Tactile Sensing of Edge Direction of an Object with a Soft Fingertip Contact

We propose a new method of tactile sensing for a fingertip of robotic hand. Using a simple fingertip with soft surface cover and a six-axis force/torque sensor, developed is a new function of measuring direction of edge when the fingertip contacts with an edge of the object. The developed function is useful not only to plan strategies for stable grasp and dexterous manipulation but also to recognize a geometrical shape of an object. Two necessary components, a six-axis force/torque sensor and the soft skin, are commercially available. They will neither restrict design of a robotic fingertip nor badly affect essential functions of stable grasping and manipulation.