We propose a new impedance controller using a multi-time-scale structure. Extended High-Gain Observers in the fastest time scale are used to estimate unmeasured system states and uncertainties in systems. Dynamic inversion in the second fastest time scale is employed to deal with uncertain input coefficients. An implicit tracking for joint-space control of workspace trajectories is realized through the dynamic inversion. The performance of the proposed impedance control is quantified by control parameters. Using the singular perturbation method, the closed-loop system stability is analyzed. The proposed control method is verified through numerical simulation.
['Joonho Lee', 'Hanz Richter']
Impedance control based on a multi-time-scale approach: Extended High-Gain Observers and dynamic inversion