Visual-Tactile Perception Based Control Strategy for Complex Robot Peg-in-Hole Process via Topological and Geometric Reasoning

Peg-hole-insertion processes of diverse shapes are typical contact-rich tasks, which need the accurate representation of object's shape, pose, and peg-hole contact states. The visual-tactile sensor can perceive the relative moving trend between the gripper and the grasped object, which could be applied in the perception of the peg-hole contact states. In order to complete peg-hole insertion tasks, this manuscript proposes a method of using the visual-tactile sensor to estimate the relative position of peg and hole. Furthermore, it introduces the theory of topological and geometric reasoning to characterize the insertion process, which could be used for various polygon shaped pegs and holes. In five different shapes of peg and hole experiments, errors of peg-hole relative position estimation using the method proposed in this manuscript are almost within 5 degrees, which can meet the needs of insertion tasks. What's more, insertion processes become more smooth by adopting the topological and geometric reasoning, indicating the effectiveness of the reasoning process.