Learning Human Ergonomic Preferences For Handovers

Our goal is for people to be physically comfortable when taking objects from robots. This puts a burden on the robot to hand over the object in such a way that a person can easily reach it, without needing to strain or twist their arm - a way that is conducive to ergonomic human grasping configurations. To achieve this, the robot needs to understand what makes a configuration more or less ergonomic to the person, i. e. their ergonomic cost function. In this work, we formulate learning a person's ergonomic cost as an online estimation problem. The robot can implicitly make queries to the person by handing them objects in different configurations, and gets observations in response about the way they choose to take the object. We compare the performance of both passive and active approaches for solving this problem in simulation, as well as in an in-person user study.