Typically FOGs are not used for aircraft navigation because this application requires a high immunity to external perturbations. Recently a FOG-based IMU has been used for inertial navigation of rovers vehicles developed by NASA for Mars exploration. For example, a FOG exhibiting bias drift around 0.001 °/h has been used in the Pleiades satellites for Earth Observation.
![fiber optic gyroscope fiber optic gyroscope](https://www.unmannedsystemstechnology.com/wp-content/uploads/2020/01/fiber-optic-gyro-vg1703spe-e1611570651578-300x177.jpg)
FOGs have been used in applications requiring medium and low performance such as robotics and automotive, but also in space applications, which require high or very high resolution. For example, bias drift typically ranges from 10 to 0.0002 °/h. Despite a considerable research amount during the last decades, FOG has not yet superseded the He–Ne RLG because of the large existing RLG-based industrial infrastructure and the FOG higher sensitivity to external perturbations (temperature changes, vibrations and so on).įOG performance can be very high, but also medium and low, depending on the used fiber and on the accuracy of the read-out optoelectronic system. The exploitation of optical fibers to realize an optical angular rate sensor was investigated with the hope of reducing cost, simplifying the fabrication process and increasing accuracy with respect to the He–Ne RLG. ➨Linearity and scale factor stability of gyroscope are easily deteriorated due toįluctuations in the intensity of incident light on the photodetector.In the late 1960s, the development of the fiber optic gyroscope (FOG) was started at US Naval Research Laboratories, Washington (USA) (Brown RB, NRL Memorandum Report N1871, 1968). Phase difference due to the Sagnac effect. ➨Detectable angular velocity is limited to +/- π/2 rad with respect to the The impact can be mitigated when multiple-axis FOG is coupled witn ➨Some designs of FOG are sensitive to vibrations. Drawbacks or disadvantages of Fiber Optic Gyroscopeįollowing are the drawbacks or disadvantages of Fiber Optic Gyroscope: ➨It offers same compactness and cost like ring laser gyroscope (RLG) and MEMS gyroscope. ➨It offers high performance due to its inherent low random noise. Moreover it does not need any preventive maintenance. It is highly raliable and offers longer life time. ➨Since it is a solid state device with no moving part nor sealed cavity. Its rotational sensitivity is superior (~ 0.1 o/Hr) andįaster compare to conventional gyroscope. Poles based on measurements of angular velocity only. Hence it helps in determining direction of the Earth's When used along with accelerometer, it provides accurate path of flight or movement of vehicle or the object.īenefits or advantages of Fiber Optic Gyroscopeįollowing are the benefits or advantages of Fiber Optic Gyroscope:.The phase shift of fiber optic gyroscope is expressed as follows. The figure-2 depicts circular loop of fiber.Navigation, guidance and control of missiles, aircrafts, robots, automobiles, spacecrafts etc. It is also known as fiber optic rotation sensor.The Sagnac effect depends on effective area of the closed optical path.
![fiber optic gyroscope fiber optic gyroscope](https://images.marinetechnologynews.com/images/maritime/w1200h1200/image-courtesy-advanced-123066.jpg)
The resultant differential phase shift is measured using interferometry in FOG. Due to Sagnac effect, the light beam travelling against the rotationĮxperiences a slightly shorter path delay compare to the other light beam.
![fiber optic gyroscope fiber optic gyroscope](https://www.skymems.com/export/galleries/template-45/product/Fiber-Optic-Gyro/FOG3000/Fiber-Optic-Gyroscope-FOG3000-1.jpg)
![fiber optic gyroscope fiber optic gyroscope](https://nedaero.com/wp-content/uploads/2019/03/palmofthehandsizefog-s-300x201.jpg)
Split the radiation from the light source into two counter propagating waves viz.Ĭlockwise and counter clockwise, in the fiber coil and to recombine the waves,Īfter propagation, on a photodetector (PD).