“…The principle is to track the object's motion and to design a mirror-like motion of the object's motion for the robot, and regulating the object at impacts. Similarly to the OGY method, this seems to mainly apply to juggling systems which satisfy M 2 (q) ≫ M 1 (q) (hence q2 remains continuous at impacts, an assumption that is widely spread in juggling systems analysis [334,159,257,59,158,216,141,335,70,275,327,140]). The dead-beat controller designed in [13,14] is shown to reduce to a mirror algorithm when this assumption holds.…”