Actuator Energy Guaranteed Mobile Charging Scheme for Wireless Sensor and Actuator Networks

Wireless Sensor and Actuator Networks (WSANs) include not only sensor nodes, but also actuator nodes. Since actuators’ capabilities such as moving, communication and event handling require much more energy than sensors, both actuators and sensors are affected by energy and make WSANs encounter serious energy constraints. Although many energy replenishment studies have been proposed for Wireless sensor networks (WSNs), they cannot work well in WSANs. To solve the energy replenishment problem of WSANs, we first analyze the characteristics in WSANs, and then present an actuator energy guaranteed mobile charging scheme (AEG) for WSANs. AEG evaluates the actuator failure risk in the network, and provides charging service for actuators exclusively when there exists an actuator failure risk. Moreover, under the condition that energy safety of actuators is guaranteed, AEG replenishes energy for sensors preferentially, which could avoid sensor failures as much as possible. We evaluate the performance of AEG by simulation, and the results indicate that AEG could reduce sensor failures and achieve lower average charging delay than existing schemes on the basis of ensuring no actuator failure.