Comparative Analysis of MIMO Adaptive Torque Control for 7-DOF Redundant Robotic Arm

In this paper, a multi-input multi-output (MIMO) direct adaptive torque controller is presented that uses a conventional fuzzy system to provide asymptotic end-effector tracking of a reference path for a 7-DOF redundant robotic arm. In order to find a control strategy that is both robust and efficient with respect to disturbances, sensor noise and poorly understood dynamics, we compare this controller with two other dynamic controllers: single-input, single-output (SISO) PID controller and multi-input, multi-output (MIMO) feedback linearization controller. It is illustrated via simulations that the MIMO adaptive controller, which drives the torque of each joint to control end-effector dynamic variables, can highly improve the robotic performance considering both its kinematics and dynamics while executing motion control or tracking a reference in work space. The efficacy of our control algorithm affects the accuracy, stability and robustness of both motion control and path tracking.