Title :
Feedback limitations in nonlinear systems: from Bode integrals to cheap control
Author :
Seron, M.M. ; Braslavsky, J.H. ; Kokotovic, P.V. ; Mayne, D.Q.
Author_Institution :
Dept. of Electr. & Comput. Eng., Newcastle Univ., NSW, Australia
fDate :
4/1/1999 12:00:00 AM
Abstract :
Feedback limitations of nonlinear systems are investigated using the cheap control approach. The main result is that in the limit, when the control effort is free, the smallest achievable L2 norm of the output is equal to the least amount of control energy (L2 norm) needed to stabilize the unstable zero dynamics. This nonlinear result is structurally similar to an earlier linear result by Qiu and Davison (1993), which, in turn, is connected with a Bode-type integral derived by Middleton (1991)
Keywords :
Bode diagrams; feedback; nonlinear control systems; stability; Bode integrals; Bode-type integral; L2 norm; cheap control approach; feedback limitations; nonlinear systems; unstable zero dynamics; Adaptive control; Control engineering; Control systems; Linear feedback control systems; Linear systems; Nonlinear control systems; Nonlinear dynamical systems; Nonlinear systems; Optimal control; State feedback;
Journal_Title :
Automatic Control, IEEE Transactions on
