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Zhang J.,Tianjin Polytechnic University | Yang T.,Tianjin University | Zhao C.,Tianjin Navigation Instruments Research Institute
International Journal of Grid and Utility Computing | Year: 2016

In wireless sensor networks, the energy consumption is one of the major issues. This paper proposes an event driven based adaptive routing algorithm that avoids the node energy consumption used for emergency monitoring. A cluster tree based on connected dominating set is constructed. When a new event takes place, the algorithm constructs a local topology in that region to quickly transfer the message through a cluster tree, so as to avoid a wide range of flood routing in the network. In addition, it proposes a periodical replacement strategy of the cluster head, which avoids too fast consumption of cluster head node energy. Only the cluster member nodes in a restricted vicinity will change their status. Simulation results show that the proposed approach avoids the node energy consumption used for emergency monitoring and the cluster head can evenly distribute loads, which effectively balances the energy consumption of network nodes, and thus efficiently extends the lifetime of network. Copyright © 2015 Inderscience Enterprises Ltd. Source


Wang J.-M.,Tianjin Polytechnic University | Wang X.,Tianjin Polytechnic University | Wang S.-B.,Tianjin Polytechnic University | Li S.-X.,Tianjin Navigation Instruments Research Institute | Leng Y.,Suzhou Entry Exit Inspection and Quarantine Bureau
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2011

Navigation is a key technology for autonomous robots, which makes them movable in an unknown environment. To tackle the difficulty of building indoor navigation map for inertial navigation systems, a new map building method for inertial/visual navigation is proposed. By limiting robot's movement within the floor areas, the global navigation map is generated from a bird-view image. An algorithm of automatic floor segmentation is proposed, which employs principal component analysis to implement dimension reduction for local color features and adopts clustering analysis to realize floor segmentation automatically. Finally, an indoor bird-view image database is built to evaluate the algorithm. The algorithm gets the worst performance, 75% averaged accurate segmentation rate, on the fourth group images because illumination reflection is found in the images. Average accurate segmentation rates on other groups are around 85%. Thus, the preprocessing algorithms, such as illumination refection detection, can help to improve the performance of the algorithm. Source


Ye F.,Harbin Engineering University | Zhang H.,Harbin Engineering University | Gu Y.,Tianjin Navigation Instruments Research Institute
Journal of Computational Information Systems | Year: 2012

On the basis of the traditional proportional fair scheduling algorithms, this paper proposes a kind of improved proportional fair resource scheduling algorithm is proposed with the purpose of improving the fairness performance of LTE system. By means of improving the scheduling opportunity of the users in the cell edge, the proposed scheduling algorithm user can effectively improve the performance of user fairness. The simulation results show that, comparing with traditional proportional fair scheduling algorithms, the proposed algorithm can achieve a higher user fairness performance. 1553-9105/Copyright © 2012 Binary Information Press. Source


Zhou G.,Harbin University | Wang J.,Tianjin Navigation Instruments Research Institute | Li K.,Harbin University
Lecture Notes in Electrical Engineering | Year: 2011

The observability of the system states are the key indexes to check the convergence accuracy and convergence speed of designed Kalman filter. First of all, the error dynamic system equation and observation equation of strapdown inertial navigation system (SINS) online calibration are described in this paper, and then the system can be demonstrated to meet the law of piece-wise constant system (PWCS).Finally,the singular value of the system states based on the singlular value decomposition, which provides the necessary foundation of online calibration, are described. © 2011 Springer-Verlag. Source


Yang G.-L.,Beihang University | Dou Y.-B.,Tianjin Navigation Instruments Research Institute | Zheng R.-C.,Tianjin Navigation Instruments Research Institute
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2010

Radar and electronic chart are important navigational equipments for vessel traffic. A method of image overlay on radar and electronic chart is proposed to improve the sailing security. The extracted radar image is processed by geometric transformation according to the local position and True North of the ship. Refer to the scanning radius of the radar, the range of electronic chart is adjusted by mercator projection transformation, and then the scale of electronic chart is changed to get the image of radar and electronic chart matching. Using electronic chart as background, radar image is overlaid in pixel level. The simulation results show that the method of image overlay on radar and electronic chart is effective for the sailing security. The coastline of electronic chart and radar image are matched well. Radar targets can be displayed in real time. The monitoring capability on ship's surrounding environment is enhanced. Source

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