Gi. Gomez et Gc. Goodwin, GENERALIZATION OF INTEGRAL CONSTRAINTS ON SENSITIVITY TO TIME-DELAY SYSTEMS, IEEE transactions on automatic control, 43(7), 1998, pp. 1008-1012
In the above-mentioned paper,(1) a robust tracking control using a nom
inal feedback controller and a variable structure compensator for a ri
gid robotic manipulator with uncertain dynamics was presented. Some co
mments on this issue are made here to point out a serious mistake and
the untenable main results in the paper.