Energy shaping nonlinear control of underactuated needle insertion

This work investigates the position control of an underactuated mechatronic system for straight needle insertions in soft tissues. The consists a pneumatic cylinder pushing slender supported at base and subject to external forces tip due interactions with dynamics is described by rigid-link model controller design purposes. main contribution this new energy shaping law that: (i) does not rely on analytical solution partial differential equations, which major hurdle techniques, require feedback linearization, known be sensitive uncertainties; (ii) accounts friction lateral acting tip, are estimated adaptively nonlinear observers. For comparison purposes, alternative that employs linearization also presented. Simulations experiments silicone rubber phantoms using axial-symmetric indicate proposed can reduce rotation corresponding deflection compared PID algorithm. In case larger insertion forces, limit depth prevent large deflections: behavior influenced specific tuning parameter, thus providing additional flexibility previous implementations. Finally, less parameter uncertainties than controller. • A designed insertions. solving PDEs or linearization. Adaptive observers compensate unknown actuator tip.