Current Issue : October - December Volume : 2014 Issue Number : 4 Articles : 5 Articles
As the core of the integrated navigation system, the data fusion algorithm should be designed seriously. In order to improve\nthe accuracy of data fusion, this work proposed an adaptive iterated extended Kalman (AIEKF) which used the noise statistics\nestimator in the iterated extended Kalman (IEKF), and then AIEKF is used to deal with the nonlinear problem in the inertial\nnavigation systems (INS)/wireless sensors networks (WSNs)-integrated navigation system. Practical test has been done to evaluate\nthe performance of the proposed method. The results show that the proposed method is effective to reduce the mean root-meansquare\nerror (RMSE) of position by about 92.53%, 67.93%, 55.97%, and 30.09% compared with the INS only,WSN, EKF, and IEKF....
Positioning accuracy is a challenging issue for location-based applications using a low-cost global positioning system (GPS). This\npaper presents an effective approach to improving the positioning accuracy of a low-cost GPS receiver for real-time navigation. The\nproposed method precisely estimates position by combining vehicle movement direction, velocity averaging, and distance between\nwaypoints using coordinate data (latitude, longitude, time, and velocity) of the GPS receiver. The previously estimated precious\nreference point, coordinate translation, and invalid data check also improve accuracy. In order to evaluate the performance of\nthe proposed method, we conducted an experiment using a GARMIN GPS 19xHVS receiver attached to a car and used Google\nMaps to plot the processed data.The proposed method achieved improvement of 4ââ?¬â??10 meters in several experiments. In addition,\nwe compared the proposed approach with two other state-of-the-art methods: recursive averaging and ARMA interpolation.The\nexperimental results showthat the proposed approach outperforms other state-of-the-art methods in terms of positioning accuracy....
In some GPS failure conditions, positioning for mobile target is difficult. This paper proposed a new method based on INS/UWB\nfor attitude angle and position synchronous tracking of indoor carrier. Firstly, error model of INS/UWB integrated system is built,\nincluding error equation of INS and UWB. And combined filtering model of INS/UWB is researched. Simulation results show that\nthe two subsystems are complementary. Secondly, integrated navigation data fusion strategy of INS/UWB based onKalman filtering\ntheory is proposed. Simulation results show that FAKF method is better than the conventional Kalman filtering. Finally, an indoor\nexperiment platform is established to verify the integrated navigation theory of INS/UWB, which is geared to the needs of coal\nmine working environment. Static and dynamic positioning results show that the INS/UWB integrated navigation system is stable\nand real-time, positioning precision meets the requirements of working condition and is better than any independent subsystem....
A compressive sensing based array processing method is proposed to lower the complexity, and computation load of array\nsystem and to maintain the robust antijam performance in global navigation satellite system (GNSS) receiver. Firstly, the spatial\nand temporal compressed matrices are multiplied with array signal, which results in a small size array system. Secondly, the 2-\ndimensional (2D) minimum variance distortionless response (MVDR) beamformer is employed in proposed system to mitigate\nthe narrowband and wideband interference simultaneously. The iterative process is performed to find optimal spatial and temporal\ngain vector by MVDR approach, which enhances the steering gain of direction of arrival (DOA) of interest. Meanwhile, the null\ngain is set at DOA of interference. Finally, the simulated navigation signal is generated offline by the graphic user interface tool and\nemployed in the proposed algorithm. The theoretical analysis results using the proposed algorithm are verified based on simulated\nresults....
Vehicle navigation systems usually simply function by calculating the shortest fastest route over a road network. In contrast,\npedestrian navigation can have more diverse concerns. Pedestrians are not constrained to road/path networks; their route may\ninvolve going into buildings (where accurate satellite locational signals are not available) and they have different priorities, for\nexample, preferring routes that are quieter or more sheltered from the weather. In addition, there are differences in how people are\nbest directed: pedestrians noticing landmarks such as buildings, doors, and steps rather than junctions and sign posts. Landmarks\nexist both indoors and outdoors. A system has been developed that uses quick response (QR) codes affixed to registered landmarks\nallowing users to localise themselves with respect to their route and with navigational instructions given in terms of these landmarks.\nIn addition, the system includes images of each landmark helping users to navigate visually in addition to through textual\ninstructions and route maps. The system runs on a mobile device; the users use the device�s camera to register each landmark�s\nQR code and so update their position (particularly indoors) and progress through the route itinerary....
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