Title: A discussion on robust multi-variable I/O fractional transfer function of types DC or FBLFD in motion control
Authors: Najah Yousfi-Allagui; Nabil Derbel; Pierre Melchior
Addresses: Control & Energy Management Laboratory (CEM), Sfax, Engineering School, University of Sfax, BP W, 3038 Sfax, Tunisia ' Control & Energy Management Laboratory (CEM), Sfax, Engineering School, University of Sfax, BP W, 3038 Sfax, Tunisia ' UMR 5218 CNRS, Bordeaux Institute of Technology, University of Bordeaux, 351 Cours de la Libération, 33405 Talence Cedex, France
Abstract: Motion control and robust path tracking design are the objective of this paper. The Multi-Input Multi-Output Quantitative Feedback Theory (MIMO-QFT) method is considered. This methodology permits to divide the MIMO system into sub-Multi-Input-Single-Output (MISO) equivalent structures. After obtaining the sub-structures, the objective is the design of the controller and prefilter in order to achieve some specifications. A multi-variable robust path tracking design is already studied based on fractional approaches. These developed approaches are based on two fractional prefilters of types Davidson Cole (DC) and Frequency Band Limited Fractional Differentiator (FBLFD). A new methodology that combines I/O (Input Output) fractional transfer function of types DC and FBLFD with a fractional PID controller tuning is studied in this paper. This approach is based on considering the I/O transfer function matrix as a fractional prefilter of types DC or FBLFD. Using this approach a reduced settling time of the I/O transfer function can be obtained. The multivariable fractional PID controller is tuned based on a multi-objective optimisation using genetic algorithm. The obtained method is tested with a SCARA robot model to demonstrate the efficacy and robustness of our approach.
Keywords: DC prefilter; FBLFD prefilter; fractional PID controller; multi-variable systems; path tracking.
International Journal of Computer Applications in Technology, 2019 Vol.59 No.4, pp.318 - 329
Received: 06 Feb 2018
Accepted: 08 May 2018
Published online: 16 Apr 2019 *