The paper presents an architecture for distributed control of multi-robot systems with
an integrated fault detection, isolation, and recovery strategy. The proposed solution is
based on a distributed observer-controller schema where each robot, by communicating
only with its direct neighbors, is able to estimate the overall state of the system; such
an estimate is then used by the controllers of each robot to achieve global missions
as, for example, centroid and formation tracking. The information exchanged among
the observers is also used to compute residual vectors that allow each robot to detect
failures on anyone of the teammates, even if not in direct communication. The proposed
strategy considers both recoverable and unrecoverable actuator faults as well as it
properly manages the possible activation of reactive local control behaviors of the
robots (e.g., the activation of obstacle avoidance strategy), which generate control inputs
different from those required by the global mission control. In particular, when the robots
are subject to recoverable faults, those are managed at a local level by computing a
proper compensating control action. On the other side, when the robots are subject to
unrecoverable faults, the faults are isolated from anyone of the teammates by means of a
distributed fault detection and isolation strategy; then, the faulty robots are removed from
the team and the mission is rearranged. The proposed strategy is validated via numerical
simulations where the system properly identifies and manages the different cases of
recoverable and unrecoverable actuator faults, as well as it manages the activation of
local reactive control in an integrated case study