scispace - formally typeset
Search or ask a question

Showing papers on "Ring laser gyroscope published in 2010"


Journal ArticleDOI
TL;DR: In this article, the role of integrated optics and photonic integrated circuit technology in the enhancement of gyroscope performance and compactness is broadly discussed, and the architecture of new slow-light integrated angular rate sensors is described.
Abstract: Photonics for angular rate sensing is a well-established research field having very important industrial applications, especially in the field of strapdown inertial navigation. Recent advances in this research field are reviewed. Results obtained in the past years in the development of the ring laser gyroscope and the fiber optic gyroscope are presented. The role of integrated optics and photonic integrated circuit technology in the enhancement of gyroscope performance and compactness is broadly discussed. Architectures of new slow-light integrated angular rate sensors are described. Finally, photonic gyroscopes are compared with other solid-state gyros, showing their strengths and weaknesses.

200 citations


Journal ArticleDOI
TL;DR: A harmonic model is proposed to describe the installation errors of an optical angular encoder, including the effects of eccentricity, swash, and distortion, and a method of OAE calibration with the ring laser gyroscope (RLG) is introduced.
Abstract: This paper deals with the installation errors of an optical angular encoder (OAE). A harmonic model is proposed to describe the installation errors, including the effects of eccentricity, swash, and distortion. Moreover, a method of OAE calibration with the ring laser gyroscope (RLG) is introduced. The calibration method can potentially reach the accuracy of 0.1". The calibration method is proved to be experimentally effective. With the harmonic model obtained from the experiment, the calibration of the OAE can be carried out in real time.

47 citations


Journal ArticleDOI
TL;DR: In this paper, the authors analyzed a system of two pairs of identical gyros (twins) with a slightly different orientation with respect to the Earth's axis, and the twin-gyro configuration has several interesting properties.
Abstract: Large scale square ring laser gyros with a length of four meters on each side are approaching a sensitivity of . This is approximately the regime required to measure the gravito-magnetic effect (Lense–Thirring) of the Earth. For an ensemble of linearly independent gyros each measurement signal depends upon the orientation of each single axis gyro with respect to the rotational axis of the Earth. Therefore at least three gyros are necessary to reconstruct the complete angular orientation of the apparatus. In general, the setup consists of several laser gyroscopes (we would prefer more than three for sufficient redundancy), rigidly referenced to each other. Adding more gyros for one plane of observation provides a cross-check against intra-system biases and furthermore has the advantage of improving the signal-to-noise ratio by the square root of the number of gyros. In this paper we analyze a system of two pairs of identical gyros (twins) with a slightly different orientation with respect to the Earth's axis. The twin-gyro configuration has several interesting properties. The relative angle can be controlled and provides a useful null measurement. A quadruple twin system could reach a 1% sensitivity after 3.2 years of data taking, provided each square ring has 6 m length on a side, the system is limited by shot noise and there is no source for 1/f-noise.

31 citations


Journal ArticleDOI
TL;DR: G-Pisa is an experiment dealing with a high sensitivity laser gyroscope with an area of the order of. It aims at improving the performances of mirror suspensions of the future-generation gravitational-wave antenna Virgo as mentioned in this paper.
Abstract: G-Pisa is an experiment dealing with a high sensitivity laser gyroscope with an area of the order of . It aims at improving the performances of mirror suspensions of the future-generation gravitational-wave antenna Virgo. The experimental set-up consists in a He–Ne ring laser with a four-mirror square cavity. The device is operational on a stable regime, with the laser operating in both single mode or multi mode. The low-frequency sensitivity, 0.001–, is limited by the environmental noise, but it has been checked that the requirements for the inverted pendulum tilt control given for AdVirgo are fulfilled ( at 30 MHz).

23 citations


Journal ArticleDOI
TL;DR: Pulse advancement is experimentally demonstrate in an under-coupled microfiber knot-type ring resonator with a Sagnac loop reflector that possesses doubled transmission and group delay comparing with the microfibers without the SagnAC loop.
Abstract: We fabricate a microfiber knot-type ring resonator with a Sagnac loop reflector, and control the light velocity using the device. In this structure, light is reflected by the Sagnac loop and passes through the ring resonator twice. Thus, it possesses doubled transmission and group delay comparing with the microfiber ring resonator without the Sagnac loop. We experimentally demonstrate pulse advancement in an under-coupled microfiber knot-type ring resonator with a Sagnac loop reflector. In the experiment, a maximum of approximately 25 ps pulse advancement was achieved for a 5-Gb/s RZ signal.

22 citations


Patent
05 May 2010
TL;DR: In this article, a high-precision laser gyroscope single-shaft rotating inertial navigation system is presented, in which the inertial measuring unit is installed on a rotating platform and carries out shock absorption by a shock absorber.
Abstract: The invention relate to a high-precision laser gyroscope single-shaft rotating inertial navigation system which comprises an inertial measuring unit, a single-shaft rotating platform, a circuit box, a UPS power supply, a display control device, and the like, wherein the inertial measuring unit 1 is installed on the single-shaft rotating platform 2 and carries out shock absorption by a shock absorber 3. The periodic rotation of the single-shaft rotating platform is used for modulating literal drift of an inertial device in the inertial measuring unit and improving the posture, speed and position precision of the inertial navigation system. The system concretely comprises precise installation and calibration of the inertial measuring unit, the selection of a single-shaft rotating way, precise multiposition initial alignment, the error analysis, modeling and temperature compensation of the inertial navigation system and the inertial device and a navigation algorithm of a single-shaft rotating strapdown inertial navigation system. The invention can provide a real-time, complete and high-precision navigation posture and speed and position information for a carrier (warship) for a long time and improve the comprehensive combat capability of the carrier.

21 citations


Proceedings ArticleDOI
11 Feb 2010
TL;DR: In this paper, a number of optical gyroscope architectures utilizing either slow or fast light have been recently proposed in the literature to enhance rotation sensitivity, with a view to separate the schemes that offer a genuine enhancement from the ones that do not.
Abstract: This paper reviews a number of optical gyroscope architectures utilizing either slow or fast light that have been recently proposed in the literature to enhance rotation sensitivity, with a view to separate the schemes that offer a genuine enhancement from the ones that do not. The overall conclusion is that although slow-light coupled-resonator systems have interesting applications in other fields, for example for filtering or switching, none of the schemes proposed to date enable any enhancement in rotation sensitivity. Simple guidelines are outlined in an attempt to help clear misconceptions and hopefully reduce the number of erroneous publications on this subject in the future. On the other hand, fast light in a ring laser gyro can potentially enhance rotation sensitivity by up to six orders of magnitude. Future research directions likely to be fruitful are also outlined.

21 citations


Journal Article
TL;DR: In this paper, a new algorithm using attitude matching method is proposed for ship deformation measurement system based on ring laser gyro units(LGUs), where the Kalman filter measurements are set up based on the two LGUs' real-time attitude information which is different from the inertial measurement matching method.
Abstract: A new algorithm using attitude matching method is proposed for ship deformation measurement system based on ring laser gyro units(LGUs).In the new algorithm,the Kalman filter measurements are set up based on the two LGUs' real-time attitude information which is different from the inertial measurement matching method.Each of the LGUs systems directly uses the ring laser gyros' outputs to update its attitude with respect to the inertial space,and the inertial frame is chosen to be the initial LGU frame,which can avoid the initial alignment problems and make full use of ring laser gyros' high angle measurement precision.Simulation results show that high frequency and accurate ship deformation measurement can be effectively realized,and the simulated measurement precision can be higher than 15″,which lays a sound fundation for actual application of ship deformation measurement based on LGUs.

20 citations


Patent
01 Dec 2010
TL;DR: In this article, a biaxial rotation modulation method was proposed to realize the modulation of errors of an inertia device in the strapdown inertial navigation system and improve the navigation precision of the system.
Abstract: The invention belongs to the technical field of modulation of a strapdown inertial navigation system and relates to a biaxial rotation modulation method of the strapdown inertial navigation system which aims at reducing the complexity and realizing the rate bias without a high angular acceleration reversing mechanism. The biaxial rotation modulation method comprises six steps of setting a coordinate system, mounting a gyroscope and an accelerometer, mounting an inertial measurement unit, carrying out biaxial rotation modulation, carrying out navigation calculation of the inertial measurement unit and carrying out demodulation and calculation of data on the strapdown inertial navigation system. The biaxial rotation modulation method adopts the biaxial rotation module and can realize the modulation of errors of an inertia device in the strapdown inertial navigation system and improve the navigation precision of the strapdown inertial navigation system. The biaxial rotation modulation method does not need the high angular acceleration reversing mechanism for the strapdown inertial navigation system using the laser gyroscope, thereby reducing the implementation complexity of the system and further reducing the implementation cost of the system.

14 citations


05 Jul 2010
TL;DR: In this article, the laser frequency noise limited sensitivity in a resonator optic gyroscope due to an intermodulation effect was first demonstrated and a bias stability of 0.055 deg/s was best demonstrated in a Resonator micro-optic Gyroscope.
Abstract: The laser frequency noise limited sensitivity in a resonator optic gyroscope due to an intermodulation effect is first demonstrated. A bias stability of 0.055 deg/s is best demonstrated in a resonator micro optic gyroscope.

14 citations


Journal ArticleDOI
TL;DR: In this paper, a novel electrostatic-driven tuning fork micromachined gyroscope with a bar structure is presented, which can operate at atmospheric pressure by electrostatic driving and capacitive sensing.
Abstract: A novel electrostatic-driven tuning fork micromachined gyroscope with a bar structure is presented. The gyroscope is fabricated by silicon–glass bonding and deep reactive ion etching (DRIE) technology. The gyroscope's driving and sensing proof masses consist of many movable bars. As the motion of the movable proof masses is parallel to the plane of fixed driving and sensing electrodes on a glass substrate, there is mainly slide film damping in the driving and sensing directions, which enables it to achieve high-quality factors and vacuum-free packaging. The gyroscope can operate at atmospheric pressure by electrostatic driving and capacitive sensing. The performances of the gyroscope are tested and the results show that the resonant frequencies and the quality factors for driving and sensing modes are 2.873 kHz and 2.989 kHz, 804 and 789 at atmospheric pressure, respectively. The scale factor and nonlinearity of the gyroscope are 17.45 mV/°/s and 0.43%, respectively.

Journal ArticleDOI
TL;DR: A new algorithm is proposed that is used to estimate the phase errors due to lock-in and so compensates for a random walk using the electric output of the RLG and significantly reduces random walks and brings robustness to the timer clock frequency.
Abstract: The main factors which reduce the performance of ring laser gyroscopes (RLGs) are lock-ins and bias errors. A lock-in is a nonlinear effect that makes the output of the RLG unmeasurable due to a coupling with the backscattered light from the mirror when the input rotation rate is low. To prevent the lock-in effect, random dithering has been applied. However, a random walk due to the random dithering can result in a degraded RLG performance. Thus, a lower value for random walks is preferable. This is done by reducing the alignment time of the Laser Inertial Navigation System (LINS). In this paper, we propose a new algorithm that is used to estimate the phase errors due to lock-ins and so compensates for a random walk using the electric output of the RLG. To verify the performance of the proposed algorithm, a simulation was performed using RLG equations. The simulation results show that the proposed algorithm significantly reduces random walks and brings robustness to the timer clock frequency, which can lead to an easier implementation of hardware and algorithms.

Patent
19 Oct 2010
TL;DR: In this paper, a rotational angle sensor with a stator, a scanning means and a laser gyroscope is used to measure the angular velocity of a rotating shaft, and the measured angle values from the scanning means are compared with reference angle values, and correction variables are formed from the differences.
Abstract: A method for calibrating a rotational angle sensor having a rotor ( 12 ) coupled to a rotating shaft ( 10 ) in a manner which is faithful to the rotational angle, a stator ( 16 ), and a scanning means ( 14 ) arranged on the stator ( 16 ). The scanning means ( 14 ) scans a material measure of the rotor ( 12 ) and generates measured angle values associated with the rotational angle position of the rotor ( 12 ). A laser gyroscope ( 18 ) measures the angular velocity of the shaft ( 10 ). The signals from the laser gyroscope ( 18 ) which are dependent on the angular velocity of the shaft ( 10 ) are integrated over time with respect to the rotational angle. The measured angle values from the scanning means ( 14 ) are compared with reference angle values, and correction variables are formed from the differences. During measurement of the rotational angle, the measured angle values are corrected using the correction variable.

Journal ArticleDOI
TL;DR: In this article, a single optical ring resonator connected to a Sagnac loop is used to demonstrate theoretically a novel narrow band optical filter response that is based on sagnac phase-shift Δ φ.
Abstract: In this paper, a single optical ring resonator connected to a Sagnac loop is used to demonstrate theoretically a novel narrow band optical filter response that is based on Sagnac phase-shift Δ φ . The given filter structure permits the Sagnac rotation to control the filter response. It is shown that by changing the Sagnac rotation rate, we can tune the filter response for desired bandwidths. To increase the wavelength selectivity of the filter, the Sagnac phase-shift should be as small as possible that is limited by the loop length. For Δ φ =0.1 rad, the obtained FWHM is 2.63 MHz for tuning loop length of 2 m. The simulation response agrees fairly with the recently reported experimental result.

Patent
05 May 2010
TL;DR: In this paper, a high-precision uniaxial rotation attitude measuring system based on a laser gyro, consisting of two parts including an inertia measurement unit A and a UMLM turntable B, is presented.
Abstract: The invention discloses a high-precision uniaxial rotation attitude measuring system based on a laser gyro, consisting of two parts including an inertia measurement unit A and a uniaxial precise machine turntable B. In the inertia measurement unit A, a laser gyro and a quartz accelerometer are fully and rigidly coupled with a bracket, the inertia measurement device A is fixed on the uniaxial precise machine turntable B by a standard fastening bolt, the relative attitude between the inertia measurement device A and the uniaxial precise machine turntable B is precisely calibrated, and the precision and the synchronism of a solving attitude of the inertia measurement device A are guaranteed. The constant drift of an inertia device in the inertia measurement unit is modulated by the periodic rotation of the uniaxial precise machine turntable, thus the alignment precision and the navigation attitude precision of the attitude measuring system are improved. The invention can provide a carrier (a ship) with real-time and complete high-precision attitude information for a long time and improve the comprehensive combat capability of the carrier.


Patent
16 Jun 2010
TL;DR: In this article, a two-way constant speed frequency-offered laser gyro north finder was proposed, which is used to improve the precision of the gyro by eliminating the influence of latchup effect on precision.
Abstract: The invention relates to a two-way constant speed frequency-offset laser gyro north finder, and belongs to the technical field of inertial navigation equipment. The laser gyro north finder is provided with a two-way constant speed frequency-offset rotary table rotating around a vertical axis; the rotary table is provided with a laser gyro and an accelerometer; the sensing axis of the laser gyro deviates the rotary plane of the rotary table by a beta angle; and the input axis of the accelerometer is parallel to the rotary plane of the frequency-offset rotary table and is parallel to a projection of the sensing axis of the laser gyro on the rotary plane of the frequency-offset rotary table. The laser gyro north finder applies two-way constant speed frequency-offset technology, thoroughly eliminates influence of latchup effect on precision of the laser gyro, and performs rotation error modulation and filtering on the errors produced by the laser gyro due to other reasons to ensure that the precision of the laser gyro is greatly improved than that of other conventional frequency-offset technology so as to manufacture the arc-second high-precision laser gyro north finder.

Patent
30 Apr 2010
TL;DR: In this paper, a gyroscope and a method of detecting rotation are provided, which includes a structure configured to be driven to move about a drive axis, in response to a Coriolis force generated by rotation of the structure about a rotational axis while moving about the drive axis.
Abstract: A gyroscope and a method of detecting rotation are provided. The gyroscope includes a structure configured to be driven to move about a drive axis. The structure is further configured to move about a sense axis in response to a Coriolis force generated by rotation of the structure about a rotational axis while moving about the drive axis. The gyroscope further includes an optical sensor system configured to optically measure movement of the structure about the sense axis. In certain embodiments, the gyroscope is a microelectromechanical system (MEMS) gyroscope.

Proceedings ArticleDOI
16 Apr 2010
TL;DR: In this article, a new method to decrease the magnetic sensitivity of DILAG by adjusting the frequency stabilization mode was proposed. But the hardware structure and software flow were not discussed.
Abstract: The magnetic-induced drift is an important error to limit the precision of four frequency differential ring laser gyro (DILAG) in navigation application. Different from the traditional magnetic shielding technology, this paper introduces a new method to decrease the magnetic sensitivity1 of DILAG, simply by adjusting the frequency stabilization mode. Firstly, the physics principle of the method is illustrated. Then, the concrete steps for implementing are given in detail, including the hardware structure and the software flow. Finally, repeatable experiments are carried out and the results verify the validity of the method, which may be helpful to researchers.

Journal Article
TL;DR: The method to rotate the inertial measurement unit is developed and the results show that the peak position errors of the four times static navigation tests for 10-day cycle are less than 1 n mile within 5 days, and 2 nmile within 10 days.
Abstract: High precision inertial navigation system is the base of integrated performance in shipsIn order to improve the performance of the inertial navigation system,a method to rotate the inertial measurement unit is developedThe hardware of the system is introduced,which mainly includes the basic configuration,the performance of ring laser gyroscope and accelerometer,and the diagram of navigation computerThe scheme of the alignment and the temperature compensation are describedThe static tests and outdoor vehicle tests are performedThe results show that the peak position errors of the four times static navigation tests for 10-day cycle are less than 1 n mile within 5 days,and 2 n mile within 10 daysThe peak position errors of the outdoor vehicle tests are less than 14 n mile within 77 h,and 25 n mile within 15 days

Proceedings ArticleDOI
04 May 2010
TL;DR: In this article, a new concept gyroscope based on superfluid Josephson effect was described and analyzed to improve the performance greatly, and two methods were discussed to solve the conflict between the high sensitivity and wide measurement range.
Abstract: A new concept gyroscope based on superfluid Josephson effect was described and analyzed to improve the performance greatly. It is a new Sagnac effect that an interferometer “loop”, formed by placing double weak links in a toroid filled with superfluid He4, can detect the interference of superfluid matter waves generated by the AC Josephson oscillation in weak links. In this paper, the potential advantages of superfluid gyroscope were estimated. The most important advantage is the very high sensitivity which could be increased theoretically by a factor of 1010 than the sensitivity of traditional Ring Laser Gyroscope. But such a superfluid gyroscope still faces some difficulties when it is used as an angular velocity measuring device for navigation, the most important one is the conflict between the high sensitivity and wide measurement range. Then, two methods were discussed to solve that conflict which is a key problem in current superfluid gyroscope research. The first method is “flux-locking”, which is a technique used in superconducting dc-SQUIDs. The principle of the method and analysis of performance were presented. It can increase measurement range to 500 times of original one. In another hand, such a superfluid gyroscope should work in a situation with limited angular acceleration. Author presented another method, called “history tracing”, and its work principle. The performance of the second method also be studied, and results showed that “history tracing” overcomes the problem of measurement range totally. Comparisons showed that “history tracing” is a better choice to develop high performance superfluid gyroscope.

Journal ArticleDOI
TL;DR: In this article, the authors observed frequency splitting phenomenon of dual transverse modes (TEM 00q and TEM 01q ) in a Nd:YAG microchip standing wave laser utilizing intracavity stress birefringence effects.
Abstract: We observed frequency splitting phenomenon of dual transverse modes (TEM 00q and TEM 01q ) in a Nd:YAG microchip standing wave laser utilizing intracavity stress birefringence effects. Four resonance frequencies ( ν 00qe , ν 00qo , ν 01qe , and ν 01qo , respectively) were produced and tuned by changing the diametral compression force applied on the laser crystal. The transverse mode frequency spacing for the same longitudinal mode number (Δ ν trans ) was 1.16 GHz, and the magnitude of frequency splitting (Δ ν ) ranged from 0 MHz to 1.16 GHz. Based on this phenomenon, a four-mode differential standing wave laser, whose signal characteristics were a little like those of a four-mode differential travelling wave laser gyro however with a much larger frequency splitting range, was produced. The theoretical analysis is in good agreement with the experimental results. This phenomenon not only can be used to make lasers with two or more frequency differences, but also can be used to make high-resolution self-sensing laser sensors (e.g. laser force sensors and laser accelerometers).

Journal ArticleDOI
04 Mar 2010
TL;DR: G-Pisa as mentioned in this paper is an experiment investigating the possibility of operating a high-sensitivity laser gyroscope with area less than 1 m2 for improving the performances of the mirrors suspensions of the gravitational wave antenna Virgo.
Abstract: G-Pisa is an experiment investigating the possibility of operating a high-sensitivity laser gyroscope with area less than 1 m2 for improving the performances of the mirrors suspensions of the gravitational wave antenna Virgo. The experimental set-up consists of a He-Ne ring laser with a 4-mirror square cavity. The laser is pumped by an RF discharge where the RF oscillator includes the laser plasma to reach a better stability. The contrast of the Sagnac fringes is typically above 50% and a stable regime has been reached with the laser operating in either single mode or multimode. The effect of hydrogen contamination on the laser was also checked. A low-frequency sensitivity, below 1 Hz, in the range of 10-8(rad/s)/?(Hz) has been measured.

Patent
Mary K. Salit1, Kenneth Salit1
07 Apr 2010
TL;DR: A ring laser gyroscope that includes a gain medium, a plurality of reflective surfaces coupled to the cavity, and at least one medium exciter operable to excite the gain medium has naturally dispersive properties associated with an index of refraction as discussed by the authors.
Abstract: A ring laser gyroscope that includes a cavity containing a gain medium, a plurality of reflective surfaces coupled to the cavity, and at least one medium exciter operable to excite the gain medium. The gain medium has naturally dispersive properties associated with an index of refraction. The reflective surfaces include at least a first reflective surface, a second reflective surface, and a third reflective surface. The first, second, and third reflective surfaces are positioned to reflect light between the plurality of reflective surfaces. The excited gain medium induces first and second laser fields within the cavity. The first and second laser fields operate at a lasing frequency corresponding to a negative slope of the index of refraction associated with the dispersive properties of the gain medium. The gain medium causes anomalous dispersion of the first and second laser fields passing through the gain medium.

Proceedings ArticleDOI
03 Nov 2010
TL;DR: In this paper, a new conceptual fiber-optic gyroscope is introduced, which employs the optical frequency-modulated continuous-wave (FMCW) interference, and the differential fiberoptic irregularity.
Abstract: A new-conceptual fiber-optic gyroscope is introduced. The gyroscope employs the two newly-emerged novel technologies: the optical frequency-modulated continuous-wave (FMCW) interference, and the differential fiber-optic gyroscope, and therefore, it can overcome the problems in the traditional fiber-optic gyroscopes, such as temperature drift and poor long-term stability. The FMCW interference, which was originally investigated in radar technology, has been successfully used to construct various fiber-optic interferometers and sensors. The advantages of this technology include accurate calibration of the phase, simple count of fringes, and easy signal processing. The interest in the application of the FMCW technique to rotation sensing has been growing for a long period. The problem in the FMCW fiber-optic gyroscope is that the gyroscope must be an unbalanced, and the initial optical path difference in the gyroscope will cause an unexpected non-reciprocal phase drift if the environmental conditions are unstable. This paper reports a differential FMCW fiber-optic gyroscope. The advantages of this fiber-optic gyroscope include: (1) Due to the nature of the differential interferometer structure, the unexpected non-reciprocal phase drift is automatically removed, and the calibration fact of the gyroscope is automatically doubled. (2) Benefited from the FMCW technology, this gyroscope has no zero-sensitivity point problem, and it has a higher resolution and a larger dynamic range.

Patent
07 Jul 2010
TL;DR: In this paper, the authors proposed a laser gyroscope with fast starting, which consists of a high-voltage power supply, a pre-amplifying circuit, a current-stabilizing current, and a control circuit.
Abstract: The utility model belongs to a gyroscope, and particularly relates to a laser gyroscope with fast starting, aiming at providing a laser gyroscope with fast starting. The laser gyroscope with fast starting comprises a high-voltage power supply, a pre-amplifying circuit, a current-stabilizing current, a laser gyro and a control circuit, wherein the laser gyro is used for moving angle rate of a sensitive carrier relative to inertial space; the high-voltage power supply is used for providing a secondary power supply needed by starting, frequency stabilizing and mechanical jittering of the laser gyro; the pre-amplifying circuit is used for pre-amplifying a photoelectric signal output by the gyro; the current-stabilizing circuit is used for controlling the size of the discharging current of two anodes; and the control circuit is mainly used for realizing the starting control, frequency stabilizing control and mechanical jittering of the gyro, wherein in an optical block body, the position capable of illuminating to the cathode is provided with a near ultraviolet light-emitting lamp. The laser gyroscope has the advantages that a light-emitting optical source of the near ultraviolet wave band carries out illumination to the cathode of the laser gyro, greatly increases the initial current carrier density of a gyro discharging cavity in short time, and shortens the starting time of the gyroscope.

Patent
29 Dec 2010
TL;DR: In this article, the authors proposed a circuit consisting of a clock oscillator, a clock frequency divider, an M sequence generator, a synchronization signal rising edge detection circuit, a falling edge spike pulse generating circuit, and a sampling hold circuit, where the full-period or half-period selection control circuit controls the on state of a nusoidal signal falling-edge spike pulse generator.
Abstract: The utility model belongs to circuits of mechanically dithered ring laser gyroscopes, in particular to a circuit capable of simultaneously sampling and simulating pseudorandom noise injection used for a mechanically dithered ring laser gyroscope. The circuit comprises a clock oscillator, a clock frequency divider, an M sequence generator, a synchronization signal rising edge detection circuit, a synchronization signal falling edge detection circuit, a rising edge spike pulse generating circuit, a falling edge spike pulse generating circuit, a full-period or half-period selection control circuit and a sampling hold circuit, wherein the full-period or half-period selection control circuit controls the on state of a nusoidal signal falling edge spike pulse generating circuit, and nusoidal signal rising edge synchronous sampling spike pulse signals and nusoidal signal falling edge synchronous sampling spike pulse signals are output after the XOR operation to obtain the synchronous sampling spike pulse signals, thereby realizing that the mechanically dithered signals can simulate the pseudorandom noise injection in a half-period simultaneous way, integrating the full-period synchronous noise injection, reducing the dynamic lock-in of the mechanically dithered ring laser gyroscope effectively, and improving the performance figures of the laser gyroscope.

Journal ArticleDOI
TL;DR: In this article, a light path improved method is proposed to eliminate the vibration sensitivity of Sagnac fiber-optic current sensor by coupling the half-waveplate in sensing fiber.
Abstract: To eliminate the vibration sensitivity,a light path improved method isproposed,which makes dis charge of Sagnac effect with Sagnac effect itself and do not disturb Farady effect at all.Then the polarization states of the lights spreading in the improved light path are analyzed with Jones matrix.The experiment results are in good agreement with the theoretical analysis results,which shows that the output of the improved sensor has nothing to do with vibration.After the coupling of the half-waveplate in sensing fiber,the vibration sensitivity of Sagnac fiber-optic current sensor has been eliminated.A feasible method for the practical use of Sagnac fiber-optic current sensor is provided.

Journal Article
TL;DR: In this paper, the mirror transducer assembly causing light path variation of ring laser gyro was analyzed and the results indicated that mirror tilt can induce a light path shift of about 10~20% aperture diameter at the aperture transverse section.
Abstract: The mirror transducer assembly causing light path variation of ring laser gyro is analyzed. This analysis reveals how the action mechanism of the mirror transducer assembly influences light path in ring laser gyro and to what extent it may have. The calculated results indicate that mirror tilt can induce a light path shift of about 10~20% aperture diameter at the aperture transverse section. A test system is built to verify that it is the tilt of mirror transducer assembly which causes the light path variation at the aperture. At last, the impact of the action mechanism of light path variation on ring laser gyro performance is discussed.

Book ChapterDOI
01 Jan 2010
TL;DR: The commercial success of the He-Ne Ring Laser Gyroscope (RLG) began in the late 1980s and early 1990s as discussed by the authors, and it has become a widely diffused commercial device.
Abstract: Commercial success of the He–Ne Ring Laser Gyroscope (RLG) began in the late 1980s and early 1990s. Since He–Ne RLG first demonstration in 1963 (Macek and Davis, Appl Phys Lett 2:67–68, 1963 [1]), a number of industrial companies have developed a great research effort for RLG technology improvement so that this optical sensor has become a widely diffused commercial device. For instance, navigation systems based on He–Ne RLGs has been installed on over 50 different aircrafts (Barbour, AiAA Guidance, Navigation and Control Conference, Montreal, Canada, 2001 [2]). Since several years, He–Ne RLG dominates the high-performance gyros market.