In this paper a new methodology for decentralized overlapping tracking control of formations of autonomous unmanned vehicles based on the expansion/contracion paradigm is proposed. The methodology is based on a specific linear formation model. Decentralized controllers for the extracted subsystems are contracted to the original space after convenient modifications. It is proved that the overall closed loop system is stable if the formation graph has a directed spanning tree. An extension to the case of dynamic output feedback control law based on decentralized observers is also proposed. Experimental results give an illustration of the performance of the proposed controller when the local design is based on the LQ methodology.