The paper deals with the global robust feedback syntheses of a bounded control for a disturbed canonical system with an unknown bounded perturbation. Our approach is based on the controllability function method created by V. I. Korobov in 1979. We find a segment where the perturbation can vary and give a positional control which is independent of the perturbation and steers any initial point to the origin for any admissible perturbation from this segment. An estimate for the time of motion is given.