Flatness-based motion planning for a non-uniform moving cantilever Euler-Bernoulli beam with a tip-mass

TL;DR

This paper develops a flatness-based motion planning method for a non-uniform Euler-Bernoulli beam with a tip-mass and a movable cantilever joint, enabling precise state transfers under certain conditions.

Contribution

It extends the generating functions approach to flatness-based control for a coupled PDE-ODE beam model, enabling motion planning for complex flexible structures.

Findings

Motion transfer is possible within a specific set of initial and final states.

Theoretical results are validated through simulations and experiments.

The approach handles non-uniform beams with tip-masses and movable joints.

Abstract

Consider a non-uniform Euler-Bernoulli beam with a tip-mass at one end and a cantilever joint at the other end. The cantilever joint is not fixed and can itself be moved along an axis perpendicular to the beam. The position of the cantilever joint is the control input to the beam. The dynamics of the beam is governed by a coupled PDE-ODE model with boundary input. On a natural state-space, there exists a unique state trajectory for this beam model for every initial state and each smooth control input which is compatible with the initial state. In this paper, we study the motion planning problem of transferring the beam from an initial state to a final state over a prescribed time interval. We address this problem by extending the generating functions approach to flatness-based control, originally proposed in the literature for motion planning of parabolic PDEs, to the beam model. We prove that such a transfer is possible if the initial and final states belong to a certain set, which also contains steady-states of the beam. We illustrate our theoretical results using simulations and experiments.