Robust Control Based on Backstepping Passivation Technique for Robotic Manipulators Including Actuator Dynamics

In this paper, a novel robust controller based on passivity theorem and fuzzy logic system is presented for robotic manipulators including actuator dynamics. In the design procedure, backstepping method is used to passivate all the subsystems in the presence of uncertainties which is called backstepping passivation technique. The manipulator and motor dynamics are considered as unknown terms and then approximated via two simple adaptive fuzzy systems. In order to overcome fuzzy approximation errors, external disturbances and un-modeled dynamics, a robustifying signal is added to the passivation procedure such that it is obtained based on an adaptation mechanism. The passivity stability analysis is utilized to guarantee the boundedness of all the states. The feasibility of the proposed voltage-based control law is shown through the simulation results applied on a robotic manipulator equipped with electrical dc motors.