Tracking and Understanding Unknown Surface With High Speed by Force Sensing and Control for Robot

Robot's blind tracking of an unknown surface with high speed is a critical problem of force control, to avoid damage to breakable objects, such as a bulb. It must deal with a typical action-based intelligence directly from force sensing to action in robot tracking and understanding of unknown external environments. Bio-inspired by human finger tracking, the realization of high-speed tracking relies on the real-time understanding and prediction of surface tendency, including the geometric feature and roughness. This paper presents an action-based intelligent frame for robot to track and understand an unknown surface with high speed using force sensing and control. The moving frame of force and position parallel control is built to obtain the differential geometric properties of an unknown surface. The motion trajectory is dynamically predicted by force sensing while tracking an unknown surface. A hybrid interpolator is developed to realize the parallel control of force and position. Moreover, a discriminant method for basic surface type recognition is investigated based on the normal curvature and geodesic torsion directly derived from the moving frame. The surface of revolution is further identified in the global understanding of unknown surface. The results of tracking a bulb with a desired contact force at a speed of 25 mm/s show the effectiveness of the proposed intelligent frame.