scholarly journals Design of Low-Voltage FO-[PD] Controller for Motion Systems

2021 ◽  
Vol 11 (2) ◽  
pp. 26
Author(s):  
Rafailia Malatesta ◽  
Stavroula Kapoulea ◽  
Costas Psychalinos ◽  
Ahmed S. Elwakil

Fractional-order controllers have gained significant research interest in various practical applications due to the additional degrees of freedom offered in their tuning process. The main contribution of this work is the analog implementation, for the first time in the literature, of a fractional-order controller with a transfer function that is not directly constructed from terms of the fractional-order Laplacian operator. This is achieved using Padé approximation, and the resulting integer-order transfer function is implemented using operational transconductance amplifiers as active elements. Post-layout simulation results verify the validity of the introduced procedure.

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shuhuan Wen ◽  
Xiao Chen ◽  
Yongsheng Zhao ◽  
Ahmad B. Rad ◽  
Kamal Mohammed Othman ◽  
...  

We present a fractional order PI controller (FOPI) with SLAM method, and the proposed method is used in the simulation of navigation of NAO humanoid robot from Aldebaran. We can discretize the transfer function by the Al-Alaoui generating function and then get the FOPI controller by Power Series Expansion (PSE). FOPI can be used as a correction part to reduce the accumulated error of SLAM. In the FOPI controller, the parameters (Kp,Ki,  and  α) need to be tuned to obtain the best performance. Finally, we compare the results of position without controller and with PI controller, FOPI controller. The simulations show that the FOPI controller can reduce the error between the real position and estimated position. The proposed method is efficient and reliable for NAO navigation.


2017 ◽  
Vol 27 (01) ◽  
pp. 1850006 ◽  
Author(s):  
Mohammad Rafiq Dar ◽  
Nasir Ali Kant ◽  
Farooq Ahmad Khanday

Realization of fractional-order double-scroll chaotic system using Operational Transconductance Amplifiers (OTAs) as active elements are presented in this paper. The fractional-order double-scroll chaotic system has been studied before as well using passive RC-ladder and tree-based structures but in this paper the requisite fractional-order integration has been accomplished through an integer-order multiple-feedback topology. As compared to double or multiple scroll chaotic systems existing in the open literature, the proposed realization offers the advantages of (a) low-voltage implementation, (b) integrablity as the design is resistor- and inductor-less and only grounded components have been employed in the design, and, (c) electronic tunability of the fractional order, time-constants and gain factors. In order to demonstrate the usefulness of the chaotic system, a simple secure message communication system has been designed and verified for its operation. The theoretical predictions of the proposed implementations have been verified by using 0.35[Formula: see text][Formula: see text]m complementary metal oxide semiconductor (CMOS) process file provided by Austrian Micro System (AMS).


2017 ◽  
Vol 27 (02) ◽  
pp. 1850023 ◽  
Author(s):  
Amr M. AbdelAty ◽  
A. G. Radwan ◽  
A. S. Elwakil ◽  
C. Psychalinos

In this paper, a fractional-order dynamic model of the photovoltaic (PV) solar module is introduced. Dynamic modeling of PV solar modules is useful when used in switching circuits and grid-connected situations. The dynamic elements of the proposed model are a fractional-order inductor and capacitor of two independent orders which allow for two extra degrees of freedom over the conventional dynamic model. The step response and transfer function of the load current are investigated for different orders under resistive and supercapacitor loading conditions. Closed-form expressions for the time response of the load current at equal orders of capacitor and inductor are derived. Stability analysis of the load current transfer function is carried out for different orders and loading conditions. The regions for pure real and pure imaginary input admittance scenarios are calculated numerically for both resistive and supercapacitor load cases. It is found that the order of the inductor has a dominant effect on the responses. As a proof of concept, the model is fitted to experimental data to show its flexibility in regenerating the actual response. The fitted fractional-order model response is compared to optimized integer-order ones from literature showing noticeable improvement.


Author(s):  
Zhifeng Pan ◽  
Xiaohong Wang ◽  
Thi Thu Giang Hoang ◽  
Ying Luo ◽  
Yangquan Chen ◽  
...  

In comparison with the traditional controller PID, the fractional order controller PIλDμ is added with two parameters (μ and λ), that increases the flexibility of the controller. The larger adjustable space makes it more favorable to the control of the nonlinear system like the three-phase grid-connected inverter. However, since the fractional calculus operator is an irrational function on the complex plane, it can’t be implemented directly in simulation or in practical applications. In this paper, the advantages of the fractional order controller PIλDμ will be analyzed, then the fractional calculus operator is fitted by the frequency domain analysis method. Based on the vector method, the fractional order controller PIλDμ of the grid-connected inverter is designed. Simultaneously, the optimal controller parameters are searched with the ITAE and IAE as the performance index. And finally, the results are compared with those of the traditional controller PID. In consideration of the defects of fractional algorithm and single discretization method, a hybrid discretization method is proposed in order to ensure that the discretized controller can keep the same time-domain response and frequency characteristics as the designed controller. The experimental results show that the proposed method has the dynamic and static characteristics better than the traditional controller PID, which proves that the application of fractional order controller in three-phase grid-connected inverter is effective and feasible.


Sign in / Sign up

Export Citation Format

Share Document