Title
A Fractional-Order Control Approach to Ramp Tracking with Memory-Efficient Implementation
Abstract
We investigate the fractional-order (FO) control of arbitrary order LTI systems. We show that, for ramp tracking or input disturbance rejection, it is advantageous to include an FO integrator to the open-loop if we have to increase the order of integration further than one. With the lower phase-loss of the FO integrator it is easier to guarantee a desired phase margin. Furthermore the flat phase response around the crossover-frequency (iso-damping property) can be achieved for a wider frequency range such that the closed-loop is more robust wrt. amplitude and phase margins. The drawback of the FO approach is the increased implementation effort and the algebraic decay, which slows down the transient response for larger times. The algebraic decay can be reduced by placing the fractional closed-loop poles to the corresponding integer-order poles. The remaining FO transfer zeros are compensated by an additional filter. We acheieve a more efficient implementation by reducing the memory needed by a direct discretization of the Grünwald-Letnikov definition. As the controller design is done in the frequency domain, we investigate the effect of the different memory truncations. All strategies are demonstrated by simulation.
Year
DOI
Venue
2020
10.1109/AMC44022.2020.9244309
2020 IEEE 16th International Workshop on Advanced Motion Control (AMC)
Keywords
DocType
ISSN
fractional-order control approach,ramp tracking,memory-efficient implementation,arbitrary order LTI systems,input disturbance rejection,FO integrator,open-loop,lower phase-loss,desired phase margin,flat phase response,crossover-frequency,iso-damping property,phase margins,FO approach,algebraic decay,transient response,closed-loop poles,remaining FO transfer zeros,controller design,frequency domain,memory truncations,integer-order poles,frequency range
Conference
1943-6572
ISBN
Citations 
PageRank 
978-1-7281-3190-0
0
0.34
References 
Authors
3
5
Name
Order
Citations
PageRank
Christoph Weise100.68
Rafael Tavares200.34
Kai Wulff334021.94
Michael Ruderman49517.14
Johann Reger54017.29