The authors proposed a moving long baseline algorithm based on the extended Kalman filter （EKF） for cooperative navigation and localization of multi-unmanned underwater vehicles （UUVs）. Research on cooperative nav...The authors proposed a moving long baseline algorithm based on the extended Kalman filter （EKF） for cooperative navigation and localization of multi-unmanned underwater vehicles （UUVs）. Research on cooperative navigation and localization for multi-UUVs is important to solve navigation problems that restrict long and deep excursions. The authors investigated improvements in navigation accuracy. In the moving long base line （MLBL） structure, the master UUV is equipped with a high precision navigation system as a node of the moving long baseline, and the slave UUV is equipped with a low precision navigation system. They are both equipped with acoustic devices to measure relative location. Using traditional triangulation methods to calculate the position of the slave UUV may cause a faulty solution. An EKF was designed to solve this, combining the proprioceptive and exteroceptive sensors. Research results proved that the navigational accuracy is improved significantly with the MLBL method based on EKF.展开更多
A multiple antenna GPS system integrated with MEMS-based INS is proposed by data fusion. The system is applied to attitude determination due to its high accuracy, the high output rate, low latency, quick initializatio...A multiple antenna GPS system integrated with MEMS-based INS is proposed by data fusion. The system is applied to attitude determination due to its high accuracy, the high output rate, low latency, quick initialization, and good robustness and redundancy. The mathematical method for realizing the system is given. The system can provide attitude and other navigation information even without GPS measurement for a period of time. Experimental results show that, under the condition of 200 Hz, the attitude, the position, the velocity, the acceleration, and the angular rate can achieve 0. 08°/s, 1.5 m, 0. 1 m/s, 0. 12 m/s^2 and 0. 1°/s.展开更多
The NAVSTAR Global Positioning System （GPS）, a networked system providing three-dimenslon user position and timing, is widely used during the past ten years. However, interferences to GPS introduce great dangers to ...The NAVSTAR Global Positioning System （GPS）, a networked system providing three-dimenslon user position and timing, is widely used during the past ten years. However, interferences to GPS introduce great dangers to GPS users. This paper gives an assessment of interferences to the GPS positioning signal. The work is mainly concentrated on effects of wide band interferences. Effects of traditional interferences such as continuous wave （CW）, as well as broadband noise and pulse interference are studied. Furthermorre, according to the GPS＇ s signal characteristics, another kind of wideband interferences, named m sequence interference in this paper, is also studied. Simulation results show that m sequence interference is the most harmful to GPS C/A code if special m sequence is adopted and thus special countermeasures should be used to eliminate this effect.展开更多
It is shown to be a relevant study involving terrestrial methods of measurement, such as： forward and backward intersections, geometric leveling, trigonometric leveling with short distance targeted and spatial positi...It is shown to be a relevant study involving terrestrial methods of measurement, such as： forward and backward intersections, geometric leveling, trigonometric leveling with short distance targeted and spatial positioning GNSS methods, for the definition of field reference points and field-object points located in rough terrain. The geodesic structures were implemented in the Historic Site of Olinda employing GNSS （global navigation satellite system） receivers, total stations and digital level. The historical site of Olinda was recorded by UNESCO as Historical and Cultural Heritage of Humanity. The study area is located in the center of the busiest site with a quite roughly relief. This area has been studied since 2007 involving Research of Scientific Initiation and Pos-Graduation Course. This paper aims to present the realized experiments for the implementation and definition of geodesic structures in environments with very rough relief, including large old houses and historic monuments.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.60875071the High Technology Research and Development Program of China under Grant No.2007AA0676the Program for New Century Excellent Talents in University under Grant No.NCET-06-0877
文摘The authors proposed a moving long baseline algorithm based on the extended Kalman filter （EKF） for cooperative navigation and localization of multi-unmanned underwater vehicles （UUVs）. Research on cooperative navigation and localization for multi-UUVs is important to solve navigation problems that restrict long and deep excursions. The authors investigated improvements in navigation accuracy. In the moving long base line （MLBL） structure, the master UUV is equipped with a high precision navigation system as a node of the moving long baseline, and the slave UUV is equipped with a low precision navigation system. They are both equipped with acoustic devices to measure relative location. Using traditional triangulation methods to calculate the position of the slave UUV may cause a faulty solution. An EKF was designed to solve this, combining the proprioceptive and exteroceptive sensors. Research results proved that the navigational accuracy is improved significantly with the MLBL method based on EKF.
文摘A multiple antenna GPS system integrated with MEMS-based INS is proposed by data fusion. The system is applied to attitude determination due to its high accuracy, the high output rate, low latency, quick initialization, and good robustness and redundancy. The mathematical method for realizing the system is given. The system can provide attitude and other navigation information even without GPS measurement for a period of time. Experimental results show that, under the condition of 200 Hz, the attitude, the position, the velocity, the acceleration, and the angular rate can achieve 0. 08°/s, 1.5 m, 0. 1 m/s, 0. 12 m/s^2 and 0. 1°/s.
基金Sponsored by Foundation of Harbin Institute of Technology(Grant No. HIT.02.07).
文摘The NAVSTAR Global Positioning System （GPS）, a networked system providing three-dimenslon user position and timing, is widely used during the past ten years. However, interferences to GPS introduce great dangers to GPS users. This paper gives an assessment of interferences to the GPS positioning signal. The work is mainly concentrated on effects of wide band interferences. Effects of traditional interferences such as continuous wave （CW）, as well as broadband noise and pulse interference are studied. Furthermorre, according to the GPS＇ s signal characteristics, another kind of wideband interferences, named m sequence interference in this paper, is also studied. Simulation results show that m sequence interference is the most harmful to GPS C/A code if special m sequence is adopted and thus special countermeasures should be used to eliminate this effect.
文摘It is shown to be a relevant study involving terrestrial methods of measurement, such as： forward and backward intersections, geometric leveling, trigonometric leveling with short distance targeted and spatial positioning GNSS methods, for the definition of field reference points and field-object points located in rough terrain. The geodesic structures were implemented in the Historic Site of Olinda employing GNSS （global navigation satellite system） receivers, total stations and digital level. The historical site of Olinda was recorded by UNESCO as Historical and Cultural Heritage of Humanity. The study area is located in the center of the busiest site with a quite roughly relief. This area has been studied since 2007 involving Research of Scientific Initiation and Pos-Graduation Course. This paper aims to present the realized experiments for the implementation and definition of geodesic structures in environments with very rough relief, including large old houses and historic monuments.
