Passivity monitor and software limiter which guarantee asymptotic stability of robot control systems

In this paper, we propose a passivity monitor which evaluates stability of a system based on the concept of passivity, and a software limiter which turns the system stable if it is originally unstable. It is shown that asymptotic stability will be guaranteed for arbitrary robots with arbitrary control schemes and environments, even if their properties are unknown. The validity of the passivity monitor and the software limiter is verified by numerical simulations and experiments performed on various unstable systems.