BikeGPS

Abstract

The past few years have seen a surge of stationless bike sharing services in many modern cities. The service allows the bikes to be dropped off freely, and to be found through GPS localization. For maximum convenience, the bikes are often parked in close proximity to the buildings, where GPS may perform poorly, making bike search a challenging task. This paper proposes a novel approach to addressing this problem. Inspired by multi-antenna systems, our method tries to collect GPS signals from multiple distributed bikes, by organizing a group of bikes into a network, called the BikeGPS. Formed by pedestrian users who opportunistically measure interbike distance via radio sensing and step tracking, the generated network permits one to map all the nodes' satellite range measurements into a single lead node's view. By considering both signal and geometry properties of satellite raw measurements, and using an asynchronous coarse time navigation algorithm, the lead node can accurately derive the locations of all the network nodes. Real-world experiments show that BikeGPS significantly improves the localization performance, in terms of both accuracy and solution availability, compared with the naive GPS approach and a high-level cooperative localization method.