Fractional approaches based on fractional prefilters in MIMO path tracking design

Abstract

This paper is devoted to the study of robust path tracking and motion control. A method based on fractional prefilter synthesis was already advanced and extended to multivariable systems. In previous study, an approach using fractional prefilter of type Davidson Cole is advanced and tested on MIMO systems. The contribution of this work is to extend the precedent work using a fractional prefilter of type Frequency Band Limited Fractional Differentiator (FBLFD), whose important characteristics are to eliminate overshoots and to have maximum control value at starting time, through two techniques of optimization of prefilter parameters. Firstly, only the prefilter parameters are optimized and in a second stage the global transfer function is assimilated to a FBLFD prefilter and a general optimization is considered. The MIMO-QFT (Multiple Input Multiple Output Quantitative Feedback theory) design mixed with CRONE control methodology is used to select the feedback controller. Thereafter, the procedure of prefilter parameters optimization is explained. A comparative study is discussed through a simulation results applied on a SCARA robot model.