Loading...
Search for:
crossover-frequency
0.008 seconds
Desirably adjusting gain margin, phase margin, and corresponding crossover frequencies based on frequency data
, Article IEEE Transactions on Industrial Informatics ; Volume 13, Issue 5 , 2017 , Pages 2311-2321 ; 15513203 (ISSN) ; Tavazoei, M. S ; Sharif University of Technology
Abstract
This paper presents an analytical method to tune a fixed-structure fractional-order compensator for satisfying desired phase and gain margins with adjustable crossover frequencies. The proposed method is based on the measured frequency data of the plant. Since no analytical model for the plant is needed in the compensator tuning procedure, the resulted compensator does not depend on the order and complexity of the plant. Also, sufficient conditions for the existence of a compensator with no zero and pole in the right half-plane for satisfying the aforementioned objectives are analytically derived. Furthermore, different hardware-in-the-loop experimental results are presented to show the...
Analytical Design of Fixed-structure Fractional-order Controllers in Frequency Domain
, Ph.D. Dissertation Sharif University of Technology ; Tavazoei, Mohammad Saleh (Supervisor)
Abstract
Due to the simplicity and generality, design of feedback control systems in the frequency domain is among the most prominent topics in the control systems engineering. The problem of compensation means properly adjusting the loop frequency response at critical frequencies. Considering the point that the traditional methods usually use trial and error procedures for compensation, analytical design of fixed-structure controllers for exactly adjusting such values has great importance. Benefitting from the capability of fractional-order dynamics, the compensation problem is studied from three aspects in this thesis. At first according to the importance of adjusting the system frequency response...
Robust fractional-order compensation in the presence of uncertainty in a pole/zero of the plant
, Article IEEE Transactions on Control Systems Technology ; Volume 26, Issue 3 , May , 2018 , Pages 797-812 ; 10636536 (ISSN) ; Tavazoei, M. S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper deals with robust frequency compensation in control of fractional-order plants with an uncertain fractional pole/zero (or specially in control of integer-order plants with an uncertain pole/zero). The specifications yielding a robust compensation are introduced, and fractional-order compensators are proposed for satisfying these specifications in the set-point tracking control of the above-mentioned plants. Also, the infinite ranges for the uncertain parameter of the plant, in which satisfying robust compensation specifications is possible by the obtained compensators, are exactly specified. Furthermore, the stability of the obtained control system is analytically analyzed....
Frequency data-based procedure to adjust gain and phase margins and guarantee the uniqueness of crossover frequencies
, Article IEEE Transactions on Industrial Electronics ; Volume 67, Issue 3 , 2020 , Pages 2176-2185 ; Tavazoei, M. S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
Analytical data-driven tuning procedures with the aim of adjusting the values of frequency-domain specifications, e.g., gain margin, phase margin, and corresponding crossover frequencies, are among the most popular control techniques in industrial control. But, the multiplicity of crossover frequencies, as an Achilles' heel in these procedures, may cause that the obtained control system does not meet the intended frequency-domain objectives. Motivated by this fact, this paper improves a newly proposed data-driven tuning procedure for arbitrarily setting the values of gain and phase margins and crossover frequencies, in the viewpoint of guaranteeing the uniqueness of crossover frequencies....