At last I have published the information of the paper “ Motion Control of Differential Wheeled Robots with Joint Limit Constraints” and the slides for the presentation at the ROBIO 2011 conference:
Here there is a video of the locomotion of a variation of the Miniskybot printbot with limited wheels. Even if the wheels cannot turn freely, the robot can achieve locomotion:
It opens the door to new research lines such as fault-tolerant motion in mobile robots, locomotion with non-standard rounded wheels, bioinspired controllers for limited wheels and fault-tolerant path planning.