| dc.description.abstract | The latest technology in electronic transmission systems (ETS) and wireless sensors for bicycles bring a high potential to automate gear shifting on bicycles. An optimal gear selection system (GSS) for road bicycles with an ETS was developed. The system interacted with a commercial Shimano Di2 6870 ETS, resulting in a fully automatic transmission system (ATS) that selected an optimal gear for the user. The interconnection between the ETS and GSS required a customization on the ETS hardware. Mechanical button switches on ETS were replaced with a transistor based circuit to enable electronic control of gear shifts.
Optimal gearing and system behavior was determined from knowledge acquisition from both practical and theoretical aspects. Knowledge-based system was developed for optimal gear selection, using fuzzy logic control. Sensors were used to measure speed, pedaling rate (cadence), pedaling power and riding position. By fusion of the sensor data and the acquired knowledge, the GSS selected an optimal gear that maintained the cadence within a predefined optimal range for a given situation. NI LabVIEW was used for development of the GSS and ANT+ toolkit for LabVIEW was used for data acquisition from ANT+ bike sensors.
The GSS prototype was installed on a demo bike equipped with an ETS and tested on a stationary indoor trainer, according to a test plan document.
The system performance was tested in terms of maintaining cadence at a preset goal cadence. Two separate tests were done for goal cadences CADgoal = 80RPM and CADgoal = 90RPM. The results showed that the system performed well in maintaining a consistent cadence, but the average cadence the system maintained was higher than the set goal cadence. The effect of each individual input variable on the system was tested and results confirmed that the GSS performed according to the predefined requirements | nb_NO |
