Depth Restoration of Hand-Held Transparent Objects for Human-to-Robot Handover

Transparent objects are common in daily life, while their unique optical properties pose challenges for RGB-D cameras, which struggle to capture accurate depth information. For assistant robots, accurately perceiving transparent objects held by humans is essential for effective human-robot interaction. This paper presents a Hand-Aware Depth Restoration (HADR) method for hand-held transparent objects based on creating an implicit neural representation function from a single RGB-D image. The proposed method introduces the hand posture as an important guidance to leverage semantic and geometric information. To train and evaluate the proposed method, we create a high-fidelity synthetic dataset called TransHand-14K with a real-to-sim data generation scheme. Experiments show that our method has a better performance and generalization ability compared with existing methods. We further develop a real-world human-to-robot handover system based on the proposed depth restoration method, demonstrating its application value in human-robot interaction.

Visual-tactile Fusion for Transparent Object Grasping in Complex Backgrounds

The accurate detection and grasping of transparent objects are challenging but of significance to robots. Here, a visual-tactile fusion framework for transparent object grasping under complex backgrounds and variant light conditions is proposed, including the grasping position detection, tactile calibration, and visual-tactile fusion based classification. First, a multi-scene synthetic grasping dataset generation method with a Gaussian distribution based data annotation is proposed. Besides, a novel grasping network named TGCNN is proposed for grasping position detection, showing good results in both synthetic and real scenes. In tactile calibration, inspired by human grasping, a fully convolutional network based tactile feature extraction method and a central location based adaptive grasping strategy are designed, improving the success rate by 36.7% compared to direct grasping. Furthermore, a visual-tactile fusion method is proposed for transparent objects classification, which improves the classification accuracy by 34%. The proposed framework synergizes the advantages of vision and touch, and greatly improves the grasping efficiency of transparent objects.