Time-varying formation control of a collaborative heterogeneous multi agent system

•A set of heterogeneous multi-agent systems is considered.•The dynamics of different agents are studied.•A virtual-leader structure is applied to the rigid formation.•A time-varying formation is modeled.•A Lyapunov based controller is proposed to achieve time-varying formation.

In this paper, coherent formation control of a multi-agent system in the presence of time-varying formation is studied. For special application of rescue and surveillance, a set of agents, consisting of unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) are considered. Due to different degrees of freedom of the UAVs and the UGVs, the collaboration between the agents confronts many problems. A Lyapunov based controller is presented to stabilize the swarming and lead the system to a rigid formation using decentralized control approach. In the proposed control signal of each agent, a signal of the neighbors’ error is considered to cope with variation in performance and to provide synchronization, which means that the state error of the agents converges to zero nearly at the same time. The decentralized approach provides reliability of the performance in unknown environment, since the controller of each agent is designed based on local knowledge. This algorithm is evaluated in simulation and the results approve the accepted performance of the proposed approach.