Cooperative control of differential wheeled mobile robots for box pushing problem

We present a decentralized cooperative control algorithm for a box pushing problem using two ground robots. The main framework of the algorithm is composed of a sequence of three behaviors, Approach, Align, and Push. We define two rotational and one translational motion primitives to manipulate the box. A point-tracking controller is derived for differential wheeled mobile robots to push the point on the box defined by the motion primitives. For cooperation, robots communicate their status variables and an efficient role assignment scheme is proposed. We present experimental results obtained using our multi-robot testbed.