Fault-Tolerant Sliding Mode Controller For a 4 Degree of Freedom Robotic Manipulator

This paper presents an active fault-tolerant control system for a 4 degree of freedom robotic manipulator based on the sliding mode controller via linear extended state observer. Firstly, mathematical equations related to dynamic of robotic manipulator and mathematical model of the fault occurring during the operation of the system are described. This active fault-tolerant controller consists of linear extend state observer with a view to estimating uncertain factors and sliding mode controller which contributes to the precision of the manipulator in tracking the desired trajectory. Uncertain factors which are put into consideration are related to friction and the loss of performance. Finally, some simulations on the 4-DOF robotic manipulator are implemented in order to demonstrate the superiority of the proposed controller compared to other controllers.