CoM Constraint Example Overview

Overview for examples/04_com_constraint_example.py.

What It Demonstrates

• configure_com_constraint() with a 2D support polygon
• Safety margin shrinking of the active polygon
• Optional proximity activation near polygon boundary
• Visual feedback for CoM status (inside/near/outside)

API Walkthrough

The example keeps the same registered-task IK path and adds a hard CoM support-polygon constraint:

Step	API calls	Purpose
Register IK tasks	add_frame_task("ee_task", target_link), add_posture_task("posture")	Track the end-effector marker with a posture bias underneath.
Configure support polygon	configure_com_constraint(...)	Keep the 2D CoM projection inside the active polygon.
Tune relaxation	frame_task.solve_mode, allow_min_error_fallback, posture_task.solve_mode	Explore strict scaling versus minimum-error fallback near constraints.
Solve update	solve_position_step(q_current, target_pose, "ee_task", step_opts)	Apply one IK update using the registered tasks and CoM constraint.
Inspect diagnostics	result.task_modes_effective, result.task_used_fallback, result.task_scales	Display effective mode, fallback use, and scale while the demo runs.

Use examples/04_com_constraint_example.py for the exact slider values, visualization markers, and support-polygon setup.

Run

Install and copy the example bundle once using the Installation Guide. Then run:

cd embodik_examples
python 04_com_constraint_example.py

For repository development, use Pixi:

pixi run python examples/04_com_constraint_example.py

The example defaults to the Panda preset; pass --robot <key> to use another configured model.