Sensor replacement in the rechargeable wireless sensor network (R-WSN) is important to provide continuous sensing services once sensor node failure or damage occurs. However, satisfactory solutions have not been found yet in developing a sustainable network and effectively prolonging its lifetime. Thus, we propose a new technique for detecting, reporting, and handling sensor failure, called sector-based replacement (SBR). Base station (BS) features are utilized in dividing the monitoring field into sectors and analyzing the incoming data from the nodes to detect the failed nodes. An airplane robot (Air-R) is then sent to a replacement task trip. The goals of this study are to (i) increase and guarantee the sustainability of the R-WSN; (ii) rapidly detect the failed nodes in sectors by utilizing the BS capabilities in analyzing data and achieving the highest performance for replacing the failed nodes using Air-R; and (iii) minimize the Air-R effort movement by applying the new field-dividing mechanism that leads to fast replacement. Extensive simulations are conducted to verify the effectiveness and efficiency of the SBR technique. Information 2017, 8, 70 2 of 16the potential for actual industrial applications [7,8]. This technology possesses high-energy transfer efficiency, even under omni-directional transmission; it does not require line of sight, and it is insensitive to the neighboring environment [9,10]. The charging energy of R-WSNs is reliable and stable.Progress in wireless power transfer techniques has advanced research activities in the direction of battery recharging, with high expectations for its application to WSNs. A hybrid charging scheme combines charging by a mobile charger with a directional antenna and energy trading (e.g., transferring and harvesting between neighboring sensor nodes) [11]. Sensor replacement techniques have also been widely studied as a means of providing service continuity in the network. Recharging or replacing the sensor nodes that are running out of energy can be identified and researched as two main objectives. Mobile robots are used as solutions for the execution of either recharging or replacing tasks automatically and autonomously to maintain the WSN, thus reducing human intervention [12].This study focuses on the manner in which R-WSNs are deployed and efficiently serve a complex geography. R-WSNs can collect information, monitor, and perform other multiple tasks. They are sustainable networks and have high performance, which are important factors for WSNs. For example, in a forest-monitoring system, we need to deploy numerous sensor nodes to cover the entire sensing field. We assume that all nodes have the same amount of energy, capacity, and transmission capabilities. These nodes can determine their location automatically from the first time after deployment. In the case of detecting failure or damaged nodes in the network, several problems may affect network sustainability, data collection, and field-monitoring results. Our approach shows good results in detecting...