Special Unitary Parameterized Estimators of Rotation

arXiv cs.RO / 4/20/2026

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Key Points

  • The paper revisits rotation estimation by reformulating Wahba’s problem using special unitary matrices (SU(2)) to produce multiple solution forms with linear constraints on quaternion parameters.
  • It leverages these linear constraints to devise efficient solution methods for related rotation-estimation problems.
  • Building on the theoretical results, the authors propose two new continuous rotation representations designed for learning rotations in neural networks.
  • Extensive experiments are reported to demonstrate the effectiveness of the proposed learning methods and constraint-based formulations.

Abstract

This paper revisits the topic of rotation estimation through the lens of special unitary matrices. We begin by reformulating Wahba's problem using SU(2) to derive multiple solutions that yield linear constraints on corresponding quaternion parameters. We then explore applications of these constraints by formulating efficient methods for related problems. Finally, from this theoretical foundation, we propose two novel continuous representations for learning rotations in neural networks. Extensive experiments validate the effectiveness of the proposed methods.