408 research outputs found

    DexROV: Enabling effective dexterous ROV operations in presence of communication latency

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    Subsea interventions in the oil & gas industry as well as in other domains such as archaeology or geological surveys are demanding and costly activities for which robotic solutions are often deployed in addition or in substitution to human divers - contributing to risks and costs cutting. The operation of ROVs (Remotely Operated Vehicles) nevertheless requires significant off-shore dedicated manpower to handle and operate the robotic platform and the supporting vessel. In order to reduce the footprint of operations, DexROV proposes to implement and evaluate novel operation paradigms with safer, more cost effective and time efficient ROV operations. As a keystone of the proposed approach, manned support will in a large extent be delocalized within an onshore ROV control center, possibly at a large distance from the actual operations, relying on satellite communications. The proposed scheme also makes provision for advanced dexterous manipulation and semi-autonomous capabilities, leveraging human expertise when deemed useful. The outcomes of the project will be integrated and evaluated in a series of tests and evaluation campaigns, culminating with a realistic deep sea (1,300 meters) trial in the Mediterranean sea

    Study of extravehicular protection and operations

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    Extravehicular protection and operation

    Design and Shape Optimization of Strain Gauge Load Cell for Axial Force Measurement for Test Benches

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    The load cell is an indispensable component of many engineering machinery and industrial automation for measuring and sensing force and torque. This paper describes the design and analysis of the strain gauge load cell, from the conceptional design stage to shape optimization (based on the finite element method (FEM) technique) and calibration, providing ample load capacity with low-cost material (aluminum 6061) and highly accurate force measurement. The amplifier circuit of the half Wheatstone bridge configuration with two strain gauges was implemented experimentally with an actual load cell prototype. The calibration test was conducted to evaluate the load cell characteristics and derive the governing equation for sensing the unknown load depending on the measured output voltage. The measured sensitivity of the load cell is approximately 15 mV/N and 446.8 µV/V at a maximum applied load of 30 kg. The findings are supported by FEM results and experiments with an acceptable percentage of errors, which revealed an overall error of 6% in the worst situation. Therefore, the proposed load cell meets the design considerations for axial force measurement for the laboratory test bench, which has a light weight of 20 g and a maximum axial force capacity of 300 N with good sensor characteristic

    The Research on Soft Pneumatic Actuators in Italy: Design Solutions and Applications

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    Interest in soft actuators has increased enormously in the last 10 years. Thanks to their compliance and flexibility, they are suitable to be employed to actuate devices that must safely interact with humans or delicate objects or to actuate bio-inspired robots able to move in hostile environments. This paper reviews the research on soft pneumatic actuators conducted in Italy, focusing on mechanical design, analytical modeling, and possible application. A classification based on the geometry is proposed, since a wide set of architectures and manufacturing solutions are available. This aspect is confirmed by the extent of scenarios in which researchers take advantage of such systems’ improved flexibility and functionality. Several applications regarding bio-robotics, bioengineering, wearable devices, and more are presented and discussed

    RoboGlove-A Grasp Assist Device for Earth and Space

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    The RoboGlove is an assistive device that can augment human strength, endurance or provide directed motion for use in rehabilitation. RoboGlove is a spinoff of the highly successful Robonaut 2 (R2) system developed as part of a partnership between General Motors and NASA. This extremely lightweight device employs an actuator system based on the R2 finger drive system to transfer part or the entire grasp load from human tendons to artificial ones contained in the glove. Steady state loads ranging from 15 to 20 lbs. and peaks approaching 50 lbs. are achievable. Work is underway to integrate the RoboGlove system with a space suit glove to add strength or reduce fatigue during spacewalks. Tactile sensing, miniaturized electronics, and on-board processing provide sufficient flexibility for applications in many industries. The following describes the design, mechanical/electrical integration, and control features of the glove in an assembly-line configuration and discusses work toward the space suit application

    Kinematics and Robot Design IV, KaRD2021

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    This volume collects the papers published on the special issue “Kinematics and Robot Design IV, KaRD2021” (https://www.mdpi.com/journal/robotics/special_issues/KaRD2021), which is the forth edition of the KaRD special-issue series, hosted by the open-access journal “MDPI Robotics”. KaRD series is an open environment where researchers can present their works and discuss all the topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”. KaRD2021, after the peer-review process, accepted 12 papers. The accepted papers cover some theoretical and many design/applicative aspects

    3D locomotion biomimetic robot fish with haptic feedback

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    This thesis developed a biomimetic robot fish and built a novel haptic robot fish system based on the kinematic modelling and three-dimentional computational fluid dynamic (CFD) hydrodynamic analysis. The most important contribution is the successful CFD simulation of the robot fish, supporting users in understanding the hydrodynamic properties around it

    Analysis of ANN and Fuzzy Logic Dynamic Modelling to Control the Wrist Exoskeleton

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    Human intention has long been a primary emphasis in the field of electromyography (EMG) research. This being considered, the movement of the exoskeleton hand can be accurately predicted based on the user's preferences. The EMG is a nonlinear signal formed by muscle contractions as the human hand moves and easily captured noise signal from its surroundings. Due to this fact, this study aims to estimate wrist desired velocity based on EMG signals using ANN and FL mapping methods. The output was derived using EMG signals and wrist position were directly proportional to control wrist desired velocity. Ten male subjects, ranging in age from 21 to 40, supplied EMG signal data set used for estimating the output in single and double muscles experiments. To validate the performance, a physical model of an exoskeleton hand was created using Sim-mechanics program tool. The ANN used Levenberg training method with 1 hidden layer and 10 neurons, while FL used a triangular membership function to represent muscles contraction signals amplitude at different MVC levels for each wrist position. As a result, PID was substituted to compensate fluctuation of mapping outputs, resulting in a smoother signal reading while improving the estimation of wrist desired velocity performance. As a conclusion, ANN compensates for complex nonlinear input to estimate output, but it works best with large data sets. FL allowed designers to design rules based on their knowledge, but the system will struggle due to the large number of inputs. Based on the results achieved, FL was able to show a distinct separation of wrist desired velocity hand movement when compared to ANN for similar testing datasets due to the decision making based on rules setting setup by the designer

    Semi Wireless Underwater Rescue Drone with Robotic Arm

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    Wireless communication with underwater drones plays a vital role in rescuing an after-ship accident, and it is considered one of the most challenging technologies nowadays. The wireless underwater drone also contributes significantly to navy, gas and oil companies, underwater infrastructure, aquaculture industry, commercial diving, and deep archeological investigations. Bangladesh, a developing country with many rivers and seashores used by many water transport vehicles, faces boat and ship accidents as a typical scenario every year. Many lives, dead bodies, ships, boats, and valuable objects do not get rescued because of the lifetime risk of the divers or the rescue team. The rescue operation is exceptionally troublesome because of the absence of wireless underwater drone technology at the cheapest cost, whose innovation and function are very challenging for Bangladesh. Considering these problematic situations, in this paper, we have proposed a prototype of a semi wireless underwater drone designed and structured with the best quality PVC pipe of 6mm diameter, considering the weight as lowest as possible, maintaining its buoyancy properly. In this prototype, we have used three propellers, each connected with three servo motors, to move it up, down, back, and forth. A robotic arm is also utilized to rescue objects from under the water, and a 4K HD EKEN camera and two waterproof fog lights to search and visualize underwater objects on the mobile screen from the land. For wireless communication between the controller and the drone, we have used two nRF24L01 modules; one is for the controller, and the other is for the drone’s receiver to send and obtain the signals from the controller to the drone. 12V and 24V lithium-ion batteries are employed as power sources for the controller and receiver, respectively. Finally, real experimental tests of the proposed underwater device were performed in a swimming pool facility
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