Formation flight control design in the presence of unknown leader commands

In this paper we develop stable adaptive formation control algorithms for two-dimensional point-mass models of aircraft dynamics. The algorithms effectively compensate for uncertain leader commands. It is shown that the adaptive formation control design in the body frame of the follower aircraft contains only two adjustable parameters, while in the case of design in the body frame of the lead aircraft there are four parameters that need to be adjusted to assure the stability of the system. In the latter case the information on the bounds on the rates of the commands is also needed to implement the controller. In both cases the adaptive algorithms are based on the variable structure control design technique. A simulation example is included to illustrate the properties of the proposed approach.