Feizhou Zhang

Simulation study of underwater passive navigation system based on gravity gradient

Gravity gradient based passive navigation for autonomous underwater vehicle (AUV) is proposed in this paper. Its basic principle and two working modes are analyzed in detail. Simulation test has been done and the results show that the proposed method can provide high precision positioning information for AUV

Intelligent scheduling of public traffic vehicles based on a hybrid genetic algorithm

Abstract A genetic algorithm (GA) and a hybrid genetic algorithm (HGA) were used for optimal scheduling of public vehicles based on their actual operational environments. The performance for three kinds of vehicular levels were compared using one-point and two-point crossover operations. The vehicle scheduling times are improved by the intelligent characteristics of the GA. The HGA, which integrates the genetic algorithm with a tabu search, further improves the convergence performance and the optimization by avoiding the premature convergence of the GA. The results show that intelligent scheduling of public vehicles based on the HGA overcomes the shortcomings of traditional scheduling methods. The vehicle operation management efficiency is improved by this essential technology for intelligent scheduling of public vehicles.

Simulation design of underwater terrain matching navigation based on information fusion

The data preprocessing, algorithm analysis and performance evaluation were done making full use of various information related to the ocean geographical features, then intelligent data fusion was used to design the underwater passive navigation system simulation module. Simulation results show that the underwater terrain matching assisted navigation can modify the error from inertial navigation system and provide precise navigation for underwater navigation system

Study on data fusion method in geographic information system for transportation

In order to make it convenient for sharing and maintaining data, this paper structures the independent real-time traffic information database, seamless merging real-time traffic information and GIS data through data fusion method. In order to realize this purpose, a unified base-line net is set up in the traffic information data model. Base-line net is composed of base points and base lines.

Spatial information integration modes and its key technologies

With regard to the basic characteristics of spatial information, the mutuality and integrated mode of Global Positioning System (GPS), geographic information system (GIS) and remote sensing (RS) is presented in this paper. The requirement and feasibility of SIT integration are analyzed and the feasibility of integrating spatial information and mobile communication is discussed. Based on the analysis of necessity and feasibility of their integration the integrating mode and method including the integration of SIT with communication technology are studied. The key technologies of the system integration are discussed and the architecture of SIT integration is proposed. The application fields and prospect of spatial information integration are expatriated through the analysis of some typical cases.

Multi-agent design of urban oriented traffic integration control system

In order to solve the key technologies of urban traffic in China, the intelligent means and approach, combined artificial intelligent with tradition control ones, are adopted in the paper. Some hypotheses are elicited on the basis of the characteristics of Chinese urban traffic control system structure and function requirement, a kind of frame structure of urban traffic intelligent control system is stated based on multi-agents cooperation. A kind of better design ways and means for urban traffic real-time, rational and reasonable control system is established according to the frame structure, the system design of urban cross control and area control based on multi-agents is implemented. In this way, successful realization of goal for urban traffic intelligent control is insured so as to increase the capacity of urban road network and to improve our urban traffic control and management modes. Therefore urban surroundings quality will be enhanced. And the comfortable and delightful traffic surroundings will be built.

Establishment of Beijing underground pipeline information system based on ArcSDE

Using GIS, network and database technologies, Beijing underground pipeline information system is established. After detailed analysis of the actuality and specialty of the present underground pipeline database managed by Beijing Institute of Surveying and Mapping (BISM), the paper systematically presents the studying purpose, meanings and primary contents. According to the study of pipeline data features, a spatio-temporal pipeline database classified by pipeline types is built. Based on the database, the urban underground pipeline information system is designed and developed by BISM, which unifies data from planning department and other departments, realizing modernized managements of underground pipeline data input, management, analysis and output.

Terrain matching image pre-process and its format transform in autonomous underwater navigation

Underwater passive navigation technology is one of the important development orientations in the field of modern navigation. With the advantage of high self-determination, stealth at sea, anti-jamming and high precision, passive navigation is completely meet with actual navigation requirements. Therefore passive navigation has become a specific navigating method for underwater vehicles. The scientists and researchers in the navigating field paid more attention to it. The underwater passive navigation can provide accurate navigation information with main Inertial Navigation System (INS) for a long period, such as location and speed. Along with the development of micro-electronics technology, the navigation of AUV is given priority to INS assisted with other navigation methods, such as terrain matching navigation. It can provide navigation ability for a long period, correct the errors of INS and make AUV not emerge from the seabed termly. With terrain matching navigation technique, in the assistance of digital charts and ocean geographical characteristics sensors, we carry through underwater image matching assistant navigation to obtain the higher location precision, therefore it is content with the requirement of underwater, long-term, high precision and all-weather of the navigation system for Autonomous Underwater Vehicles. Tertian-assistant navigation (TAN) is directly dependent on the image information (map information) in the navigating field to assist the primary navigation system according to the path appointed in advance. In TAN, a factor coordinative important with the system operation is precision and practicability of the storable images and the database which produce the image data. If the data used for characteristics are not suitable, the system navigation precision will be low. Comparing with terrain matching assistant navigation system, image matching navigation system is a kind of high precision and low cost assistant navigation system, and its matching precision directly influences the final precision of integrated navigation system. Image matching assistant navigation is spatially matching and aiming at two underwater scenery images coming from two different sensors matriculating of the same scenery in order to confirm the relative displacement of the two images. In this way, we can obtain the vehicles location in fiducial image known geographical relation, and the precise location information given from image matching location is transmitted to INS to eliminate its location error and greatly enhance the navigation precision of vehicle. Digital image data analysis and processing of image matching in underwater passive navigation is important. In regard to underwater geographic data analysis, we focus on the acquirement, disposal, analysis, expression and measurement of database information. These analysis items structure one of the important contents of underwater terrain matching and are propitious to know the seabed terrain configuration of navigation areas so that the best advantageous seabed terrain district and dependable navigation algorithm can be selected. In this way, we can improve the precision and reliability of terrain assistant navigation system. The pre-process and format transformation of digital image during underwater image matching are expatiated in this paper. The information of the terrain status in navigation areas need further study to provide the reliable data terrain characteristic and underwater overcast for navigation. Through realizing the choice of sea route, danger district prediction and navigating algorithm analysis, TAN can obtain more high location precision and probability, hence provide technological support for image matching of underwater passive navigation.

Model architecture of intelligent data mining oriented urban transportation information

Aiming at solving practical problems in urban traffic, the paper presents model architecture of intelligent data mining from hierarchical view. With artificial intelligent technologies used in the framework, the intelligent data mining technology improves, which is more suitable for the change of real-time road condition. It also provides efficient technology support for the urban transport information distribution, transmission and display.

The design of urban geographical information system for transportation

With the fast development of national economy and society, urban transportation has not been suitable for the current situation. The traffic jam, traffic accident and environmental pollution are becoming more and more serious. Due to its complexity, the transportation problem can not be solved only through considering the vehicle or road. Therefore, to establish modern intelligent transportation system (ITS) by integrating vehicle, road and users with various high-techs such as AI, computer network, information processing, telecommunications, is the important solutions. This paper adopts special information technology to set up Geographical Information System for Transportation, which provide advanced and effective conditions and measures for the real-time collection, integration storing, deep knowledge mining, analyze and application of transportation information. Then it can resolve the problem of urban transportation effectively. earthquake etc can be predicted and prevented in some extent.