  Advancements in the domain of physical human-robot interaction (pHRI) have
tremendously improved the ability of humans and robots to communicate,
collaborate, and coexist. In particular, compliant robotic systems offer many
characteristics that can be leveraged towards enabling physical interactions
that more efficiently and intuitively communicate intent, making compliant
systems potentially useful in more physically demanding subsets of human-robot
collaborative scenarios. Tensegrity robots are an example of compliant systems
that are well-suited to physical interactions while still retaining useful
rigid properties that make them practical for a variety of applications. In
this paper, we present the design and preliminary testing of a 6-bar spherical
tensegrity with force-sensing capabilities. Using this prototype, we
demonstrate the ability of its force-sensor array to detect a variety of
physical interaction types that might arise in a human context. We then train
and test a series of classifiers using data from unique and representative
interactions in order to demonstrate the feasibility of using this physical
modality of sensing to reliably communicate goals and intents from a human
operator in a human-robot collaborative setting.
