Maintaining stable grasps during highly dynamic robot trajectories

Abstract

One of the key advantages of robots is the high speeds at which they can operate. In industrial settings, increased velocities can lead to higher throughputs and improved efficiency. Some manipulation tasks might require the robot to perform highly dynamic operations such as shaking, or swinging while grasping an object. These fast movements may produce high accelerations and thus give rise to inertial forces that can cause a grasped object to slip. In this paper a method is proposed to determine the inertial forces that arise on a grasped object during a trajectory, find the instances at which the object might slip, and avoid these slippages by changing the trajectory, namely the orientation of the object. To exemplify the usage of this approach, two grasping tasks are realised: a prehensile and a non-prehensile grasp, and strategies to successfully perform these tasks without changing the overall duration of the trajectory are defined and evaluated.