Distro	Build dev	Build releases	Stable version
ROS 2 Humble (u22.04)		amd64 arm64
ROS 2 Jazzy @ u24.04		amd64 arm64
ROS 2 Kilted @ u24.04		amd64 arm64
ROS 2 Lyrical (u26.04)		amd64 arm64
ROS 2 Rolling (u26.04)		amd64 arm64

mola_imu_preintegration

A lightweight package for IMU preintegration routines, IMU data manipulation, and basic IMU calibration.

This repository provides:

• mola::imu::IMUIntegrator: A C++ class to integrate IMU accelerations and angular velocities.
• mola::imu::ImuTransformer: Transforms IMU readings from an arbitrary sensor pose to the vehicle reference base_link.
• mola::imu::LocalVelocityBuffer: Holds a short window of local velocities, accelerations, and global orientation, from external estimators and an IMU.
• mola::imu::trajectory_from_buffer(): Reconstruct a trajectory from a LocalVelocityBuffer.

Build and install

Refer to the root MOLA repository.

Docs and examples

See this package page in the documentation.

License

This package is released under the GNU GPL v3 license. Other options available upon request.

Contributions require acceptance of the Contributor License Agreement (CLA).

Changelog for package mola_imu_preintegration

1.17.1 (2026-07-17)

• Merge pull request #10 from MOLAorg/fix/imu-transformer-near-duplicate-timestamp-dt fix: guard against near-zero dt in ImuTransformer angular-accel finite difference
• style: clang-format fix
• fix: guard against near-zero dt in ImuTransformer angular-accel finite difference Some IMU drivers (e.g. the Hesai built-in IMU) emit consecutive messages with near-duplicate timestamps a few microseconds apart. Dividing the finite-difference angular-acceleration term by such a near-zero dt amplified an otherwise negligible angular-velocity delta into a huge spurious lever-arm correction, corrupting the transformed acceleration for that sample. Reproduced end-to-end: ImuInitialCalibrator's pitch/roll came out ~33 deg off on a dataset where the true tilt (per the bag's own static transforms) is ~2 deg, with about a third of samples in the calibration window affected. Widen the existing fallback-rate guard to treat any dt at or below 1 ms the same as the dt<=0 case. Add a regression test.
• Contributors: Jose Luis Blanco-Claraco

1.17.0 (2026-07-04)

• Merge pull request #9 from MOLAorg/fix/trajectory-empty-on-insufficient-data
• Merge pull request #8 from MOLAorg/fix/imu-initial-calibrator-rotated-mount-orientation
• fix: apply IMU extrinsics to orientation in ImuInitialCalibrator
• Merge pull request #7 from MOLAorg/improve/imu-review-fixes
• ci: update and fix CI jobs
• fix: prune relative to true latest timestamp, not just-inserted time
• fix: clear() preserves parameters; documents what is reset
• docs: add agents.md with key insights for the package
• test: add unit tests for ImuTransformer
• feat: lossless timestamp encoding in LocalVelocityBuffer YAML
• refactor: remove unused tolerance_search_stamp parameter
• docs: fix incorrect doxygen comments
• fix: guard against empty IMU samples in trajectory_from_buffer
• docs: add ROS 2 Lyrical badge row, update Rolling to Ubuntu 26.04 (resolute)
• ci: fix Jazzy Jalisco EOL date in CI workflow comment (May 2024 - May 2029)
• Contributors: Jose Luis Blanco-Claraco

1.16.1 (2026-05-11)

• Merge pull request #6 from MOLAorg/simplify-ci CI: simplify clang-format helpers and use ros: docker images for stable builds

• CI: simplify clang-format helpers and use ros: docker images for stable builds

  • Replace complex Python-based clang_git_format with a simple scripts/formatter.sh supporting --check
  • Standardize formatter to scripts/formatter.sh (renamed from clang-formatter.sh)
  • Simplify check-clang-format.yml to just apt-install clang-format-14 and run the script

  - Use ros:humble / ros:jazzy pre-built images for stable CI builds (faster, no setup-ros needed) Co-Authored-By: Claude Sonnet 4.6 <<noreply@anthropic.com>>

• Merge pull request #5 from MOLAorg/bump-cmake-version bump min req cmake version to 3.22

• CI: sensible job names

• bump min req cmake version to 3.22

• Merge pull request #4 from MOLAorg/feat/window_since2 feat(mola_imu_preintegration): MOLA_IMU_PREINTEGRATION_HAS_WINDOW_SINCE macro + tests

• feat(mola_imu_preintegration): MOLA_IMU_PREINTEGRATION_HAS_WINDOW_SINCE macro + tests Expose MOLA_IMU_PREINTEGRATION_HAS_WINDOW_SINCE at the end of the LocalVelocityBuffer header so downstream packages in separate repos (mola_lidar_odometry's online gravity rebake) can guard usage with __has_include + this macro and stay buildable against older mola_imu_preintegration checkouts. Add unit tests for window_since covering open-ended and bounded windows, the (from, to] boundary semantics, and the empty-result case. Co-Authored-By: Claude Opus 4.7 <<noreply@anthropic.com>>

• Merge pull request #3 from MOLAorg/feat/window_since feat: Add API entry window_since()

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