Energy Shaping Control for Robotic Needle Insertion

Abstract

This work investigates the use of energy shaping control to reduce deflection in slender beams with tip load and actuation at the base. The ultimate goal of this research is a buckling avoidance strategy for robotic-assisted needle insertion. To this end, the rigid-link model of a flexible beam actuated at the base and subject to tip load is proposed, and an energy shaping approach is employed to construct a nonlinear controller that accounts for external forces. A comparative simulation study highlights the benefits of the proposed approach over a linear control baseline and a simplified nonlinear control.

Adaptive energy shaping control of robotic needle insertion

“…Two nonlinear control laws are designed, and a direct physical interpretation is provided in terms of mechanical energy of the closed-loop system. The controllers extend our preliminary work [24] by including an adaptive observer designed with the Immersion and Invariance methodology [25,26] to compensate the unknown friction forces of the pneumatic actuator 2. The corresponding stability conditions are studied with a Lyapunov approach and tuning guidelines for the controller parameters are discussed.…”

“…This scenario is valuable from a theoretical point of view, but it is not necessarily clinically representative. Figure 5 shows that setting = 0, which corresponds to our preliminary work without friction compensation [24], the actuator friction is not compensated and the regulation goal is not achieved even though no lateral force is present. In particular, with Controller 1 the piston position stops at approximately 75 mm, while with Controller 2 the piston does not move at all employing the current tuning = 20.…”