Rotary object dexterous manipulation in hand: a feedback-based method

We focus on manipulating the object of unknown shape, weight and friction properties in hand task. Unlike the traditional method considering the manipulation as multi times grasp planning, we follow the behavior robotics opinion and propose the reactive manipulation strategy. Firstly, we design the compact closed loop control (local controller) to manipulate object in the neighbor area of its current configuration. The local controller is robust to unmodel error (i.e. initial contact position error, rolling or sliding between the fingertip and the object etc.) because of its nature of feedback control. Then we employ global planner to manage the role of fingers (active/passive) and modify robot hand to new comfort grasp posture for new local manipulation. Concretely, passive fingers grip the object stably and active finger contact the new point on the object. While the object and hand reach to the new configuration, local controller will start working again. A physics-based simulation setup which is similar with real robot hand is used to prove our manipulation concepts–using four fingers manipulate one rotary object in hand. Only commercial available sensors feedback values are used in simulation in order to facilitate the algorithm transferring to real robot platform. Result shows the object can be manipulated in ideal and simulated artificial noise cases.