Todays, use of combination of two or more methods was considered to control of systems. In this paper ispresented how to design of a nonlinear H∞ (NL-H∞) controller for flexible joint robot (FJR) based on boundedUKF state estimator. The UKF has more advantages to standard EKF such as low bios and no need toderivations. In this research, based on spong primary model for FJRs, same as rigid robot...