ITER Radiological and Environmental Monitoring Systems conceptual design elements

Author(s):  
Lorenzo Perna ◽  
Sabrina Molinaro ◽  
Michel Berruyer
2021 ◽  
Vol 5 (3) ◽  
pp. 1-30
Author(s):  
Gonçalo Jesus ◽  
António Casimiro ◽  
Anabela Oliveira

Sensor platforms used in environmental monitoring applications are often subject to harsh environmental conditions while monitoring complex phenomena. Therefore, designing dependable monitoring systems is challenging given the external disturbances affecting sensor measurements. Even the apparently simple task of outlier detection in sensor data becomes a hard problem, amplified by the difficulty in distinguishing true data errors due to sensor faults from deviations due to natural phenomenon, which look like data errors. Existing solutions for runtime outlier detection typically assume that the physical processes can be accurately modeled, or that outliers consist in large deviations that are easily detected and filtered by appropriate thresholds. Other solutions assume that it is possible to deploy multiple sensors providing redundant data to support voting-based techniques. In this article, we propose a new methodology for dependable runtime detection of outliers in environmental monitoring systems, aiming to increase data quality by treating them. We propose the use of machine learning techniques to model each sensor behavior, exploiting the existence of correlated data provided by other related sensors. Using these models, along with knowledge of processed past measurements, it is possible to obtain accurate estimations of the observed environment parameters and build failure detectors that use these estimations. When a failure is detected, these estimations also allow one to correct the erroneous measurements and hence improve the overall data quality. Our methodology not only allows one to distinguish truly abnormal measurements from deviations due to complex natural phenomena, but also allows the quantification of each measurement quality, which is relevant from a dependability perspective. We apply the methodology to real datasets from a complex aquatic monitoring system, measuring temperature and salinity parameters, through which we illustrate the process for building the machine learning prediction models using a technique based on Artificial Neural Networks, denoted ANNODE ( ANN Outlier Detection ). From this application, we also observe the effectiveness of our ANNODE approach for accurate outlier detection in harsh environments. Then we validate these positive results by comparing ANNODE with state-of-the-art solutions for outlier detection. The results show that ANNODE improves existing solutions regarding accuracy of outlier detection.


Author(s):  
G. Kemper ◽  
R. Vasel

To combine various sensors to get a system for specific use became popular within the last 10 years. Metric mid format cameras meanwhile reach the 100 MPix and entered the mapping market to compete with the big format sensors. Beside that also other sensors as SLR Cameras provide high resolution and enter the aerial surveying market for orthophoto production or monitoring applications. Flexibility, purchase-costs, size and weight are common aspects to design multi-sensor systems. Some sensors are useful for mapping while others are part of environmental monitoring systems. Beside classical surveying aircrafts also UL Airplanes, Para/Trikes or UAVs make use of multi sensor systems. Many of them are customer specific while other already are frequently used in the market. This paper aims to show some setup, their application, what are the results and what are the pros and cons of them are.


2021 ◽  
Author(s):  
Mohd Nazri Md Noor ◽  
Javier Abreu ◽  
Alexandr Demyanov ◽  
Nabil Batita

Abstract A new valve has been designed and qualified to reduce interventions during packer-setting operations. In a typical well, completion with a hydraulic-production packer, the tubing string must be plugged to create the required pressure differential for packer actuation. At desired depth, delivering a preselected circulation rate actuates the tool and converts the string to a closed system, enabling the packer to be set hydraulically. Before designing the valve, an operator's engineering and operational requirements were collected and understood. Then a conceptual design was evaluated, and a prototype device was manufactured. The valve was tested for autofill capability, actuation parameters and pressure integrity. The critical design elements of the valve are the choking and spring mechanisms, which enable circulation without prematurely actuating the valve and then enable tubing autofill. A visual inspection post qualification test was conducted to validate the components’ condition and integrity. During the qualification process, the valve working envelope was developed. After the successful qualification test, the valve was deployed in a customer well with a production packer that has a blanking device consisting of a ceramic disc. Prior to deployment, hydraulic simulation was done to determine the required flow rate to achieve desired pressure drop across the valve for actuation. During deployment, the tubing was filled automatically, validating the valve autofill capability. Upon reaching setting depth, the completion string was circulated at the required circulation rate to actuate the valve and close the system. Pressure integrity in the tubing validated the valve functionality. Surface pressure was applied against the blanking device, and the production packer was set hydraulically. Subsequently, before completing the well, the blanking device was broken using a slickline run, and the well was put on production. The deployment technique using the valve requires only one slickline run whereby in typical operation four slickline runs are required. This project represented true problem-solving engineering approaches. The operator requirements were properly understood and conceptual design was validated, and product realization phase was initiated. The efficient product development methodology improves the lead time from conceptualization to product realization. During the first well deployment, hydraulic simulation during the prejob planning proved to be critical to understanding the required circulation rates to actuate the valve.


2020 ◽  
Vol 54 (6) ◽  
pp. 77-83
Author(s):  
David G. Aubrey ◽  
Jennifer Wehof ◽  
Stephen O'Malley ◽  
Rajai Aghabi

AbstractFloating LiDAR systems (FLS) and other moored environmental monitoring systems are used extensively for wind and environmental assessments in offshore wind projects. In addition, wave energy converters (WECs) are being evaluated for more extensive use in coastal and deeper waters, most of which also require anchoring to the seabed. Since these systems must be moored, heavy anchors and typically heavy chain are used to secure the mooring and measurement/WEC buoy to the seabed. Disadvantages of present mooring technology include 1) damage to the seabed and benthic communities in vicinity of the mooring, as chain sweeps over the sea bottom; 2) an unnecessarily large watch circle at the water's surface; 3) slightly increased likelihood of marine mammal entanglement; 4) mooring damage from nearby fishing activity; and 5) likelihood of mooring failure due to self-entanglement within the mooring itself. This study presents an alternative mooring using mechanically compliant, elastomeric hoses to connect the buoyed system to the bottom anchor. Modeling the two mooring types with a typical buoy used in wind resource assessments shows a significant decrease in anchor drag area and surface watch circle with the use of the elastomeric hose versus the traditional chain and polyethylene line mooring. The hose also is equipped with copper conductors and/or fiber-optic conductors, providing power and data transmission between the bottom and the surface. For WEC solutions, the elastomeric hose provides similar benefits as for FLS and environmental monitoring systems, with the added advantage of being able to transmit power to the seafloor for distribution. For one WEC application, we have developed an elastomeric solution containing not only larger copper conductors to enable power transmission but also fiber-optic conductors to permit data transfer from a garage mounted on the bottom (servicing an autonomous underwater vehicle [AUV] or unmanned underwater vehicle [UUV], for instance) to the surface buoy for onward transmission to shore.


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