Grasping strategy of two robot arms based on tactile and slippage sensation of optical three-axis tactile sensor system

This paper presents a new grasping strategy of two robot arms based on active tactile and slippage sensation using a novel optical three-axis tactile sensor system. The tactile sensors are mounted on the tip of robotic hands of two robot arms. In the robot motion control, a recurrent mechanism was implemented in which the next behavior is induced by the tactile data to make the robot accept intention embedded in the environment. Since this mechanism is based on the tactile data, it is possible to apply it to communication between the hand-arms to obtain the best timing for cooperative work. A slippage distribution analysis was conducted which result shows that slippage occurred according to direction of force applied to the sensing elements. In experiments, the two-hand-arm robot performed object grasping, twisting, transferring and assembling tasks. Experimental results show that the proposed strategy has great potential to improve grasping performance of robot hand because appropriate behavior is induced according to tactile and slippage direction.