2,493 research outputs found
Amphibious NDT Robots
Oil, petrochemical, and food processing industries worldwide store their raw materials and product in tens of thousands of storage tanks. The tanks are mostly constructed using
welded steel plates and therefore subject to corrosion and weld cracking. Testing the structural integrity of these storage tanks with non-destructive testing (NDT) techniques is an expensive and time consuming activity. The walls of a large tank can usually be tested manually (for corrosion thinning and weld defects using ultrasonic techniques) from outside
the tank. Access to most areas of a wall is obtained by constructing scaffolding or abseiling down from the top. However, erecting scaffolding is expensive and the inspection is tedious and slow. These costs can be reduced and the inspection speeded up by using climbing robots that deploy ultrasonic probes with scanning arms
Do androids dream of electric fences? Safety-aware reinforcement learning with latent shielding
The growing trend of fledgling reinforcement learning sys- tems making their way into real-world applications has been accompanied by growing concerns for their safety and ro- bustness. In recent years, a variety of approaches have been put forward to address the challenges of safety-aware rein- forcement learning; however, these methods often either re- quire a handcrafted model of the environment to be pro- vided beforehand, or that the environment is relatively simple and low-dimensional. We present a novel approach to safety- aware deep reinforcement learning in high-dimensional envi- ronments called latent shielding. Latent shielding leverages internal representations of the environment learnt by model- based agents to “imagine” future trajectories and avoid those deemed unsafe. We experimentally demonstrate that this approach leads to improved adherence to formally-defined safety specifications
Signal quality of endovascular electroencephalography
Objective, Approach. A growing number of prototypes for diagnosing and treating neurological and psychiatric diseases are predicated on access to high-quality brain signals, which typically requires surgically opening the skull. Where endovascular navigation previously transformed the treatment of cerebral vascular malformations, we now show that it can provide access to brain signals with substantially higher signal quality than scalp recordings. Main results. While endovascular signals were known to be larger in amplitude than scalp signals, our analysis in rabbits borrows a standard technique from communication theory to show endovascular signals also have up to 100Ă— better signal-to-noise ratio. Significance. With a viable minimally-invasive path to high-quality brain signals, patients with brain diseases could one day receive potent electroceuticals through the bloodstream, in the course of a brief outpatient procedure
Keynote: Robotic Non Destructive Testing
This keynote paper aims to highlight the application of mobile robots to perform inspection and non destructive testing (NDT) in industries such as aerospace, large scale fabrication, pipelines, petro-chemical storage and power generation. It describes industrial tasks where regular inspection is essential to ensure the integrity of infrastructure such as storage tanks, pressure vessels, pipelines, aircraft, ships, etc, and to provide managers of capital assets with data to plan outages and to make decisions on the life span of their infrastructure. The development of robot prototypes is described for these industrial tasks. These robots deploy NDT systems by first providing access to large vertical structures or to test sites that are inaccessible to humans. They are designed to reduce outage time, or where possible, carry out the NDT online thus preventing costly outages
Development of Climbing Robots with Different Types of Adhesion
There is enormous potential in industrial inspection tasks for climbing robots than can work in hazardous environments, climb on different types of surfaces and enter into very small spaces that have difficult access. For example when cleaning, painting, repairing and diagnostic inspection of walls of general buildings, or performing non destructive testing inspection and maintenance of oil storage tanks, nuclear power plants, petrochemical factories, medical applications etc.
The paper describes several types of robot adhesion in different environments, some of which have been incorporated into wall climbing robot designs. The adhesion methods discussed generate forces with permanent magnets, vacuum suction cups, propellers, needles or grippers, glue or adhesive tape, and Van der waal’s effect
Climbing Robot Cell For Fast And Flexible Manufacture Of Large Scale Structures
This paper describes the specification stages of a project which seeks to modernise and take into the future the technology
of the manufacture of large fixed welded structures such as box girder bridges, storage tanks, ships and other steel
fabrications which arise on construction sites, in large chemical and foodstuff plants, on offshore oil platforms etc,
bringing the world of fast and flexible manufacturing to areas were construction is presently carried out by traditional use
of manual labour, scaffolding and cranes and the inconvenient delivery by road of large factory prefabricated components.
The Project will achieve this by creating a transportable manufacturing cell (CROCELLS) consisting of a team of
cooperating climbing robot work tools whose activities are coordinated and integrated through a central intelligence.
Unlike factory based cells the robot work tools must be mobile and small so that they are able to climb over long distances, to great heights and over curved surfaces and surfaces with ridges or protusions such as nodal joints providing many technical robotics problems to be solved. Small robots have payload limitations but the essence of the cooperating robot concept is that large payloads of work tools can be achieved with small robots by distributing the payload over several robots. Each robot will be dedicated to a different task to optimise overall system performance, hence there could be be a surface profiler and navigator, welder, bolt and rivet placer, hot weld quality inspector, and cold weld inspector on separate platforms. The cell will be deployed through every stage of a product life cycle, during construction where the system will perform instant weld quality diagnostics and repairs, in service inspection and repair, and final lifetime assessment.
The CROCELLS concept is described in detail and system specifications are given which arise from an analysis of the
industrial problems to be solved in a first exploitation phase addressed to the business requirements of the end users in the
project. Then the hardware and software Architecture optimized for these specifications is presented for a prototype system presently under construction. Presently large fabrications on construction sites suffer from long fabrication times
prescribed by traditional methods. The proposed mobile manufacturing cell will greatly reduce these times with economic benefits estimated at 630 M€ per annum in save time and 1956M€ per annum equipment sales taking EU export markets into account, with data for the global market being typically a factor of 4 highe
Design of a Climbing Robot for Inspecting Aircraft Wings and Fuselage
This paper focuses on the design of a wall climbing
robot. The robot carries a Cartesian scanning arm and a payload
of various non-destructive testing (NDT) sensors while walking on the topside and downside of wings and on varying surface
curvatures presented by the fuselage of different types of aircraft. The robot uses pneumatic cylinders to actuate the robots motion in X and Y directions. It uses suction cups to adhere the robot to the surface. The main achievement of this robot is the capability to cope with varying surface curvature when climbing around the aircraft while carrying a payload of up to 18kg. The robot achieves this capability with sufficient flexibility in its structure, feet and suctions cups to cope with varying surface curvature while remaining rigid once the robot feet adhere to the surface. Robot rigidity ensures a stable climbing motion and the vibration free deployment of the NDT sensors
PDA Depth Control of a FPSO Swimming Robot
This paper introduces a Proportional, Derivative and
Adaptive (PDA) depth control method for a swimming and
walking robot designed for Floating Production Storage and
Offloading vessel (FPSO) inspections. The depth of the robot is
controlled by adjusting the mass of the buoyancy tank on the top of the robot while keeping the overall robot volume constant, so that the robot weight is adjusted around its neutral buoyancy point. The robot can swim to a given depth in short time without too much overshoot, and maintain that depth even with the disturbance from the thrusters that drive the robot moving horizontally. The control algorithm is adaptive to varying depth to let the robot have similar dynamic performance in any depth in the tank
Recycling Strategy for Bioaqueous Phase via Catalytic Wet Air Oxidation to Biobased Acetic Acid Solution
The bioaqueous phase generated during biomass conversion to biofuel and biochemicals, e.g., fast pyrolysis and ex situ catalytic pyrolysis, contains a large number of organics, leading to a high chemical oxygen demand (COD) for its treatment. In this study, we demonstrate its catalytic conversion to bioacetic acid solution and propose a recycling strategy thereof. We found that the diluted bioaqueous phase (e.g., C content 90%) converted to acetic acid with nondetectable impurities in solution. The solution contains 1.3-1.5 wt % acetic acid and can be directly used for demineralization of biomass in the biorefineries. This recycling strategy enhances the sustainability of the biobased economy and sheds light on production of biobased acetic acid, which has been recognized as a smart drop-in chemical
DMCVR: Morphology-Guided Diffusion Model for 3D Cardiac Volume Reconstruction
Accurate 3D cardiac reconstruction from cine magnetic resonance imaging
(cMRI) is crucial for improved cardiovascular disease diagnosis and
understanding of the heart's motion. However, current cardiac MRI-based
reconstruction technology used in clinical settings is 2D with limited
through-plane resolution, resulting in low-quality reconstructed cardiac
volumes. To better reconstruct 3D cardiac volumes from sparse 2D image stacks,
we propose a morphology-guided diffusion model for 3D cardiac volume
reconstruction, DMCVR, that synthesizes high-resolution 2D images and
corresponding 3D reconstructed volumes. Our method outperforms previous
approaches by conditioning the cardiac morphology on the generative model,
eliminating the time-consuming iterative optimization process of the latent
code, and improving generation quality. The learned latent spaces provide
global semantics, local cardiac morphology and details of each 2D cMRI slice
with highly interpretable value to reconstruct 3D cardiac shape. Our
experiments show that DMCVR is highly effective in several aspects, such as 2D
generation and 3D reconstruction performance. With DMCVR, we can produce
high-resolution 3D cardiac MRI reconstructions, surpassing current techniques.
Our proposed framework has great potential for improving the accuracy of
cardiac disease diagnosis and treatment planning. Code can be accessed at
https://github.com/hexiaoxiao-cs/DMCVR.Comment: Accepted in MICCAI 202
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