BikeGPS

Abstract

The past few years have witnessed a rapid growth of stationless bike sharing services. The service allows the bikes to be dropped off freely and to be found through GPS localization. In practice, the bikes are often parked in close proximity to buildings, where GPS accuracy suffers, making bike search a challenging task. This article 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 a BikeGPS network. Formed by pedestrian users who opportunistically measure inter-bike 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. Experiments in real-world scenarios 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.