Robust Model Reference Adaptive Control with Combined Adaptation under Finite Excitation Condition

arXiv:2608.22562 2026 Dynamics 1 ideas extracted · analyzed Sep 1, 2026

What the math gives to ML

The paper offers a constructive finite-excitation memory mechanism: once a finite set of regressors is sufficiently independent, Modified Gram-Schmidt constructs an orthogonal memory matrix whose coefficient in the parameter-error dynamics is the identity. This removes the usual dependence of adaptation speed on the regressor Gramian's condition number or excitation magnitude, while retaining an explicit ultimate bound under bounded uncertainty. The most direct neural-network transfer is an orthogonalized gradient-memory optimizer for a linear output head or low-rank adapter, where a finite buffer of feature vectors is compressed into a well-conditioned basis and used to isotropically correct parameter errors.

Ideas from this paper

Failed on benchmark 2026

Finite-Excitation Orthogonal Gradient Memory

For a neural network with a trainable linear head or low-rank adapter, store feature vectors from recent minibatches and select a finite set that is sufficiently independent. Apply Modified Gram-Schmidt to obtain orthonormalized memory directions, then add residual corrections along these directions so the local parameter-error dynamics have an identity coefficient matrix rather than a poorly conditioned empirical Gramian. The method predicts a sharp transition after the buffer first contains…

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Paper: Robust Model Reference Adaptive Control with Combined Adaptation under Finite Excitation Condition arXiv:2608.22562