A Bio-inspired Approach for Regulating Visco-elastic Properties of a Robot Arm

Neurophysiological studies show that humans possess the capability of generating appropriate motor behaviors to different uncertain environmental conditions by combining a forward action, produced by the internal forward dynamic model, and a feedback control, realising the transformation from sensory information to motor commands. To this regard, a control system based on the combination of a feedfornard and a feedback control loop has been developed in order to provide Q robot ann with human-like adaptation capabilities. The work analyses the role of biological coactiuation in the mechanism of adjustable uisco-elastic arm properties and proposes a function for the eualuation of the robot ann coactivation based on the measure of the position error and the interaction force. The coactiuation function is used to update the proportional and derivative parameters of the feedback controller and, consequently, the ann uisco-elasticity in unpredictable environmental conditions. Finally, experimental results on the evolution of the coactiuation in the adaptation and de-adaptation phases are provided an the last section of the paper.