Journal of the Franklin Institute 340 (2003) 435–460 Independent force and position control for cooperating manipulators K.G. Tzierakis, F.N. Koumboulis* Department of Automation, Halkis Institute of Technology, 34400 Psachna Evias, Greece Abstract The problem of independent force and position control of multitask cooperating manipulators is studied. Each manipulator is in a non-singular configuration and the object can be driven by the contact forces exerted by the end effectors of the manipulators. The design requirement is to control each coordinate of the position of the object as well as each component of the ‘‘rest’’ forces, except the moving forces that are determined uniquely from the object’s position. The present design requirement has been proved to be always satisfied together with asymptotic and BIBO stability. A class of controllers solving the above simultaneous problem is analytically determined. The proposed state feedback controller does not depend upon the specific object dynamics and thus the resulting closed-loop multi- manipulator system performs as required, not only when handling various objects but also when the dynamics of the objects are unknown or hard to compute or disturbed by external forces. r 2003 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. Keywords: Cooperating manipulators; Force/position control; Linear systems; State feedback; Decoupling 1. Introduction Cooperating manipulator systems appear to be a case study of growing interest in the recent literature (see e.g. [1–14,18] and the references therein). Such systems are capable of performing a wide range of tasks that are beyond the capability of a single manipulator such as handling large objects, assembling, etc. In multimanipulator systems, apart from position control, it is important to have direct control of the internal forces between the manipulators and the object handled, since excessive or ARTICLE IN PRESS *Corresponding author. E-mail address: fkms@athena.domi.gr (F.N. Koumboulis). 0016-0032/$30.00 r 2003 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jfranklin.2003.10.002