                    -   ! "## $ %" " &# $ ’ % #% %$$ (#%") *+, $ " " ) -./ Robust Decoupling Control for Mobile Manipulators Based on Disturbance Observer Mohamed Jallouli 1 , Mohamed Boukattaya 2 , Tarak Damak 2 1 intelligent Control Design and Optimization of Complex Systems Unit 2 Unité de Commande des Procédés Industriels University of Sfax-Sfax Engineering School (ENIS), BPW,1173 Sfax, Tunisia Mohamed.jallouli@enis.rnu.tn, Mohamed.boukattaya@gmail.com, tarak.damak@enis.rnu.tn Abstract. This paper describes a robust approach exploiting input-output decoupling controller for mobile manipulators. The robust controller consists of using a classical proportional-derivative (PD) feedback structure to stabilize the position error plus an additional disturbance observer (DOB) to compensate external disturbances and uncertainties. Simulation results on a mobile platform with 2-DOF manipulator show the satisfactory performance of the proposed control schemes even in the presence of large modeling uncertainties and external disturbances. keywords. Mobile manipulators, input-output decoupling controller, disturbance observer. 1. Introduction A mobile manipulator refers to the mobile system that has a mobile platform carrying a robotic manipulator. Such systems combine the advantages of mobile platforms and robotic arms to reduce their drawbacks. For instance, the mobile platform extends the arm workspace, whereas an arm offers much operational functionality. Applications for such systems could be found in mining, construction, forestry, planetary exploration, and human assistance [1, 2, 3]. The combined system introduces new issues that are not present in the analysis of each subsystem considered separately. First, the dynamics of the combined system are much more complicated because they include dynamic interactions between mobile platform and manipulator. Second, due to complex structure of the mobile manipulator, the constraints which are valid only for one subsystem will also hold for the whole