  In this paper, a strategy to handle the human safety in a multi-robot
scenario is devised. In the presented framework, it is foreseen that robots are
in charge of performing any cooperative manipulation task which is
parameterized by a proper task function. The devised architecture answers to
the increasing demand of strict cooperation between humans and robots, since it
equips a general multi-robot cell with the feature of making robots and human
working together. The human safety is properly handled by defining a safety
index which depends both on the relative position and velocity of the human
operator and robots. Then, the multi-robot task trajectory is properly scaled
in order to ensure that the human safety never falls below a given threshold
which can be set in worst conditions according to a minimum allowed distance.
Simulations results are presented in order to prove the effectiveness of the
approach.
