326 research outputs found

    Comparative Study on Electrochemical Corrosion and Natural Corrosion of Reinforced Concrete Components

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    Based on the study of the corrosion characteristics of reinforced concrete members under electrochemical corrosion and natural corrosion, such as the corrosion principle, product formation, morphology and microstructure of steel corrosion pits, the differences and similarities of the basic mechanical properties of steel bars and the mechanical properties of concrete members under two corrosion states are analyzed, and the applicability of accelerated corrosion of steel bars in concrete is discussed. In the study of the mechanical properties of corroded steel bars, the non-uniform electrochemical corrosion can be used to replace the natural corrosion. When the research object needs to consider the corrosion expansion force and the corrosion current density model, the difference between the two cannot be ignored

    Flipbot: Learning Continuous Paper Flipping via Coarse-to-Fine Exteroceptive-Proprioceptive Exploration

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    This paper tackles the task of singulating and grasping paper-like deformable objects. We refer to such tasks as paper-flipping. In contrast to manipulating deformable objects that lack compression strength (such as shirts and ropes), minor variations in the physical properties of the paper-like deformable objects significantly impact the results, making manipulation highly challenging. Here, we present Flipbot, a novel solution for flipping paper-like deformable objects. Flipbot allows the robot to capture object physical properties by integrating exteroceptive and proprioceptive perceptions that are indispensable for manipulating deformable objects. Furthermore, by incorporating a proposed coarse-to-fine exploration process, the system is capable of learning the optimal control parameters for effective paper-flipping through proprioceptive and exteroceptive inputs. We deploy our method on a real-world robot with a soft gripper and learn in a self-supervised manner. The resulting policy demonstrates the effectiveness of Flipbot on paper-flipping tasks with various settings beyond the reach of prior studies, including but not limited to flipping pages throughout a book and emptying paper sheets in a box.Comment: Accepted to International Conference on Robotics and Automation (ICRA) 202

    Learn to Grasp via Intention Discovery and its Application to Challenging Clutter

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    Humans excel in grasping objects through diverse and robust policies, many of which are so probabilistically rare that exploration-based learning methods hardly observe and learn. Inspired by the human learning process, we propose a method to extract and exploit latent intents from demonstrations, and then learn diverse and robust grasping policies through self-exploration. The resulting policy can grasp challenging objects in various environments with an off-the-shelf parallel gripper. The key component is a learned intention estimator, which maps gripper pose and visual sensory to a set of sub-intents covering important phases of the grasping movement. Sub-intents can be used to build an intrinsic reward to guide policy learning. The learned policy demonstrates remarkable zero-shot generalization from simulation to the real world while retaining its robustness against states that have never been encountered during training, novel objects such as protractors and user manuals, and environments such as the cluttered conveyor.Comment: Accepted to IEEE Robotics and Automation Letters (RA-L
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