Solar-powered, wireless smart camera network: An IoT solution for outdoor video monitoring

Abstract

In this paper, we present SlugCam, a solar-powered, wireless smart camera network that can be used in a variety of outdoor applications including video surveillance of public spaces, habitat and environmental monitoring, wildfire prevention and detection, to name a few. SlugCam was designed such that it can be deployed and left unattended for extended periods without requiring regular maintenance, e.g., frequent battery replacement. The system is built with off-the-shelf components which not only keeps it modular and low cost, but also facilitates its prototyping, rapid duplication, and evolution. SlugCam’s on-board processing capability allows computer vision software to run locally and autonomously. Energy efficiency in SlugCam is accomplished both in: (1) hardware by micro-managing low-power components; as well as in (2) software by having the system’s operation duty cycles automatically adapt to the current state of the battery in order to balance the trade-off between application-level requirements and power awareness. For example, SlugCam’s smart camera node changes its monitoring behavior based on how much battery charge remains. Additionally, using its computer vision software, the system only records and transmits information upon event detection which contributes both to the system’s energy efficiency as well as its low network bandwidth requirements. SlugCam’s networking functionality enables camera nodes to transfer video files, as well as collaborate on tasks such as visual processing, event detection, and object tracking. It allows node-to-node, as well as scoped- or full broadcast communication. For point-to-point communication, SlugCam uses on-demand power-aware multi-path routing to transfer video files efficiently. Another important contribution of SlugCam is to provide an open-source wireless camera network that can adapt to address the requirements of future outdoor video monitoring applications. SlugCam also includes a Web-based server where video data is stored as well as a Web-based user interface that allows end users to interact with the system, tag, query and retrieve video files, and manage SlugCam nodes remotely. In addition to a detailed description of SlugCam, this paper presents an extensive power characterization of the system’s operation and showcases its deployment in a lab testbed and a real world scenario.