Coverage Algorithm For Directional Sensor Networks Based On Probability Sensing Model

Wireless sensor networks has provided human with a safe and convenient way that we can obtain information from the natural world, and greatly improved the ability of learning about the nature and utilizing the natural resources. It has widely applied in the military battlefield monitoring, the maintenance and management of the civil public facilities, inspection and maintenance of industrial equipment, the scientific observation of the dynamic plant habitat, and so on. In this paper, the deployment problem of the directional sensor network is studied.Firstly we introduce all kinds of characteristics and properties both omnidirectional sensors and directional sensors in this paper, in the light of sensor’s characteristics which are low power consumption, low rate, data central and the limited available resources, this paper makes effective analysis about the differences and limitations between the omni-directional sensing model and directional sensing model. We analyse the research status about the coverage and the node deployment of the directional sensors networks, On this basis this paper proposes the model of probabilistic sensing of directional sensor, the evaluation indicators about the coverage rate, stability, redundancy of the node and energy consumption, etc, are established.For the area coverage problem of the directional sensor network which was randomly deployed, based on the model of probabilistic sensing of directional sensor, we set the default standard work direction of the sensor nodes in the network, with the joint probability of perception to the grid point between the node, the algorithm makes the probability of grid point which is perceived by the sensor network equal or exceed the perception threshold in the monitoring area, then compares the theoretical position of the work node with actual position, by adopting the distributed algorithm to awaken the nodes. The method uses fewer nodes to cover the monitoring areas and achieves the goal of the coverage rate, the simulation results show that, the algorithm has realized the distribution of nodes reasonably, reduced the number of nodes in the monitoring areas, improved the network coverage and lifetime.With the foundation of the video probabilistic sensing model that sensing direction is steerable, the study on path coverage enhancement algorithm for video sensor networks has been improved. The position of effective center of mass is analysed in the sensor’s model, then the network calculates the gravitation between the target track points and the trace nodes, and the repulsive force between both trace nodes of the target track points, then the trace node adjusts its sensing direction according to the joint forces, make the probability of the target track points which is perceived by the sensor network equals or exceeds the perception threshold. The simulation result shows that, the improved algorithm has made further improvement on the perception of the target which is move in the coverage area, it uses more fewer directional video nodes, but the video sensor network is fully and high effectively covering the target trajectory.