Efficient Coverage of Agricultural Field with Mobile Sensors by Predicting Solar Power Generation

Wireless sensor networks (WSNs) that periodically collect the environmental information such as temperature, humidity, and so on require the coverage of a given target field anytime and the operation lifetime longer than an expected duration by the minimum number of sensor nodes. For these WSNs, we propose a method deciding a schedule of node movement to cover the target agricultural field from plant to harvest by the minimal number of nodes in order to reduce the node deployment cost. The proposed method computes a moving schedule of each mobile sensor node so that all the nodes cover the target field without depleting battery of some of the nodes by predicting solar power generation at each point of the target field where shadow areas change depending on time, orbit of the sun, and height of crops. We conducted computer simulations and compared the performance of the proposed method with a conventional method. As a result, our method achieves 4% reduction of the number of nodes and 10% extension of the operation lifetime compared to the method without estimation of power generation amount.