Demonstrating the benefits of variable impedance to telerobotic task execution

Inspired by human physiology, variable impedance actuation has been shown to benefit safety with its ability to modulate impact forces. But humans also continually adjust impedance during contact and throughout manipulation tasks. We examine the value and effect of continual impedance variation on quasi-static manipulation. We approach this challenge from the perspective of telerobotics where the operator can explicitly modulate the robotic impedance. Using a three degree of freedom planar teleoperation system we explore two quasi-static tasks: inserting a rigid peg into a tight hole and throwing a switch without overshoot. The work finds that no single impedance can optimally accomplish both tasks. Instead user-controlled impedance variations achieve the desired results, demonstrating the benefits of variable impedance to quasi-static applications in telerobotics.