The local force control loop approach in bilateral control of master-slave systems

In this paper we consider to merge the stability problem for bilateral teleoperators and the contact force control problem for manipulators during constrained motion, tackling them jointly. In particular we evaluate the effects of the presence of a slave local force loop in a force reflecting master slave equipment with time delay in the communication channels. The study keeps into account the digital synthesis of the controller, which usually represents the most critical and undervalued aspect of the problem. Simulative and experimental results are given, in particular showing that the local integral force control can be tuned to the delay in the communication channel in order to guarantee stability, and, up to certain extent, a favourable transient behaviour.