Configuration¶

Pelorus is configured with a single ratslang file. The binary ships the complete default configuration, so a file of your own only has to carry what differs from it.

flowchart LR
    A["built-in defaults<br/>pelorus_core/default.rl"] --> B["your pelorus.rl<br/>-c / --config-path"] --> C["-o KEY=VALUE<br/>on the command line"] --> D["effective configuration"]

Each stage wins over the one to its left. Anything you leave out keeps its default, so most configuration files are short.

Generating a file¶

# prepend 'ros2 run pelorus' if you only have the ROS 2 package installed
pelorus config generate recommended > pelorus.rl

This writes the starter configuration, which holds the options that depend on your hardware or on what you want out of the run. pelorus config generate full writes every option instead, which is useful to read but unwieldy to maintain.

For editing, there is a Ratslang extension for VS Code and plugins for Neovim and Helix.

Validating¶

pelorus config verify pelorus.rl

Nothing printed means the file is valid. The path defaults to pelorus.rl, and - reads from standard input. Pelorus runs the same validation at start-up, where a problem either stops the run or produces a warning. Running it yourself catches mistakes earlier.

Unknown keys are an error. The configuration is type checked and usage checked at compile time, so an invalid configuration cannot reach the pipeline at all.

Overriding a single value¶

Any key can be overridden on the command line. The flag is repeatable and takes ratslang syntax, units included:

pelorus offline my_bag -c pelorus.rl \
  -o registration.map.resolution=0.25m \
  -o output.odometry_rate=ImuAndLidar

Overrides are applied after the file, so they win over both the file and the defaults. This is the right way to sweep a parameter without editing the file between runs.

Writing values¶

Blocks can be written nested or as a dotted path, whichever reads better:

registration.map.resolution = 50cm

registration {
  map {
    resolution = 50cm
  }
}

Where to look next¶

• The starter configuration is what pelorus config generate recommended writes, with the comments intact.
• The reference documents every option, generated from the same file the binary embeds.
• Calibration covers the IMU options whose values have to be measured.