Sutton, AndrewFidan, BarisVan der Walle, Dirk2015-12-13July 6-119781123478902http://hdl.handle.net/1885/84474In this paper, we analyze the problem of rigidly maintaining a formation of three unmanned aerial vehicles (UAVs), whilst surveying a region of interest following, as a team, a particular pre-defined (spiral) trajectory. The UAVs in the formation are constrained to fly at constant speeds and to maintain certain pre-defined inter-agent distances. A decentralized proportional-integral (PI) control scheme (involving certain nonlinear switching terms) is developed for the surveillance and formation maintenance tasks above, based on a hierarchical (i.e. leader-first follower-second follower) sensing and control structure.Keywords: Constant speed; Control structure; Cooperative navigation; Cooperative surveillance; Formation control; Maintenance tasks; Multi-vehicle systems; Nonlinear switching; Proportional-integral control; Region of interest; Trajectory tracking and path followin Cooperative navigation; Multi-vehicle systems; Trajectory tracking and path following200810.3182/20080706-5-KR-1001.39212016-02-24