Action-Intention-Based Grasp Control With Fine Finger-Force Adjustment Using Combined Optical-Mechanical Tactile Sensor

This paper presents a control method that makes it possible for a home-use manipulation system to easily grasp objects with various weights and hardnesses. To provide easy operability for nonprofessional persons, an action-intention-based man-machine interaction method was developed. To enable the fine finger-force control required for grasping various objects, a combined optical-mechanical tactile sensing method with high-sensitivity slip detection was also developed. In addition, as a platform for manipulation systems with many sensors, a hierarchical multiprocessor controller was built. The developed methods were evaluated experimentally by using a prototype manipulation system consisting of a robotic hand and a user interface. The evaluation results demonstrate that the manipulator system can be used to easily grasp various objects, such as a rolled-up paper towel (weighing 4 g) and a clay-filled cardboard tube (weighing 500 g). Operability in remote control was also evaluated. The developed methods make it possible to fine-tune the finger force according to target object on the basis of tactile sensing information.