We present an assistive suitcase system, BBeep, for supporting blind people when walking through crowded environments. BBeep uses pre-emptive sound notifications to help clear a path by alerting both the user and nearby pedestrians about the potential risk of collision. BBeep triggers notifications by tracking pedestrians, predicting their future position in real-time, and provides sound notifications only when it anticipates a future collision. We investigate how different types and timings of sound affect nearby pedestrian behavior. In our experiments, we found that sound emission timing has a significant impact on nearby pedestrian trajectories when compared to different sound types. Based on these findings, we performed a real-world user study at an international airport, where blind participants navigated with the suitcase in crowded areas. We observed that the proposed system significantly reduces the number of imminent collisions.

We thank the Allegheny County Airport Authority and all study participants. This work was sponsored in part by JST CREST (JPMJCR14E1), JST AIP-PRISM (JPMJCR18ZG), NSF NRI award (1637927), NIDILRR (90DPGE0003), Uptake (CMU ML for Social Good fund) and Shimizu Corporation.