A static obstacle collision mitigation control scheme for flexible formation of nonholonomic mobile robots, with experiments

In this paper, a static obstacle collision mitigation scheme is proposed for flexible formation of nonholonomic mobile robots. The aim of the collision mitigation scheme is to prevent a flexible formation of mobile robots from colliding with online detected static obstacles or to decrease the kinetic energy of the collision through coordinated formation braking. The key thrust of the proposed control scheme is that the scheme is able to guarantee a formation braking solution that prevents a formation of mobile robots from colliding with the detected static obstacles under some practically feasible assumptions. The control scheme is based on an online obstacle collision detection module and a formation braking module equipped on each robot to perform the obstacle collision mitigation. The scheme was validated in numerical simulations and partial experiments were conducted for proof-of-concept in some off-road environments at speeds up to 3 m/sec.