In the past few decades, science, technology, engineering, and math (STEM) education has become a driving force for innovators throughout the world (Atkinson & Mayo, 2010; Bybee, 2010). STEM education has also become an economic factor in developing countries (Kennedy & Odell, 2014). Currently, many countries are struggling with how to effectively promote STEM education. The United States (U.S.) provides an interesting case study. Despite being one of the global economic leaders, it is behind in STEM education compared to other nations (Atkinson & Mayo, 2010; Dugger, 2010). STEM education helps to build world leaders including marketable and knowledgeable employees because it teaches and exposes students to problems in the real world, especially in their community (Brown, Brown, Reardon, & Merrill, 2011; Gomez & Albrecht, 2013). Accordingly, the purpose of this study was to answer the question: how does designing and implementing an engineering-based unit of instruction impact student attitudes toward engineering for 6th graders? The method for implementing more engineering consisted of teaching a unit based around mechanical engineering, civil engineering, city planning, and public health to 6th graders. The heart of the unit was an activity that allowed the students to make electric bikes by engaging in the engineering processes of hands-on learning and problem-solving, while evaluating transportation to and from school. The data was collected using two methods. The first used a survey instrument called the Technology and Engineering Attitudes Scale (TEAS), the second method involved observing and interviewing the participants. The results reveal that student interest in engineering increased after participating in the study. Another key finding is that with more engineering experience, student confidence for problem-solving and engineering activities increased.

El proyecto Electric Road, nace de la pasión de variosdelos integrantes del equipo de trabajo por el ciclismoy la cada vez másevidente necesidad de convertirloen un medio de transporte más eficiente tanto ecológicamente hablando como a comparación de los transportes tradicionales, en este trabajo se evaluará un modelo de negocio que nos permita gestionar esta idea de emprendimiento buscando la mejor estrategia de ejecución que nos permita tener una cadena de suministro eficiente, efectivas campañas publicitarias, gestión optima de los recursos financieros, eficiente delimitación de procesos operativos, optima gestión del capitalhumano, entre otras características que nos permitan tener éxito una vez iniciadas las operaciones. Nuestra propuesta es una empresa que brinda a personas naturales con bicicletas la conversión de estas en bicicletas eléctricas mediante kits de conversión, de esta manera la bicicleta podrá viajar a velocidades de hasta 35 kilómetros por hora mejorando los tiempos de viaje de nuestros clientes y reduciendo el desgaste físico requerido para grandes tramos. / The Electric Road project was born from the passion of several of the work team members for cycling and the increasingly evident need to make it a more efficient means of transport both ecologically speaking and compared to traditional transport, in this work, a business model will be evaluated that allows us to manage this entrepreneurial idea looking for the best execution strategy that allows us to have an efficient supply chain, effective advertising campaigns, optimal management of financial resources, efficient delimitation of operational processes, optimal management of human capital, among other characteristics that allow us to be successful once operations have started.Our proposal is a company that provides natural persons with bicycles the conversion of these into electric bicycles through conversion kits, in this way the bicycle can travel at speeds of up to 35 kilometers per hour, improving the travel times of our customers and reducing the physical wear and tear required for large stretches. / Trabajo de investigación

Η παρούσα διπλωματική εργασία, η οποία εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών, πραγματεύεται την κατασκευή ενός ηλεκτρικού δικύκλου. Σκοπός είναι η κατασκευή και ο έλεγχος ενός ηλεκτρικού ποδηλάτου και συγκεκριμένα ο σχεδιασμός και η εγκατάσταση ενός κατάλληλου ηλεκτροκινητήριου συστήματος σε ένα συμβατικό ποδήλατο. Αρχικά γίνεται μια σύντομη περιγραφή των συμβατικών και των ηλεκτρικών ποδηλάτων, η οποία περιλαμβάνει την ιστορική εξέλιξή τους, τα μέρη από τα οποία αποτελούνται, τους τύπους στους οποίους διακρίνονται και τα νομικά πλαίσια που διέπουν τη λειτουργία τους. Στη συνέχεια, περιγράφεται το ηλεκτροκινητήριο σύστημα, το οποίο εγκαταστάθηκε στο πλαίσιο του ποδηλάτου που παραχωρήθηκε για το σκοπό αυτό από την εταιρεία Ideal Bikes Μανιατόπουλος Α.Ε., τα κριτήρια επιλογής του κινητήρα, των ηλεκτροχημικών συσσωρευτών και των επιμέρους στοιχείων που το απαρτίζουν. Ακολουθεί η ανάλυση των Brushless μηχανών, τα κατασκευαστικά χαρακτηριστικά και η αρχή λειτουργίας τους. Το επόμενο βήμα είναι η θεωρητική μελέτη του τριφασικού αντιστροφέα τάσης που απαιτείται για την οδήγηση του κινητήρα. Παρατίθενται τα αποτελέσματα που προέκυψαν από την προσομοίωση της λειτουργίας του ηλεκτροκινητήριου συστήματος μέσω του προγράμματος Matlab/Simulink. Κατόπιν, περιγράφεται η κατασκευή του τριφασικού αντιστροφέα τάσης, τα στοιχεία που τον απαρτίζουν και ο λόγος για τον οποίο επιλέχθηκαν. Δίνεται μια σύντομη περιγραφή του μικροελεγκτή που χρησιμοποιήθηκε, των δυνατοτήτων που παρέχει αλλά και η λογική του ελέγχου που υλοποιεί. Τέλος, ακολουθούν οι πειραματικές μετρήσεις και τα συμπεράσματα που προέκυψαν από τη λειτουργία της κατασκευής. / The purpose of this thesis is the construction of an electric two-wheeled vehicle. The work was conducted in the Laboratory of Electromechanical Energy Conversion, in the Department of Electrical and Computer Engineering at University of Patras. The main aim is the study, the construction and the control of an electric bike. In order to achieve this, it is necessary to design and install a suitable electric motor system to a conventional bicycle. Initially, there is a brief overview of the conventional and the electric bicycles, along with their history, their main parts, the types in which they are divided and the legal frameworks that govern their operation. Secondly, the electric motor system, which was installed in the bicycle frame granted for this purpose by the company Ideal Bikes, Nikos Maniatopoulos S.A., the criteria for the selection of the motor and the batteries are described. In addition, there is a short description of Brushless motors, their types and the principle of their operation. Furthermore, the theoretical study of the three phase inverter required for driving the motor is given. Moreover, the results obtained from the simulation of the operation of the motor system through the Matlab / Simulink are provided. The construction of the three phase inverter, the constituent elements and the reason for their selection are also analyzed. Last but not least, there is a short description of the microcontroller which is used and its capabilities, in order to facilitate the study and design of the structure. Finally, the experimental measurements and the conclusions that derive from the construction and the operation of the electric bike are presented and future improvements concerning the construction are proposed.