An infinite number of differential drive robots, with wheel radius continuously varying from 0.5 to 1.5, are arranged in a circle. Even though each robot receives exactly the same control inputs, they can be steered asymptotically to the origin. The robots are represented by a black line. Trajectories of 5 specific robots are drawn as well.
![](https://i.ytimg.com/vi/PAdmASfMqAk/maxresdefault.jpg)