Moving away from big expensive robots to light homemade things (that can bump, fall on or be lifted by us with no harm) is a great way to revisit past design decisions and explore alternatives. Being incented to make robots cheaper, reduce their number of actuators and complexity, we end up with new morphologies that don't fit exactly the bill of previous ideas. Interesting things lie in this not exactly! In this presentation, we take a look at two existing ideas that are important in legged locomotion, contact stability and whole-body control, and see how they fit Upkie, a wheeled biped with a low-cost onboard computer. Another idea comes to the rescue: the theoretical and empirical evidence that balance control is a low-frequency task. We build open source software upon it that allows us to prototype most of our robot's brain in Python, while achieving its goals of balancing, crouching and going places.
|Wrench cone inequalities for fixed surface contacts|
|Whole-body impedance control on IHMC's Atlas|
|Whole-body admittance control with internal forces|
|Walking controller with whole-body admittance control|
|Whole-body control of Ascento|