Control of flexible manipulators: A survey

Abstract

A survey of the field of control for flexible multi-link robots is presented. This research area has drawn great attention during the last two decades, and seems to be somewhat less “attractive” now, due to the many satisfactory results already obtained, but also because of the complex nature of the remaining open problems. Thus it seems that the time has come to try to deliver a sort of “state of the art” on this subject, although an exhaustive one is out of scope here, because of the great amount of publications. Instead, we survey the most salient progresses – in our opinion – approximately during the last decade, that are representative of the essential different ideas in the field. We proceed along with the exposition of material coming from about 119 included references. We do not pretend to deeply present each of the methods quoted hereafter; however, our goal is to briefly introduce most of the existing methods and to refer the interested reader to more detailed presentations for each scheme. To begin with, a now well-established classification of the flexible arms control goals is given. It is followed by a presentation of different control strategies, indicating in each case whether the approach deals with the one-link case, which can be successfully treated via linear models, or with the multi-link case which necessitates nonlinear, more complex, models. Some possible issues for future research are given in conclusion.

On the Necessity of Including Joint Passive Dynamics in the Impedance Control of Robotic Legs

“…Additionally, if a wider workspace is needed because the form of the steady-state error is known, the control law could be modified to include a feed-forward term to pre-compensate for this error. This approach is commonly used in the control of flexible manipulators [40].…”

Wave-based control of under-actuated flexible structures with strong external disturbing forces

“…[1][2][3][4]) as well as encyclopaedic review papers (e.g. [5][6][7][8]). These books and papers refer in turn to many hundreds of papers on the topic.…”

Timoshenko Beam Theory based Dynamic Modeling of Lightweight Flexible Link Robotic Manipulators

“…The complexity of modeling and control of lightweight flexible manipulators is widely reported in the literature. Detailed discussions can be found in (Kanoh et al, 1986;Baruh & Taikonda, 1989;Book, 1990;Yurkovich, 1992;Book, 1993;Junkins & Kim, 1993;Canudas de Wit et al, 1996;Moallem et al, 2000;Benosman et al, 2002;Robinett et al, 2002;Wang & Gao, 2003;Benosman & Vey, 2004;Dwivedy & Eberhard, 2006, Tokhi & Azad, 2008. In order to fully exploit the potential advantages offered by these lightweight robot arms, one must explicitly consider the effects of structural link flexibility and properly deal with (active and/or passive) control of vibrational behavior.…”