Stable pushing manipulation with controlled two-point contact conditions for two-arm differential drive mobile robot

In this paper, we present a stable pushing manipulation of a large object with a differential-driving-mobilebase robot with two arms. To model the holding of an object with two arms, we consider the variation of friction at the two contact points between the robot and the object. This model allows us to find a relation between the location of the stable radius of pushing motion and the mobile robot wheel speeds. Also, this model unifies the grasping motion of the robot arm while pushing a large object stably, which can be done in the framework of mobile robot's pushing mechanism. The overall path planning is obtained from A* algorithm in a grid map. We verify the idea using V-rep simulation and show that the motion with shaper turns can be realized, thus the object can be pushed stably along an optimal path without switching the contact points.