21,357 research outputs found

    Fabrication and characterization of nanostructured fluorine doped tin oxide thin film for dssc by hydrothermal method

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    Nanostructured Fluorine Doped Tin Oxide (FTO) thin film has been successfully synthesized on top of bare FTO layer substrates using hydrothermal method. The performance of FTO thin film including conductivity and transparency depend on the surface morphology and the properties of the material. Hydrothermal method has proven to be a very good method for the fabrication of novel metal oxides. Thus, a new nanostructured FTO thin film like nanorice has been fabricated using one step hydrothermal method. FTO nanorice thin films were obtained from the reaction of tin (iv) chloride (SnCl4), ammonium fluoride (NH4F), acetone, deionized water and hydrochloric acid (HCl). The compound was prepared in an autoclave at 150°C hydrothermal temperature for different reaction times of 5 hours, 10 hours, 15 hours, and 20 hours. FESEM studies on the surface morphologies of all the samples showed that nanorice structure had formed to fully cover the bare FTO substrate. Then, to further the optimization of FTO nanorice thin film, this research focused on studying the effect of hydrothermal temperature on FTO nanorice thin films. The experiments were conducted at 130°C, 140°C, 150°C, 160°C, and 170°C of hydrothermal temperature in constant reaction time of 10 hours. Basically, there were six properties studied; surface morphology, structural, element composition, thickness measurement, electrical and optical properties. At the end of this research, homogeneous FTO thin film has been successfully prepared. By controlling the reaction time and hydrothermal temperature, a transparent FTO film with beyond 85% percentage of transmittance was developed. The FTO thin film produced at 10 hour reaction time and 150°C of hydrothermal temperature time gave the low sheet resistance of 0.012 Ohm/sq with high transparency. The DSSC fabricated using the optimized FTO film gave higher efficiency of 2.77% compared to commercial FTO of 1.93%

    Folding Assembly by Means of Dual-Arm Robotic Manipulation

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    In this paper, we consider folding assembly as an assembly primitive suitable for dual-arm robotic assembly, that can be integrated in a higher level assembly strategy. The system composed by two pieces in contact is modelled as an articulated object, connected by a prismatic-revolute joint. Different grasping scenarios were considered in order to model the system, and a simple controller based on feedback linearisation is proposed, using force torque measurements to compute the contact point kinematics. The folding assembly controller has been experimentally tested with two sample parts, in order to showcase folding assembly as a viable assembly primitive.Comment: 7 pages, accepted for ICRA 201

    Ground Robotic Hand Applications for the Space Program study (GRASP)

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    This document reports on a NASA-STDP effort to address research interests of the NASA Kennedy Space Center (KSC) through a study entitled, Ground Robotic-Hand Applications for the Space Program (GRASP). The primary objective of the GRASP study was to identify beneficial applications of specialized end-effectors and robotic hand devices for automating any ground operations which are performed at the Kennedy Space Center. Thus, operations for expendable vehicles, the Space Shuttle and its components, and all payloads were included in the study. Typical benefits of automating operations, or augmenting human operators performing physical tasks, include: reduced costs; enhanced safety and reliability; and reduced processing turnaround time

    NASA space station automation: AI-based technology review. Executive summary

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    Research and Development projects in automation technology for the Space Station are described. Artificial Intelligence (AI) based technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics

    Human-Machine Interface for Remote Training of Robot Tasks

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    Regardless of their industrial or research application, the streamlining of robot operations is limited by the proximity of experienced users to the actual hardware. Be it massive open online robotics courses, crowd-sourcing of robot task training, or remote research on massive robot farms for machine learning, the need to create an apt remote Human-Machine Interface is quite prevalent. The paper at hand proposes a novel solution to the programming/training of remote robots employing an intuitive and accurate user-interface which offers all the benefits of working with real robots without imposing delays and inefficiency. The system includes: a vision-based 3D hand detection and gesture recognition subsystem, a simulated digital twin of a robot as visual feedback, and the "remote" robot learning/executing trajectories using dynamic motion primitives. Our results indicate that the system is a promising solution to the problem of remote training of robot tasks.Comment: Accepted in IEEE International Conference on Imaging Systems and Techniques - IST201

    Safety-related Tasks within the Set-Based Task-Priority Inverse Kinematics Framework

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    In this paper we present a framework that allows the motion control of a robotic arm automatically handling different kinds of safety-related tasks. The developed controller is based on a Task-Priority Inverse Kinematics algorithm that allows the manipulator's motion while respecting constraints defined either in the joint or in the operational space in the form of equality-based or set-based tasks. This gives the possibility to define, among the others, tasks as joint-limits, obstacle avoidance or limiting the workspace in the operational space. Additionally, an algorithm for the real-time computation of the minimum distance between the manipulator and other objects in the environment using depth measurements has been implemented, effectively allowing obstacle avoidance tasks. Experiments with a Jaco2^2 manipulator, operating in an environment where an RGB-D sensor is used for the obstacles detection, show the effectiveness of the developed system

    Feasibility of Warehouse Drone Adoption and Implementation

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    While aerial delivery drones capture headlines, the pace of adoption of drones in warehouses has shown the greatest acceleration. Warehousing constitutes 30% of the cost of logistics in the US. The rise of e-commerce, greater customer service demands of retail stores, and a shortage of skilled labor have intensified competition for efficient warehouse operations. This takes place during an era of shortening technology life cycles. This paper integrates several theoretical perspectives on technology diffusion and adoption to propose a framework to inform supply chain decision-makers on when to invest in new robotics technology
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