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Publications

Publications by CRIIS

2018

SQUIRLROB: A DO IT YOURSELF ARDUINO AND SMARTPHONE HARDWARE AND SOFTWARE PLATFORMS FOR ROBOTICS EDUCATION

Authors
Costa, V; Santos, D; Sousa, A;

Publication
12TH INTERNATIONAL TECHNOLOGY, EDUCATION AND DEVELOPMENT CONFERENCE (INTED)

Abstract
The use of Robotics as a teaching tool to foster knowledge in Science, Technology, Engineering and Mathematics - STEM for high school students is growing. Within this context, the need for solutions that decreases the overall cost of hardware is mandatory. In this work, a 25 euros Android-based mobile robot that allows connecting a smartphone to different robot "bodies" (each composed by different hardware: Arduino, LEGO, etc.) is proposed, targeting mainly high school students. The mobile platform was built using 3D printed parts and uses an Arduino board to control the servos used for the locomotion. To communicate with the Android application, a Bluetooth module is also used. The Android application takes advantage of the smartphone camera and has some pre-implemented image processing modules, allowing actions such as coloured line following, colour proximity detection and coloured object tracking. Another import feature present in the Android application is its coding capability, thanks to an embedded code interpreter. This feature was implemented using BeanShell, a lightweight script interpreter for Java. It allows writing scripts in Java programming language, which are then executed by the robot. This interpreter also provides a way for the user to write a set of instructions that defines the behaviour of the robot, primarily by checking the current status of the sensors and the smartphone camera, and manipulating the velocity of the motors. All of the necessary components (3D source CAD + STLs) of the mobile platform presented here are available online, enabling the recreation of a replica of the robot body. A detailed list of electronic components and its connections are also provided, as well as the Arduino source code along with the installation file needed for the Android application. All the necessary information can be accessed at: https://github.com/ee09115/squirlrob. The high school students are then challenged to solve classical robotics tasks like line following, obstacle avoidance, and using the virtual sensors to create new challenges. By providing this set of tools (Android app, source code, 3D CAD models, documentation), a promotion of knowledge is expected, thus developing enthusiast students in robotics multidisciplinary fields, such as mechanical designing, electronics designing, mathematics, coding, etc. (in short, all the relevant STEM areas). Finally, a general analysis of the usability, interoperability and feature extension capacity is made, always taking into consideration the educational purposes of this work.

2018

Design of an Embedded Multi-Camera Vision System-A Case Study in Mobile Robotics

Authors
Costa, V; Cebola, P; Sousa, A; Reis, A;

Publication
ROBOTICS

Abstract
The purpose of this work is to explore the design principles for a Real-Time Robotic Multi Camera Vision System, in a case study involving a real world competition of autonomous driving. Design practices from vision and real-time research areas are applied into a Real-Time Robotic Vision application, thus exemplifying good algorithm design practices, the advantages of employing the "zero copy one pass" methodology and associated trade-offs leading to the selection of a controller platform. The vision tasks under study are: (i) recognition of a "flat" signal; and (ii) track following, requiring 3D reconstruction. This research firstly improves the used algorithms for the mentioned tasks and finally selects the controller hardware. Optimization for the shown algorithms yielded from 1.5 times to 190 times improvements, always with acceptable quality for the target application, with algorithm optimization being more important on lower computing power platforms. Results also include a 3-cm and five-degree accuracy for lane tracking and 100% accuracy for signalling panel recognition, which are better than most results found in the literature for this application. Clear results comparing different PC platforms for the mentioned Robotic Vision tasks are also shown, demonstrating trade-offs between accuracy and computing power, leading to the proper choice of control platform. The presented design principles are portable to other applications, where Real-Time constraints exist.

2018

Automatic Generation of Disassembly Sequences and Exploded Views from SolidWorks Symbolic Geometric Relationships

Authors
Costa, CM; Veiga, G; Sousa, A; Rocha, L; Oliveira, E; Cardoso, HL; Thomas, U;

Publication
2018 IEEE INTERNATIONAL CONFERENCE ON AUTONOMOUS ROBOT SYSTEMS AND COMPETITIONS (ICARSC)

Abstract
Planning the optimal assembly and disassembly sequence plays a critical role when optimizing the production, maintenance and recycling of products. For tackling this problem, a recursive branch-and-bound algorithm was developed for finding the optimal disassembly plan. It takes into consideration the traveling distance of a robotic end effector along with a cost penalty when it needs to be changed. The precedences and part decoupling directions are automatically computed in the proposed geometric reasoning engine by analyzing the spatial relationships present in SolidWorks assemblies. For accelerating the optimization process, a best-first search algorithm was implemented for quickly finding an initial disassembly sequence solution that is used as an upper bound for pruning most of the non-optimal tree branches. For speeding up the search further, a caching technique was developed for reusing feasible disassembly operations computed on previous search steps, reducing the computational time by more than 18%. As a final stage, our SolidWorks add-in generates an exploded view animation for allowing intuitive analysis of the best solution found. For testing our approach, the disassembly of two starter motors and a single cylinder engine was performed for assessing the capabilities and time requirements of our algorithms. © 2018 IEEE.

2018

Pedagogical and technological replanning: a successful case study on integration and transversal skills for engineering freshmen

Authors
Torres, MF; Sousa, AJ; Torres, RT;

Publication
INTERNATIONAL JOURNAL OF TECHNOLOGY AND DESIGN EDUCATION

Abstract
Replanning is often used to optimize results of an activity in an ever changing world. To address the challenge of preparing future engineers for success, a special course was created for all engineering freshmen of the Faculty of Engineering of the University of Porto, in Portugal. Presented as a case study, this special course underwent a careful replanning as a result of several years of experience in teaching practice alongside with a theoretical deepening in pedagogical and technological issues, under the aegis of the action-research methodology. Within the context of the case study course, the mentioned replanning was also based on a theoretical approach that clearly identifies teaching-learning-assessment methodologies that promote regulation from those that foster emancipation, using a specific instrument: a taxonomy of educational processes. The replanning was designed to globally boost results regarding the educational aims of the course such as furthering freshmen's integration into work environment and preparing them for success by fostering transversal skills (needed for study and work). Technology is seen as a mean of education enrichment as well as a productivity tool. The introduced innovations include fun-but-educational activities, several types of assessment over time and specific technological tools which were critical for the educational impact/achievement of this course. Success is demonstrated by encouraging feedback from the stakeholders, high students' classifications and a steady reduction in retention. It is advocated that large portions of the reasoning behind the replanning can be extrapolated to other courses.

2018

Welcome to Engineering: Gender Equality in Learning and Integration among First Year Students

Authors
Torres, M; Ferreira, S; Sousa, A; Moreira, L; Torres, R;

Publication
INTERNATIONAL JOURNAL OF ENGINEERING EDUCATION

Abstract
The presented research explores four years of newcomer engineering students at FEUP, one of the largest faculties of engineering in Portugal. The students are surveyed in a mandatory course common to all engineering programs at the mentioned faculty, totalling an involvement of about four thousand. This research explores the perceptions of 1198 newcomer students regarding learning and satisfaction, workload, integration into academic work environment and institutional support whilst trying to find gender differences regarding the following variables: engineering program, academic year and change of residence. The questionnaire used in the presented research was validated and its internal consistency was excellent. The findings reveal that students' perceptions on learning and satisfaction as well as on institutional support (two out of four factors) are consistently similar between genders throughout the four years of the study. The differences found between male and female students on integration and workload, however consistent, are small if not marginal. The study is significant because it shows the relevance of the optimization efforts for integration (in the academic work environment) introduced in a mandatory course at the start of engineering degrees in order to bridge the gap between male and female students. This research shows that we are walking towards gender equality in engineering, but we feel that there is still some effort to be done, namely through inspiring scholars to analyse and act upon academic contexts and higher education governance without prejudice and with an open mind: a commitment that is as hard as necessary.

2018

Redundant robot localization system based in wireless sensor network

Authors
Reis, R; Mendes, J; dos Santos, FN; Morais, R; Ferraz, N; Santos, L; Sousa, A;

Publication
2018 IEEE INTERNATIONAL CONFERENCE ON AUTONOMOUS ROBOT SYSTEMS AND COMPETITIONS (ICARSC)

Abstract
Localization and Mapping of autonomous robots in an harsh and unstable environment such as a steep slope vineyard is a challenging research topic. Dead Reckoning systems can fail due to the harsh conditions of the terrain, and the Global Position System can be affected by noise or even be unavailable. Agriculture is moving towards precision agriculture, with advanced monitoring systems and wireless sensor networks. These systems and wireless sensors are installed in the crop field and can be considered relevant landmarks for robot localization. In this paper the distance accuracy provided by bluetooth based sensors is deeply studied and characterized. It is considered a multi antenna receiver bluetooth system and obtained the transfer functions (from Received Signal Strength Indication (RSSI) to distance estimation) for each set of antenna and sensors. The performance of this technology is compared against Time-of-flight based technologies (Pozyx). The obtained results show that the agricultural wireless sensors can be used as redundant artificial landmarks for localization purposes. Besides, the RSSI characterization allowed to improve the previous results of our Beacon Mapping Procedure (BMP) required for accurate and reliable localization systems. © 2018 IEEE.

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