Application of low-cost sensors for accurate ambient temperature monitoring

In structures with reduced monitoring budgets, the high cost of commercial metering devices is always an obstacle for monitoring structural health. This might be an issue when temperatures must be measured for both structural and environmental reasons. To fill this gap, in this paper, a novel monitoring system is proposed for the accurate measurement of indoor temperature in buildings. This protocol is characterized by its generality, as it can be easily adapted to measure any structural or environmental parameters on site. The proposed monitoring system uses from one to eight low-cost sensors to obtain multiple measurements of the ambient temperatures. The accuracy ranges of the developed monitoring systems with different numbers of sensors are statistically analysed. The results indicate that the discrepancy of the measurements decreases with the increase in the number of sensors, as the maximum standard deviation of 10 sensors (0.42) decreases to 0.32 and 0.27 for clusters of 20 and 30 sensors, respectively.This research was funded by the Spanish Ministry of Economy and Competitiveness (grant number BIA2013-47290-R, BIA2017-86811-C2-1-R, and BIA2017-86811-C2-2-R) and by the Universidad de Castilla La Mancha (grant number 2018-COB-9092).Peer ReviewedPostprint (published version

Low-cost sensors accuracy study and enhancement strategy

Today, low-cost sensors in various civil engineering sectors are gaining the attention of researchers due to their reduced production cost and their applicability to multiple nodes. Low-cost sensors also have the advantage of easily connecting to low-cost microcontrollers such as Arduino. A low-cost, reliable acquisition system based on Arduino technology can further reduce the price of data acquisition and monitoring, which can make long-term monitoring possible. This paper introduces a wireless Internet-based low-cost data acquisition system consisting of Raspberry Pi and several Arduinos as signal conditioners. This study investigates the beneficial impact of similar sensor combinations, aiming to improve the overall accuracy of several sensors with an unknown accuracy range. The paper then describes an experiment that gives valuable information about the standard deviation, distribution functions, and error level of various individual low-cost sensors under different environmental circumstances. Unfortunately, these data are usually missing and sometimes assumed in numerical studies targeting the development of structural system identification methods. A measuring device consisting of a total of 75 contactless ranging sensors connected to two microcontrollers (Arduinos) was designed to study the similar sensor combination theory and present the standard deviation and distribution functions. The 75 sensors include: 25 units of HC-SR04 (analog), 25 units of VL53L0X, and 25 units of VL53L1X (digital).The authors are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided through the research project BIA2017-86811-C2-1-R, directed by José Turmo, and BIA2017-86811-C2-2-R, directed by Jose Antonio Lozano-Galant. All these projects are funded with FEDER funds. Authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya, Catalunya, Spain for the funding provided through Agaur (2017 SGR 1482). It is also to be noted that funding for this research has been provided for Seyedmilad Komarizadehasl by the Spanish Agencia Estatal de Investigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant (PRE2018-083238).Peer ReviewedPostprint (published version

A novel data acquisition system for obtaining thermal parameters of building envelopes

Owing to the high energy consumption in the building sector, appraising the thermal performance of building envelopes is an increasing concern. Recently, a few in situ methodologies to diagnose the thermal parameters of buildings have been considered. However, because of their limitations such as low accuracy, limited number of measurements, and the high cost of monitoring devices, researchers are seeking a new alternative. In this study, a novel hyper-efficient Arduino transmittance-meter was introduced to overcome these limitations and determine the thermal parameters of building envelopes. Unlike conventional methodologies, the proposed transmittance-meter is based on synchronized measurements of different parameters necessary to estimate the transmittance parameter. To verify the applicability of the transmittance-meter, an experimental study was conducted wherein a temperature-controlled box model was thermally monitored, and the outputs of the transmittance-meter employed were compared with those captured by a commercial device. The results revealed a high level of reduction in cost and a low range of difference compared with the latter, thereby validating the applicability of the proposed thermal monitoring system.This research was funded by the Spanish Ministry of Economy and Competitiveness, grant numbers BIA2013-47290-R, BIA2017-86811-C2-1-R, and BIA2017-86811-C2-2-R, and Ministerio de Ciencia Innovación y Universidades: PRE2018-085172.Peer ReviewedPostprint (published version

EVALUATION OF LOW-COST ANGULAR MEASURING SENSORS

One of the main issues for performing Structural Health Monitoring (SHM) is the high cost of metering devices. In order to make it applicable to the conventional structures with low defined budgets, low-cost sensors have been widely utilized. In this paper, the characteristics of a low-cost circuit (MPU9250) with low power consumption for measuring angles are studied. This circuit is composed of an accelerometer, a gyroscope, and a magnetometer. There are two ways of coding and using this sensor for angular measurements. In the first application, the accelerometer and the gyroscope of the circuit are only used to get angle around X and Y-axis. In the second application, the gyroscope is going to be added to the other two sensors in order to get angular measurements of all axis. The data accuracy plus the advantages and disadvantages of the response of this circuit regarding each code has been studied in this paper by using the codded sensor in some experiments. Although the second application showed less error from the expected results, it was less stable than the first application.Uno de los principales problemas para llevar a cabo la monitorización de la salud estructural (SHM) es el elevado coste de los dispositivos de medición. Con el fin de para que sea aplicable a las estructuras convencionales con bajos presupuestos definidos, se han utilizado ampliamente sensores de bajo coste. En este trabajo se estudian las características de un circuito de bajo coste (MPU9250) con bajo consumo de energía para la medición de ángulos. estudiado. Este circuito está compuesto por un acelerómetro, un giroscopio y un magnetómetro. Hay dos formas de codificar y utilizar este sensor para las mediciones angulares. En la primera aplicación, el acelerómetro y el giroscopio del circuito sólo se utilizan para obtener el ángulo alrededor de los ejes X e Y. En la segunda aplicación, el giroscopio se añadirá a los otros dos sensores para dos sensores para obtener mediciones angulares de todos los ejes. La precisión de los datos y las ventajas e inconvenientes de de la respuesta de este circuito con respecto a cada código se ha estudiado en este trabajo utilizando el sensor codificado en algunos experimentos. Aunque la segunda aplicación mostró menos error respecto a los resultados esperados, fue menos estable que la primera aplicación

Structural Health Monitoring of 2D Plane Structures

This paper presents the application of the observability technique for the structural system identification of 2D models. Unlike previous applications of this method, unknown variables appear both in the numerator and the denominator of the stiffness matrix system, making the problem non-linear and impossible to solve. To fill this gap, new changes in variables are proposed to linearize the system of equations. In addition, to illustrate the application of the proposed procedure into the observability method, a detailed mathematical analysis is presented. Finally, to validate the applicability of the method, the mechanical properties of a state-of-the-art plate are numerically determinedEste artículo presenta la aplicación de la técnica de observabilidad para la identificación de sistemas estructurales de modelos 2D. A diferencia de las aplicaciones anteriores de este método, las variables desconocidas aparecen tanto en el numerador como en el denominador del sistema de matriz de rigidez, lo que hace que el problema sea no lineal e imposible de resolver. Para llenar este vacío, se proponen nuevos cambios en las variables para linealizar el sistema de ecuaciones. Además, para ilustrar la aplicación del procedimiento propuesto en el método de observabilidad, se presenta un análisis matemático detallado. Finalmente, para validar la aplicabilidad del método, se determinan numéricamente las propiedades mecánicas de una placa de última generació

DETAILED EVALUATION OF LOW-COST RANGING SENSORS FOR STRUCTURAL HEALTH MONITORING APPLICATIONS

To evaluate the safety of structures, choosing a proper maintains protocol to assess the performance/ workability of the structures in the future, Structural health monitoring (SHM) applications are required. The SHM application usually applies to unique structures with high budgets. For using them on structures with low-budgets low-cost sensors required. Low-cost sensors are getting considerable attention compared with the expensive traditional alternatives. This paper introduces 3 types of low-cost displacement measuring sensors. These sensors were programmed and controlled by an Arduino. Acquiring data from them was done by a connected computer to the Arduino. By engaging these sensors in a few experiments and evaluating their responses, their functionality and accuracy in different situations are investigated. Moreover, the pros and cons of each one of them for each test are illustrated. By taking into account their price, their advantages on exceptional circumstances, and their reliability, different sensors for different situations have been proposedPara evaluar la seguridad de las estructuras, elegir un protocolo de mantenimiento adecuado para evaluar el rendimiento/la viabilidad de las estructuras en el futuro, se requieren aplicaciones de monitorización de la salud estructural (SHM). La aplicación SHM suele aplicarse a estructuras únicas con presupuestos elevados. Para utilizarlas en estructuras con presupuestos bajos se necesitan sensores de bajo coste. Los sensores de bajo coste están recibiendo una atención considerable en comparación con las costosas alternativas tradicionales. En este trabajo se presentan 3 tipos de sensores de medición de desplazamiento de bajo coste. Estos sensores fueron programados y controlados por un Arduino. La adquisición de datos de los mismos se realizó mediante un ordenador conectado al Arduino. Mediante la participación de estos sensores en algunos experimentos y la evaluación de sus respuestas, se investiga su funcionalidad y precisión en diferentes situaciones. Además, se ilustran los pros y los contras de cada uno de ellos para cada prueba. Teniendo en cuenta su precio, sus ventajas en circunstancias excepcionales y su fiabilidad, se han propuesto diferentes sensores para diferentes situacione

New Image Recognition Technique for Intuitive Understanding in Class of the Dynamic Response of High-Rise Buildings.

In the last years, more and more studies have highlighted the advantages of complementing traditional master classes with additional activities that improve students’ learning experience. This combination of teaching techniques is specially advised in the field of structural engineering, where intuition of the structural response it is of vital importance to understand the studied concepts. This paper deals with the introduction of a new (and more encouraging) educational tool to introduce students intuitively to the dynamic response of structures excited with an educational shaking table. Most of the educational structural health monitoring systems use sensors to determine the dynamic response of the structure. The proposed tool is based on a radically different approach, as it is based on low-cost image-recognition techniques. In fact, it only requires the use of an amateur camera, a black background, and a computer. In this study, the effects of both the camera location and the image quality are also evaluated. Finally, to validate the applicability of the proposed methodology, the dynamic response of small-scale buildings with different typologies is analyzed. In addition, a series of surveys were conducted in order to evaluate the activity based on student´s satisfaction and the actual acquisition and strengthening of knowledgepost-print8992 K

DETERMINATION OF ENVIRONMENTAL PARAMETERS BASED ON ARDUINO BASED LOW-COST SENSORS

Taking into account that the age of structures is closely connected to their energy consumption, the monitoring of structures is a crucial task for engineers. This article deals with application of Arduino based low-cost sensors for environmental monitoring of buildings. To do so, open source platform Arduino as well as four environmental sensors, DHT22, have been used for measuring variation of temperature and humidity. In order to check accuracy of the utilized data acquisition system, statistical approach was used to check the repeatability and discrepancy of the recorded data. Statistical calculations indicate that the sensor is more accurate in terms of measuring temperature rather than humidity one since discrepancy of the temperature parameter is less than the humidity one. The maximum range of standard deviation derived for temperature and humidity parameters are less than 0.13 and 1.33 respectively.Teniendo en cuenta que la edad de las estructuras está estrechamente relacionada con su consumo energético, la supervisión de las estructuras es una tarea crucial para los ingenieros. Este artículo trata de la aplicación de sensores de bajo coste basados en Arduino para la ambiental de los edificios. Para ello, se ha utilizado la plataforma de código abierto Arduino, así como cuatro sensores ambientales, DHT22 para medir la variación de la temperatura y la humedad. Para comprobar la precisión del sistema de adquisición de datos utilizado de datos utilizado, se utilizó un enfoque estadístico para comprobar la repetibilidad y la discrepancia de los datos registrados. Los cálculos estadísticos indican que el sensor es más preciso en la medición de la temperatura que en la de la humedad, ya que la discrepancia de de la temperatura es menor que la de la humedad. El rango máximo de desviación estándar obtenido para los parámetros de temperatura y humedad son inferiores a 0,13 y 1,33 respectivamente

Comparison of different low-cost sensors for structural health monitoring

Recently, the need for Structural Health Monitoring (SHM) and inspection is growing as a result of the increasing age of the structural stock worldwide. SHM includes bringing into use a sensor or an array of sensors into an engineered structure. This paper evaluates the practical aspects to consider when choosing different low-cost sensors for using in a SHM application. For this reason, a microcontroller (Arduino) with attached sensors (Ultrasonic, Laser, Gyroscope, Accelerometer, Temperature-humidity, SD-module) has been used throughout different controlled ambient situations and experiments. During the sensor installation and data acquisition, some issues related to the Arduino codes and position of the sensors arise. In this article solutions for tackling faced problems have been presented for achieving an efficient way of using these electronic devices. Their data have been collected to assess and compare their tolerances as well as advantages and disadvantages of their use, cost among them. The information from this article could be used either to choose the appropriate sensors either for static or for dynamic Structural System Identification (SSI).The authors are indebted to the Spanish Ministry of Economy and Competitiveness for the funding pro-vided through the research project BIA2017-86811-C2-1-R directed by José Turmo and BIA2017-86811-C2-2-R, directed by Jose Antonio Lozano-Galant. All these projects are funded with FEDER funds. Authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya for the funding provided through Agaur (2017 SGR 1481). It is also to be noted that funding for this re-search has been provided for MR. SEYEDMILAD KOMARIZADEHASL by Agencia Estatal de Inves-tigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant (PRE2018-083238).Postprint (published version

Detailed evaluation of low-cost ranging sensors for structural health monitoring applications

To evaluate the safety of structures, choosing a proper maintains protocol to assess the performance/ workability of the structures in the future, Structural health monitoring (SHM) applications are required. The SHM application usually applies to unique structures with high budgets. For using them on structures with low-budgets low-cost sensors required. Low-cost sensors are getting considerable attention compared with the expensive traditional alternatives. This paper introduces 3 types of low-cost displacement measuring sensors. These sensors were programmed and controlled by an Arduino. Acquiring data from them was done by a connected computer to the Arduino. By engaging these sensors in a few experiments and evaluating their responses, their functionality and accuracy in different situations are investigated. Moreover, the pros and cons of each one of them for each test are illustrated. By taking into account their price, their advantages on exceptional circumstances, and their reliability, different sensors for different situations have been proposed.The authors are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided through the research project BIA2017- 86811-C2-1-R directed by José Turmo and BIA2017-86811-C2-2-R, directed by Jose Antonio Lozano-Galant. All these projects are funded with FEDER funds. Authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya for the funding provided through Agaur (2017 SGR 1482). It is also to be noted that funding for this research has been provided for MR. Seyedmilad Komarizadehasl by Agencia Estatal de Investigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant (PRE2018-083238).Postprint (published version