Accurate Positioning of Bicycles for Improved Safety

Cyclists are not well protected in accidents with other road users, and there are few active safety systems available for bicycles. In this study we have evaluated the use of inexpensive Real-Time Kinematic Satellite Navigation (RTK-SN) receivers with multiple satellite constellations together with dead reckoning for accurate positioning of bicycles to enable active safety functions such as collision warnings. This is a continuation of previous work were we concluded that RTK-SN alone is not sufficient in moderately dense urban areas as buildings and other obstructions degrade the performance of RTK-SN significantly. In this work we have added odometry to the positioning system as well as extending RTK-SN with multiple satellite constellations to deal with situations where the view of the sky is poor and thus fewer satellites are in view. To verify the performance of the positioning system we have used Ultra-Wideband radios as an independent positioning system to compare against while testing during poor conditions for RTK-SN. We were able to verify that adding dead reckoning and multiple satellite constellations improves the performance significantly under poor conditions and makes the positioning system more useful for active safety systems.