U-model Based 2DoF Multi-variable IMC for Improved Input-Disturbance Rejection: A Case Study on a 2-Link Robot Manipulator

A 2-degree-of-freedom internal model control strategy based on U-model is presented for an unknown multivariable nonlinear systems. The proposed algorithm focuses the case where the noise is added at the input of the system and makes use of a local disturbance rejector. The unknown multivariable nonlinear system is identified by the control oriented U-model and the inverse controller is established using Newton-Raphson method. The proposed algorithm is tested in real-time on a 2-link robot manipulator.