Fibre Optic Gyroscopes for Inertial Navigation
Inertial navigation systems are critical for the measurement of heading and position used for GPS unassisted navigation. Sensors, such as optical gyroscopes, represent the current state-of-the-art in terms of sensitivity and are ubiquitous to most high-performance commercially available navigation systems. With the recent developments in autonomous vehicles, the development of sensors for inertial navigation systems has pushed toward developing high performance sensors able to maintain a low per unit cost.
At the Applied Metrology Laboratory, we leverage digital interferometric methods to develop high performance, low cost fibre optic gyroscopes. Digital interferometry, by introducing a layer of digitally controlled optical coherence, can circumvent several technical limits which restrict the development of current optical gyroscopes - the most immediate of which is Rayleigh backscattering. We also draw on the multiplexing capability of digital interferometry to track multiple synthesised interferometers using the same optical hardware, enabling the system to self-calibrate and obtain long-term stability.
Work in this area is highly targeted towards developing a commercially viable prototype. Due to the close knit collaboration between multiple academic and industry partners, we are able to leverage expertise in mechanical design, electronics and optical miniaturisation as well as feedback from industry end-users to ensure that the final optical system is fit for purpose.
A fibre optic gyroscope prototype developed in collaboration with our industry partners. The orange disc is a potted fibre optic spool – optical fibre encased in resin for mechanical and thermal stability. The surrounding case is a metal construction resistant to parasitic magnetic fields.