gravity-comp

Holds both arms in gravity-compensation mode so you can move them by hand.

Each free joint has no position stiffness, light damping (--kd) and a torque that cancels the modelled gravity.
Joints not in the free set hold their current position with their configured kp and kd, and are still gravity-compensated.
The grippers hold their current positions softly.

This command is configured through draccus (see Command configuration). The per-joint gains, masses and stiffness are on the nested axol config, such as --axol.left_stiffness or --axol.left.elbow.mass. They are listed in full in Gravity Compensation Config Parameters.

Flag	Description
`--left_channel <ch\|null>` / `--right_channel <ch\|null>`	CAN channel per arm; `null` disables that arm.
`--free_joints [J1,J2,...]`	Joints to leave free, e.g. `[WRIST_3]` or `[SHOULDER_1,ELBOW]`. The other arm joints hold in place. Default `null`: all 7 joints free.
`--record PREFIX`	Record the arm joint positions and torques to `PREFIX_gc.npz`, to build a reference motion with `motion.build`. Unset records nothing.
`--kd FLOAT`	Damping on free joints (Nm·s/rad). Higher feels less floppy and slows any slow drift. Default 0.5
`--rate_hz FLOAT`	Control loop rate in Hz (default: 250)
`--log_level {DEBUG,INFO,WARNING,ERROR}`	Default: `INFO`
`--config_path PATH`	Load a whole-config JSON/YAML file. Flags override it.
`--settings_path PATH` / `--no_settings`	Read another shared settings file, or ignore it. By default `~/.almond/settings.json` applies, beneath `--config_path` and the flags.

axol gravity-comp                                 # all 7 joints free, both arms
axol gravity-comp --right_channel null            # left arm only, all joints free
axol gravity-comp --kd 1.0                        # heavier damping
axol gravity-comp --free_joints [WRIST_3]         # only WRIST_3 free; everything else held rigid
axol gravity-comp --right_channel null --free_joints [SHOULDER_1,WRIST_3]   # one-arm, two-joint isolation
axol gravity-comp --record demo1                  # hand-guide a motion, then: axol motion.build

Use --free_joints to test gravity compensation one joint at a time. Only the named joints move freely, and the rest of the arm holds its pose. With --record, a bare name is saved in ~/.almond/recordings/. The file keeps the last 5 minutes or so and is written when the session ends.

If the arm sags or pushes back, tune the per-joint mass and com fields on AxolConfig. See Gravity compensation.

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gravity-comp