A passivity-based adaptive admittance control strategy for physical human-robot interaction in hands-on tasks.

In hands-on tasks, operator arm and robot are linked together, forming a unique dynamical system whose stability is crucial to guarantee a safe and comfortable human-robot interaction. To this extent, a passivity-based adaptation strategy is here proposed, allowing to modify the parameters of the robot control system, in accordance with changes in the operator arm impedance, so that stability is guaranteed. Experimental results, including a comparison with the methodology introduced in [1], demonstrate the importance of considering human arm impedance changes in the adaption strategy, in order to guarantee stability without causing excessive changes in admittance filter parameters.