Low-Cost Compact Instrumentation, Control, and Aerial Surveillance Payload Support for Small UAVs

Abstract

*† ‡ § Applications of aerial surveillance include homeland security, law enforcement, environmental monitoring, and damage inspection after natural disasters. This paper discusses the use of unmanned aerial vehicles (UAV) as low cost and easy to operate solutions for aerial reconnaissance. Currently, the use of UAVs is limited by the cost of the systems and the need for skilled operators of the equipment. A new flight control system was developed which will reduce the cost of autonomous UAV platforms. The emphasis of the flight controller design was to reduce the cost of implementing an unmanned aerial surveillance system. The costs were reduced two ways. First, the weight and volume of the flight control and payload hardware was reduced so that smaller UAVs could be used. Second, the cost of the hardware was decreased by using standard commercial off-the-shelf (COTS) components to build the hardware. This paper will cover the requirements of the autonomous flight control and payload system for aerial surveillance, the work done to reduce the weight of the system, and the selection of COTS hardware for the flight controller. Flight control for the aerial surveillance platform is divided into four parts: instrumentation, control, communication, and power. The UAV control system designed supports autonomous flight including takeoff and landing which eliminates the need for a skilled RC pilot to operate the system. The system is designed specifically for applications with shorter flights within three to five miles of the ground station. GPS and inertial measurement sensors localize the UAV and are inputs in the flight control algorithm. A wireless communication link between the UAV and the ground station receives flight commands and waypoints from the mission planner and transmits status monitoring information. A safety pilot can manually override the autonomous flight controller with an RC communication link. Aerial surveillance payloads include a system to collect and wirelessly transmit video. Many also have a pan-tilt-zoom unit to position the camera to get video from different orientations. Several applications also require analog sensors and/or other digital I/O. Lowering the flight controller and payload weight to use smaller UAVs and using COTS parts in the design reduced the cost of implementing an aerial surveillance system. Using smaller UAVs reduced the vehicle platform costs by a factor of three to five. Integrating the flight control hardware and the payload support hardware was the primary way the weight was reduced. Many of the components in one system were duplicated in the other. Eliminating the duplicate parts and subsystems lowered the component weight and volume (thus reducing the packaging weight). This also helps decrease the hardware costs without sacrificing the function of the flight controller or aerial surveillance payload. All of the components are standard COTS parts with the exception of the printed circuit boards.