“…Moreover, most model-based controller design methods neglect, on the one hand, the significant non-linear variations in the dynamics of this type of manipulator when operating at high speeds or under rapid payload changes (Bellezza et al, 1991;Li et al, 1998;Mohamed and Tokhi, 2004). On the other hand, most model-based studies do not incorporate the very significant non-linear effects of friction at low speeds: an effect capable of generating additional modes of oscillations in the system (Hisseine and Lohmann, 2001;Kim and Parker, 1993;Rokui and Khorasani, 1997). Besides, several robust control strategies and on-line identification techniques have been reported for improving controller performance under model uncertainties, bonded disturbance effects and friction (Atashzar et al, 2010;Erfanian and Kabganian, 2009;Lee et al, 2007;Mamani et al, 2011); however, there is merit in the continuing evaluation of the real-time cost of implementing these robust schemes.…”