This device is mounted on one of the internal walls of a high rise building. In particular, the following gyroscope type devices are considered. Osa compensation of the laser parameter fluctuations in. Its digital io enables integration into almost any system, which is illustrated by its use in a. Rlg sigma 40 is an inertial navigation system which is based on ring laser gyro technology. This shift the sagnac fre quency can be easily measured letting the two beams beat. It operates on the principle of the sagnac effect which shifts the nulls of the internal standing wave pattern in response to angular rotation. It contains a rotor that is held between extremely free pivots. Note that the operating life, specified as,2000 hrs, is defined as time during which the gyro is economically repairable a photograph of the gyroscope is shown in figure 12. Firstprinciple treatments of the nature of quantum noise in the ring laser gyro and various methods designed to avoid lowrotationrate lockin are presented. A dynamically tuned gyro is a mechanical gyroscope.
Light takes longer to complete the journey if the path is rotating in the same direction as the light is traveling. Ring laser gyroscopes are inertial sensor based on the sagnac e. Pdf time series modeling of the ring laser gyroscopes. If the platform is rotating, one laser wavelength will become out of phase. Longterm errors result from instability of gyro compensation parameters and include the following terms. Development of control algorithm for ring laser gyroscope p. This concludes that since the source is same, the generated photons are at one specific frequency. In chapter 11 we defined the ring laser gyroscope rlg as an active resonator optical gyro. Accordingly, the hardware was designed and fabricated based on concepts existing at the time for laboratory testing applications only, and involved no development effort.
Abstract ring laser gyro rlg is a sensor to sense angular information very precisely. What links here related changes upload file special pages permanent. Large frame ring laser gyroscopes as geophysical tools. Gg20an digital laser gyro the honeywell gg20 digital. Hene ring laser gyroscopes are, at present, the most precise devices for absolute angular velocity measurements. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks. Recall that uniform linear motion cannot be detected by any means internal to the system, while uniform rotation makes a non. During any movement of the aircraft, or on other vehicle it is mounted on, the angular rate is measured by determining the frequency shift in inertial guidance use. It operates on the principle of the sagnac effect which shifts the nulls of the. Do not operate the devices outside parameters specified in the manual. Laser gyroscope experimental instructions institute of applied physics university of bern figure 1.
As it turned out, the breakthrough came from what would seem a totally unexpected quarter. Effects of rf cleaning on ring laser gyro components. The operating principles of the ring laser are developed and discussed, with special emphasis given to the problems associated with the achievement of greater sensitivity and stability. Specification and test requirements for a singleaxis ring laser gyro rlg for use as a sensor in attitude control systems, angular displacement measuring systems, and angular rate measuring systems are defined. Performance modeling of ring laser gyro in inertial.
Development of control algorithm for ring laser gyroscope. Longitudinal mode faraday rotator ring laser free spectral range gain curve. The result is a reliable and cost effective sensor for inertial sensing requiring accuracy and integrity. The rlg600h ring laser gyro rlg represent the smallest lightest designed to provide the functions required for volume, weight, and highest precision rlg systems. Are the new mems gyros accurate enough to detect and. The navy is using laser gyroscope tech to navigate in gps. Another scheme devised to increase the sensitivity of an optical gyroscope is the introduction of an active laser medium in a ring cavity, as shown in figure 2. A ring laser gyroscope rlg consists of a ring laser having two independent counterpropagating resonant modes over the same path. The whole ring laser is set up on a motorized rotational platform. Analysis of ring laser gyroscopes including laser dynamics. The navy is using laser gyroscope tech to navigate in gpsdenied environments. Pdf towards a solidstate ring laser gyroscope researchgate. Huang et al kerreffect in fiberoptic brillouin ring laser gyroscopes 367 h 2 600 v 2 400 6. The best reported shortterm sensitivities of sagnac gyroscopes are 0.
This document presents theresults of r f cleaning ring laser gyro. Abstract this experiment is designed to demonstrate an important application of lasers. Inertial navigation system ins and ring laser gyroscope for beginners by a beginner. The major concept was to introduce a laser cavity into the light path, in order to increase the strength of the sagnac e. We propose a method for estimating the longterm drift of the laser. The beam is split into two beams that travel the same path but in opposite directions. Thus, around the mid70s years, the laser or, ring laser gyro rlg finally reached the status of the fully understood, producible and highperformance device as we know it today. Laser gyroscopes, or more precisely, the ring laser gyroscopes that comprise the core of some of. This system has state of the art technology which is completely advanced and rugged. In a ring laser type gyroscope, the ring is the part of the laser whereas, in a fiber optic gyroscope, light from an external laser is passed through a fiber optic cable. Limitations to their performance come from the nonlinear dynamics of the laser. We show that the backscatter problem of the ring laser gyroscopes is negligible with a proper analysis of the data. North finding system using a mems gyroscope lucian ioan iozan 1, martti kirkkojaakkola 2, jussi collin, jarmo takala, and corneliu rusu1 1 technical university of clujnapoca, romania email. Laser gyroscope in this experiment you will explore a heliumneon laser with a triangular cavity and observe the sagnac effect which is used for measurements of rotation rate.
Ring laser gyroscope is a single axis laser gyro angle sensor designed and developed for high accuracy launch vehicle navigation systems. They are well suited for high precision strap down inertial navigation systems ins due to very high accuracy, high bias, scale factor stability, low scale factor nonlinearity and wide dynamic range. This paper is a short analysis of key technological advantages of fiberoptic gyroscope fog technology for high performance applications over competing technologies. Pdf in this paper, we report our recent progress towards a solidstate ring laser gyroscope rlg, where mode competition is circumvented by. Ring laser gyro with spatially resolved eigenstates. Measuring the earths rotation rate using a lowcost mems.
This system has been designed by sagem specially for navy applications and it fulfills most demanding navigation criteria and weapon stabilization requirements. The ring laser gyro rlg is widely used in commercial aviation. Following lamb semiclassical theory, we find a set of critical parameters affecting the time stability of the system. Research on lockin correction for mechanical dithered ring laser gyro. The basic interferometer is modified to become a ring resonator with l as the perimeter. Inertial navigation system ins and ring laser gyroscope. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. The gyroscope is an active laser gyroscope and contains a ring laser consisting of an open frame hene tube and a triangular resonator. Measured beat frequency bias as a function of,rotation rate. Vertical integration enables us to supply the entire ring laser gyroscope package. Pdf the authors recall the basic principles and advantages of the ring laser gyro rlg which is the most widely developed of all optical.
Gyroscopes are critical rotation sensing elements used in navigation systems inertial navigation systems ins, attitude and heading reference systems. The underground locapon beneath more than m of rock. Ieee standard specification format guide and test procedure for singleaxis laser gyros abstract. Pdf ringlaser gyro with spatially resolved eigenstates. Optical kerreffect in fiberoptic brillouin ring laser. Both optical gyroscopes, the ring laser gyro rlg and the fiberoptic gyro fog, are based on the same sagnac effect 1 and 2, which shows that light traveling along a closed ring path in opposite directions allows one to detect rotation with respect to inertial space.
Principles of aircraft gyroscopic instruments aircraft. Media in category ring laser gyroscopes the following 10 files are in this category, out of 10 total. Gg20an digital ring laser gyroscope honeywell aerospace. Sagnac showed that when he rotated the turntable, the light traveling with. An overview of optical gyroscopes theory, practical. Gingerino is a large frame laser gyroscope investigating the ground motion in the most inner part of the underground international laboratory of the gran sasso, in central italy. A ccw rotation i cw 100 50 0 50 100 rotation rate r degsec fig. The accumulated gyro pulses, however, are corrupted by both longterm and shortterm errors. Neelima department of electronics and communications engineering, mrits, jntuh, hyderabad. Inertial navigation system is a type of navigation system, used to guide aircrafts, guided missiles etc. In particular, we show the advantages of the fog technology over the ring laser gyroscope rlg technology.
Large ring laser gyroscope rlg technology1 pro vides very sensitive. These gyros are inertial guidance, aided or midcourse navigation, and vehicle stabilization and control to a wide variety. Undoubtedly, the rlg has been the first unquestionable success of laser and electrooptics. The ring laser gyro rlg functions in the following way. Several days of continuous measurements have been collected, with the apparatus running unattended. Specification format guide and test procedure for singleaxis laser gyros. According to industry developers, the latest generation of ring laser gyro systems use two counterpropagating laser beams directed at a photo detector. The bias drift of ring laser gyroscope rlg with temperature cant be ignored in high accuracy strapdown inertial navigation system sins. The basis for rlg operation is that it takes time for light to travel around a stationary, nonrotating circular path. Performance of ring laser gyros rlgs solely depends upon the. As the microelectromechanical system mems technology has evolved rapidly during the last years, accurate lowcost gyroscopes are now available. The idea behind the ring laser gyroscope actually dates back to 19, when a french physicist, georges sagnac, experimented with rays of light moving in opposite directions around a circular cavity on a turntable. These results not only allow to improve the performance of large scale ring laser gyro.
784 1006 541 196 113 639 1590 1149 1335 1234 630 639 305 400 391 281 738 916 1167 552 86 1033 1094 971 1356 293 699 154 521 121 856 1568 394 1482 282 208 559 257 1292 1302 1180 1184 663 971