Is a graph with IMU and unary poses under-constrained

[Brice Rebsamen]

Consider a (batch) graph with only IMU factors (combined) and 6 DOF
poses as unary constraints. Is it under-constrained (velocity)? or is
the IMU factor somehow incorporating some sort of relation between
pose delta and velocity that suffices to constrain the graph?

[Rafael Spring]

Is it under-constrained (velocity)?

No.

is the IMU factor somehow incorporating some sort of relation between pose delta and velocity that suffices to constrain the graph?

Yes. It has to. Otherwise it wouldn't be able to constrain pose from acceleration.

Rafael Spring

CTO, Co-Founder

DotProduct LLC

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[Dellaert, Frank]

A graph with only IMU factors is under constrained. Unary pose factors will typically make it observable.

Best!

Frank

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From: gtsam...@googlegroups.com <gtsam...@googlegroups.com> on behalf of Rafael Spring <raf...@dotproduct3d.com>
Sent: Wednesday, August 6, 2025 11:18:50 AM
To: Brice Rebsamen <brice.r...@gmail.com>
Cc: gtsam users <gtsam...@googlegroups.com>
Subject: Re: [GTSAM] Is a graph with IMU and unary poses under-constrained

 

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