Tuning rules: Graphical analysis and experimental validation of a simplified fractional order controller for a class of open‐loop unstable systems

2021 ◽  
Author(s):  
Prakash Dwivedi ◽  
Sandeep Pandey
Mathematics ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 1166 ◽  
Author(s):  
Eva-Henrietta Dulf

Classical fractional order controller tuning techniques usually establish the parameters of the controller by solving a system of nonlinear equations resulted from the frequency domain specifications like phase margin, gain crossover frequency, iso-damping property, robustness to uncertainty, etc. In the present paper a novel fractional order generalized optimum method for controller design using frequency domain is presented. The tuning rules are inspired from the symmetrical optimum principles of Kessler. In the first part of the paper are presented the generalized tuning rules of this method. Introducing the fractional order, one more degree of freedom is obtained in design, offering solution for practically any desired closed-loop performance measures. The proposed method has the advantage that takes into account both robustness aspects and desired closed-loop characteristics, using simple tuning-friendly equations. It can be applied to a wide range of process models, from integer order models to fractional order models. Simulation results are given to highlight these advantages.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2928 ◽  
Author(s):  
Arkadiusz Mystkowski ◽  
Andrzej Kierdelewicz

An industrial-oriented water tank level control system with PLC- and Simulink-based fractional-order controller realizations is presented. The discrete fractional-order and integer-order PID implementations are realized via the PLC and Simulink simulator. The benefits of the fractional-order PID compared to the integer-order PID control are confirmed by the hardware-in-the-loop (HIL) simulations and experiments. HIL simulations are realized using real-time communication between PLC and Simulink. The fractional-order controller is obtained for a desired phase/gain margin and validated via HIL simulations and experimental measurements.


Modified pendulum is a commonplace trial territory for the investigation of control hypotheses. The adjusting of a reversed pendulum by moving a truck along a flat track is a commonplace issue in the zone of control. So as to improve the capacity of PID controller reacting for the heap unsettling influence, controller tuning guidelines assume fundamental job. This work engaged with enhancement of the PID control parameters for controlling the pendulum in upstanding position particularly with the best heartiness and contrasting it tentatively and ideal settings of a fragmentary PIλDμ controller which can satisfy five distinctive plan details for the shut circle framework, exploiting the fragmentary requests, λ and μ. Since these partial controllers have two parameters more than the customary PID controller improves the presentation of the framework. The pendulum has been adjusted in the upstanding position utilizing the two techniques and the exploratory outcomes are analyzed and announced. The recreation just as exploratory aftereffects of ordinary PID controller demonstrate that the arrangement of new and tuned controller parameters are furnishing the outcomes with better shut circle execution thought about than other tuning methods. And furthermore the control ability and the framework execution furnished by fragmentary request PID controller with the determined new arrangement of parameters has been tentatively demonstrated that the partial request PID controller gives controller execution relatively superior to the customary one along these lines it isn't just controlling the ongoing framework with better adjustment and following control yet additionally have heartiness to aggravations


2018 ◽  
Vol 41 (8) ◽  
pp. 2319-2327 ◽  
Author(s):  
S Seyedtabaii ◽  
S Zaker

The aim is to acquire low variance roll responses (performance robustness) of control of an Aerosonde despite the high level of tolerances in aerodynamic parameters and working speed. In this respect, fractional-order proportional plus integral and derivative (FOPID) is a valuable option; others are H∞ and μ synthesis. FOPID can tolerate system uncertainty by maintaining a wide open-loop flat phase margin band. All three methods are worked out using the linearized system model and deliver (at least initially) high-integer-order controllers. The uncertainty level is not explicitly considered in H∞, but it may be presented in the μ synthesis and FOPID. The uncertainty presentation in the modified fractional-order controller (mFOC) design is through a Φd curve. The Φd curve is fitted to the mean of the upper and lower bands of the phase margins distribution map of the random systems. It is shown that the mFOC design perfectly secures the desired phase margin flatness. The controllers are applied to the roll of an unmanned aircraft vehicle with a 30% tolerance in the aerodynamic parameters, and operation speed and robustness in performance is evaluated. The simulation results indicate that the mFOC design renders more coherent responses than what H∞ and µ synthesis design deliver. This is confirmed through extensive simulations.


2021 ◽  
Vol 4 (3) ◽  
pp. 50
Author(s):  
Preeti Warrier ◽  
Pritesh Shah

The control of power converters is difficult due to their non-linear nature and, hence, the quest for smart and efficient controllers is continuous and ongoing. Fractional-order controllers have demonstrated superior performance in power electronic systems in recent years. However, it is a challenge to attain optimal parameters of the fractional-order controller for such types of systems. This article describes the optimal design of a fractional order PID (FOPID) controller for a buck converter using the cohort intelligence (CI) optimization approach. The CI is an artificial intelligence-based socio-inspired meta-heuristic algorithm, which has been inspired by the behavior of a group of candidates called a cohort. The FOPID controller parameters are designed for the minimization of various performance indices, with more emphasis on the integral squared error (ISE) performance index. The FOPID controller shows faster transient and dynamic response characteristics in comparison to the conventional PID controller. Comparison of the proposed method with different optimization techniques like the GA, PSO, ABC, and SA shows good results in lesser computational time. Hence the CI method can be effectively used for the optimal tuning of FOPID controllers, as it gives comparable results to other optimization algorithms at a much faster rate. Such controllers can be optimized for multiple objectives and used in the control of various power converters giving rise to more efficient systems catering to the Industry 4.0 standards.


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