Toward a Smart Actuating System for Service Robots

Owing to the increasing engagement of service robots in everyday life, significant requirements are imposed on their control systems to ensure safe interaction between robots and humans. The stiffness of the motion executed by the service robots is not high, as with industrial robots, but has to be variable depending on the defined task. Therefore, a service robot needs to have soft actuation, delivering “human-like” motion dependant on the interaction force between the robot and its environment. Such an operation requires switching from the trajectory tracking (position control) mode to the interaction (force control) mode, and
vice versa
. Conventional control methods, based on hybrid position/force control, or switching between a position and force controller, may fail short in these cases. Thus, we have previously proposed a new control method, denoted as universal motion controller, that merges the position and force control into a single control structure. The control method is elaborated in this article, and its experimental validation is presented for the first time for multi-degree-of-freedom systems.