Showing papers in "Gyroscopy and Navigation in 2016"
TL;DR: Current trends in the development of nonlinear filtering algorithms for map-aided navigation algorithms are discussed and some new lines in identification of error models and the use of information on the probable vehicle motion are considered.
Abstract: This paper deals with the problem of map-aided navigation. Based on the previous overview of nonlinear filtering algorithms for this problem solution, current trends in the development of such algorithms are discussed. Some new lines in identification of error models and the use of information on the probable vehicle motion are considered.
35 citations
TL;DR: In this article, the Allan variance and its modifications have been developed for characterizing the instabilities in precision clocks and oscillators over the past 50 years, and these variances have been shown to be efficient descriptors of these processes.
Abstract: Over the past 50 years, Allan variance and its modifications have been developed for characterizing the instabilities in precision clocks and oscillators These instabilities are often modeled by non-stationary processes, and these variances have been shown to be efficient descriptors of these processes The timedomain and frequency-domain relationships are shown along with the strengths and weaknesses of the proposed variances These variances are also shown to be useful elsewhere, as in navigation
25 citations
TL;DR: In this article, a modified type of a quadrotor with tiltable rotors is presented, which in contrast to common quadrotors is able to perform independent velocity and attitude movements.
Abstract: Micro Aerial Vehicles (MAV) with vertical takeoff and landing capabilities such as quadrotors are often used as sensor platforms. The carried equipment like cameras or LASER range finders has to be aligned to some point of interest. In this article a modified type of a quadrotor will be presented: a quadrotor with tiltable rotors which in contrast to common quadrotors is able to perform independent velocity and attitude movements. This ability makes additional aligning equipment to move the payload redundant. After a system description, the used control algorithm based on Nonlinear Inverse Dynamics (NID) is explained. In this article an extension of this approach is presented. The pseudo control hedging method removes the influence of the actuator dynamics from the control loop. The extension and its integration into the control algorithm are explained and the influence on the quality of control is demonstrated by simulation results.
21 citations
TL;DR: In this paper, the unbalance components of the hemispherical resonator gyro (HRG) with a shell of variable thickness in meridian direction are obtained, and various laws of thickness reduction from the pole to the edge are considered.
Abstract: Formulas for the unbalance components of the hemispherical resonator gyro (HRG) with a shell of variable thickness in meridian direction are obtained. Various laws of thickness reduction from the pole to the edge are considered. It is shown that for the second form of excited oscillations, relative error in unbalance components (with the thickness variation neglected) can reach 10–15%. The obtained formulas for unbalance components, taking into account the variable thickness of the shell, can significantly improve the accuracy of HRG balancing, which is the most important process in the manufacture of medium and high precision devices.
16 citations
TL;DR: In this paper, the error characteristics for a gyro-free system were derived for a stationary system with only accelerometers, and a comparison between different configurations of accelerometers was conducted.
Abstract: For a stationary system, coarse alignment is used to initially determine the orientation of the INS by utilizing the Earth gravity and rotation vectors. Yet, a gyro-free INS has only accelerometers and hence cannot measure the Earth rotation vector and thus cannot deduce its yaw angle. In this paper, we formulate the coarse-alignment procedure and derive error characteristics for a gyro-free system. In addition, a comparison between different configurations of accelerometers is being conducted.
14 citations
TL;DR: The simulation of the considered algorithms performance and the results of the sea trials using a marine autonomous robotic complex (MARC), including an AUV and an ASV, are discussed.
Abstract: This paper is devoted to navigation of autonomous underwater vehicles (AUV) with a mobile hydroacoustic beacon transported by an autonomous surface vehicle (ASV) Two algorithms for AUV positioning using information on the distance to a single beacon and the data from the onboard autonomous navigation system have been studied The first algorithm is based on the application of the extended Kalman filter, and the other one uses the particle filter The simulation of the considered algorithms performance and the results of the sea trials using a marine autonomous robotic complex (MARC), including an AUV and an ASV, are discussed
13 citations
TL;DR: In this article, the sources of fundamental noises in FOG measurement signal were described and methods of excess relative intensity noise (RIN) compensation were considered, and a technique improving the compensation method using division of signals from two photodetectors for noise suppression was proposed and implemented.
Abstract: The paper describes the sources of fundamental noises in FOG measurement signal. Methods of excess relative intensity noise (RIN) compensation are considered. Technique improving the compensation method using division of signals from two photodetectors for noise suppression is proposed and implemented. Functional simulation is conducted, which estimates the limiting theoretical value of noise suppression by the selected compensation method with the photodetector power of min 10 µW. Test results for FOG experimental prototype are presented. Allan variance plots for the cases with and without compensation are constructed.
12 citations
TL;DR: In this article, a low cost GNSS receiver is added to the widely known GNSS/INS system to achieve effective spoofing detection, and models of pseudorange/carrier phase double difference under normal and spoofing conditions are built and analyzed.
Abstract: GNSS Spoofing is a technique that intentionally fools a receiver into generating incorrect position and/or time solution. A low cost GNSS receiver is added to the widely known GNSS/INS system to achieve effective spoofing detection. Models of pseudorange/carrier phase double difference under normal and spoofing conditions are built and analyzed. With the aid of INS, double difference observations are calculated and compared with the actual measurements to construct the test statistic. A full detection process with constant false alarm rate is set up and its detection ability is verified by live signal experiment in a static case.
11 citations
TL;DR: In this article, the authors proposed a procedure for studying the errors of MEMS accelerometer triad which reduces the test duration as compared with traditional methods and allows estimation of mutual geometrical arrangement of sensors in the triad.
Abstract: The procedure proposed for studying the errors of MEMS accelerometer triad reduces the test duration as compared with traditional methods and allows estimation of mutual geometrical arrangement of sensors in the triad. The proposed approach consists in studying the static characteristics of sensors in oscillating angular motion mode and estimates error coefficients in mathematical model of accelerometer readings along with location of accelerometer triad in the closed IMU casing. Results of studying the errors of MEMS accelerometer triad are presented.
10 citations
TL;DR: piNAV L1 is a GPS L1 receiver for position determination of the small satellites at LEO orbits that was tested by the ReGen software GPS simulator for static and dynamic scenarios.
Abstract: piNAV L1 is a GPS L1 receiver for position determination of the small satellites at LEO orbits. The receiver was tested by the ReGen software GPS simulator for static and dynamic scenarios. The typical horizontal position error for static scenario is 2.5 m (95%). The position errors for dynamic scenarios are affected by the dynamic stress errors.
10 citations
TL;DR: This work presents an overview of parametric FP methods that use model-based representations of the survey data, and studies different approaches that use path loss models, and methods that using Gaussian mixtures.
Abstract: The term fingerprint-based (FP) positioning includes a wide variety of methods for determining a receiver’s position using a database of radio signal strength measurements that were collected earlier at known locations. Nonparametric methods such as the weighted k-nearest neighbor (WKNN) method are infeasible for large-scale mobile device services because of the large data storage and transmission requirements. In this work we present an overview of parametric FP methods that use model-based representations of the survey data. We look at three different groups of parametric methods: methods that use coverage areas, methods that use path loss models, and methods that use Gaussian mixtures. Within each group we study different approaches and discuss their pros and cons. Furthermore, we test the positioning performance of several of the analyzed approaches in different scenarios using real-world WLAN indoor data and compare the results to those of the WKNN method.
TL;DR: The method uses the Kalman filter in SINS navigation mode and estimates errors in gyro and accelerometer delays and scale factors, sensitivity axes misalignment and drift, coordinates of accelerometer proof masses in the body-fixed frame, minimizing the resulting SINS error.
Abstract: The article presents a method of determining gyro and accelerometer delays during calibration of strapdown inertial navigation systems (SINS) of navigation accuracy. The method uses the Kalman filter in SINS navigation mode and estimates errors in gyro and accelerometer delays and scale factors, sensitivity axes misalignment and drift, coordinates of accelerometer proof masses in the body-fixed frame. Application of SINS navigation mode during calibration reduces the requirements to accuracy of the rate table. The obtained estimates of calibration parameters are self-consistent, minimizing the resulting SINS error. The method was tested during calibration of FOG-based SINS.
TL;DR: This paper proposed a method against GPS signal spoofing based on combination of GPS and GLONASS regarding to pseudorange behavior in spoofing situations and showed a big improvement in Root Mean Square (RMS) error in comparison with GPS-only positioning in all spoofed scenarios.
Abstract: After renewed GLObal NAvigation Satellite System (GLONASS) was completed and it became world wide as its U.S. counterpart, Global Positioning System (GPS), the best way for increasing the number of satellites in the user’s view is combining these two systems. On the other hand, as it is possible for GPS satellites to be spoofed or blocked, combining becomes more efficacious. In this paper, GPS and GLONASS are used for positioning using Kalman filter. Kalman filter is utilized here because it is one of the cheapest and applicable tools for implementing on cheap processors. In addition, in this paper, we proposed a method against GPS signal spoofing based on combination of GPS and GLONASS regarding to pseudorange behavior in spoofing situations. The proposed method is not only easy to implement, but also low cost and high precision. This method without any need for expensive receiver has ability for real-time recognition of spoofing attacks and eliminating its effects. The recorded data was collected using an implemented GPS, and GLONASS RF front-end in stationary mode and in order to show spoofing effects on positioning an artificial spoofing was applied on GPS satellite signals in different scenarios. The simulation results showed a big improvement in Root Mean Square (RMS) error in comparison with GPS-only positioning in all spoofed scenarios.
TL;DR: In this article, the application of modern global geopotential models to estimate the navigation informativity of the Earth's anomalous gravity field (EAGF) is considered from the viewpoint of its use in autonomous (correlation-extreme) navigation.
Abstract: Application of modern global geopotential models to estimate the navigation informativity of the Earth’s anomalous gravity field (EAGF) is considered from the viewpoint of its use in autonomous (correlation- extreme) navigation. Various algorithms for calculating the characteristics of route and area navigation informativity, for which the authors use the variance and correlation radius of a measured EAGF parameter, are presented. The results of the experimental studies on estimation of the EAGF navigation informativity are discussed by analyzing vertical deflections and second derivatives of the perturbing potential in the Sea of Okhotsk with the use of the model EGM-2008 to degree 2190. It is shown that second derivatives of the geopotential demonstrate higher informativity as applied to navigation purposes.
TL;DR: The accuracy capabilities of revitalized GLONASS in standalone and in mixed mode of operation with GPS on basis of studies made using real-life data from different parts of India collected over 2012–2014 are discussed.
Abstract: GLONASS is declared fully operational in its revitalized form since late 2011. This generated interest for using it for redundancy and system independence and for a robust Multi-GNSS navigation environment. This paper discusses the accuracy capabilities of revitalized GLONASS in standalone and in mixed mode of operation with GPS on basis of studies made using real-life data from different parts of India collected over 2012–2014. The results show the potentials of GLONASS as an independent global navigation system and the advantages of it as an active component of usable Multi-GNSS from India and the surrounding regions.
TL;DR: In this paper, the distortion of nuclear magnetic resonance line in a quantum rotation sensor caused by the feedback in the cell while detecting the nuclear magnetization was considered, and the detection circuit was based on Faraday effect during longitudinal electronic paramagnetic resonance in alkali metal vapor.
Abstract: The paper considers the distortion of nuclear magnetic resonance line in a quantum rotation sensor caused by the feedback in the cell while detecting the nuclear magnetization. Detection circuit is based on Faraday effect during longitudinal electronic paramagnetic resonance in alkali metal vapor.
TL;DR: In this article, the errors of an autonomous platformless inertial navigation system (INS) with fiber-optic gyros (FOG), the inertial measurement unit (IMU) of which is mounted in a two-axis gimbal suspension, are analyzed.
Abstract: The errors of an autonomous platformless inertial navigation system (INS) with fiber-optic gyros (FOG), the inertial measurement unit (IMU) of which is mounted in a two-axis gimbal suspension, are analyzed The quality criteria and the kinematic scheme of the gimbal are considered The optimal law of IMU rotation from the standpoint of the selected minimum criterion has been calculated Simulation was carried out to study the effects of different errors of the IMU sensors on the INS accuracy The results obtained are confirmed by the development tests of a FOG-based INS designed by Concern CSRI Elektropribor
TL;DR: A comparative analysis of IRNSS and GPS navigational satellites shows that theIRNSS consists of sufficient number of satellites for regional navigation system and it can also exhibit better performance.
Abstract: The Indian Regional Navigation Satellite System (IRNSS) is a seven-satellite constellation developed by Indian Space Research Organization (ISRO), India. IRNSS provides two services, with the standard positioning service open for civilian use, and for authorized users (including the military) with an assured absolute positional accuracy. IRNSS is designed to cover all the parts of India and also extending beyond the Indian borders. The coverage area of IRNSS with routes of satellites means and includes area covering entire Pakistan, Afghanistan, most of China and Middle East along with Indian Ocean. IRNSS downlink signals have two bands: S1 band and L5 Band. Presently Indian users are dependent on the civil GPS signals with a positional accuracy of 5 m. IRNSS system is intended to provide an absolute position accuracy of (i) better than 10 m throughout Indian landmass (ii) better than 20 m over the Indian Ocean and (iii) approximately in a region of 1500 km around India. There are 15 ground stations across the country responsible for operating and/or monitoring the IRNSS seven satellite constellation. A comparative analysis of IRNSS and GPS navigational satellites shows that the IRNSS consists of sufficient number of satellites for regional navigation system and it can also exhibit better performance. The main parameters selected for our study are orbital characteristics, position accuracy and positional error including Circular Error Probable (CEP), Altitude variation, Geometric Dilution of Precision (GDOP) with respect to Number of Satellites (NSAT), variations in Carrier to Noise (C/N0) ratio and scintillation effect of both GPS and IRNSS satellite systems. Our analysis showed that IRNSS systems shall be used as stand-alone systems.
TL;DR: In this paper, a path following control for a robot with omni wheels is synthesized using differential geometry methods through nonlinear transformation of the initial dynamic model, and the main results are presented in the form of nonlinear control algorithm and experimental data.
Abstract: The paper focuses on the problem of synthesis of path following control for a robot with omni wheels. Control is synthesized using differential geometry methods through nonlinear transformation of the initial dynamic model. The main results are presented in the form of nonlinear control algorithm and experimental data.
TL;DR: The paper provides brief information of the history of development of e-Navigation concept, its definition, modern understanding of its main statements, and the first implementation results.
Abstract: The paper provides brief information of the history of development of e-Navigation concept, its definition, modern understanding of its main statements, and the first implementation results.
TL;DR: In this paper, a finite algorithm for determining a vehicle's position by differences in measured pseudoranges to known reference points is considered, and a convenient complex-valued form of the problem solution is obtained for the coplanar case.
Abstract: A finite algorithm for determining a vehicle’s position by differences in measured pseudoranges to known reference points is considered. Equations are derived for the case of excessive number of reference points and for coplanar reference points. A convenient complex-valued form of the problem solution is obtained for the coplanar case.
TL;DR: The main features of the software used for calculation and visualization of the library are described in sufficient detail and a method for calibration of a computer vision system using a pair of images with several calibration patterns is presented.
Abstract: Computer vision hardware and software for navigation and mapping are discussed. The system includes two video cameras. The main features of the software used for calculation and visualization of the library are described in sufficient detail. A method for calibration of a computer vision system using a pair of images with several calibration patterns is presented. The testing equipment for estimation of accuracy in determining navigation parameters with the computer vision system is considered. The results are discussed.
TL;DR: A Pedestrian Integrated Navigation System (PINS), which includes micro Inertial Measurement Units, Global Positioning System module, magnetometer and barometric altimeter, mounted on pedestrian’s waist, shows good results when the GPS signal is present.
Abstract: A Pedestrian Integrated Navigation System (PINS) is presented in this paper. PINS includes micro Inertial Measurement Units (IMU), Global Positioning System (GPS) module, magnetometer and barometric altimeter. It is mounted on pedestrian’s waist. When a pedestrian walks, his position, velocity and altitude can be obtained by PINS. The pedestrian gait big or small is detected automatically. According to the information of IMU, GPS, magnetometer and barometric altimeter, Extended Kalman Filter (EKF) is provided. Indoor and outdoor test results show that when the GPS signal is present, the azimuth error is better than 0.5 degrees, the position error is better than 5 meters, and when the GPS signal is absent, the azimuth error is better than 1 degree, the position error is better than 3 percents of the total route, the height error is better than 1 meter and the interior floor can be identified clearly.
TL;DR: In this article, the relationship between Allan variance and error variance of sensor bias estimate obtained by averaging over a certain period is discussed, and it is shown that bias estimation accuracy can be improved using nonlinear filtering methods in the conditions of uncertain error model.
Abstract: The paper discusses the relationship between Allan variance and error variance of sensor bias estimate obtained by averaging over a certain period. Allan variance is shown to coincide with this variance in some cases. Bias estimation accuracy can be improved using nonlinear filtering methods in the conditions of uncertain error model.
TL;DR: An improved attitude algorithm in MEMS-RSINS aided by compass/rotary encoder is proposed and detailed, and simulation is conducted to prove the validity of this improved attitudes algorithm.
Abstract: The paper focuses on two problems of conventional attitude algorithm in MEMS rotary SINS. One is that the yaw error diverges, and the other is that the high-resolution rotary encoder is relied on. In order to solve the problems mentioned, an improved attitude algorithm in MEMS-RSINS aided by compass/rotary encoder is proposed and detailed. Then simulation is conducted to prove the validity of this improved attitude algorithm.
TL;DR: The paper describes a navigation and information system of precise transport positioning using low-cost GNSS equipment and the GLONASS ground infrastructure that provides decimeter positioning accuracy.
Abstract: The paper describes a navigation and information system of precise transport positioning using low-cost GNSS equipment and the GLONASS ground infrastructure. The system consists of structurally complementary component parts and provides decimeter positioning accuracy.
TL;DR: In this article, measurements of output signals of SINS laser gyros are used to analyze the behavior of their spectral characteristics and to estimate the performance of methods to determine the components of laser gyro random drift.
Abstract: Measurements of output signals of SINS laser gyros are used to analyze the behavior of their spectral characteristics and to estimate the performance of methods to determine the components of laser gyro random drift.
TL;DR: The basic methods for determining deflections of the vertical on a moving base are considered and the classification criteria of these methods are proposed.
Abstract: The basic methods for determining deflections of the vertical on a moving base are considered. The classification criteria of these methods are proposed. The comparative analysis of the methods has been performed based on the proposed criteria.
TL;DR: In this paper, a MEMS RR-type gyro design, immune to translational vibration and constant linear accelerations, is proposed, which improves the gyro mechanical performance through arranging the electrodes of the torquer and angular sensor on elastic suspension of certain stiffness.
Abstract: A MEMS RR-type gyro design, immune to translational vibration and constant linear accelerations, is proposed. The gyro mechanical performance is improved through arranging the electrodes of the torquer and angular sensor on elastic suspension of certain stiffness. Design features of the proposed gyro are described, analytical formulas relating the natural frequencies of inertial body suspension and the electrode are given, along with the results of mathematical modeling of gyro dynamics on a vibrating foundation.
TL;DR: The state-of-the-art Russian star trackers, inertial sensors, and onboard computer systems intended for orientation and stabilization systems are considered and the problems and prospects for their further development are discussed.
Abstract: The requirements for orientation and stabilization systems of space vehicles are formulated. The state-of-the-art Russian star trackers, inertial sensors, and onboard computer systems intended for orientation and stabilization systems are considered. The problems and prospects for their further development are discussed.