Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/55656
Title: Direct tip regulation of a single-link flexible manipulator by adaptive variable structure control
Authors: Xu, J.-X. 
Cao, W.-J.
Issue Date: Jan-2001
Source: Xu, J.-X.,Cao, W.-J. (2001-01). Direct tip regulation of a single-link flexible manipulator by adaptive variable structure control. International Journal of Systems Science 32 (1) : 121-135. ScholarBank@NUS Repository.
Abstract: Direct tip position regulation of flexible manipulators is one of the most challenging control tasks. There are mainly three problems to be addressed in order to achieve good performance. The first two control problems arise owing to the unstable zeros and complex poles in the system nominal part which is dominated by a transfer function. The third problem is the existence of unstructured uncertainties owing to the truncation of high-order resonance modes and system nonlinearities. Because of the above difficulties and in particular the non-minimum-phase nature, tip regulation task of flexible manipulators is usually solved indirectly: direct control of joint angle and suppression of the flexible link vibration. The aim of this study is to investigate the direct approach for tip regulation. Since the tip transfer function contains unstable zeros and the first few dominant flexible modes (complex poles), a reference model of the same order is selected which does not have any finite zero but all negative real poles. In order to force the system to follow the reference model in the presence of the unstructured uncertainties, a variable structure controller is adopted in which the switching surface is derived from the reference model. When in sliding mode, the system performs as the reference model. Hence there will be no vibration and the tip position regulation can be achieved when the system approaches steady state. To improve the system responses further, an adaptation law with dead-zone scheme is combined with the variable structure controller. Simulation results show that link vibrations have been eliminated and the control profile is fairly smooth.
Source Title: International Journal of Systems Science
URI: http://scholarbank.nus.edu.sg/handle/10635/55656
ISSN: 00207721
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Page view(s)

15
checked on Dec 7, 2017

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.