Pattern preserving path following of unicycle teams with communication delays

In this paper, we study pattern preserving path following control of unicycle teams with communication delays. The pattern of the vehicle team is said to be preserved if the distance between it and the desired one remains in some given range. A virtual vehicle formation is introduced such that each virtual vehicle becomes the pursuit target for the corresponding real vehicle. First, an input-driven consensus protocol is used to force the virtual vehicle formation close to the desired vehicle formation. Then a controller is designed to achieve model reference tracking for each vehicle with constrained motion. It is shown that, by our strategy, the pattern can be maintained if the formation speed is less than some computable value, and the desired formation pattern can be eventually achieved if this speed tends to zero.