  The problem of distributed formation control of nonholonomic mobile robots is
addressed in this paper, in which the robots are designed to track a formation.
Collision avoidance among agents is guaranteed using a control law based on a
repulsive force. In an uncertain environment where obstacles exist, the
construction of repulsive force and rotational direction enables agents to
avoid and pass the obstacles. The control inputs of each robot are designed to
be bounded. Numerical simulations with different formations are implemented to
demonstrate the efficacy of the proposed scheme.
