Electric bikes have become a popular means of transportation over the years. This report examined whether or not it is plausible to upgrade old bicycles to electrical bikes, thereby, using the already existing bicycles and avoiding the need of unnecessary manufacturing. A prototype of the mountable motor was designed and manufactured. The device consisted of two units, a mounting unit and a motor unit. A controller was connected to the motor and could be placed on the handlebar. The controller both enabled control and monitoring of the power given to the motor. The prototype’s durability, potential velocity and control system were tested to answer the research questions and give recommendation to further developments of the project. No major malfunctions were found in the construction after testing. For a voltage of 12V and a payload of 22kg, the bicycle obtained a top speed about 3m/s. The control system gave a smooth transition between velocities with hardly any noise to the signals. / Den elektriska cykeln har under åren blivit ett populärt transportmedel. Denna rapport kommer att undersöka huruvida det är rimligt att uppgradera traditionella cyklar till elcyklar. Istället för att nyproducera elcykelramar kan redan befintliga cyklar användas. En prototyp av en monterbar och avtagbar cykelmotor byggdes. Prototypen bestod av två enheter, en infästningsenhet och en motorenhet. Motorenheten var kopplad till ett kontrollsystem som gick att fästa på styret. Via kontrollsystemet kunde man både kontrollera och övervaka effekten från motorn. Prototypens tålighet, potentiella hastighet och kontrollsystem testades för att besvara forskningsfrågorna och lägga en grund för vidareutveckling av konceptet. Det hittades inga allvarliga brister eller skador av konstruktionen efter testerna. Vid en motorspänning på 12V och en last på 22kg så nåddes en maxhastighet på lite över 3m/s. Kontrollsystemet gav en jämn övergång mellan de olika hastigheterna, utan påverkande brus i signalerna.

As a conventional transportation modality, bicycles have been gradually electrified to meet the desire for convenient and green commuting patterns, especially in developed urban areas. The electric bicycle battery pack and its management system are core elements that determine key performance metrics such as electric range and output power. With respect to electric bicycle applications, focused research on the battery, its management system, and performance has received less attention compared to other energy storage applications. In this thesis, a well-developed conversion kit produced by BionX is studied. A data collecting system is first installed to record both mechanical and electrical data, such as speed, power and voltage; this enables defining two standard riding cycles at different riding conditions. Two benchmarking tests are performed to investigate the battery life in pure electric mode and at different threshold levels of optimal assistance. A novel quadratic programming based fitting algorithm is derived and applied in both time and frequency domain parameter identification tests. The proposed algorithm is able to fit single/multiple pulses by applying a masking vector. Sensitivity study and experimental results show the high robustness and fast computation time of the approach compared to existing and commonly used methods, such as fmincon. The comparison between hybrid power pulse characterization (HPPC) and electrochemical impedance spectrum (EIS) tests are performed in terms of extracted internal resistance. A second-order RC battery model is developed using parameters extracted from HPPC tests. The model is validated by experimental riding cycles and used to generate the reference SOC profiles that are employed in a SOC estimation study. Four estimation strategies, including extended Kalman Filter (EKF), Sigma point Kalman Filter (SPKF), Cubature Kalman Filter (CKF), and joint extended Kalman Filter (JEKF), are compared systematically in terms of accuracy, robustness and computation complexity. / Thesis / Master of Applied Science (MASc)