Passive Energy-based Control via Energy Tanks and Release Valve for Limit Cycle and Compliance Control

The problem of generating periodic solutions for a fully actuated robot is considered in this work. The result is achieved by extending the concept of limit cycle control via energy regulation, in order to guarantee passivity of the closed-loop system. Such a feature is particularly relevant in case of physical interaction with the environment, since a non-passive system could cause problems in terms of stability, robustness and safety. As energy-based limit cycle control can be used also for regulation control, the paper extends as well recent results in passivation of projection-based null space compliance control to the case of adjustable maximum allowed activity in the system.