Elastic Structure Preserving Impedance Control for Nonlinearly Coupled Tendon-Driven Systems

Traditionally, most of the nonlinear control techniques for elastic robotic systems focused on achieving a desired closed-loop behavior by modifying heavily intrinsic properties plant. This is also case tendon-driven systems, where highly couplings lead to several challenges. Following current philosophy exploiting mechanical compliance rather than fighting it, this letter proposes an Elastic Structure Preserving impedance (ESPi) with coupled tendinous transmissions. Our strategy achieves globally asymptotically stable system that minimally shapes inertial and structure. It further allows impose link-side behavior. Simulations performed index finger DLR robot David show satisfactory results interaction set-point regulation.