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Main Authors: Lopez-Custodio, P. C., Bharath, K., Kucukyilmaz, A., Preston, S. P.
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2310.19561
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author Lopez-Custodio, P. C.
Bharath, K.
Kucukyilmaz, A.
Preston, S. P.
author_facet Lopez-Custodio, P. C.
Bharath, K.
Kucukyilmaz, A.
Preston, S. P.
contents Many of the tools available for robot learning were designed for Euclidean data. However, many applications in robotics involve manifold-valued data. A common example is orientation; this can be represented as a 3-by-3 rotation matrix or a quaternion, the spaces of which are non-Euclidean manifolds. In robot learning, manifold-valued data are often handled by relating the manifold to a suitable Euclidean space, either by embedding the manifold or by projecting the data onto one or several tangent spaces. These approaches can result in poor predictive accuracy, and convoluted algorithms. In this paper, we propose an "intrinsic" approach to regression that works directly within the manifold. It involves taking a suitable probability distribution on the manifold, letting its parameter be a function of a predictor variable, such as time, then estimating that function non-parametrically via a "local likelihood" method that incorporates a kernel. We name the method kernelised likelihood estimation. The approach is conceptually simple, and generally applicable to different manifolds. We implement it with three different types of manifold-valued data that commonly appear in robotics applications. The results of these experiments show better predictive accuracy than projection-based algorithms.
format Preprint
id arxiv_https___arxiv_org_abs_2310_19561
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Non-parametric regression for robot learning on manifolds
Lopez-Custodio, P. C.
Bharath, K.
Kucukyilmaz, A.
Preston, S. P.
Robotics
Machine Learning
Many of the tools available for robot learning were designed for Euclidean data. However, many applications in robotics involve manifold-valued data. A common example is orientation; this can be represented as a 3-by-3 rotation matrix or a quaternion, the spaces of which are non-Euclidean manifolds. In robot learning, manifold-valued data are often handled by relating the manifold to a suitable Euclidean space, either by embedding the manifold or by projecting the data onto one or several tangent spaces. These approaches can result in poor predictive accuracy, and convoluted algorithms. In this paper, we propose an "intrinsic" approach to regression that works directly within the manifold. It involves taking a suitable probability distribution on the manifold, letting its parameter be a function of a predictor variable, such as time, then estimating that function non-parametrically via a "local likelihood" method that incorporates a kernel. We name the method kernelised likelihood estimation. The approach is conceptually simple, and generally applicable to different manifolds. We implement it with three different types of manifold-valued data that commonly appear in robotics applications. The results of these experiments show better predictive accuracy than projection-based algorithms.
title Non-parametric regression for robot learning on manifolds
topic Robotics
Machine Learning
url https://arxiv.org/abs/2310.19561