With the aim of further enabling the exploitation of intentional impacts in
robotic manipulation, a control framework is presented that directly tackles
the challenges posed by tracking control of robotic manipulators that are
tasked to perform nominally simultaneous impacts. This framework is an
extension of the reference spreading control framework, in which overlapping
ante- and post-impact references that are consistent with impact dynamics are
defined. In this work, such a reference is constructed starting from a
teleoperation-based approach. By using the corresponding ante- and post-impact
control modes in the scope of a quadratic programming control approach, peaking
of the velocity error and control inputs due to impacts is avoided while
maintaining high tracking performance. With the inclusion of a novel interim
mode, we aim to also avoid input peaks and steps when uncertainty in the
environment causes a series of unplanned single impacts to occur rather than
the planned simultaneous impact. This work in particular presents for the first
time an experimental evaluation of reference spreading control on a robotic
setup, showcasing its robustness against uncertainty in the environment
compared to three baseline control approaches.Comment: 14 pages, 10 figures. Submitted for publication to IEEE Transactions
on Robotics (T-RO) in September, 202