Force-based Formation Control of Omnidirectional Ground Vehicles

Formation control of multi-robot systems has been largely studied due to its wide application domain. Several methods in the literature rely on explicit communication among the robots, which in realistic scenarios may lead to reduced performance or even instability due to delays and packet loss or corruption. Nonetheless, multi-robot coordination based solely on implicit communication has been proposed in cooperative manipulation problems. Taking inspiration from this, we propose a method to solve the formation control problem for a group of ground robots not relying on direct communication among them. Instead, the robots are physically constrained to a common object through elastic cables in order to exploit forces as a means of indirect communication. After deriving the dynamic equations, the control and planning approaches are explained, and the stability of the controlled system is discussed using Lyapunov's stability theory. Numerical simulations are presented to support the method.