Autonomous search, tracking and classification by multiple cooperative UAVs

Abstract

In this paper we propose a cooperative control algorithm for a group of UAVs carrying out surveillance --- search, tracking and classification --- over a large region which includes a number of targets. The goal is to track and classify detected targets as well as search for new targets. The UAVs are assumed to be equipped with Ground Moving Target Indicator (GMTI) radars, which measure the locations of moving ground targets as well as their radial velocities (Doppler). In addition, a classification sensor is mounted on each UAV that can obtain target class information. The surveillance region is divided into a number of sectors and it is assumed that the GMTI sensor on each UAV scans a fixed number of such sectors in each period of its operation. The sensor responsible for class information can scan only a small circular region around the predicted position of a target. In this paper, a decentralized cooperative control algorithm is proposed, according to which each UAV transmits the current scan information (either kinematic or class information) and detection information (including "negative information") to the other UAVs. Each UAV makes its scan decision and path decision separately, based on information-based objective functions, which incorporate target state information as well as target detection probability and survival probability due to possible hostile fire by targets and collision with other UAVs. The proposed algorithm requires limited communication and modest computation and it can handle failure in communication and loss of UAVs.