Two-Time Scale Fuzzy Logic Controller With Vibration Stabilizer for Robot Manipulators with Oscillatory Bases

This paper deals with active damping control problems of robot manipulators with oscillatory bases. A first investigation of two-time scale fuzzy logic controller with stabilizer for such structures has been proposed, where the dynamics of a robotic system is strongly affected by disturbances due to the base oscillation. Under the assumption of two-time scale, its stability and design procedures are presented for a multiple link manipulator with multiple dimension oscillation. The slow-subsystem fuzzy logic controller dominates the trajectory tracking, and the fast-subsystem controller will damp out the vibration of the oscillatory bases. It can be guaranteed the stability of the internal dynamics by adding a boundary-layer correction based on singular perturbations approach. Experimental results have shown that the proposed control model offers several implementation advantages such as reduced effect of overshoot and chattering, smaller steady state error, and a fast convergent rate. The results of this study can be feasible to various mechanical systems, such as mobile robot, gantry cranes, underwater robot, and other dynamic systems mounted on oscillatory bases.