An Unmanned System for Persistent Surveillance in GPS-Denied Environments

Abstract

View Video Presentation: https://doi.org/10.2514/6.2022-0118.vid Autonomous systems are being proposed for exploration work, such as entering unknown indoor environments, collecting data and transmitting it back to the entrance. In this work, a system-of-systems approach was taken to address the challenge of autonomously placing unattended relay-sensor devices, which can extend indoor wireless communications and collect data. The proposed solution includes a ground robot with autonomous navigation capability, a mechanized trailer to transport and deploy the relay-sensor devices, and a companion quadrotor unmanned aerial system (UAS) to explore further afield and place relay-sensor devices in more remote locations. In testing, the ground robot demonstrated its ability to autonomously navigate and map an unknown environment. A novel trailer was designed and prototyped that houses a conveyer-belt system for transporting and deploying relay-sensor devices directly on the ground, or up to a companion UAS. A semi-autonomous quadrotor UAS was developed and tested to carry and deploy the same relay-sensor devices. The UAS includes several interesting autonomy features, including a vision-based velocity estimator to improve stability and flight handling and an adaptive controller to ensure consistent flight characteristics when adding and removing payload. In total, feasibility was demonstrated of a combined air-ground autonomous system-of-systems that can navigate an unknown mission space, and deploy payloads as needed. Such a system could significantly enhance the capabilities and safety of human teams operating in hostile or hazardous environments.