Energetic approach for actuator fault accommodation: Application to bilateral teleoperation

This paper introduces a fault tolerant control approach based on direct compensation of the power, which is generated by a fault source located at the input of the controlled system. The power of the fault is estimated from the energy balance of the controlled system. The control law, proposed for fault accommodation, depends directly on the estimated fault power and it is formulated such to avoid large, unimplementable control signals that could appear in some specific operating conditions of the system. The method is directly applicable to guarantee the stability of bilateral control systems in the presence of communication delay between the master and the slave. The resulting control algorithm is an extended Passivity Observer - Passivity Controller scheme, which guarantees that the magnitudes of the control signals always remain in an admissible domain. Simulations and realtime experimental measurements are presented to show the efficiency of the proposed control scheme.