CRAVES: Controlling Robotic Arm with a Vision-based Economic System

Training a robotic arm to accomplish real-world tasks has been attracting increasing attention in both academia and industry. This work discusses the role of computer vision algorithms in this field. We focus on low-cost arms on which no sensors are equipped and thus all decisions are made upon visual recognition, e.g., real-time 3D pose estimation. This requires annotating a lot of training data, which is not only time-consuming but also laborious. In this paper, we present an alternative solution, which uses a 3D model to create a large number of synthetic data, trains a vision model in this virtual domain, and applies it to real-world images after domain adaptation. To this end, we design a semi-supervised approach, which fully leverages the geometric constraints among keypoints. We apply an iterative algorithm for optimization. Without any annotations on real images, our algorithm generalizes well and produces satisfying results on 3D pose estimation, which is evaluated on two real-world datasets. We also construct a vision-based control system for task accomplishment, for which we train a reinforcement learning agent in a virtual environment and apply it to the real-world. Moreover, our approach, with merely a 3D model being required, has the potential to generalize to other types of multi-rigid-body dynamic systems.Comment: 10 pages, 6 figure

Dynamic Transmission Characteristics during Soft-Start of Hydro-Viscous Drive Considering Fluid-Inertia Item

Considering the influence of the fluid-inertia item on dynamic transmission characteristics during soft-start of hydro-viscous drive (HVD), theoretical models were derived with the aim of revealing the effect of engagement pressure, lubricant viscosity, viscosity-temperature characteristics, surface roughness and the ratio of inner and outer radius of plates on total torque and viscous torque. The results indicate that the increase of engagement pressure and lubricant viscosity shortens soft-start time and increases peak total torque in the stage of mixed lubrication. The decrease of surface roughness and effective contact area of plates can both shorten soft-start time. And yet two cases of time to reach peak total torque are in different stages. Fluid-inertia item included can help to avoid fluctuation of the total torque while increasing lubricant viscosity or reducing surface roughness. It can increase soft-start time obviously when considering viscosity-temperature characteristics. In short, the research reveals the influence rules of the fluid-inertia item on dynamic transmission characteristics of HVD; additionally, fluid-inertia item included contributes to reduce oscillation of the total torque and the decline in efficiency. Therefore, the research results lay a theoretical foundation for the design of high-power HVD device

supplement_figure2 – Supplemental material for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis

<p>Supplemental material, supplement_figure2 for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis by Qian Huang, Yonghai Peng and Fangwei Xie in The International Journal of Biological Markers</p

supplement_figure_1 – Supplemental material for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis

<p>Supplemental material, supplement_figure_1 for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis by Qian Huang, Yonghai Peng and Fangwei Xie in The International Journal of Biological Markers</p

supplementfigure4 – Supplemental material for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis

<p>Supplemental material, supplementfigure4 for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis by Qian Huang, Yonghai Peng and Fangwei Xie in The International Journal of Biological Markers</p

Supplementary_material – Supplemental material for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis

<p>Supplemental material, Supplementary_material for Fecal fusobacterium nucleatum for detecting colorectal cancer: a systematic review and meta-analysis by Qian Huang, Yonghai Peng and Fangwei Xie in The International Journal of Biological Markers</p

A Novel Magnetorheological Fluid with High-Temperature Resistance

A magnetorheological fluid (MR fluid) is mainly composed of soft magnetic particles, surfactants, and the base carrier fluid. Among these, soft magnetic particles and the base carrier fluid influence the MR fluid significantly in a high-temperature environment. Therefore, a study was carried out to investigate the changes in the properties of soft magnetic particles and base carrier fluids in high-temperature environments. On this basis, a novel magnetorheological fluid with high-temperature resistance was prepared, and the novel magnetorheological fluid had excellent sedimentation stability, of which the sedimentation rate was only 4.42% after heat treatment at 150 °C followed by one-week placement. At 30 °C, the shear yield stress of the novel fluid was 9.47 kPa under the magnetic field of 817 mT: higher than the general magnetorheological fluid with the same mass fraction. Moreover, its shear yield stress was less affected by the high-temperature environment, reducing by only 4.03% from 10 °C to 70 °C. The novel MR fluid can be applied to a high-temperature environment, effectively expanding the application range of MR fluid