Traffic Sign Recognition (TSR) is one of the many utilities made possible by embedded systems with internet connections. Through the usage of vehicular cameras, it’s possible to capture and classify traffic signs in real time with Artificial Intelligence (AI), more specifically, Convolutional Neural Networks (CNNs) based techniques. This article discusses the implementation of such TSR systems, and the building process of datasets for AI training. Such datasets include a brand new class to be used in TSR, vegetation occlusion. The results show that this approach is useful in making traffic sign maintenance faster since this application turns vehicles into moving sensors in that context. Leaning on the proposed technique, identified irregularities in traffic signs can be reported to a responsible body so they will eventually be fixed, contributing to a safer traffic environment. This paper also discusses the usage and performance of different YOLO models according to our case studies.
13 October 2020 in Journal of Control, Automation and Electrical Systems
This work presents a methodology to estimate solar irradiance using Kalman filter for systems with unknown inputs, an approach more adequate to system characteristics than the standard formulation of this tool. A system with photovoltaic panel, dc–dc converter and load was modeled and simulated in order to analyze the proposed methodology in situations of clear, almost clear and cloudy sky days. The proposed estimator and an analytical method are compared with respect to the ability to compute the irradiance and tested against uncertainties in modeling parameters and noise in the voltage and current measurements of the system. The results show that, through a single sensor, the developed methodology allows to estimate and filter not only solar irradiance, but also output current of photovoltaic system and output voltage of converter. This brings benefits in reducing costs with sensors, allows real-time measurements and avoids propagating noisy measures in the management of a solar system.
This work presents a methodology to obtain discrete adjustments for overcurrent relays and fuse selection using Genetic Algorithm. The purpose is to minimize the protection devices time and therefore reduce the impact caused by short circuits in an electrical installation. In addition, the mathematical formulation presented aims to ensure that the resulting protection system is coordinated and selective. The choice of fuses is made with the aid of Curve Fitting, which makes the results more accurate. The objective function presented penalizes the mismatches, so that the search for the solution does not converge to infeasible solutions. The method is tested in an electrical radial topology system and the results show its effectiveness.
25 August 2023 in International Journal of Dynamics and Control