Estimation of Involuntary Components of Human Arm Impedance in Multi-Joint Movements via Feedback Jerk Isolation
Abstract:
Stable and efficient coordination in physical human-robot interaction requiresconsideration of human feedback behavior. In unpredictable tasks, where voluntarycognitive feedback is too slow to guarantee desired task execution, the human mustrely on involuntary intrinsic and reflexive feedback. The combined effects of thesetwo feedback mechanisms and the inertial characteristics can be summarized in theinvoluntary impedance components. In this work, we presenta method for the estimationof the involuntary impedance components of the human arm in multi-joint movements.We apply force perturbations to evoke feedback jerks that can be isolated using ahigh pass filter and limit the duration of the estimation interval to guarantee exclusionof voluntary cognitive feedback. Dynamic regressor representation of the rigid bodydynamics of the arm and first order Taylor series expansion ofthe feedback behavioryield a model that is linear in the involuntary impedance components. The constantvalues of the inertial parameters are estimated in a static posture maintenance task andsubsequently inserted to estimate the remaining components in a dynamic movementtask. The method is validated with simulated data of a neuromechanical model ofthe human arm and its performance is compared to establishedmethods from theliterature. The results of the validation demonstrate superior estimation performance formoderate movement velocities, and less influence of the variability of the movements.The applicability to real data and the plausibility of the limited estimation interval aresuccessfully demonstrated in an experiment with human participants.
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Stable and efficient coordination in physical human-robot interaction requiresconsideration of human feedback behavior. In unpredictable tasks, where voluntarycognitive feedback is too slow to guarantee desired task execution, the human mustrely on involuntary intrinsic and reflexive feedback. The combined effects of thesetwo feedback mechanisms and the inertial characteristics can be summarized in theinvoluntary impedance components. In this work, we presenta method for the estimationof...
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