Xd. Ye et Jp. Jiang, ADAPTIVE NONLINEAR DESIGN WITHOUT A-PRIORI KNOWLEDGE OF CONTROL DIRECTIONS, IEEE transactions on automatic control, 43(11), 1998, pp. 1617-1621
Without a priori knowledge of the signs of certain parameters, so-call
ed control directions since they represent effectively the direction o
f motion under any control, a systematic procedure is developed for de
signing global adaptive control of a class of nonlinear systems. The c
lass of systems possesses a triangular structure and can be of arbitra
ry dynamic order. No growth restrictions are imposed.