Quasi-Static Control of Discrete Cosserat Rod

TL;DR

This paper develops feedback control laws for soft robots modeled as Cosserat rods using a discretization approach, enabling effective trajectory and shape control through nonlinear ODE models.

Contribution

It introduces a novel control design method for Cosserat rod-based soft robots using PCS discretization and state-feedback linearization, improving control accuracy.

Findings

Control laws enable precise end-effector trajectory tracking.

Shape control of soft robots is effectively achieved.

Numerical results demonstrate robust performance of the control laws.

Abstract

In this paper, we design feedback control laws for soft robots modelled using the Cosserat rod, which is spatially discretised using the Piecewise Constant Strain (PCS) approach. The PCS approach transforms the nonlinear PDEs describing the Cosserat rod to a system of nonlinear ODEs. This simplification results in a model describing soft robots which is similar to the serial rigid-link manipulators. We design feedback control laws for the quasi-static PCS model by using the external end-effector wrench as control input. The control laws are designed based on state-feedback linearisation in strain and task spaces. An extensive set of numerical results demonstrates the performance of the control laws for end-effector trajectory tracking and shape control of soft robots.