I want to give external force based on heel contact.

[Kakeru Yamasaki]

Based on tutorial 4C, I want to use GaitStateController to give a perturbation to a person when the heel of the right foot is placed on the ground.
However, I don't know how to achieve it using GaitStateController (or any other function). If anyone has a good idea, please let me know.

[Thomas Geijtenbeek]

The easiest way to do that is via a ScriptController. You can use the contact_force() method on the foot body to detect the heel-strike events, and then use the add_external_force() method on the pelvis to add the perturbation force.

You can check Tutorial 6c for inspiration, even though your script will probably more straightforward than that.

[Kakeru Yamasaki]

Thank you for your reply!!
The tutorial was very easy to understand, and I was able to get it working successfully in the end. Thank you very much!!!

[Thomas Geijtenbeek]

Thank you!