[Objective] To water content monitoring study the application of wireless sensor network in field so and to discuss the methods for solving the problems of low sampling rate, high cost and poor real-time in actual mon...[Objective] To water content monitoring study the application of wireless sensor network in field so and to discuss the methods for solving the problems of low sampling rate, high cost and poor real-time in actual monitoring. [Method] The architecture of wireless sensor network, network nodes, hardware design as well as principle for the program structure of software operating system and corresponding parameters were analyzed to illustrate the characteristics of monitoring system for field soil water content based on wireless sensor network, and the advantages in application of this system. [Result] Sensor nodes could correctly collect and transmit soil water content, realize stable data transmission of soil water content, indicating that wireless sensor network is suitable for real-time monitoring of field soil water content. [Conclusion] This study indicates that wireless sensor network possesses a widely application foreground in the development of agriculture.展开更多
An autonomous underwater vehicle (AUV) must use an algorithm to plan its path to distant, mobile offshore objects. Because of the uneven distribution of obstacles in the real world, the efficiency of the algorithm dec...An autonomous underwater vehicle (AUV) must use an algorithm to plan its path to distant, mobile offshore objects. Because of the uneven distribution of obstacles in the real world, the efficiency of the algorithm decreases if the global environment is represented by regular grids with all of them at the highest resolution. The framed quadtree data structure is able to more efficiently represent the environment. When planning the path, the dynamic object is expressed instead as several static objects which are used by the path planner to update the path. By taking account of the characteristics of the framed quadtree, objects can be projected on the frame nodes to increase the precision of the path. Analysis and simulations showed the proposed planner could increase efficiency while improving the ability of the AUV to follow an object.展开更多
基金Supported by the National High-tech R&D Program of China(2006AA100223)~~
文摘[Objective] To water content monitoring study the application of wireless sensor network in field so and to discuss the methods for solving the problems of low sampling rate, high cost and poor real-time in actual monitoring. [Method] The architecture of wireless sensor network, network nodes, hardware design as well as principle for the program structure of software operating system and corresponding parameters were analyzed to illustrate the characteristics of monitoring system for field soil water content based on wireless sensor network, and the advantages in application of this system. [Result] Sensor nodes could correctly collect and transmit soil water content, realize stable data transmission of soil water content, indicating that wireless sensor network is suitable for real-time monitoring of field soil water content. [Conclusion] This study indicates that wireless sensor network possesses a widely application foreground in the development of agriculture.
基金Supported by the National Natural Science Foundation of China under Grant No. 60875071
文摘An autonomous underwater vehicle (AUV) must use an algorithm to plan its path to distant, mobile offshore objects. Because of the uneven distribution of obstacles in the real world, the efficiency of the algorithm decreases if the global environment is represented by regular grids with all of them at the highest resolution. The framed quadtree data structure is able to more efficiently represent the environment. When planning the path, the dynamic object is expressed instead as several static objects which are used by the path planner to update the path. By taking account of the characteristics of the framed quadtree, objects can be projected on the frame nodes to increase the precision of the path. Analysis and simulations showed the proposed planner could increase efficiency while improving the ability of the AUV to follow an object.
