The controls team pulled it together at the last minute and submitted a solution to the problem of pushing the leg cart in a smooth, controlled fashion. “Controlled” in this context means that it can’t lift itself off the ground and foot slippage has to be minimal.
The control code here is 100% student written, from the joint controllers to the kinematics to the trajectory generation. Go team!
For reference, the dots are 1m apart. The simulation makes it clear that we really need to watch out for reaction torques about the yaw axis (note that the whole cart twists itself… this is with a relatively realistic friction coefficient on the wheels). We will probably want to look at this more closely before putting anything on hardware.