On the discretization of nonholonomic dynamics in $\mathbb{R}^n$

TL;DR

This paper develops geometric integrators for nonholonomic mechanical systems, ensuring the preservation of constraints and providing a foundation for analyzing discretized dynamics within the Lagrangian framework.

Contribution

It introduces a method to discretize nonholonomic systems via geometric integrators derived from the Lagrange-d'Alembert principle, ensuring constraint preservation and consistency.

Findings

Existence and uniqueness of solutions on the distribution manifold.

Construction of D-preserving geometric integrators.

Application to the nonholonomic particle example.

Abstract

In this paper we explore the nonholonomic Lagrangian setting of mechanical systems in local coordinates on finite-dimensional configuration manifolds. We prove existence and uniqueness of solutions by reducing the basic equations of motion to a set of ordinary differential equations on the underlying distribution manifold $D$. Moreover, we show that any $D-$preserving discretization may be understood as beeing generated by the exact evolution map of a time-periodic non-autonomous perturbation of the original continuous-time nonholonomic system. By means of discretizing the corresponding Lagrange-d'Alembert principle, we construct geometric integrators for the original nonholonomic system. We give precise conditions under which these integrators generate a discrete flow preserving the distribution $D$. Also, we derive corresponding consistency estimates. Finally, we carefully treat the example of the nonholonomic particle, showing how to discretize the equations of motion in a reasonable way, particularly regarding the nonholonomic constraints. The exploration in this paper lays the ground to analyze the dynamics of appropriate discretizations of nonholonomic mechnical systems in the Lagrangian framework and to relate that dynamics to the dynamics of the original nonholonomic systems. We postpone this analysis to a series of forthcoming papers.