Tracking control of multiple mobile robots: a case study of inter-robot collision-free problem

A virtual robot tracking control approach with a consideration of clearance is proposed. An algorithm which is used to avoid collision between robots is also introduced using a transformation of Cartesian to distance coordinate. Each robot is indexed by different priority numbers to indicate that which robot is prior to another. A small interval feedback control is applied to a low-priority robot to avoid collision with the higher one when it detects a possibility of collision. At the end of small-interval feedback control, the collision-free condition is established. The virtual robot tracking control is applied again to maintain the overall formation. As a result, the distribution of robots in a system is guaranteed to be in limited communication range along the motion. Numerical simulation highlights the efficiency of our control techniques.