Efficient Object Rearrangement via Multi-view Fusion

The prospect of assistive robots aiding in object organization has always been compelling. In an image-goal setting, the robot rearranges the current scene to match the single image captured from the goal scene. The key to an image-goal rearrangement system is estimating the desired placement pose of each object based on the single goal image and observations from the current scene. In order to establish sufficient associations for accurate estimation, the system should observe an object from a viewpoint similar to that in the goal image. Existing image-goal rearrangement systems, due to their reliance on a fixed viewpoint for perception, often require redundant manipulations to randomly adjust an object's pose for a better perspective. Addressing this inefficiency, we introduce a novel object rearrangement system that employs multi-view fusion. By observing the current scene from multiple viewpoints before manipulating objects, our approach can estimate a more accurate pose without redundant manipulation times. A standard visual localization pipeline at the object level is developed to capitalize on the advantages of multi-view observations. Simulation results demonstrate that the efficiency of our system outperforms existing single-view systems. The effectiveness of our system is further validated in a physical experiment.Comment: 7 pages, 4 figure

The Research of Simulation on Eddy Current Separation Process Based on MATLAB and COMSOL

AbstractThe separation process of eddy current separator is effected by the structure parameters of magnetic roller, the working parameters of the separator and some parameters of the scrap metal, such as the material, the shape, the size and so on. This is a complex process of electric field and magnetic field coupling. During this process, the sorting function of separator is powered by the existence of the eddy current power in waste particles, and the separation effect is directly determined by the flying distance of the scrap metal in the separation process. This paper armed for studying the eddy current power and the flying distance of the waste particles in separation to realize the simulation of the separation process. The eddy current force was obtained by the finite element analysis of the magnetic roller based on COMSOL, and the flying distance was got by the joint simulation of COMSOL and MATLAB

GraspGPT: Leveraging Semantic Knowledge from a Large Language Model for Task-Oriented Grasping

Task-oriented grasping (TOG) refers to the problem of predicting grasps on an object that enable subsequent manipulation tasks. To model the complex relationships between objects, tasks, and grasps, existing methods incorporate semantic knowledge as priors into TOG pipelines. However, the existing semantic knowledge is typically constructed based on closed-world concept sets, restraining the generalization to novel concepts out of the pre-defined sets. To address this issue, we propose GraspGPT, a large language model (LLM) based TOG framework that leverages the open-end semantic knowledge from an LLM to achieve zero-shot generalization to novel concepts. We conduct experiments on Language Augmented TaskGrasp (LA-TaskGrasp) dataset and demonstrate that GraspGPT outperforms existing TOG methods on different held-out settings when generalizing to novel concepts out of the training set. The effectiveness of GraspGPT is further validated in real-robot experiments. Our code, data, appendix, and video are publicly available at https://sites.google.com/view/graspgpt/.Comment: 15 pages, 8 figure

Mg-doped NiCoP microflower grown on Ni foam for high-capacity supercapacitor electrode

In this work, a binder-free electrode Mg-doped NiCoP/Ni foam (MNCP-x/NF) was prepared via hydrothermal and phosphorization process, in which echinoid microflower-like MNCP-x was densely loaded on the NF skeleton. By regulating the Mg2+ doping amount, remarkable enhancements in the morphology, mass-loading of MNCP, electrode conductivity and overall electrochemical capacitive properties of MNCP-x/NF have been achieved. Particularly, moderate doped MNCP-0.5/NF exhibits the best energy storage performances with a superior specific capacity (4461 mC cm−2 @ 2 mA cm−2), acceptable rate capability (retaining 50.1% @ 50 mA cm−2), and striking cyclability (retaining 83% over 5000 cycles). Moreover, a solid-state asymmetric supercapacitor constructed with MNCP-0.5/NF as cathode, graphene hydrogel/NF (GH/NF) as anode, PVA/KOH gel as electrolyte, outputs the notable energy density of 39.8 Wh kg−1 (1.8 mWh cm−3) and power density of 16674 W kg−1 (750 mW cm−3), companied by a superior cyclability (retaining 87% over 5000 cycles)

Mechanical Properties of Nano-SiO2 Reinforced Geopolymer Concrete under the Coupling Effect of a Wet–Thermal and Chloride Salt Environment

In this study, the mechanical behaviors of nano-SiO2 reinforced geopolymer concrete (NS-GPC) under the coupling effect of a wet–thermal and chloride salt environment were investigated through a series of basic experiments, and a simulation on the coupling effect of a wet–thermal and chloride salt environment and SEM test were also included. During the experiments for the coupling effect of the wet–thermal and chloride salt environment, an environment simulation test chamber was utilized to simulate the wet–thermal and chloride salt environment, in which the parameters of relative humidity, temperature, mass fraction of NaCl solution and action time were set as 100%, 45 °C, 5% and 60 d, respectively. The content of nano-SiO2 (NS) particles added in geopolymer concrete (GPC) were 0, 0.5%, 1.0%, 1.5% and 2.0%. The result indicated that the mechanical properties of NS reinforced GPC decreased under the coupling effect of the wet–thermal and chloride salt environment compared to the control group in the natural environment. When the NS content was 1.5%, the cube and splitting tensile strength, elastic modulus and impact toughness of GPC under the coupling environment of wet–thermal and chloride salt were decreased by 9.7%, 9.8%, 19.2% and 44.4%, respectively, relative to that of the GPC under the natural environment. The addition of NS improved the mechanical properties of GPC under the coupling effect of the wet–thermal and chloride salt environment. Compared to the control group without NS, the maximum increment in cube compressive strength, splitting tensile strength and elastic modulus of NS–GPC under the coupling effect of the wet–thermal and chloride salt environment due to the incorporation of NS reached 25.8%, 9.6% and 17.2%, respectively. Specifically, 1.5% content of NS increased the impact toughness, impact numbers of initial crack and the ultimate failure of GPC by 122.3%, 109% and 109.5%, respectively

Extrapolation methods to compute hypersingular integral in boundary element methods

National Natural Science Foundation of China [11101247, 11201209, 11101317]; Shandong Provincial Natural Science Foundation of China [ZR2011AQ020]; Shandong Province Higher Educational Science and Technology Program [J11LE08]; National Basic Research Program of China [2005CB321701]; Reward Fund of CAS for National PrizeThe composite trapezoidal rule for the computation of Hadamard finite-part integrals in boundary element methods with the hypersingular kernel 1/sin(2)(x - s) is discussed, and the main part of the asymptotic expansion of error function is obtained. Based on the main part of the asymptotic expansion, a series is constructed to approach the singular point. An extrapolation algorithm is presented and the convergence rate is proved. Some numerical results are also presented to confirm the theoretical results and show the efficiency of the algorithms

Image Sensor Based Visible Light Positioning System with Improved Positioning Algorithm

We optimize an image sensor-based indoor visible light positioning (VLP) system by improving the positioning algorithm. Specifically, we derive a close-form expression to determine the receiver's position and orientation using the singular value decomposition (SVD) technique, which speeds up the positioning process and enhances the robustness. Simulation results show that the proposed SVD-based noniterative positioning algorithm is 50-80 times faster than the conventional iterative Levenberg-Marquardt-based algorithm and avoids the possible failures caused by the bad initial guesses. Meanwhile, we theoretically investigate the VLP system by deriving the Cramer-Rao lower bound and the root mean square error bound as the positioning accuracy limit and study the impact of system parameters on the positioning error. Finally, we experimentally evaluate the performance of the improved VLP system. It achieves highly robust and fast 3-D positioning with centimeter-level accuracy.Published versio