Foot force control
In Stephane's paper, there is the notion of Foot Force Difference Control. This is only during double support phase, and it only concerns the vertical z-axis.
Thanks to the last property, a simple heuristics is certainly enough to distribute the vertical component between right and left. Therefore, it can be tested even before having solved the problems with the QP distribution. I am testing it in simulation and it seems to work well.
Additionally, I am implementing an admittance control on the swing foot, so that if the impact force is too string this will mitigate it. Simulations results seem encouraging