Design, implementation, and verification of a low-cost terminal guidance system for small fixed-wing UAVs

A terminal guidance control system for small fixed-wing unmanned aerial vehicles (SUAV, with a wingspan of around 1.5 m) is proposed in this paper based on a visible light strap-down seeker. The system is implemented using low-cost, open-source components with a cost less than $2000 and proved to be feasible, transplantable and effective for different types of SUAVs, achieving a good terminal guidance accuracy (circular error probable = 1.5 m) against a nonmaneuvering target on the ground. Impacts of low-cost and low-precision electrical modules mainly include influence on terminal guidance information, measurement of SUAV state values and the presented system's time-delay. We examine the practical median flow algorithm for target tracking, the attitude pursuit guidance law for terminal guidance control and the pursuit image frame method for large delay interception to eliminate adverse effects. Furthermore, the performance and robustness are evaluated by laboratory tests as well as field flight trials on two different SUAV platforms. This paper provides a robust, effective and proven reference for the development of the aggressive SUAV for SUAV swarms.