Paper Info
Title
Force control in a parallel manipulator through virtual foundations.
Abstract
An overwhelming controller provides robustness against uncertain parameters, disturbances and un-modelled dynamics. A simplified inverse dynamics model is used in the present paper to develop an overwhelming controller for a parallel manipulator (a Stewart platform), where the controller accommodates modelling uncertainties such as the simplifications made for development of the inverse model in order to improve the computational efficiency. Such a control strategy leads to good trajectory tracking accuracy in the presence of unknown disturbances. However, in addition to trajectory tracking performance, the controller for a Stewart platform should also be able to control or limit the interaction forces in applications such as robot assisted surgery and low-impact docking. The environmental forces can be accommodated during the interaction period by modulating the impedance at the interface of manipulator and environment through virtual flexible foundations. The positional error induced during the force control phase can be recovered during the free flight or idle phase. While this approach has been used successfully in the past to control serial manipulators, the closed loop kinematic architecture in a parallel manipulator introduces many difficulties. This paper proposes a modified overwhelming control scheme for parallel manipulators with compensations for interaction force control and positional error recovery. Bond graph modelling is used as an integrated model and controller development tool. Force controlled machining on a spherical surface, which is akin to a surgical operation, is considered as an example application of the developed control strategy. The simulation results from the bond graph model of the controlled Stewart platform are presented to demonstrate the performance of the developed hybrid position force controller.
Year
DOI
Venue
2012
10.1177/0959651812442604
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING
Keywords
Field
DocType
Parallel manipulator,overwhelming control,virtual foundation,force control,bond graph
Parallel manipulator,Control theory,Control theory,Robustness (computer science),Control engineering,Inverse dynamics,Engineering,Robot,Stewart platform,Trajectory,Mobile manipulator
Journal
Volume
Issue
ISSN
226
I8
0959-6518
Citations 
PageRank 
References 
4
0.49
25
Authors
4
Name
Order
Citations
PageRank
Tarun Kumar Bera1102.90
Rochdi Merzouki211725.83
Belkacem Ould Bouamama311719.31
Arun K. Samantaray4325.37