How Much Haptic Surface Data Is Enough?

The Proton Pack is a portable visuo-haptic surface interaction recording device that will be used to collect a vast multimodal dataset, intended for robots to use as part of an approach to understanding the world around them. In order to collect a useful dataset, we want to pick a suitable interaction duration for each surface, noting the tradeoff between data collection resources and completeness of data. One approach frames the data collection process as an online learning problem, building an incremental surface model and using that model to decide when there is enough data. Here we examine how to do such online surface modeling for the initial problem of learning a kinetic friction model. With a long dataset consisting of force, vibration, and speed recorded by a human operator moving a tooling ball end-effector across a flat vinyl surface, we find a good stopping point at 55.4 s.