. RAVIKUMARProfessor, Department of Mechanical Engineering Bangalore Institute of Technology Bangalore

BANGALORE INSTITUTE OF TECHNOLOGYDepartment of Mechanical Engineering Post Graduate Studies

M. Tech in MACHINE DESIGNBatch-2014-2016Mr. PRUTHVIRAJ A1BI14MMD08May -June- 2015

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The device for measuring or maintaining orientationClassification based on working principle

The GyroscopeTypePrincipleSpinning mass Gyro Conservation of angular momentumVibrating gyro Coriolis effectOptical Gyro Sagnac effectSuperfluid gyro Quantum PrincipleNuclear Magnetic Resonance Gyro Magnetic effect



Spinning mass gyroscopeThe spinning mass tend to resist any change in its angular momentum and hence orientation. LimitationsSize, weight, priceBearing Friction and wearShock and vibration sensitiveHigher initialization timeHigher power consumption

Fig.1: Spinning mass gyro



Vibrating gyroscopesIt works on the principle that a vibrating mass remains in the same plane even though the base is movedThe frequency is chosen close to resonance such that large amplitudes of vibration are observedAnim.1: Halteres in some two winged insectsact as gyroscope



MEMS GyroMicro-mass connected to housing through springsThe housing connected to fixed circuit board by set of secondary orthogonal springsThe motion is measured as a change in capacitanceMEMS commercially available and inexpensive and small in size

Fig.2: MEMs Gyro Construction



Bosch MEMs Gyro Sensor

Anim.2: Bosch Vehicle stability control system utilizing MEMS Gyro



Hemispherical Resonator GyroDriven by electrostatic forces generated by electrodesRequire very high Q-FactorIt is not sensitive external environmental perturbations & vibrations, accelerations and shocksIt requires sophisticated manufacturing tools. Fig.3: Hemispherical Resonator Gyroscope or wine-glass gyroscope or mushroom gyro



Optical GyroInterferometry techniquesPrinciple constancy of speed of lightStationary source and moving source path difference Sagnac effectThe path phase difference angular velocity

Fig.4: Principle of Optical Gyro



Ring Laser Gyro (RLG)It is active (laser is resonator) gyroLaser is guided by mirrorsCommonly used is He-Ne LaserNotable ApplicationsAgni III, Shaurya missile, HAL Tejas, Boeing 777, Airbus A320Limitationslarge size and weight Fabrication and cost

Anim.3: Principle of Laser Ring Gyroscope



Optic Fiber Gyroscope (FOG)AdvantagesPropagation medium doesn't have any effectInsensitive to vibration, noise and shockLong Life No moving partsLimitationsEnvironmental effects (Temperature)Length Vs. Sagnac effect

Fig.5: Principle of Optic fiber gyro



Superfluid Gyro

Fig.6: Principle of superfluid Gyro



Nuclear Magnetic Resonance GyroIsotopes Nuclei non-zero overall spin angular moment & magnetic moment parallel to it. Exposure to external magnetic field not parallel to the magnetic moment precession of spin axis about external field

Fig.7: Construction of NMR Gyro



TypePerformanceCostSizeMechanical*****ExpensiveLargeOptical*****ModerateModerateVibration***CheapSmall

Comparison of GyroscopesOptical Gyro are suited for Higher Performance applications such as in Inertial NavigationVibrating Gyroscopes are suite for low cost applications such as in Smartphones where performance is not a major factor



ApplicationsConsumer ElectronicsGamingSports trackingToysSmartphonesInertial Navigation SystemsStability controlIndustrial Robotics and Precision MachineryOptical Image stabilization



Inertial Navigation systemsAnim.4: Applications to Submarine, Ships and Space Vehicles



Optical Image Stabilization

Anim.5: Gyro Controlled helicopter for Photography. Anim.6: Manually handled Camera for Photography



Robotics and MachineryUsed in machinery for precise motion controlsAnim.7: Robots without (Left) and with(right) gyro



Stability Control

Anim.10: Ryno Motors MonocycleAnim 11: The McLean Wheel



THANK YOU



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Advances in Gyroscope Technologies