On IMU preintegration: A nonlinear observer viewpoint and its application

TL;DR

This paper offers a new nonlinear observer perspective on IMU preintegration, revealing its equivalence to PEBO, and introduces novel methods for hybrid observer design and noise handling in estimation tasks.

Contribution

It provides a novel interpretation of IMU preintegration from a nonlinear observer viewpoint and proposes new approaches for hybrid sampling and noise robustness.

Findings

Preintegration can be viewed as recursive PEBO implementation.

The approaches are equivalent under perfect measurements.

New hybrid observer design and noise robustness methods are introduced.

Abstract

The inertial measurement unit (IMU) preintegration approach nowadays is widely used in various robotic applications. In this article, we revisit the preintegration theory and propose a novel interpretation to understand it from a nonlinear observer perspective, specifically the parameter estimation-based observer (PEBO). We demonstrate that the preintegration approach can be viewed as recursive implementation of PEBO in moving horizons, and that the two approaches are equivalent in the case of perfect measurements. We then discuss how these findings can be used to tackle practical challenges in estimation problems. As byproducts, our results lead to a novel hybrid sampled-data observer design and an approach to address statistical optimality for PEBO in presence of noise.