Local Measurement Based Formation Navigation of Nonholonomic Robots with Globally Bounded Inputs and Collision Avoidance

In this work, we consider the local relative measurement based leader-follower formation navigation problem of nonholonomic robots with globally bounded inputs and collision avoidance constraints. It is assumed that each robot can only measure the relative distances and bearings of its leaders in its local coordinate frame. No global coordinate information is available. Digital communication between robots is also prohibited considering payload or transmission medium restrictions. Under these conditions, two novel globally bounded leader-follower formation controllers are first proposed for both the distance-bearing and the distance-distance formation cases assuming known leaders' state information. Then, the unavailable information of the leader/leaders is handled by Extended Kalman Filters (EKFs). To guarantee the global boundedness of the observer-based distance-distance formation navigation controller, a switching control strategy is designed and analyzed. Barrier function based collision avoidance method is then employed to guarantee the safety of the robots during the whole formation navigation process. Simulation examples are provided to illustrate the effectiveness of the proposed controllers.