中文摘要：

视觉传感器网络中节点感知模型为有向感知模型,感知范围被限定在节点的视野范围内.节点拥有多个感知方向,在一个工作时刻,节点只能工作于一个方向.针对视觉传感器网络的有向感知模型的点目标覆盖问题,提出一种贪婪算法（GreedyAlgorithm）,在优化网络对于目标点覆盖的同时,解决了节点自身覆盖冲突的问题.在此基础上,引入＂贡献率＂概念反映节点在其感知方向上对于覆盖的贡献,提出了基于贡献率的贪婪算法（Contribution Rate Greedy Algorithm）以增大网络覆盖率.仿真实验表明了该算法的有效性.

英文摘要：

The node sensing model of Vision Sensor Networks is directional sensing model,their sensing range is limited in the node field of view.There are serial sensing directions in the sensor node,however,in one time;sensor node can only work in one direction.This paper proposes a Greedy Algorithm to solve the target point coverage problem in the Vision Sensor Networks.Based on this,we introduce a novel ＂contribution rate＂ to reflect the node contribution for coverage in its sensing direction and propose Contribution Rate Greedy Algorithm.The proposed algorithm can increase the network coverage rate and avoid the problem of coverage conflict.Finally,simulation results validate the claims.