3,278 research outputs found

    Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

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    INE/AUTC 10.0

    The design and evaluation of Wireless Sensor Networks for applications in industrial locations

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    In manufacturing industries, there exist many applications where Wireless Sensor Networks (WSN\u27s) are integrated to provide wireless solution for the automated manufacturing processes. It is well known that industrial environments characterized by extreme conditions such as high temperature, pressure, and electromagnetic (EM) interference that can affect the performance of the WSN\u27s. The key solution to overcome this performance issue is by monitoring the received Signal Strength Index (RSSI) at the received sensor of the WSN device and track frame error rate of wireless packets. ZigBee is a wireless sensor network (WSN) standard designed for specific needs of the remote monitoring sensor system. Zigbee networks can be established by three different topologies: start, hybrid, and mesh. In this research project, the interest in analyzing the characteristics of the Zigbee performance was completed using a star topology network. Three performance parameters were obtained: the RSSI signal to monitor the received wireless packets from the sending node, path-lost exponent to determine the effect of industrial environment on wireless signals, and the frame error rate to know the discontinue time. The study was in three phases and took place in two settings: The first was at the manufacturing laboratory at the University of Northern Iowa, the second and the third were at the facility of a Midwestern manufacturing company. The study aimed to provide an analytical tool to evaluate the performances of Zigbee networks in industrial environments and compare the results to show that harsh environments do affect its performance. The study also involved testing the performance of WSN. This was done by simulating input/output Line passing with digital and analog data. Packets were sent from one node and counted at the receiving side to measure the packet error rate of WSN in industrial environment. In conclusion, investigating the WSN\u27s systems performance in industrial environment provides is crucial to identify the effects of the harsh conditions. It is necessary to run similar investigation to prevent the malfunction of the manufacturing applications. Testing a simple WSN in industrial environment can be capable of predicting the performance of the network. It is also recommended to have an embedded approach to WSN applications that can self-monitor its performance

    Is There Light at the Ends of the Tunnel? Wireless Sensor Networks for Adaptive Lighting in Road Tunnels

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    Existing deployments of wireless sensor networks (WSNs) are often conceived as stand-alone monitoring tools. In this paper, we report instead on a deployment where the WSN is a key component of a closed-loop control system for adaptive lighting in operational road tunnels. WSN nodes along the tunnel walls report light readings to a control station, which closes the loop by setting the intensity of lamps to match a legislated curve. The ability to match dynamically the lighting levels to the actual environmental conditions improves the tunnel safety and reduces its power consumption. The use of WSNs in a closed-loop system, combined with the real-world, harsh setting of operational road tunnels, induces tighter requirements on the quality and timeliness of sensed data, as well as on the reliability and lifetime of the network. In this work, we test to what extent mainstream WSN technology meets these challenges, using a dedicated design that however relies on wellestablished techniques. The paper describes the hw/sw architecture we devised by focusing on the WSN component, and analyzes its performance through experiments in a real, operational tunnel

    Wireless Sensor Networks in Structural Health Monitoring: a Modular Approach

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    In this paper, we present the Modular Monitoring System (MMS), a low-power wireless architecture dedicated to Structural Health Monitoring (SHM) applications. Our solution features an easily customizable modular architecture, fulfilling the needs of many SHM applications. The MMS supports mesh network topology and offers excellent coverage and reliability, taking advantage of Wireless Sensor Networks (WSN) technology. In this preliminary work we show how the flexibility of our approach offers great advantages with respect to the current state-of-the-art systems dedicated to SHM

    A wireless system for crack monitoring in concrete structures

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    The formation of cracks in concrete is a normal phenomenon. However, effective control and prevention of the formation of cracks is the key for successful life of concrete structures. Specifically, cracks represent a path of least resistance for moisture and corrosive ionic agents from de-icing salts to reach embedded steel in concrete. Commercial wireless sensor networks utilizing crack gauge sensors can be applied for crack monitoring in the common concrete structure. The crack sensors circuits\u27 boards, which are used to stimulate the cracks, are currently unavailable for the SG-Link module platform. The SG-Link module is an ultra-low-power module for use in sensor networks, monitoring applications and rapid application prototyping. Therefore, a crack sensor circuit board for the SG-Link module platform has been developed. The development of a smart wireless sensor network for the crack monitoring system is divided into four parts: a crack gauge sensor, signal conditioning, the SG-Link module, and a base station unit. The signal conditioning module consists of a crack gauge sensor, a wheatstone bridge, an amplifier, and a filter. The SG-Link module consists of an analog to digital converter (ADC), a microcontroller unit (MCC), and a transmitter with an antenna. The base station unit includes an antenna and a receiver module connected to the base station or computer. In this study, cracks are monitored based on the change of the electrical resistance between the sensor\u27s two terminals that are taken from the simulation model of the crack sensor board consisting of a crack gauge sensor and signal conditioning. This thesis looked at the effectiveness of a wireless system for crack monitoring in concrete structures. Tests were conducted in a laboratory to monitor the cracks in the structures and explore the validity and reliability of the monitoring mechanism and data transmission

    Taking Arduino to the Internet of things: the ASIP programming model

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    Micro-controllers such as Arduino are widely used by all kinds of makers worldwide. Popularity has been driven by Arduino’s simplicity of use and the large number of sensors and libraries available to extend the basic capabilities of these controllers. The last decade has witnessed a surge of software engineering solutions for “the Internet of Things”, but in several cases these solutions require computational resources that are more advanced than simple, resource-limited micro-controllers. Surprisingly, in spite of being the basic ingredients of complex hardware–software systems, there does not seem to be a simple and flexible way to (1) extend the basic capabilities of micro-controllers, and (2) to coordinate inter-connected micro-controllers in “the Internet of Things”. Indeed, new capabilities are added on a per-application basis and interactions are mainly limited to bespoke, point-to-point protocols that target the hardware I/O rather than the services provided by this hardware. In this paper we present the Arduino Service Interface Programming (ASIP) model, a new model that addresses the issues above by (1) providing a “Service” abstraction to easily add new capabilities to micro-controllers, and (2) providing support for networked boards using a range of strategies, including socket connections, bridging devices, MQTT-based publish–subscribe messaging, discovery services, etc. We provide an open-source implementation of the code running on Arduino boards and client libraries in Java, Python, Racket and Erlang. We show how ASIP enables the rapid development of non-trivial applications (coordination of input/output on distributed boards and implementation of a line-following algorithm for a remote robot) and we assess the performance of ASIP in several ways, both quantitative and qualitative

    Operational deformations in long-span bridges

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    Journal ArticleLong-span bridges deform quasi-statically and dynamically under a range of operational conditions including wind, traffic and thermal loads, in varying patterns, at different timescales and with different amplitudes. While external loads and internal forces can only rarely be measured, there are well-developed technologies for measuring deformations and their time and space derivatives. Performance data can be checked against design limits and used for validating conceptual and numerical models which can in turn be used to estimate the external loads and internal forces. Changes in performance patterns and load–response relationships can also be used directly as a diagnostic tool, but excessive deformations themselves are also a concern in terms of serviceability. This paper describes application of a range of measurement technologies, focusing on response to extreme loads, for suspension bridges over the River Tamar (with 335 m main span) and Humber (with 1410 m man span). The effects of vehicular, thermal and wind loads on these very different structures are compared, showing that apart from rare extreme traffic and wind loads, temporal and spatial temperature variations dominate quasi-static response. Observations of deformation data and sensor performance for the two bridges are used to highlight limitations and redundancies in the instrumentation

    Taking Arduino to the Internet of things: the ASIP programming model

    Get PDF
    Micro-controllers such as Arduino are widely used by all kinds of makers worldwide. Popularity has been driven by Arduino’s simplicity of use and the large number of sensors and libraries available to extend the basic capabilities of these controllers. The last decade has witnessed a surge of software engineering solutions for “the Internet of Things”, but in several cases these solutions require computational resources that are more advanced than simple, resource-limited micro-controllers. Surprisingly, in spite of being the basic ingredients of complex hardware–software systems, there does not seem to be a simple and flexible way to (1) extend the basic capabilities of micro-controllers, and (2) to coordinate inter-connected micro-controllers in “the Internet of Things”. Indeed, new capabilities are added on a per-application basis and interactions are mainly limited to bespoke, point-to-point protocols that target the hardware I/O rather than the services provided by this hardware. In this paper we present the Arduino Service Interface Programming (ASIP) model, a new model that addresses the issues above by (1) providing a “Service” abstraction to easily add new capabilities to micro-controllers, and (2) providing support for networked boards using a range of strategies, including socket connections, bridging devices, MQTT-based publish–subscribe messaging, discovery services, etc. We provide an open-source implementation of the code running on Arduino boards and client libraries in Java, Python, Racket and Erlang. We show how ASIP enables the rapid development of non-trivial applications (coordination of input/output on distributed boards and implementation of a line-following algorithm for a remote robot) and we assess the performance of ASIP in several ways, both quantitative and qualitative

    Wireless Sensing Based on RFID and Capacitive Technologies for Safety in Marble Industry Process Control

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    ROBUST AND RELIABLE WIRELESS COMMUNICATION BETWEEN SMART NOx SENSOR AND THE SPEEDGOAT/ENGINE CONTROL MODULE: A case study of Wärtsilä’s smart NOx sensor and W4L20 Diesel Engine

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    In recent years, the industrial applications of the wireless transmission of data acquired through sensors have been growing. Addressing the challenges or requirements that come with this needs the integration of new product designs and manufacturing techniques with automation devices. Factors like development time, security, reliability, transmission in an industrial environment, data rate, battery life with energy harvesting capabilities, etc. are of major concerns. This thesis is based on the Wärtsilä smart NOx sensor case study which investigates the possibility of replacing the existing wired CAN bus connection between the smart NOx sensor and the rapid control prototyping system speedgoat and possibly in the future the Engine Control Unit (ECU) with a wireless communication solution. The designed prototype would wirelessly transmit the smart NOx sensor data. The smart NOx sensor data is received using a CAN bus integrated with a wireless transmitter module. The wireless receiver module receives the data and then relays the CAN frames through an integrated CAN Bus to the speedgoat. A matlab simulink module has been programmed into the speedgoat to receive the CAN frames, calculate O2% and NOx ppm values and display the results on a monitor connected to the speedgoat. Criteria like transmission in industrial environments, packet loss, RSSI, bit error rate, reliability and security of the wireless solution are analyzed. According to the analysis done and best practices, a wireless solution is recommended and implemented. The wireless-CAN prototype is installed on the Wärtsilä W4L20 diesel engine in VEBIC for monitoring and observation.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format
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