Ultrasonic Positioning System for Electric Road System

Elonroad is a company that is looking into the possibility to charge electric vehicle on road. The conductor implemented on the driveway has a characteristic shape. The scope of this master thesis project is to identify the shape of the conductor and determine the relative position of the vehicle to the conductor using ultrasonic sensors. The goal is to have an update frequency of 30 Hz and a positioning error of maximum 2 cm. During the project a serial system containing 7 ultrasonic modules has been built. The sensor modules are mounted in an array and placed parallel to the road and perpendicular to the vehicles intended direction of travel. The ultrasonic modules are placed with a center distance of 10 cm on the array. A cross-correlation algorithm was implemented to determine the distance to the surface below each of the ultrasonic modules. The method to find the relative position of the vehicle uses a modified convolution algorithm which is proven to work under ideal circumstances. The distance measurement from the modules to ground can differ roughly +/-8 mm, this originates from the wavelength of the 40 kHz ultrasonic signal in air, the +/-8 mm error can, according to simulations give a positioning error of up to 5 cm. Simulations has indicated that +/-4 mm will give a positioning error less than, or equal to, 2 cm. The update frequency is assumed to be around 20 Hz, where the largest part is due to calculation time of the distance to ground. It can be lowered with more effective algorithms or with a more powerful microcontroller.Electric vehicles can charge their batteries on road by connecting to a conductor integrated in the roadway. In this specific case the integrated conductor consists in an elevated structure. This structures location relative the car needs to be tracked to ensure the car stays connected

Tidsloggning via NFC

Denna rapport beskriver utvecklandet av ett tidsrapporteringssystem som tillämpar Near-Field-Communication[NFC]-tekniken. Systemet är i första hand avsett för ett företag där systemet i sig är framtaget med moderna tekniker och utvecklades med syn på expandering och vidareutveckling. En webbapplikation har utvecklats som består utav en server, databas och webbsida. Servern kan ta emot förfrågningar för att hantera information som finns lagrad i databasen. Webbsidan kan hantera och se över tidsrapporter i ett användargränssnitt som kan nås med hjälp utav en webbläsare. Systemet innehåller en station som använder sig utav en NFC-läsare för att läsa av information ifrån externa NFC-enheter. Informationen som läses av skickas vidare, via Wi-Fi, till servern för att antingen registrera en ny station eller skapa en tidsloggning. En mobil applikation har utvecklats till mobiltelefoner som använder sig utav operativsystemet Android och har inbyggt NFC-stöd. En mobiltelefon som stödjer dessa kriterier kan svepas över en station för att utföra en tidsloggning. Mobiltelefonen kan själv utföra skapa, modifiera, ta bort och hämta tidsloggningar. GPS är integrerat för navigering och för att koppla ihop position med en tidsloggning.This report describes the development of a time reporting system that applies the Near-Field Communication [NFC] technology. The system is primarily intended for a company where the system itself is designed with modern techniques and was developed with the vision of expansion and further development. A web application has been developed that consists of a server, database, and a web page. The server can receive requests to manage the information stored in the database. The web page can manage and review the time logs in a user interface that can be accessed with a browser. The system includes a station that uses a NFC-reader to read information from the external NFC devices. The information is then forwarded, with the help of Wi-Fi, to the server to either register a new station or create a time log. It also has a mobile application developed for mobile phones that use Android as operating system and has built-in NFC support. A mobile phone that supports these criteria may be swept over a station to perform a time log. The mobile phone can carry out create, modify, delete, and view time logs. GPS is integrated for navigation and to connect a position with a time log