  The Omnid human-collaborative mobile manipulators are an experimental
platform for testing control architectures for autonomous and
human-collaborative multirobot mobile manipulation. An Omnid consists of a
mecanum-wheel omnidirectional mobile base and a series-elastic Delta-type
parallel manipulator, and it is a specific implementation of a broader class of
mobile collaborative robots ("mocobots") suitable for safe human
co-manipulation of delicate, flexible, and articulated payloads. Key features
of mocobots include passive compliance, for the safety of the human and the
payload, and high-fidelity end-effector force control independent of the
potentially imprecise motions of the mobile base. We describe general
considerations for the design of teams of mocobots; the design of the Omnids in
light of these considerations; manipulator and mobile base controllers to
achieve useful multirobot collaborative behaviors; and initial experiments in
human-multirobot collaborative mobile manipulation of large, unwieldy payloads.
For these experiments, the only communication among the humans and Omnids is
mechanical, through the payload.
