2025

Feedback Linearizable Discretization of Second-Order Mechanical Systems
Feedback Linearizable Discretization of Second-Order Mechanical Systems

Shreyas N. B., David Martin de Diego, Ravi N. Banavar

European Controls Conference 2025

Mechanical systems are most often described by a set of continuous-time, nonlinear, second-order differential equations (SODEs) of a particular structure governed by the covariant derivative. The digital implementation of controllers for such systems requires a discrete model of the system and hence requires numerical discretization schemes. Feedback linearizability of such sampled systems, however, depends on the discretization scheme employed. In this article, we utilize retraction maps and their lifts to construct feedback linearizable discretizations for SODEs which can be applied to many mechanical systems.

Feedback Linearizable Discretization of Second-Order Mechanical Systems

Shreyas N. B., David Martin de Diego, Ravi N. Banavar

European Controls Conference 2025

Mechanical systems are most often described by a set of continuous-time, nonlinear, second-order differential equations (SODEs) of a particular structure governed by the covariant derivative. The digital implementation of controllers for such systems requires a discrete model of the system and hence requires numerical discretization schemes. Feedback linearizability of such sampled systems, however, depends on the discretization scheme employed. In this article, we utilize retraction maps and their lifts to construct feedback linearizable discretizations for SODEs which can be applied to many mechanical systems.

2024

Nonlinear Infinite Dimensional Model for a Two Degree-of-Freedom Flexible WIng
Nonlinear Infinite Dimensional Model for a Two Degree-of-Freedom Flexible WIng

Shreyas N. Bharadwaj, Vivek Natarajan, Aditya A. Paranjape

AIAA SciTech Forum 2025

An infinite-dimensional nonlinear model for a two-degree-of-freedom highly flexible wing is presented in this paper. The model describes the coupled dynamics of bending and torsion in terms of a set of nonlinear partial differential equations. When torsion is ignored, the resulting transverse bending equations are identical to those for the well-known elastica. The in vacuo response and the flutter onset characteristics of the model are compared with standard aeroelastic models using numerical simulation. The nonlinear model presented here could potentially serve as a benchmark for PDE-based control design methods, providing an intermediate step between low-fidelity linear models and nonlinear simulation models whose high fidelity is usually accompanied by large computational times.

Nonlinear Infinite Dimensional Model for a Two Degree-of-Freedom Flexible WIng

Shreyas N. Bharadwaj, Vivek Natarajan, Aditya A. Paranjape

AIAA SciTech Forum 2025

An infinite-dimensional nonlinear model for a two-degree-of-freedom highly flexible wing is presented in this paper. The model describes the coupled dynamics of bending and torsion in terms of a set of nonlinear partial differential equations. When torsion is ignored, the resulting transverse bending equations are identical to those for the well-known elastica. The in vacuo response and the flutter onset characteristics of the model are compared with standard aeroelastic models using numerical simulation. The nonlinear model presented here could potentially serve as a benchmark for PDE-based control design methods, providing an intermediate step between low-fidelity linear models and nonlinear simulation models whose high fidelity is usually accompanied by large computational times.