International Federation of Automatic Control
3rd IFAC SYMPOSIUM on SYSTEM, STRUCTURE and CONTROL

Foz do Iguassu, Brazil October 17th - 19th, 2007

Friday Morning

Session FM2: Non-linear Systems Applications


Chair: Lakmal Seneviratne - United Kingdom
Co-chair: Claude Moog - France
Room: Montevideo
2007-10-19
From 10:00 to 12:00
Nonlinear Control Design for the Acrobot
Jiri Zikmund; Sergej Celikovsky; Claude H. Moog
Contact: Jiri Zikmund - Czech Republic
10:20-10:40
Abstract:
!A new control concept for a class of simple underactuated mechanical system, the so-called Acrobot, is presented here. This system consists of the two links connected by the rotary actuated joint. Despite being seemingly simple system, the Acrobot comprises many important difficulties when controlling the most challenging underactuated system - the walking robot. This paper presents the exponential stabilization of the acrobot from the wide range of initial positions, much wider than typical local results in the current literature. Moreover, contrary to standard control methods available for stabilization of such systems, the control presented herein provides a large domain of attraction and avoids any switching scheme. This result is achieved thanks to special transformation of the system combined with certain robust stabilization technique. The proposed control is then compared with other approaches based on different transformations and presented in earlier publications. Besides theoretical proofs, our approach is supported by numerical simulations. Copyright © 2007 IFAC.