I built a model of the leg cart/leg test stand in our simulation environment. Leg dimensions, masses, ranges of motion and actuator force limits are all in the model.
On the meatspace implementation the inputs to the system will be valve commands, which roughly correlate to flow rates. In an attempt to model this, we present actuator linear rates as the inputs to the model.
This week we assigned the controls team the task of controlling the cart and making it row itself along in a straight, controlled line. We’ve got groups working on joint level control, forward kinematics, inverse kinematics, trajectory generation and the nebulous “high level”. As a starting point I put together a little demo with the leg cart rowing itself along very poorly:
For reference, the cart weighs about 600 pounds and the pins weigh about 200 pounds and are 6 feet tall. When this thing exists in real life, we will have to be very careful… More videos next week when the student solution starts coming together!
~James