scholarly journals Design of FOPID controller for higher order continuous interval system using improved approximation ensuring stability

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
P. D. Dewangan ◽  
V. P. Singh ◽  
S. L. Sinha
Keyword(s):  
Controller Design ◽  
Test System ◽  
Higher Order ◽  
Phase Margin ◽  
Order Interval ◽  
Single Input Single Output ◽  
Single Output ◽  
Multipoint Padé Approximation ◽  
Single Input ◽  
Reduce Order Modeling

AbstractThis contribution deals with the design of a fractional-order proportional-integral-derivative (FOPID) controller through reduce-order modeling for continuous interval systems. First, a higher order interval plant (HOIP) is considered. The reduced-order interval plant (ROIP) for considered HOIP is derived by multipoint Padé approximation integrated with Routh table. Then, FOPID controller is designed for ROIP to satisfy the phase margin and gain cross over frequency. Thus obtained FOPID controller is implemented on HOIP also to validate the performance of designed FOPID on HOIP. A single-input-single-output (SISO) test system is taken up to elaborate the entire process of controller design. The outcomes affirm the validity of the designed FOPID controller. The designed FOPID controller produced stable results retaining the phase margin and gain cross-over frequency when implemented on HOIP. The results further proved that FOPID controller is working efficiently for ROIP and HOIP.

Control of Exoskeletons Inspired by Fictitious Variable Gain in Human

2008 ◽  
Author(s):  
Kyoungchul Kong ◽  
Masayoshi Tomizuka
Keyword(s):  
Control System ◽  
Control Algorithm ◽  
Controller Design ◽  
Assistive Device ◽  
Single Input Single Output ◽  
Variable Gain ◽  
Single Output ◽  
Single Input ◽  
Parallel Control ◽  
The Brain

A human wearing an exoskeleton-type assistive device results in a parallel control system that includes two controllers: the human brain and a digital exoskeleton controller. Unknown and complicated characteristics of the brain dynamically interact with the exoskeleton controller which makes the controller design challenging. In this paper, the motion control system of a human is regarded as a feedback control loop that consists of a brain, muscles and the dynamics of the extended human body. The brain is modeled as a control algorithm amplified by a fictitious variable gain. The variable gain compensates for characteristic changes in the muscle and dynamics. If a human is physically impaired or subjected to demanding work, the exoskeleton should generate proper assistive forces, which is equivalent to increasing the variable gain. In this paper, a control algorithm that realizes the fictitious variable gain is designed and its performance and robustness are discussed for single-input single-output cases. The control algorithm is then verified by simulation results.

scholarly journals A Procedure to Determine the Droop Constants of Voltage Controllers Coping with Multiple DG Interactions in Active Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1935
Author(s):  
Giuseppe Fusco ◽  
Mario Russo
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Reactive Power ◽  
Test System ◽  
Operating Conditions ◽  
International Standards ◽  
Single Input Single Output ◽  
Single Output ◽  
Modern Distribution ◽  
Single Input

In modern distribution systems, the presence of an increasing amount of Distributed Generation (DG) systems causes over-/under-voltage problems, due to the reverse power flows. To face these problems, the voltage-reactive power droop controllers of DG systems are commonly used for their simplicity and are required by international standards. On the other hand, the interaction among voltage droop controllers of different DG systems may introduce instability. The paper presents an effective procedure to determine the droop constants of voltage-reactive power controllers for multiple DG systems. Firstly, a multi-input multi-output model of the distribution system is introduced. Then, using the concept of the interaction measure under decentralized control, a simple constraint is added to the single-input single-output design of each droop controller. Such a constraint guarantees stability with respect to the interaction among the voltage droop controllers of all the DG systems. Eventually, the proposed procedure is applied to an LV test system with 24 nodes and six photovoltaic systems; the results of numerical simulations are presented, giving evidence of the effectiveness of the proposed procedure in various operating conditions of the distribution system.

Indirect Adaptive Fuzzy H∞ Tracking Control with Self-Structuring Algorithm for a Class of Uncertain Nonlinear SISO Systems

2013 ◽  
Vol 756-759 ◽  
pp. 622-626
Author(s):  
Sen Xu ◽  
Zhang Quan Wang ◽  
You Rong Chen ◽  
Ban Teng Liu ◽  
Lu Yao Xu
Keyword(s):  
Fuzzy Controller ◽  
Controller Design ◽  
Pendulum System ◽  
Single Input Single Output ◽  
Adaptive Fuzzy ◽  
Single Output ◽  
Inverted Pendulum System ◽  
Single Input ◽  
Indirect Adaptive Fuzzy Controller ◽  
Siso Systems

Indirect adaptive fuzzy controller with a self-structuring algorithm is proposed in this paper to achieve tracking performance for a class of uncertain nonlinear single-input single-output (SISO) systems with external disturbances. Selecting membership functions and the fuzzy rules are difficult in fuzzy controller design. As a result, self-structuring algorithm is used in this paper, which simplifies the design of fuzzy controller. Lyapunov analysis is used to prove asymptotic stability of the proposed approach. Application of the proposed control scheme to a second-order inverted pendulum system demonstrates the effectiveness of the proposed approach.

scholarly journals Modified approach to distillation column control

2017 ◽  
Vol 71 (3) ◽  
pp. 183-193
Author(s):  
Sasa Prodanovic ◽  
Novak Nedic ◽  
Vojislav Filipovic ◽  
Ljubisa Dubonjic
Keyword(s):  
Distillation Column ◽  
Controller Design ◽  
Industrial Plant ◽  
Control Analysis ◽  
Centralized Control ◽  
Single Input Single Output ◽  
Response Characteristics ◽  
Single Output ◽  
Single Input ◽  
Integral Error

This paper contains methodology research for forming the control algorithm for a distillation column, modeled as TITO (two-input two-output) process. Its modified form was obtained by connecting the two parts, and this combination hasn't been applied for such a industrial plant, until now. These parts include: a simplified decoupler which was first designed and decentralized PID controller obtained using D-decomposition method for such decoupled process. The decoupler was designed in order to make process become diagonal, and parameters of PID controllers are defined for the two SISO (single-input single-output) processes starting from relation between IE (integral error) criterion and integrator gain, taking into account desired response characteristics deriving from technological requirements of controlled plant. Their connecting provides centralized control. Analysis of the processes responses, obtained by the proposed algorithm and their comparison with the results from the literature, were performed after the completion of the simulations. The proposed approach to the centralized controller design, beside its simplicity of usage and flexibility in achieving diversity of process dynamic behavior, gives better response characteristics, in comparison with existing control algorithms for distillation column in the literature.

System Identification and Multivariate Controller Design for a Satellite Ultraquiet Isolation Technology Experiment (SUITE)

2002 ◽  
Author(s):  
Alok A. Joshi ◽  
Won-jong Kim
Keyword(s):  
Vibration Isolation ◽  
Transfer Functions ◽  
Controller Design ◽  
Input Output ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Single Input Single Output ◽  
Single Output ◽  
Single Input ◽  
Six Degree Of Freedom

A mathematical model of a six-degree-of-freedom hexapod system for vibration isolation was derived in the discrete-time domain on the basis of the experimental data obtained from a satellite. Using Box-Jenkins model structure, the transfer functions between six piezoelectric actuator input voltages and six geophone sensor output voltages are identified empirically. The 6×6 transfer function matrix is symmetric, and its off-diagonal terms indicate the coupling among different input/output channels. Though the coupling was observed among various input/output channels up to 10 Hz, the single-input single-output (SISO) controllers were designed neglecting the effect of coupling. The SISO controllers demonstrated limited performance in vibration attenuation. Using multi-input multi-output (MIMO) control techniques such as Linear Quadratic Gaussian (LQG) and H∞, high-order controllers were developed. The simulation results using these controllers obtain 33 dB, and 12 dB attenuation at 5, and 25 Hz corner frequencies, respectively.

An Approach to Design Controllers for MIMO Fractional Order System Based on RFN Method

2021 ◽  
Author(s):  
Tingxue Li ◽  
Dingyu Xue ◽  
Xinshu Cui
Keyword(s):  
Fractional Order ◽  
Controller Design ◽  
Order System ◽  
Fractional Order Systems ◽  
Control Effect ◽  
Loop Control ◽  
Single Input Single Output ◽  
Single Output ◽  
Single Input ◽  
Value Decomposition

Abstract Fractional calculus has attracted more and more attention and is applied in different fields. However the controller design techniques for fractional order systems mostly focus on single input single output (SISO) ones. This paper deals with the design of controllers for multiple inputs multiple outputs (MIMO) fractional order systems. A method to synthetize controller based on the eigenvalue function and singular value decomposition (SVD) is proposed with aid of fractional order transfer function (FOTF) MATLAB toolbox for the computation and fitting. Instead of setting specification to the controller, the method proposed aiming at achieving the target closed-loop control effect of the system as a whole. Several models evolved from fractional-order Proportional-Integral-Derivative (fPID) controller are selected to form the designed multivariable controller. The effectiveness and robustness of the proposed method are illustrated by an example via simulation.

Evaluation of the LMI-Based Multivariable PID Controller Design for Turbo Aeroengines

2010 ◽  
Author(s):  
Ai He ◽  
Daoliang Tan ◽  
Xi Wang ◽  
Lei Wang
Keyword(s):  
Gas Turbine ◽  
Pid Controller ◽  
Controller Design ◽  
Pole Placement ◽  
Linear Matrix ◽  
Single Input Single Output ◽  
Turbine Engine ◽  
Single Output ◽  
Pid Controller Design ◽  
Single Input

A variety of PID control tuning rules have been proposed for single-input single-output systems, but there is still a lack of research on PID controller design for multi-input multi-output systems. The objective in this paper is to gain some insight into multi-variable PID controller design for gas turbine engines. First of all, we present an approach to design multi-variable PID controllers based on the pole placement technique in the framework of linear matrix inequalities. Then this paper makes a comparison of four multi-variable PID controller design methods including pole-placement, iterative LMI approach, cone complementarity, and sufficient LMI condition. In terms of numerical computation, control performance, and anti-disturbance, we make an attempt to evaluate their performance and give some guidelines to gas turbine engine control. Experimental results illustrate that the pole-placement and iterative LMI methods are slightly superior to others due to their robust performance and their ease of solution and implementation.

Adaptive Controller Design for SISO Switched Nonlinear Systems with Linear Uncertain Parameters

2014 ◽  
Vol 602-605 ◽  
pp. 1362-1366
Author(s):  
Xiao Ping Zong ◽  
Miao Zhang ◽  
Pei Guang Wang
Keyword(s):  
Adaptive Control ◽  
Nonlinear Systems ◽  
Controller Design ◽  
Adaptive Controller ◽  
Model Reference ◽  
Single Input Single Output ◽  
Single Output ◽  
Switched Nonlinear System ◽  
Adaptive Laws ◽  
Single Input

This paper presents that single input single output (SISO) switched nonlinear system tracks the variation of the state error to approach the excepted values by using model reference adaptive control (MRAC) method. In order to improve the adaptive control for nonlinear systems by Using Narendra method and dividing the system into two parts: linear and nonlinear parts. The controllers are designed to guarantee that the systems are closed to the model reference system with the arbitrary switching signal. Switching systems can ensure choose the best controller so that can enhance the performance. The adaptive laws are given that are based on a class of feedback single input single output nonlinear uncertain systems which can switch feedback linear standard models. The adaptive laws are different from the classic adaptive laws, because they vary with different switching signals until the best matching one comes. Simulation results show that the proposed method is effective.

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