An Algebraic Framework for the Real-Time Solution of Inverse Problems on Embedded Systems

This article presents a new approach to the real-time solution of inverse problems on embedded systems. The class of problems addressed corresponds to ordinary differential equations (ODEs) with generalized linear constraints, whereby the data from an array of sensors forms the forcing function. The solution of the equation is formulated as a least squares (LS) problem with linear constraints. The LS approach makes the method suitable for the explicit solution of inverse problems where the forcing function is perturbed by noise. The algebraic computation is partitioned into a initial preparatory step, which precomputes the matrices required for the run-time computation; and the cyclic run-time computation, which is repeated with each acquisition of sensor data. The cyclic computation consists of a single matrix-vector multiplication, in this manner computation complexity is known a-priori, fulfilling the definition of a real-time computation. Numerical testing of the new method is presented on perturbed as well as unperturbed problems; the results are compared with known analytic solutions and solutions acquired from state-of-the-art implicit solvers. The solution is implemented with model based design and uses only fundamental linear algebra; consequently, this approach supports automatic code generation for deployment on embedded systems. The targeting concept was tested via software- and processor-in-the-loop verification on two systems with different processor architectures. Finally, the method was tested on a laboratory prototype with real measurement data for the monitoring of flexible structures. The problem solved is: the real-time overconstrained reconstruction of a curve from measured gradients. Such systems are commonly encountered in the monitoring of structures and/or ground subsidence.Comment: 24 pages, journal articl

Embedded Sensor System for Early Pathology Detection in Building Construction

Structure pathology detection is an important security task in building construction, which is performed by an operator by looking manually for damages on the materials. This activity could be dangerous if the structure is hidden or difficult to reach. On the other hand, embedded devices and wireless sensor networks (WSN) are becoming popular and cheap, enabling the design of an alternative pathology detection system to monitor structures based on these technologies. This article introduces a ZigBee WSN system, intending to be autonomous, easy to use and with low power consumption. Its functional parts are fully discussed with diagrams, as well as the protocol used to collect samples from sensor nodes. Finally, several tests focused on range and power consumption of our prototype are shown, analysing whether the results obtained were as expected or not

Designing experiments using digital fabrication in structural dynamics

In engineering, traditional approaches aimed at teaching concepts of dynamics to engineering students include the study of a dense yet sequential theoretical development of proofs and exercises. Structural dynamics are seldom taught experimentally in laboratories since these facilities should be provided with expensive equipment such as wave generators, data-acquisition systems, and heavily wired deployments with sensors. In this paper, the design of an experimental experience in the classroom based upon digital fabrication and modeling tools related to structural dynamics is presented. In particular, all experimental deployments are conceived with low-cost, open-source equipment. The hardware includes Arduino-based open-source electronics whereas the software is based upon object-oriented open-source codes for the development of physical simulations. The set of experiments and the physical simulations are reproducible and scalable in classroom-based environments.Peer ReviewedPostprint (author's final draft

Concept and development of an autonomous wearable micro-fluidic platform for real time pH sweat analysis

In this work the development of an autonomous, robust and wearable micro-fluidic platform capable of performing on-line analysis of pH in sweat is discussed. Through the means of an optical detection system based on a surface mount light emitting diode (SMD LED) and a light photo sensor as a detector, a wearable system was achieved in which real-time monitoring of sweat pH was performed during 55 minutes of cycling activity. We have shown how through systems engineering, integrating miniaturised electrical components, and by improving the micro-fluidic chip characteristics, the wearability, reliability and performance of the micro-fluidic platform was significantly improved

Low\u2010cost, High\u2010Capability, Embedded Systems for CNC Education and Research

Teaching of CNC and CAD/CAM technologies has recently taken a great importance, due to their development, to the great number of solutions available on the market, and to the frequent updates. Nevertheless, one of the most urgent need is to improve the quality of education coping with a rapidly growing number of students. Nowadays, in comparison to the past, many Open-Source technical solutions, both hardware and software, are available to realise easily and cheaply some scaled-down prototypes of numerical control machine tools: these are able to work perfectly and can be employed as a learning method. This paper shows some past experiences regarding the development of some degree thesis works. In particular, it is shown how to implement a numerical control (LinuxCNC) in two specific cheap embedded systems (Raspberry Pi and BeagleBone Black). In this way, a student has the possibility of simulating the working of a complete Numerical Control and of learning interactively its way of programming. The final result and student response have shown an excellent effectiveness of these experiences and easy to use as powerful tool in engineering education

Intelligent Systems as Tools for Measuring Residential Energy Consumption

The implementation of intelligent systems in homes for measuring energy consumption are possibilities that owe their viability to the IoT (Internet of Things and investments in R&D). Becoming fundamental for this change in the way of thinking and using electric power in households, buildings and especially in industry 4.0. The present work demonstrates an experiment focused on a residence for the analysis of energy consumption measurement, with the use of a nano arduino plate, current and voltage sensors, internet connection and use of the MQTT protocol making the integration in the Blynk platform. Obtaining as results voltage approximately 224V, electric current close to 3.89A, 356 points of samples for measurement of consumption and 255 points for preparation of graphs. Minimums for voltage and current 207.75V and 0.62A respectively and maximums 233.22V and 25.31A. A standard deviation of 5.54 for voltage and 3.33 for current. Analyses performed by Blynk, from estimates by mathematical modeling, considered by means of tests and it was observed that the behavior of current and voltage signals are close to the realities of energy distributors

An Integration of Open-Source Resources in Distance Teaching for Real-Time Embedded System Using Arduino Microcontroller and Freertos

Real-Time Embedded System (RTES) is about applying real-time system in an embedded system (e.g. microcontroller) in ways that both logical and temporal requirements are fulfilled. A special attention shall be on the temporal response analysis so that students can have a clear distinction between microcontrollers with and without real-time system. During new norms of learning and teaching from home, an affordable and accessible infrastructure in RTES course is urgently needed. Thus, this study aims to evaluate the feasibility of an integration of open source resources (i.e. Arduino platform and FreeRTOS) in teaching RTES remotely and to provide real-time learning experience about RTES concepts without additional components or wiring out of school. Results show that an obvious context switch could be observed when task pre-emption happened. Finding indicates that the proposed integration was useful for students to understand the complex RTES concepts e.g. task scheduling, pre-emption, and mutually exclusion