20 Years of KVH Fiber Optic Gyro Technology: The Evolution from Large, Low Performance FOGs to Compact, Precise FOGs and FOG-based Inertial Systems

1. 20 Years of KVH Fiber Optic Gyro
Technology:
The Evolution from Large, Low Performance FOGs to
Compact, Precise FOGs and FOG-based Inertial Systems
Presented by:
Jay Napoli
Vice President, FOG and
Inertial Systems Sales
KVH Industries

2. KVH Industries Overview
• Innovative technology company, ~ 600 employees worldwide
– Focused on mobile products and services
– Addressing large markets
• Guidance & stabilization systems
– Fiber optic gyros and navigation systems
• Mobile broadband satellite services
– Global high-speed Internet, television, and voice

3. Guidance & Stabilization
• Leading manufacturer of inertial navigation systems
– Based on our fiber optic gyro technology
• Military vehicle navigation systems
• Majority of FOG sales non-defense
• Exciting emerging applications
for FOGs
– Self-driving cars
– Autonomous vehicles
– Drones
– Gimbals

4. An Emerging, Evolving Technology
• FOGs and FOG-based IMUs have become critical components within an
expanding array of platforms and applications

5. KVH Fiber Optic Gyro Solutions
• Fiber Optic Gyros (FOGs)
– Versatile, stand-alone 1, 2, and 3 axis sensors
– Compact, rugged, solid-state
– Used in a broad range of applications / systems
• Inertial Measurement Units (IMUs)
– Combines 3 axes of FOGs & 3 accelerometers
– 6-degrees of freedom (1775 IMU is 9 DoF)
– Low-cost, highly reliable solutions
• Inertial Navigation Systems (INS)
– Combines an IMU with a GNSS receiver, pressure sensor and magnetometers
– Comprehensive navigation/positioning with or without satellite availability
– Full position, velocity & attitude sensing
– AHRS

6. How Did We Get Here?
• 20-year development and performance history
– The Andrew Corporation – Orland Park, IL
– Proprietary D-shaped optical fiber, with an elliptical core
– Revolutionary ThinFiber
– Innovative optical circuit design, component fabrication, and system integration
– Patented Digital Signal Processing (DSP) for improved performance
• A commitment to design, control, and quality at every step
– Tactical-grade performance
– Excellent reliability
– Compact designs
– Reasonable cost
• More than 90,000 FOGs produced

7. An End-to-End Manufacturer
• KVH fabricates 100% of its optical fiber and
fiber components
• We undertake all aspects of FOG manufacture:
– Drawing the fiber
– Manufacturing optical components out of the fiber
– Assembly of the optical circuit
– Final integration and calibration with the FOG electronics
• Complete control and ensures the highest level
of quality
– ISO 9001 quality certified manufacturer
– Complete traceability

8. KVH Open Loop Design
• KVH Open Loop Fiber Optic Gyros (FOGs)
– Goal: Offer a more reliable, lower cost guidance & stabilization solution
RED: KVH-manufactured polarization-maintaining, elliptical core, single mode optical fiber
GREEN: Printed circuit boards
8

9. At the Heart of the FOG – Creating Fiber
Click to Watch a Brief Tour of the KVH
Fiber Manufacturing Process

10. D-Shaped, Elliptical Core Fiber
• Polarization maintaining fiber with unique design and core
• Advantages include:
– High polarization maintaining ability (greater than 40 dB-m)
– Low sensitivity to stress and temperature
– Ideal for fiber splicing and pigtailing to other optical components
– Maintains polarization and low-loss characteristics when exposed to physical stresses and
temperature-induced changes far better than PM fiber created using stress-induced birefringence

11. Superior Optical Qualities
• D-shape fiber with elliptical core offers easy access to the light-guiding
region
– Eliminates need for grinding or polishing
• Major axis of the elliptical core is parallel to the flat of the “D”
– Allows accurate alignment of the birefringent axes
• The 1 x 3 micron elliptical core also aligns well with the 1 x 5 micron facet
of the light source, as show below
– Optimizes the core-to-facet alignment maximizes the power into the FOG’s optical circuit

12. The First Generation: 1997
• E•Core 1000 and E•Core 2000
– Available in both analog and digital variants
– Compact for their day
– Moderate but solid performance
Attribute Specification Specification
Performance E•Core 1000 E•Core 2000
Input Rotation Rate ± 100˚/sec ± 30, 60, or 100˚/sec
Angle Random Walk 0.3˚/√hr 0.08˚/√hr
Bias Instability ≤ 20˚/hr < 6˚/hr
Scale Factor
Linearity 5,000 ppm 2,000 – 4,000 ppm
Physical
Dimensions 4.3" x 3.3" x 1.6" (109mm x 84mm x 41mm) 4.41” x 4.27” x 1.69” (112mm x 108mm x 43 mm)
Weight 0.55 lbs. (0.25 kg) 0.75 lbs (0.34 kg)

13. The Shift to Digital Signal Processing
• KVH’s patented DSP technology
– Optical output from the FOG is picked up at the detector and transformed into a voltage
– Voltage is passed through an analog-to-digital converter
– DSP approach permits analyzing and correcting this digitized data on the fly
• For Example:
– KVH FOGs monitor their internal temperature and then compensate for temperature errors by using
a lookup table stored in memory

14. 2003-2004: The DSP Family Emerges
• Substantial improvement in performance in DSP line
• Form factor roughly the size of a deck of cards
Attribute Specification
Performance
Input Rotation Rate ± 375˚/sec
Angle Random Walk ≤ 0.067˚/√hr
Bias Instability ≤ 1˚/hr
Scale Factor Linearity < 500 ppm
Physical
Dimensions 3.5" x 2.3" x 1.3" (88.9mm x 58.4mm x 33mm)
Weight 0.6 lbs. (0.26 kg)

15. 2009: Emergence of KVH’s ThinFiber
• E•Core FOGs used optical fiber with diameter of ~240 microns
• Most DSP FOGs use ThinFiber: a diameter of ~170 microns
– 30% less volume
– Enables reduction in physical size of FOGs
• Maintain or improve performance overall vs. traditional E•Core fiber
– A longer fiber length can be wound on a smaller bobbin, which translates into several improved
performance attributes

16. 2009-2010: ThinFiber-based FOGs
• The DSP-1750 introduced in 2009
– The world’s smallest high-performance FOG
– Single- and dual-axis configurations
• Revolutionary performance levels for a unit its size
– Input rates 5-10 times faster than original E•Core FOGs
– Angle random walk (ARW) 5times better than DSP-3000 series
– Bias stability is 8 times better than the DSP-3000 series
– Performance on par with larger, more expensive closed-loop
fiber optic gyros and ring laser gyros
Attribute Specification
Performance
Input Rotation Rate ± 490˚/sec (standard) or ± 1000˚/sec
Angle Random Walk ≤ 0.013˚/√hr
Bias Instability ≤ 0.1˚/hr
Scale Factor Linearity < 200 ppm
Physical
Dimensions 1.7" Dia x 0.9" H (45.7mm Dia x 22.9mm H )
Weight Single axis: 0.24 lbs (0.11 kg)
Dual axis: 0.30 lbs, (0.14 kg)

17. The DSP-1760: The Logical Progression
• Available in 1-, 2-, or 3-axis configurations
• Each FOG axis built using quadrupole winding
• Improved software and algorithms
• Higher processing power and improved
electronics
Attribute Specification
Performance
Input Rotation Rate ± 490˚/sec
Angle Random Walk ≤ 0.012˚/√hr
Bias Instability ≤ 0.05˚/hr
Sale Factor Linearity < 50 ppm
Physical
Dimensions 3.5" Dia x 2.9" H (88.9mm Dia x 73.7mm H )
Weight Single axis: 1.1 lbs (0.5 kg)
Dual axis: 1.2 lbs, (0.54 kg)
3-axis: 1.3 lbs (0.60 kg)

18. 2012: Expanding Capabilities with High-
performance Fully Integrated Systems
• KVH high-performance FOGs ideally suited for
higher level of integration within inertial systems
• The 1750 IMU introduced in 2012:
– E•Core ThinFiber
– Very low noise, solid state MEMS accelerometers
– A commercial-off-the-shelf IMU
• KVH’s 1750 IMU provides:
– Highly accurate 6-DOF angular rate and acceleration data
– Bias instability: <0.05degrees/hr
– A cylindrical package that measures only 89 mm diameter x 74 mm high
(3.5" in diameter x 2.9" high)
– Weight of <0.6 kg (less than 1.4 lbs)
• Two additional performance variants: 1725 IMU and 1775 IMU

19. 2016: Inertial Navigation Systems
• GEO-FOG 3D and GEO-FOG 3D Dual
– 1750 IMU
– 3-axis magnetometer
– Barometric pressure sensor
– Dual or triple frequency RTK GNSS receiver
– Breakthrough sensor fusion algorithms
• automatically switch from loosely- to tightly-coupled
filtering for improved performance under poor GNSS signal conditions
• What they deliver:
– Reliable, real-time, centimeter-level positioning and orientation measurements
– High-speed update rates
– Rapid north-seeking gyrocompass capabilities
– GEO FOG 3D Dual: Ideal for high-accuracy heading in environments when magnetometers and
GNSS-aided heading cannot be used

20. Where to Now: FOG and Integrated Inertial
System Design
• The creation and implementation of a continuous flow
manufacturing process
– Eliminate the need for splicing optical components together
– Improve performance
– Reduce the manufacturing and calibration time required
• Continued research into smaller, more accurate FOGs and
FOG-based systems
• Significant cost reductions via FOG design

21. The Next Challenges
• The evolution of smaller, mass produced, low cost,
high-performance FOGs
• Solutions that support mass markets, such as automotive
• Provide a level of performance unmatched by
alternative gyro technology

22. KVH Industries, Inc.
www.kvh.com/imu