Showing papers in "Gyroscopy and Navigation in 2011"
TL;DR: The GAIN (Gravimetric Atom Interferometer) as mentioned in this paper is a mobile and robust gravimeter based on interfering ensembles of laser cooled 87Rb atoms in an atomic fountain configuration.
Abstract: We present the new mobile and robust gravimeter GAIN (Gravimetric Atom Interferometer), which is based on interfering ensembles of laser cooled 87Rb atoms in an atomic fountain configuration. With a targeted accuracy of a few parts in 1010 for the measurement of local gravity, g, this instrument should offer about an order of magnitude improvement in performance over the best currently available absolute gravimeters. Together with the capability to perform measurements directly at sites of geophysical interest, this will open up the possibility for a number of interesting applications.
71 citations
TL;DR: In this paper, an overview of the research and development of gyroscopic technologies in Russia in the past 15 years is presented, and the current status and prospects for advancement of inertial technologies in the future are analyzed.
Abstract: The article presents an overview of the research and development of gyroscopic technologies in Russia in the past 15 years. The current status and prospects for advancement of inertial technologies in the future are analyzed.
54 citations
TL;DR: This paper presents a numerical probabilistic approach to the map-matching problem within the framework of the Bayesian theory based on the sequential Monte Carlo method—the so-called particle filtering.
Abstract: This paper presents a numerical probabilistic approach to the map-matching problem within the framework of the Bayesian theory. The proposed solution is based on the sequential Monte Carlo method—the so-called particle filtering. This algorithm can be adapted for implementation on real-time portable car navigation systems equipped with GPS or dead reckoning sensors. The reliability and accuracy of this algorithm were investigated using simulated data and data from real-world driving tests in urban environments.
28 citations
TL;DR: In this paper, the results of airborne gravimetric surveys conducted in 2007-2009 on the shelf of Greenland are given, and special features of using a Chekan-AM gravimeter in airborne GC surveys are discussed.
Abstract: Special features of using a Chekan-AM gravimeter in airborne gravimetric surveys are discussed. Software and procedures for gravimetric data processing are described. The results of airborne gravimetric surveys conducted in 2007–2009 on the shelf of Greenland are given.
26 citations
TL;DR: This article is in honor of the 80th birthday of Rudolf Emil Kalman and some trends in the development of applied methods for solution of filtering problems are analyzed.
Abstract: This article is in honor of the 80th birthday of Rudolf Emil Kalman. A brief biography of R.E. Kalman is presented. The most important facts concerned with the creation of the celebrated Kalman filter are briefly outlined. Some trends in the development of applied methods for solution of filtering problems are analyzed. Kalman’s relations and contacts with Russian scientists as well as their contribution to filtering theory and its applications are discussed.
24 citations
TL;DR: In this paper, an inertial system for railway track diagnostics is presented, which consists of a set of inertial measurement units (IMUs) based on MEMS gyros and accelerometers which are mounted directly on the axle-boxes (bearing covers) of the wheel pairs.
Abstract: This paper presents an inertial system for railway track diagnostics. The key element of the system is a set of inertial measurement units (IMUs) based on MEMS gyros and accelerometers, which are mounted directly on the axle-boxes (bearing covers) of the wheel pairs. The system made it possible to investigate how the car-track dynamic interaction affects measurements of geometrical deformations and to determine parameters, such as defects of rail treads.
23 citations
TL;DR: In this paper, the authors discuss a mobile gravimeter Chekan-AM, which is the further development of sea gravimetric systems created by the CSRI Elektropribor in the course of thirty years.
Abstract: The paper discusses a mobile gravimeter Chekan-AM, which is the further development of sea gravimetric systems created by the CSRI Elektropribor in the course of thirty years. The basic designs of the gravity sensor and gyro stabilization system are considered. The results of long-term operation of gravimeters used by Russian and foreign companies for marine geophysical surveys conducted in different areas of the Arctic, Atlantic, Indian and Pacific Oceans are presented. The comparison of the results obtained with the results of seismic survey has shown that gravimetric data offer considerable promise for oil and gas searching on the shelf.
19 citations
TL;DR: In this article, a suboptimal gravimetric smoothing filter was proposed for the GT-2M, which is as simple in implementation as the Kalman filter and performs nearly as good as the optimal Kalman-Wiener smoother.
Abstract: Data processing for the marine gravimeter GT-2M developed and manufactured at the Scientific and Technical Company Gravimetric Technology is discussed. The free air gravity anomaly is evaluated by the instrument in real time, no post-processing is required. The paper discusses the suboptimal gravimetric smoothing filter specially designed for this purpose. The filter is as simple in implementation as the Kalman filter and performs nearly as good as the optimal Kalman-Wiener smoother. The structural diagram and the frequency responses of the filter are presented. Results of industrial marine surveys with GT-2M are discussed.
18 citations
TL;DR: In this article, it was shown that both gravity networks and absolute ballistic gravimeters can be the measurement standards in gravimetry, i.e., the standards of the acceleration unit in the measurement of free-fall acceleration.
Abstract: The analysis of the definition of a measurement standard in metrology applied to the field of gravimetry shows that both gravity networks and absolute ballistic gravimeters can be the measurement standards in gravimetry, i.e., the standards of the acceleration unit in the measurement of free-fall acceleration. Currently, the absolute ballistic method is recognized as the primary reference method for the measurement of free-fall acceleration. As the measurement standard of acceleration, a derived physical quantity, the ballistic gravimeter should be traceable to the measurement standards of length and time (frequency) units. The accuracy level of absolute ballistic gravimeters may be determined by comparing the results of their measurements organized at sites where several gravimeters can perform measurements simultaneously according to a specified technical protocol.
17 citations
TL;DR: In this article, an Automatic Ground Collision Avoidance System (Auto GCAS) is proposed to provide an extension of collision avoidance technology to systems that not only warn the pilot but also fly the aircraft out of danger before returning control to the pilot.
Abstract: Currently, the majority of collision avoidance systems on fighter aircraft depend on the pilot taking action whenever a warning is issued by the manual system. Any future substantial reductions in mishap rates will require extending the collision avoidance technology to systems that not only warn the pilot but also take control and fly the aircraft out of danger before returning control to the pilot. An Automatic Ground Collision Avoidance System (Auto GCAS) will provide this extension of collision avoidance technology.
16 citations
TL;DR: Decentralized integration of global positioning system (GPS), synthetic aperture radar (SAR), and terrain referenced navigation (TRN) system into an inertial navigation system (INS) is analysed in comparison to the centralized integration method in this paper.
Abstract: Decentralized integration of global positioning system (GPS), synthetic aperture radar (SAR), and terrain referenced navigation (TRN) system into an inertial navigation system (INS) is analysed in comparison to the centralized integration method in this paper. Many publications have shown different decentralized integration methods. The main advantage of the decentralized filter architecture is flexibility and modularity. Especially the federated no-reset filter has received considerable attention in literature because of improved fault detection and isolation (FDI) capability, which is an important feature in multi-sensor navigation systems. Fault detection capability of the federated no-reset filter is well-established. However, this filter type combines sensor data in a suboptimal way and a loss of accuracy compared to the centralized Kalman filter is generally observed. Other publications mentioned this loss of accuracy, but did not give the amount of accuracy loss for SAR/TRN/GPS/INS systems. In this paper additionally a slight modification of the federated filter is presented. Typically a GPS/INS filter tends to be overoptimistic due to long-term timecorrelated atmospheric errors of the GPS pseudo-range measurements. A rather simple modification of the federated filter is given to take into account this overoptimistic behaviour. A covariance correction yields a more reasonable covariance of the GPS/INS local filter and an improved overall position estimation of the federated filter.
TL;DR: In this paper, the authors considered the differences in accuracy criteria for gyros in two applications: measuring rotation about a fixed axis and measuring rotation at a point, and they described the class of gyro noise with zero spectral density at zero frequency, which does not cause errors in angles of rotation to accumulate with time, but lead to accumulation of errors in attitude determined by strapdown inertial systems.
Abstract: The paper considers the differences in accuracy criteria for gyros in two applications: measuring rotation about a fixed axis and measuring rotation about a point. We describe the class of gyro noise with zero spectral density at zero frequency. This noise does not cause errors in angles of rotation (i.e., integrals of angular velocity projections on the gyro sensitivity axis) to accumulate with time, but lead to accumulation of errors in attitude determined by strapdown inertial systems. Ways of identifying gyro noise structure using the known lower order variances are analyzed: two-sample variance (Allan variance), three-sample variance (Hadamar variance), and proposed higher order variances [1].
TL;DR: In this article, the authors consider the methods of compensation of these drifts by means of special control of the vibrating pattern by a sectioned parametric electrode, which is achieved through amplitudes of voltage and phase manipulations at the sectioned electrodes.
Abstract: A parametric electrode is normally used in hemispherical resonator gyroscopes, operating in the whole angle regime, for maintaining the amplitudes of vibratory patterns. It is well known that, due to variation of the gap between the resonator and parametric electrode, a drift of the vibrating pattern is obtained. This drift is similar to the gyro drift stipulated by the Q-factor imperfections and substantially deteriorates the quality of the hemispherical resonator gyroscope. In the present paper, we consider the methods of compensation of these drifts by means of special control of the vibrating pattern by a sectioned parametric electrode. Compensation of the drifts is achieved through amplitudes of voltage and phase manipulations at the sectioned parametric electrodes. The side effect of this control consisting of spurious splitting of frequencies of the vibrating pattern is discussed.
TL;DR: In this article, the results of development of MEMS sensors for control systems of Tu-204, Il-96, Tu-334, and Yak-130 aircraft performed at the Moscow Institute of Electromechanics and Automatics are presented.
Abstract: Results of development of MEMS sensors for control systems of Tu-204, Il-96, Tu-334, Yak-130 aircraft performed at the Moscow Institute of Electromechanics and Automatics are presented. Design features and obtained technical parameters of the developed devices are considered. Prospects for their application in a wide range of aircraft are shown.
TL;DR: A short introduction to theory of SAW-based SSGs and a brief overview of the existing design concepts, which are described, analyzed, and compared with each other are discussed in this article.
Abstract: Modern MEMS gyros are widely used nowadays, however, the field of high-dynamic moving objects is still hardly accessible for them because of rigid requirements for the sensors to be shock-resistant. Solid-state gyros (SSG), namely, those that are based on surface acoustic waves (SAW), are likely to become the solution to this problem. This paper provides a short introduction to theory of SAW-based SSGs and a brief overview of the existing design concepts, which are described, analyzed, and compared with each other. The main advantages, problems, and prospects for further development of SAW-based SSGs are discussed.
TL;DR: In this article, the authors address the issue regarding dead zones in interferometric closed-loop fiber-optic gyros (FOGs) and analyze the causes of dead zones and their suppression methods.
Abstract: This paper addresses the issue regarding dead zones in interferometric closed-loop fiber-optic gyros (FOGs). The causes of dead zones and their suppression methods are analyzed. Test methods for dead-zone detection and measurement are discussed. Dead-zone values are presented for FOGs produced by various companies—both Russian (Optolink, Perm Research and Production Instrument Company, and Elektropribor) and foreign (Honeywell and IXSEA).
TL;DR: In this article, a new digitally controlled coriolis vibrating gyroscope is presented, which combines force-to-rebalance (FTR) and whole-angle (WA) modes in order to improve performance.
Abstract: Coriolis vibrating gyroscopes using axisymmetrical or near-axisymmetrical resonators, such as Sagem Quapason™, hemispherical resonator gyros, cylindrical vibrating gyros, and axisymmetrical MEMS gyros, may work in whole-angle (WA) or in force-to-rebalance (FTR) (angle-rate) mode. Although a specific industrial process is implemented, including defect identification and correction, ageing effects cannot be compensated and affect drift and scale factor stability. This paper shows how the equations governing the relations between defects, commands, and errors can be used to define a new control mode, which combines FTR and WA modes in order to greatly improve performance. The implementation of those principles to the Quapason™ gyro leads to the GVNG gyro (French acronym for Gyro Vibrant Nouvelle Generation — New Generation Vibrating Gyro), a new digitally controlled coriolis vibrating gyroscope. Its experimental results are presented in this paper. The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) for the Clean Sky Joint Technology Initiative under grant agreement no. CSJU-GAM-SFWA-2008-001.
TL;DR: The proposed E-L correlator was implemented to the FPGA of the experimental software GNSS receiver and was tested on the GALILEO E1b, E1c and E5a signals.
Abstract: The new and modernized GNSS navigation systems will provide various navigation services and signals for civil user. The system operators work on basic interoperability agreements which simplify multi-system navigation receiver architecture and reduce its cost. The most current GNSS signals of GPS, GLO- NASS and GALILEO can be processed by one or several classical E-L correlators with a look up table PRN generator of length 10230 chips. Most signals are processed optimally, but for some signals, like Galileo E1b and E1c or GPS L1C, this signal processor does not utilize all signal components and properties. The proposed E-L correlator was implemented to the FPGA of the experimental software GNSS receiver and was tested on the GALILEO E1b, E1c and E5a signals. The target multi-system GNSS receiver architecture based on an ExpressCard peripheral card for the standard PC computer or notebook is described in the paper. Up to hundred universal correlators and also signal snapshot capture unit for DSP acquisition are programmed to the receiver FPGA.
TL;DR: In this paper, the development and test results of a fiber-optic gyro of 0.01 deg/h accuracy grade designed at Concern CSRI Elektropribor, JSC, in cooperation with St. Petersburg State University of Information Technologies, Mechanics, and Optics are discussed.
Abstract: This paper presents the development and test results of a fiber-optic gyro of 0.01 deg/h accuracy grade designed at Concern CSRI Elektropribor, JSC, in cooperation with St. Petersburg State University of Information Technologies, Mechanics, and Optics. The problems regarding gyro accuracy, stability of output characteristics, drift compensation, dead-zone suppression, and the magnetic field effect are discussed.
TL;DR: In this paper, the influence of outer space conditions on the navigation processing algorithms has been analyzed and the main problems that need to be solved by researchers in developing procedures for digital signal processing in onboard satellite navigation equipment have been described.
Abstract: The influence of outer space conditions on the navigation-processing algorithms has been analyzed. The main problems that need to be solved by researchers in developing procedures for digital signal processing in onboard satellite navigation equipment have been described. It has been shown that navigation accuracy depends on the quality of the models for satellite motion and the onboard clock. It has been pro-posed that the stochastic “random walk” model based on the Kalman filter should be used for clock modeling. It has been demonstrated that this model is much more efficient than the classical polynomial model for GEO satellite navigation. Together with the precise satellite dynamic model, it allows three-dimensional accuracy on the order of 30 m, even in the case when a standard temperature-compensated crystal oscillator is used.
TL;DR: The algorithms and errors of a GPS-aided inertial system—integrated attitude and navigation system (IANS)—in attitude determination of a moving vehicle are studied and the elimination of the phase measurement ambiguity is made possible.
Abstract: The problem of determining a vehicle’s attitude parameters is considered. The solution to this problem is based on the integration of data from a strapdown inertial measurement unit (SIMU) on MEMS sensors and two receivers of the Global Navigation Satellite System (GNSS) with spaced antennas with the aim to form phase measurements. The algorithms and errors of a GPS-aided inertial system—integrated attitude and navigation system (IANS)—in attitude determination of a moving vehicle are studied. Coprocessing of data is carried out with the use of the algorithm of an extended Kalman filter (EKF) with feedback for the whole state vector of the system. A specific feature of the IANS considered here is that the data from the SIMU and GNSS receiver unit (RU) are integrated with primary phase measurements from two receivers with antennas spaced on a certain base. The elimination of the phase measurement ambiguity is made possible due to the SIMU data. The results of office studies of the data obtained during sea tests of an SIMU prototype on MEMS sensors, developed by CSRI Elektropribor, and a GNSS RU with two receivers (Ashtech G12 and Kotlin developed by the Russian Institute of Radionavigation and Time, JSC (RIRT)).
TL;DR: A method for verifying external navigation data for a local level inertial navigation system using optimal filtering algorithms in a closed-loop correction circuit and special attention is paid to verification of data from an electromagnetic log.
Abstract: This paper considers a method for verifying external navigation data for a local level inertial navigation system using optimal filtering algorithms in a closed-loop correction circuit. Special attention is paid to verification of data from an electromagnetic log. Examples of processing measurements containing various errors are presented.
TL;DR: The theory of airborne gravimetry and gradiometry, the sensitivities of various components of the gravitation vector, and the gradient tensor to position and attitude (rate) errors are reviewed to show that present gyro technology is sufficient to meet requirements for existing airborne gradiometers, but requires improvement for future gradient sensors.
Abstract: Airborne measurements of the gravitation vector and its gradients require auxiliary measurements of position and attitude, not just for registration (geolocation) purposes, but also to separate gravitational from kinematic accelerations (and gradients) according to the principle of equivalence. Very precise positioning is needed to compute accelerations by numerical differentiation, and very accurate angular rates are needed to compute orientation (by integration) and angular acceleration (by differentiation). GPS positioning and gyro data can be used for these purposes, but limits in accuracy of current technology thus also constrain the useful performance of the principal gravimetric sensors. This paper reviews the theory of airborne gravimetry and gradiometry, the sensitivities of various components of the gravitation vector, and the gradient tensor to position and attitude (rate) errors. Generally, one may conclude that scalar gravimetry and vector gravimetry are limited by orientation error coupled to the acceleration environment of the vehicle, as well as positioning (i.e., kinematic acceleration) uncertainty, while gradiometry depends, instead, on very precise angular rates of the measurement frame. The necessary error tradeoff between future developments in gradiometers and gyro technology is thereby also illustrated and shows that present gyro technology is sufficient to meet requirements for existing airborne gradiometers, but requires improvement for future gradient sensors.
TL;DR: This paper presents the development and study results of an attitude determination algorithm using GLONASS and GPS signals, selecting the optimal combination of integer ambiguities by the maximum likelihood criterion.
Abstract: This paper presents the development and study results of an attitude determination algorithm using GLONASS and GPS signals. The probability of correct ambiguity resolution in attitude determination is assessed for an exhaustive method, selecting the optimal combination of integer ambiguities by the maximum likelihood criterion. Unlike the existing algorithms, the method determines the antenna separation distance, along with the vehicle’s attitude.
TL;DR: In this article, the results from the tests of an RR-type MEMS gyro developed by Elektropribor, St. Petersburg, Russia, were presented, and the experimental estimates of gyro performance variation during centrifuge, vibration, and shock tests were given.
Abstract: The paper presents the results from the tests of an RR-type MEMS gyro developed by Elektropribor, St. Petersburg, Russia. The experimental estimates of gyro performance variation during centrifuge, vibration, and shock tests are given. The dependences of the gyro parameters on the mechanical effects are obtained, and ways of reducing the vibration and shock influence on the gyro performance are found.
TL;DR: In this article, the authors consider vertical references, which determine UAV pitch and roll angles and are built as two-gyro pendulum-positioned systems, and strapdown attitude reference systems based on MEMS inertial sensors and pyrometers.
Abstract: The paper considers vertical references, which determine UAV pitch and roll angles and are built as two-gyro pendulum-positioned systems, and strapdown attitude reference systems based on MEMS inertial sensors and pyrometers.
TL;DR: In this article, a method of fast first fix using a low-cost GNSS receiver is presented, which makes it possible to significantly reduce the time to first fix when GNSS ephemerides and good estimates of the initial user position and time are available.
Abstract: A method of fast first fix using a low-cost GNSS receiver is presented. The method makes it possible to significantly reduce the time to first fix when GNSS ephemerides and good estimates of the initial user position and time are available. It is also proposed to use Doppler measurements for the initial estimation of user coordinates. The expected time to first fix is calculated depending on the input GNSS signal power.
TL;DR: For continuous survey in wellbores of different orientations, those well known and under development, and the prospects for their future are discussed in this paper, with a focus on gyroscopic inclinometers.
Abstract: Various gyroscopic inclinometers (GIs) for continuous survey in wellbores of different orientations, those well known and under development, have been analyzed and compared. The prospects for their future are discussed.
TL;DR: The paper considers the applications of sensitivity theory to analyzing data processing and control systems in nondesign modes, to reducing error models, to simplifying filters in data processing systems and regulators in control systems, and to synthesizing systems with low or minimum sensitivity to modeling errors.
Abstract: The paper considers the applications of sensitivity theory to analyzing data processing and control systems in nondesign modes, to reducing error models, to simplifying filters in data processing systems and regulators in control systems, and to synthesizing systems with low or minimum sensitivity to modeling errors.
TL;DR: In this article, a randomized algorithm, which filters out arbitrary external noise in observations, is proposed to predict the values of a random process, where uncertainties generating the process studied are assumed to be of a statistical nature, and observations are carried out with unknown, but bounded, disturbances.
Abstract: The problem of predicting the values of a random process is considered. The uncertainties generating the process studied are assumed to be of a statistical nature, and observations are carried out with unknown, but bounded, disturbances. A randomized algorithm, which filters out arbitrary external noise in observations, is proposed. The operability of the new algorithm at irregular noises in observations is illustrated by simulation as compared to traditional approaches.