Task-based grasp quality measures for grasp synthesis

To facilitate manipulation tasks, grasp should be selected intelligently to fulfill different stability properties and manipulative requirements in the tasks. In this paper, two task-dependent grasp quality measures are introduced: task wrench coverage measure and the manipulator efficiency measure. The first one measures the ability of a grasp to provide required interactive wrench during a task, while the second measures the effort that the manipulator takes for the whole manipulation process in facilitating the required instrument motion, which is determined by the grasp when the motion of the instrument is defined. The proposed measures are then used in selecting grasps for three typical manipulation tasks in simulations and using a real robotic system and produced successful grasp synthesis outcomes that satisfy manipulative requirements.