Design of coal mine wireless sensor networks based on piezoelectric sensors for gas monitoring

In order to improve the reliability of gas monitoring in coal mine, we design a wireless sensor networks with the piezoelectric gas sensors, The wireless sensor networks is suitable for gas monitoring in the severe environment of coal mine. The networks´ topology is sub-cluster type, and the cluster head node is selected in competitive method. Data fusion and routing of the cluster nodes are controlled by the cluster head node. In order to reduce information redundancy and energy consumption, we use coverage configuration protocol (CCP) to control nodes states to switch between three states of working, listening and sleeping, thus to maximize the number of sleeping nodes. We use a new type of thin film piezoelectric acoustic sensor (TFPAS) as the sensor node, this kind of sensor is of low power consumption, high sensitivity, which is suitable for wireless sensor networks.