Comprehensive Unified Control Strategy for Underactuated Two-Link Manipulators

Author

Lai, Xu-zhi ; She, Jin-hua ; Yang, Simon X. ; Wu, Min

Author_Institution

Sch. of Inf. Sci. & Eng., Central South Univ., Changsha

Volume

39

Issue

2

fYear

2009

fDate

4/1/2009 12:00:00 AM

Firstpage

389

Lastpage

398

Abstract

This paper presents a unified treatment of the motion control of underactuated two-link manipulators, including acrobots and pendubots. The motion space is divided into two areas: swing-up and attractive; and control laws are designed for each. First, a control law based on a weak-control Lyapunov function (WCLF) is employed to increase the energy of and control the posture of the actuated link in the swing-up area. Next, one parameter of the WCLF is chosen to be a nonlinear function of the state to avoid singularities. Then, another parameter of the control law is adjusted based on the state to improve the control performance. Finally, an optimal control law is designed for the attractive area. Stability is guaranteed in the swing-up area by the use of a WCLF based on LaSalle´s invariance principle. Moreover, the global stability of the control system is guaranteed by integrating the WCLF and a nonsmooth Lyapunov function.

Keywords

Lyapunov methods; manipulators; motion control; nonlinear control systems; optimal control; stability; LaSalle invariance principle; acrobots; global stability; motion control; nonlinear function; nonsmooth Lyapunov function; pendubots; underactuated two-link manipulators; unified control strategy; weak-control Lyapunov function; Acrobot; LaSalle´s invariance principle; nonsmooth Lyapunov function (NSLF); singularity; stabilization; underactuated manipulator; weak-control Lyapunov function (WCLF);

fLanguage

English

Journal_Title

Systems, Man, and Cybernetics, Part B: Cybernetics, IEEE Transactions on

Publisher

ieee

Conference_Location

12/16/2008 12:00:00 AM

ISSN

1083-4419

Type

jour

DOI

10.1109/TSMCB.2008.2005910

Filename

4717257