FIBER OPTIC GYRO / THEORY & APPLICATIONS Yves PATUREL, MELAHA - PowerPoint PPT Presentation

FIBER OPTIC GYRO / THEORY & APPLICATIONS Yves PATUREL, MELAHA Alexandria, September 2014

2 Contents  Long term navigation key parameter  FOG principle  Key orders of magnitude  Key features  Comparison with other technologies  IXBLUE catalog examples Melaha laha 2014 14 Alexand andria ria

3 Earth rotation vector module error Composite bias : bias + effect of scale factor error on module Composite bias Earth Rotation Melaha laha 2014 14 Alexand andria ria

4 Earth rotation vector module error Composite bias : bias + effect of scale factor error on module Composite bias Earth Rotation Melaha laha 2014 14 Alexand andria ria

5 Longitude error during a 60 hour navigation Melaha laha 2014 14 Alexand andria ria

6 FOG - Sagnac effect NO ROTATION Opti ptical cal Coupler er COI Opti ptical cal Optical Fiber er source Coil Optical Optical detecto tor detecto tor Modulation Modulation Detecti tion Detecti tion « All All-Digita tal » « All All-Digita tal » Module Module Module Module Proces essing Proces essing Functi tion Functi tion Digit ital al Signal l Digit ital al Signal l Process essing ing Process essing ing Melaha laha 2014 14 Alexand andria ria

7 FOG - Sagnac effect Opti ptical cal Coupler er COI Opti ptical cal Optical Fiber er source Coil Optical Optical detecto tor detecto tor Modulation Modulation Detecti tion Detecti tion « All All-Digita tal » « All All-Digita tal » Module Module Module Module Proces essing Proces essing Functi tion Functi tion Digit ital al Signal l Digit ital al Signal l Process essing ing Process essing ing Melaha laha 2014 14 Alexand andria ria

8 Response of the interferometer Melaha laha 2014 14 Alexand andria ria

9 The « sensing sub-assembly » One fundamental principle : reciprocity Melaha laha 2014 14 Alexand andria ria

10 Single-axis fiber gyro Melaha laha 2014 14 Alexand andria ria

11 Light source Er Er-do doped ped fiber er 980 980nm laser er FBG Isolat olator or 1550 50 nm nm 980 0 nm nm Melaha laha 2014 14 Alexand andria ria

12 Some interesting orders of magnitude  Best present results for fiber gyro :  Wavelength : l = 1550 nm Fiber length L  few km  few 10 9 l Bias stability : 0.001 deg/h over 28 deg/second ( p phase shift) i.e. 10 -8 of the wavelength  Relative detection of optical path length : few 10 -18 !  With a relative variation of 7 x 10 -6 / º C for light velocity in the silica fiber !  RECIPROCITY (perfect common-mode rejection) Melaha laha 2014 14 Alexand andria ria

13 Actual configuration of a fiber gyro Multi-function Broadband Light Source IOC Fiber Coupler Coil Detector Digital A D Logics / / D A Rotation signal  Polarization-preserving fiber coil with typically 100 m to 10 km (manufactured by iXBlue).  Proton-exchanged LiNbO 3 integrated-optic circuit very high polarizer rejection (manufactured by iXBlue).  Y-junction and pair of push-pull low-voltage phase modulators.  Broad-spectrum source : unpolarized erbium ASE source for best performance (manufactured by iXBlue).  All-digital processing electronics (invented by iXblue). Melaha laha 2014 14 Alexand andria ria

14 FOG comparison with other technologies  FOG has no lock-in zone Always true in open-loop design.  In closed loop design, no dead zone in principle, but a “dead zone “ may appear  if electronics design is not perfect (cross talk between modulation & detection chains) In RLG (Ring Laser Gyro), lock-in is by-passed with dithering : this increases  ARW, and provides acoustic noise  FOG has not (yet ?) reached a performance limit , while RLG faces a “non reciprocity” Melaha laha 2014 14 Alexand andria ria

15 FOG is easily scalable OCTANS PHINS MARINS QUADRANS AHRS INS INS IMU 50 IMU 90 IMU 120 IMU 200 Average Diameter (mm) 45 68 94 171 Bias Stability* ( ° /h) 0,05 0,025 0,01 0,001 Typical ARW (10 -4 °/√h) 60 35 10 2 * Bias stability over the temperature range, -10 to +80 ° C à 1 σ Melaha laha 2014 14 Alexand andria ria

16 FOG 50 IMU 50 Melaha laha 2014 14 Alexand andria ria

17 FOG 50 APPLICATIONS  Marine and Navy IMO gyrocompass  Land survey, stabilization  Military land navigation  Airborne survey Melaha laha 2014 14 Alexand andria ria

18 FOG 90 OCTANS ADVANS LANDINS Melaha laha 2014 14 Alexand andria ria

19 FOG 90 APPLICATIONS  Navy & marine gyrocompass  Land survey  Military land navigation  Artillery (qualified on 105 mm gun) Melaha laha 2014 14 Alexand andria ria

20 FOG 120 PHINS ADVANS ASTRIX 120 Melaha laha 2014 14 Alexand andria ria

21 FOG 120 APPLICATIONS  Navy & Marine navigation system  Land military navigation  Artillery (on 155 mm gun)  Airborne survey Melaha laha 2014 14 Alexand andria ria

22 FOG 200 MARINS ASTRIX 200 Melaha laha 2014 14 Alexand andria ria

23 FOG 200 APPLICATIONS  Submarine navigation and high-end surface vessels Melaha laha 2014 14 Alexand andria ria

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25 Construction complexity decreases Computing complexity increases Melaha laha 2014 14 Alexand andria ria

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28 CONCLUSION  FOG technology is very reliable, very robust and has extremely long life time  44 FOG axes are on orbit around Earth cumulating more than 9300000 hours (106 years) without failure  FOG technology provides navigation for many marine applications : Reliable and no maintenance gyrocompass,  Low power consumption inertial navigation system (especially suitable for AUV)  High performance navigation system for surface vessels and submarines  Melaha laha 2014 14 Alexand andria ria

29 اركش Come and visit visit us at at our our booth booth in exhibi biti tion on hall Melaha laha 2014 14 Alexand andria ria