SE(3) comparison¶

Documentation / Analysis / Comparison

tools/px4_compare compares two or more recorded runs from one analysis profile. The current CLI intentionally supports the se3 profile only because its controller-comparison semantics are explicitly defined.

Basic usage¶

./tools/px4_compare BAG_A BAG_B [BAG_C ...]

At least two bags are required.

Output directory¶

If all bags are direct children of one sequence study's bags/ directory and that study contains manifest.json, output defaults to:

<study>/comparison/

For standalone bags or bags from different locations, provide an explicit output directory:

./tools/px4_compare \
  /path/to/bag-a \
  /path/to/bag-b \
  --output /path/to/comparison

Offboard alignment¶

Each bag is analyzed independently, then comparison runs are aligned to confirmed PX4 Offboard entry. This avoids treating process start, recorder start, or mode-request time as the common physical origin.

That alignment is especially important because prestream and handoff timing can differ slightly between runs.

Labels¶

When experiment metadata is available, comparison uses the configured handoff/direct-controller identity. The standard labels correspond to:

Acceleration
Attitude
Rate
Geometric
PX4 rate
Geometric physical

Duplicate labels are disambiguated using bag information rather than silently merging runs.

Trajectory-aware metrics¶

Add the configured trajectory name to resolve segment boundaries from the canonical trajectory YAML:

./tools/px4_compare \
  BAG_A BAG_B BAG_C \
  --trajectory full_excitation

This enables segment-aware metrics in addition to the common whole-run physical comparison.

Handoff study example¶

After:

source ros2/runtime_env.sh
./tools/run_sequence config/sequences/se3/handoff_comparison.yaml

compare the finalized bags from that study, for example:

./tools/px4_compare \
  bags/se3_handoff_comparison/<timestamp>/bags/* \
  --trajectory full_excitation

The shell expansion should resolve only finalized bag directories from the study.

Outputs¶

Comparison writes:

comparison/
├── summary.txt
└── *.png

The plot set focuses on common physical quantities that remain meaningful across different handoff boundaries, with segment context when requested.