Abstract
The aim of this paper is to propose new robust controls for multivariable parametric uncertain systems and to validate their efficiency in robots path tracking. An automated fractional multivariable Quantitative Feedback Theory is developed. The principle is to obtain desired performances on the basis of controllers and pre filters without using loop shaping process. The proposed approach has benefited from the robustness of fractional control. Indeed, the method is based on a combination of intelligent fractional (PID mu)-D-alpha controller with both diagonal and non-diagonal Frequency Band Limited Fractional Differentiator. A bi-objective optimisation based on genetic algorithm is utilised to find the controller parameters. The developed methodologies are applied to a SCARA robot model and the findings highlight the robustness of the designed controller and the success of the diagonal pre-filter to eliminate loop interactions.