scholarly journals A Novel Ambiguity Parameter Estimation and Elimination Strategy for GNSS/INS Tightly Coupled Integration

2020 ◽  
Vol 12 (21) ◽  
pp. 3514
Author(s):  
Chun Ma ◽  
Qiuzhao Zhang ◽  
Xiaolin Meng ◽  
Nanshan Zheng ◽  
Shuguo Pan
Keyword(s):  
Parameter Estimation ◽  
Navigation System ◽  
Coupled System ◽  
State Equations ◽  
Fixed Rate ◽  
Positioning Accuracy ◽  
Coupled Method ◽  
Estimation Process ◽  
Tightly Coupled ◽  
Ambiguity Parameter

The estimation of ambiguity in the global navigation satellite system/inertial navigation system (GNSS/INS) tightly coupled system is a key issue for GNSS/INS precise navigation positioning. Only when the ambiguity is solved correctly can the integrated navigation system obtain high-precision positioning results. Aiming at the problem of ambiguity parameter estimation in GNSS/INS tightly coupled system, a new strategy for ambiguity parameter estimation and elimination is proposed in this paper. Here, the ambiguity parameter is first added to the state equations of GNSS/INS in the estimation process. Then, the strategy of eliminating the parameter is used to improve efficiency. A residual test is carried out based on introducing the ambiguity parameter, thereby reducing or avoiding its influence on the filtering estimation process. Two groups of experiments were carried out and compared with GNSS positioning results. The results showed that, in the open sky observation environment, the positioning accuracy of the GNSS/INS tightly coupled method proposed in this paper was within 5 cm, and the ambiguity fixed rate was more than 97%, which is basically consistent. In a GNSS-denied environment, the positioning accuracy of the GNSS/INS tightly coupled method proposed in this paper was obviously better than that of GNSS, and the positioning accuracy in X, Y, and Z directions was improved by 82.46%, 78.87%, and 79.67%, respectively. The fixed rate of ambiguity increased from 73% to 78.57%. Therefore, in a GNSS-challenged environment, the novel strategy of the GNSS/INS tightly coupled system has higher ambiguity fixed rate and significantly improves positioning accuracy and continuity.

scholarly journals SINS/BDS Tightly-Coupled Integrated Navigation Algorithm for Hypersonic Vehicle

2021 ◽  
Author(s):  
kai chen ◽  
Sen-sen PEI ◽  
Cheng-zhi ZENG ◽  
Gang DING
Keyword(s):  
Navigation System ◽  
Maximum Velocity ◽  
Field Tests ◽  
Hypersonic Vehicle ◽  
Integrated Navigation ◽  
State Equations ◽  
Integrated Navigation System ◽  
Near Space ◽  
Navigation Algorithm ◽  
Tightly Coupled

Abstract A tightly-coupled integrated navigation system (TCINS) for hypersonic vehicles is proposed when the satellite signals are disturbed. Firstly, the architecture of the integrated navigation system for the hypersonic vehicle is introduced. This system applies fiber SINS, BeiDou satellite receiver (BDS) and SOPC missile-born computer. Subsequently, the SINS mechanization for hypersonic vehicle is presented. The J2 model is employed for the normal gravity of the near space. An algorithm for updating the attitude, velocity and position is designed. State equations and measurement equations of SINS/BDS tightly-coupled integrated navigation for hypersonic vehicle are given, and a scheme of validity for satellite data is designed. Finally, the SINS/BDS tightly-coupled vehicle field tests and hardware-in-the-loop (HWIL) simulation tests are carried out. The vehicle field test and HWIL simulation results show that the heading angle error of tightly-coupled integrated navigation is within 0.2°, the pitch and roll angle errors are within 0.05°, the maximum velocity error is 0.3m/s, and the maximum position error is 10m.

Data Fusion for Indoor Mobile Robot Positioning Based on Tightly Coupled INS/UWB

2017 ◽  
Vol 70 (5) ◽  
pp. 1079-1097 ◽  
Author(s):  
Qigao Fan ◽  
Biwen Sun ◽  
Yan Sun ◽  
Yaheng Wu ◽  
Xiangpeng Zhuang
Keyword(s):  
Mobile Robot ◽  
Navigation System ◽  
Kinematic Model ◽  
Inertial Navigation ◽  
Coupled Model ◽  
Navigation Systems ◽  
Integrated Navigation ◽  
Order Error ◽  
Positioning Accuracy ◽  
Tightly Coupled

This paper proposes a novel sensor fusion approach using Ultra Wide Band (UWB) wireless radio and an Inertial Navigation System (INS), which aims to reduce the accumulated error of low-cost Micro-Electromechanical Systems (MEMS) Inertial Navigation Systems used for real-time navigation and tracking of mobile robots in a closed environment. A tightly-coupled model of INS/UWB is established within the integrated positioning system. A two-dimensional kinematic model of the mobile robot based on kinematics analysis is then established, and an Auto-Regressive (AR) algorithm is used to establish third-order error equations of the gyroscope and the accelerometer. An Improved Adaptive Kalman Filter (IAKF) algorithm is proposed. The orthogonality judgment method of innovation is used to identify the “outliers”, and a covariance matching technique is introduced to judge the filter state. The simulation results show that the IAKF algorithm has a higher positioning accuracy than the KF algorithm and the UWB system. Finally, static and dynamic experiments are performed using an indoor experimental platform. The results show that the INS/UWB integrated navigation system can achieve a positioning accuracy of within 0·24 m, which meets the requirements for practical conditions and is superior to other independent subsystems.

Research on GNSS/SINS Tightly Coupled Integrated Navigation System

2014 ◽  
Vol 1049-1050 ◽  
pp. 1832-1835 ◽  
Author(s):  
Yao Wei Chang ◽  
Shuai Chen
Keyword(s):  
High Precision ◽  
Navigation System ◽  
Error Compensation ◽  
Coupled System ◽  
Compensation Method ◽  
Integrated Navigation ◽  
Selection Algorithm ◽  
Integrated Navigation System ◽  
Tightly Coupled ◽  
Multiple Step

When a missile runs under the complex situation such as high dynamic flying, receiver signal being blocked and so on, the GNSS receiver sometimes gets less than four satellites. For the loosely coupled system, the navigation accuracy will decrease over time. In this paper ,tightly coupled integrated navigation system which is based on pseudo range and pseudo range rate dynamically adjusts the dimension of the system according to the number of visible satellites, in order to achieve seamlessly navigation; a multiple step optimum precision factor satellite selection algorithm is proposed, an error compensation method which is based on the state transition is designed and implemented. Experiments show that when the number of visible satellites changes, tightly coupled system can seamlessly switch, when more than four satellites are received, the multiple step optimum precision factor selection algorithm can provide a combination of high precision satellites, by applying the error compensation method to calibrating the system, high-precision navigation can be achieved.

Synthesis of a basic satellite radio navigation system

2021 ◽  
pp. 3-16
Author(s):  
Т.С. Аббасова ◽  
В.И. Привалов ◽  
В.Г. Бондаренко
Keyword(s):  
Navigation System ◽  
Initial Step ◽  
Positioning Accuracy ◽  
Phase Measurements ◽  
Positioning Systems ◽  
Radio Navigation ◽  
Satellite Radio Navigation System ◽  
Radio Navigation System ◽  
Effective Procedures ◽  
Basic Version

На основе анализа особенностей навигационно-временных определений и методологических основ проектирования в системах высокоточного позиционирования проведена генерация вариантов спутниковой радионавигационной системы, исходным шагом в которой является синтез её базового варианта. Рассмотрены наиболее эффективные процедуры разрешения неоднозначности фазовых измерений, основанных на избыточности фазовых измерений, а также процедуры, заключающиеся в целочисленной максимизации функции неоднозначности, выбранной из характера периодичности сигналов навигационного космического аппарата. Сформулирован критерий точности позиционирования. Based on the analysis of the features of navigation-time definitions and methodological foundations of design in high-precision positioning systems, the generation of options for a satellite radio navigation system was carried out, the initial step in which is the synthesis of its basic version. The most effective procedures for resolving the ambiguity of phase measurements based on the redundancy of phase measurements, as well as procedures involving the integer maximization of the ambiguity function, selected from the nature of the periodicity of the signals of the navigation spacecraft, are considered. A criterion for positioning accuracy is formulated.

Analysis on Signal-in-Space Range Error and Positioning Accuracy of BDS-3

2021 ◽  
Author(s):  
Weiping Liu ◽  
Bo Jiao ◽  
Jinming Hao ◽  
Zhiwei Lv ◽  
Jiantao Xie ◽  
...  
Keyword(s):  
Navigation System ◽  
Convergence Time ◽  
Asia Pacific ◽  
Single Frequency ◽  
Earth Orbit ◽  
Positioning Accuracy ◽  
Point Positioning ◽  
Range Error ◽  
Space Range ◽  
Better Than

Abstract Being the first mixed-constellation global navigation system, the global BeiDou navigation system (BDS-3) designs new signals, the service performance of which has attracted extensive attention. In the present study, the Signal-in-space range error (SISRE) computation method for different types of navigation satellites was presented. And the differential code bias (DCB) correction method for BDS-3 new signals was deduced. Based on these, analysis and evaluation were done by adopting the actual measured data after the official launching of BDS-3. The results showed that BDS-3 performed better than the regional navigation satellite system (BDS-2) in terms of SISRE. Specifically, the SISRE of the BDS-3 medium earth orbit (MEO) satellites reached 0.52 m, slightly inferior compared to 0.4 m from Galileo, marginally better than 0.57 m from GPS, and significantly better than 2.33 m from GLONASS. And the BDS-3 inclined geostationary orbit (IGSO) satellites achieved the SISRE of 0.90 m, on par with that of the QZSS IGSO satellites. However, the average SISRE of BDS-3 geostationary earth orbit (GEO) satellites was 1.15 m, which was marginally inferior to that of the QZSS GEO satellite (0.91m). In terms of positioning accuracy, the overall three-dimensional single-frequency standard point positioning (SPP) accuracy of BDS-3 B1C, B2a, B1I, and B3I gained an accuracy level better than 5 m. Moreover, the B1I signal exhibited the best positioning accuracy in the Asian-Pacific region, while the B1C signal set forth the best positioning accuracy in the other regions. Owing to the advantage in signal frequency, the dual-frequency SPP accuracy of B1C+B2a surpassed that of the transitional signal of B1I+B3I. Since there are more visible satellites in Asia-Pacific, the positioning accuracy of BDS-3 was moderately superior to that of GPS. The precise point positioning (PPP) accuracy of BDS-3 B1C+B2a or B1I+B3I converged to the order of centimeters, marginally inferior to that of the GPS L1+L2. However, these three combinations had a similar convergence time of approximately 30 minutes.

scholarly journals Robust Adaptive Cubature Kalman Filter and Its Application to Ultra-Tightly Coupled SINS/GPS Navigation System

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2352 ◽  
Author(s):  
Xin Zhao ◽  
Jianli Li ◽  
Xunliang Yan ◽  
Shaowen Ji
Keyword(s):  
Kalman Filter ◽  
Navigation System ◽  
Kinematic Model ◽  
Tracking Performance ◽  
Typical Application ◽  
Gross Error ◽  
Cubature Kalman Filter ◽  
Tightly Coupled ◽  
Robust Adaptive ◽  
High Dynamics

In this paper, we propose a robust adaptive cubature Kalman filter (CKF) to deal with the problem of an inaccurately known system model and noise statistics. In order to overcome the kinematic model error, we introduce an adaptive factor to adjust the covariance matrix of state prediction, and process the influence introduced by dynamic disturbance error. Aiming at overcoming the abnormality error, we propose the robust estimation theory to adjust the CKF algorithm online. The proposed adaptive CKF can detect the degree of gross error and subsequently process it, so the influence produced by the abnormality error can be solved. The paper also studies a typical application system for the proposed method, which is the ultra-tightly coupled navigation system of a hypersonic vehicle. Highly dynamical scene experimental results show that the proposed method can effectively process errors aroused by the abnormality data and inaccurate model, and has better tracking performance than UKF and CKF tracking methods. Simultaneously, the proposed method is superior to the tracing method based on a single-modulating loop in the tracking performance. Thus, the stable and high-precision tracking for GPS satellite signals are preferably achieved and the applicability of the system is promoted under the circumstance of high dynamics and weak signals. The effectiveness of the proposed method is verified by a highly dynamical scene experiment.

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