International Journal of Automation and Control (50 papers in press)
The Research on Digital and Intelligent Management System for Large Castings Based on Internet+
by Qinglin Chang, Hongyuan Fan, Li Hou, Hongjun Chen, Yang Duan, Peng Cai, Lan Luo
Abstract: In this paper the status and demands of casting production for large wind power and nuclear power companies was taken as the background. This paper aimed at problems in large casting companies such as various products but in small batch, low data utilization rate, complex management structure, slow data collection and transmission speed, inconsistent exchange of current software information and so on, to target the integration of equipment, process, software, production, project management, supply chain and customer management. The model using the top-down and taking current software/system into consideration was adopted, and the usage requirement of casting enterprise is analyzed in this paper. A casting system management platform based on Internet+ was obtained, of which the frame for sub function, system and module to realize it was divided. Research on data storage model and interaction pattern was conducted to provide reference for the development and implementation of information and intelligent platform for casting enterprises.
Keywords: Casting; Informationization; Management System; Internet+.
Complete Synchronization of Non-Identical Fractional Order Hyperchaotic Systems Using Active Control
by Shikha Singh, Muzaffar Ahmad Bhat
Abstract: This manuscript investigates the complete synchronization of non-identical fractionalorder hyperchaotic system via active control technique. The hyperchaotic fractional order Chen system is taken as master system and a new fractional order hyperchaotic system is taken as a slave system. The controllers are constructed using active control technique to ensure the complete synchronization between master and slave system. Simulations results show that our scheme can not make the two systems synchronized, but also let them remain chaotic states.
Keywords: Fractional order hyperchaotic system; active control; stability; synchronization.
A Mixed-method for order reduction of linear time invariant systems using Big Bang-Big Crunch and Eigen spectrum Algorithm
by Akhilesh Gupta, Deepak Kumar, Paulson Samuel
Abstract: In this article, a novel mixed approach is presented for order reduction of complex higher order linear time invariant systems by merging the attributes of Big bang-Big crunch (BB-BC) optimization and Eigen spectrum algorithm. The cosmological theory based BB-BC optimization has the advantage of numerical simplicity with relatively fewer control parameters which makes this algorithm easier to implement.BB-BC optimization technique is based on the generation of random points in first step and contraction of these to a typical point in following step by the center of mass or minimal cost approach. On the other hand, Eigen permutation is based on the retention of dominant poles with simultaneous cluster formation of remaining real and complex poles which guarantee the stability of resulting reduced order model for a stable original model. In the proposed approach, denominator polynomial of the reduced order model (ROM) is determined by the Eigen permutation approach whereas the minimization of the fitness function,i.e.integral square error (ISE) by the BB-BC algorithm approach is adopted for the computation of numerator polynomial coefficients. The effectiveness of the proposed approach over well-known methods is validated with the help of numerical examples by the comparison of transient parameters and performance indices.
Keywords: Big bang-big crunch; Eigen spectrum; ISE; ITSE; IAE; ITAE; MOR; Reduced order model.
A linear algebra controller based on reduced order models applied to trajectory tracking for mobile robots: An experimental validation
by Leonardo Guevara Guevara, Oscar Camacho, Andres Rosales, Javier Guevara, Gustavo Scaglia
Abstract: A Linear Algebra Controller (LACr) based on an empirical linear model of the system is presented in this paper. The controller design is based on a First Order Plus Dead Time (FOPDT) model and can be tuned using the characteristic parameters obtained from the reaction curve. In previous studies, the versatility of this proposed controller was tested by simulations, proving be an alternative to control many kinds of processes. In this paper, the proposed controller is implemented for trajectory tracking using a real mobile robot platform. The performance results are compared against a PI controller using the ISE performance index to measure it.
Keywords: numerical method controller; linear algebra; reduced order models; characteristic parameters; pioneer 3-DX; mobile robot; trajectory tracking.
Control of Continuous-Time Chaotic (Hyperchaotic) Systems: F-M Synchronization
by Adel Ouannas, Ahmad Taher Azar, Toufik Ziar
Abstract: In this paper, a new type of chaos synchronization between differentrndimensional chaotic systems is proposed. The novel scheme is called F-Mrnsynchronization, since it combines the inverse generalized synchronization withrnthe matrix projective synchronization. In particular, the proposed approachrnenables F-M synchronization to be achieved between n-dimensional masterrnsystem and m-dimensional slave system in different dimensions. The technique,rnwhich exploits nonlinear controllers, stability property of integer-order linearrncontinuous-time dynamical systems and Lyapunov stability theory, proves to berneffective in achieving the F-M synchronization. Finally, simulation results arernreported, with the aim to illustrate the capabilities of the novel scheme proposed
Keywords: Chaotic systems; Different dimensions; Matrix projectivernsynchronization; nonlinear controllers; Inverse generalized synchronization.
Derivative Adaptive Predictive Control for a Tempering Process
by DANIEL VIUDEZ-MOREIRAS
Abstract: The modeling threshold problem made hard the Adaptive Predictive (AP/ADEX) controllers implementation in processes that, due to their dynamics behavior, require a control period below a certain value. However, a new concept named Guidance System for derivative control (GS), originally developed for the aerospace sector, overcomes this problem. This paper presents the first industrial application from this new concept, applied to an illustrative industrial tempering process, characterized by a multivariable, highly non-linear and time-varying dynamics. Thus, the new design is based on Adaptive Predictive Expert (ADEX) control, and extended with a new concept, the Guidance Block, required to overcome the ADEX methodology restrictions when it has to be applied with reduced control periods in order to deal satisfactorily with high disturbances and non-linear dynamics. This paper also presents a comparison between the new control system and the conventional control system (LCS), previously implemented in this industry and based on PID methodology, showing the benefits of implementing the new system.
Keywords: Optimized Adaptive Control; Predictive Control; Adaptive Predictive Control; Derivative Control; Guidance System; Process Control; Tempering Process.
CDM Based Two Degree of Freedom PI Controller Tuning Rules for Stable and Unstable FOPTD Processes and Pure Integrating Processes with Time Delay
by Somasundaram S, Benjanarasuth T
Abstract: This work proposes the Coefficient Diagram Method (CDM) based two degree of freedom Proportional Integral (CDM-PI) controller tuning rules for stable and unstable First Order Plus Time Delay (FOPTD) processes and Pure Integrating Processes with Time Delay (PIPTD). To derive the tuning rules, a general First Order Plus Time Delay (FOPTD) model, the first order Taylor denominator approximation technique and the pole allocation strategy named CDM is used. The tuning rules derived here are novel and they relate the controller parameters to the process model parameters directly. The performance of the CDM-PI controller utilizing the proposed tuning rules is tested with numerical examples of stable, unstable and pure integrating processes with time delay models. The test results indicate that the proposed tuning rules yield promising results over the other PI controllers. Performance measures confirm the effectiveness of the proposed tuning method.
Keywords: CDM-PI; Two degree of freedom; Tuning rules; Process models; Performance measures.
Modified PSO based Non-Linear Controllers Applied to a DC-DC Converter
by Hadjer Abderrezek, Ameur Aissa, M.N. Harmas
Abstract: Control of dc/dc Buck converter is a complex task due to the nonlinearity inherent in the converter and introduced by the external changes. A robust synergetic controller for the control of dc/dc Buck converter is described in this study. An adaptive terminal synergetic control is developed based on robust synergetic control theory and terminal attractor techniques. The method estimates the boundary of parameter uncertainty and external disturbance by adaptive law. The idea behind this strategy is to use the terminal synergetic control (TSYC) approach to assure finite time convergence of the output voltage error to the equilibrium point, and integrate an adaptive law to handle uncertainties is provided resulting in enhancing robustness as well as a better transient performance compared to the conventional control. In addition, Modified PSO algorithms will be used to optimize controllers parameters using an ITAE criterion. The results show and demonstrate the effectiveness and feasibility of the proposed approach.
Keywords: synergetic control; terminal; TSYC; Adaptive; ATSYC; particle swarm optimization; PSO; Lyapunov; finite time; MPSO.
Parabolic Angle-based Anti-sway Control for Container Cranes with Limited Dynamic Loads
by Kamal Khandakji, Victor Busher, Lubov Melnikova
Abstract: A novel anti-sway control system for cranes is proposed. The proposed method is based on the formation of a predetermined angle of deviation as a piecewise-continuous parabolic function, the second derivative of which does not experience discontinuity, and its third derivative is a rectangular pulse of certain variable-sign amplitude, which eliminates the mechanical stress in the crane construction and kinematic gears. The proposed method provides damping of the oscillations of the suspended load during its horizontal motion (in two orthogonal coordinates) and hoisting/lowering. The control method is invariant to the mechanism/payload mass ratio, lift height and hoisting speed.
Keywords: Anti-sway system; motion control; oscillations damping; container crane.
An algorithm to diagnose manufacturing hybrid systems
by Omaima BENATIA, Fouad BELMAJDOUB
Abstract: We propose in this paper a new method for diagnosing manufacturing hybrid systems. We are inspired by two methods: one is based on continuous Petri nets and the other is based on discrete Petri nets. The combination of these two methods will be based on hybrid Petri nets. Our approach is proposed in the form of an algorithm that treats the different steps to diagnose a manufacturing hybrid system whose discrete part controls the continuous part. We consider that the set of fault classes is partitioned into two subsets: continuous fault classes and discrete fault classes.
Keywords: Diagnosis; manufacturing hybrid systems; discrete Petri nets; continuous Petri nets; hybrid Petri nets; fault classes; continuous fault classes; discrete fault classes.
Resonance Compensation in Dual-stage Hard Disk Drive Servo System
by Md. Arifur Rahman, Alamgir Hossain, Md. Raju Ahmed
Abstract: This paper presents a simulation analysis of resonance compensation in dual-stage actuator system. To enhance the speed and precision, piezoelectric micro-actuator made form PZT (Lead-Zirconium-Titanium) is used as the secondary actuator in dual-stage hard disk drive (HDD) where a voice coil motor (VCM) is used as the primary actuator. Both VCM actuator and PZT micro-actuator (MA) have the problem of mechanical resonance. Conventional approach is to use a pre-compensator notch filter for each actuator to suppress the resonance. Since this method is based on inversion technique, it needs a very accurately identified plant model which is always difficult to obtain. On the other hand, a simple controller in the feedback path is a good solution for suppressing the resonance which does not require a very precise plant model. With the proper design of dual-stage controller, it is possible to bypass VCM actuator's resonance uncertainty by PZT micro-actuator in the high-frequency band. However, the resonance of the micro-actuator is detrimental to the stability of the dual-stage servo control loop. Therefore, proper design of resonance compensator of PZT loop is needed with the consideration of PZT actuator's resonance uncertainty. This paper presents a feedback resonant controller designed in simple way to suppress the resonant modes of PZT micro-actuator actuator in a dual-stage HDD servo system. The design is based on an integrated approach where M-norm minimization and mixed passivity, negative-imaginary, small-gain theorem are used. This approach results in a robust stable controller which provides better performance over the conventional notch filter. Simulation results substantiate the effectiveness of the proposed controller.
Keywords: Dual-stage HDD; VCM actuator; PZT micro-actuator; Resonant controller.
Designing dynamic fractional terminal sliding mode controller for a class of nonlinear system with uncertainties
by Arash Pourhashemi, Amin Ramezani, Mahdi Siahi
Abstract: In this paper, a novel terminal sliding manifold is introduced. Then, based on new sliding surface, we proposed two new fast converging robust controllers. The first controller is a fractional terminal sliding mode controller for a class of fractional order chaotic system in order to decrease singularity problem as well increasing fast convergence. Stability analysis of the system have been proved by Lyapunov stability theorem. The second one is the fractional dynamic terminal sliding mode controller for a class of fractional second order chaotic system so as to reduce chattering problem. For each, numerical simulations have been done to show the applicability and effectiveness of the proposals.
Keywords: Fractional Calculous; Terminal Sliding Mode Control; Dynamic Sliding Mode Control; Stabilization.
Development of New Cable-driven Minimally Invasive Surgical Robot
by Longwang Yue, Kong Fah Tee, Baoguo Liu, Tengfei Feng
Abstract: Operation intuitiveness and force feedback are two main problems of MIS robots. In order to solve these problems, a new type of robot-assisted MIS system has been proposed. Focusing on the cable-driven MIS robot, which is a core component of the system, the following steps in developing the underlying theory have been conducted. Firstly, the driving cable layout, motion mapping and symmetrical decoupling structures of all types of MIS robot joints are analyzed. Secondly, the mathematical formulation of the cable-driven layout of each joint based on the crossing number is derived. Finally, as an example of a cable-driven MIS robot, the kinematic analysis of the symmetrical spatial intersecting joints is developed based on D-H method and the crossing number. The results show that the cable driven symmetrical intersecting joints could improve the operation intuitiveness and realize direct force feedback.
Keywords: Minimally Invasive Surgery (MIS); Robot Design; Intuitive Operation; Cable-driven; Force Feedback; Cross Number; Specula Symmetry Mapping; Central Symmetry Mapping.
A Hardware / Software Architecture Dedicated to Model Predictive Control Law and Implemented into an FPGA Platform
by Sirine TELMOUDI BRINI, Badreddine Bouzouita, Faouzi Bouani
Abstract: Model Predictive Control (MPC) is an optimization-based strategy for high-performance control engineering practice and real-time applications. It has been widely used for slow dynamic process. This method needs to solve online a Quadratic Programming (QP) problem at each sample time to find optimal control sequence. However, the computational load for this control strategy is very high and is often restrictive for proper implementation. This means that an appropriate technology and a design approach should be applied. In this paper, a new optimized MPC architecture is presented, to meet the high sampling frequency demand of real-time control applications for a gradient-based QP solver to implement linear MPC on a Field-Programmable Gate Array (FPGA) platform with a fixed 20-MHz clock, which allows obtaining high-quality performances (in control quality, speed and hardware utilization). This MPC implementation achieves comparable results to those obtained with an AMD Turiom (Tm) II Dual core 2.2 GHz, which offers a promising platform to expand the field of the application of this technique to control embedded systems. This work is the first that has used this technique of conception thanks to the benefits of used chip components. However, this approach requires a manual programming of the high-level C/C ++ code in opposition to the other presented approaches, which automatically generates the code. The efficiency of the proposed approach is completed with real time control of the water level of a single tank system running on a Nanoboard 3000XN FPGA chip using a conception environment (Altium Designer), while comparing between the MPC and PID controllers.
Keywords: FPGA; predictive control; quadratic optimization problem; PID controller; Altium Designer; MPC.
A FPGA-based state space controller
by Ananthan T
Abstract: Many years digital controllers have been implemented using microprocessors, microcontrollers, digital signal processors etc. Recently, field programmable gate arrays (FPGA) is found to be an alternative because of its reconfigurability, high processing speed and the reduced cost of computation. Comparatively the performance of FPGA is appreciable in implementing controllers which involves intensive matrix computations. In this context, this paper presents the implementation of State Space Controller (SSC) on FPGA. It is one of the widely used controllers to obtain the desired response of dynamic systems in diverse fields of engineering. SSC contains an observer to estimate the system unknown states variables. Matrix multiplications involved in this estimation take most of the computation time of the controller. In order to make SSC much more competent for controlling fast dynamic systems, a new FPGA based parallel architecture is proposed. The reduction in computation time with optimal hardware resources is achieved by developing an efficient Multistage Matrix Multiplication algorithm (MMM). In addition, the proposed architecture has a high throughput. The performance of FPGA-based SSC is validated by implementing it in an inverted pendulum control system in Matlab Simulnk environment using electronic design automation (EDA) simulator. The design is mapped on xilinx virtex-5 FPGA device with a maximum frequency of 449.438MHz. Application specific integrated circuit (ASIC) implementation of SSC is also carried out using Cadence RTL compiler.
Keywords: FPGA; state feedback control; Parallel architecture ASIC.
Nominal Model Selection and Guidance Computer Design for Antitank Guided Missile
by A.N. Ouda, Gamal El-Sheikh, Yehia Elhalwagy, Mahmoud Ashry
Abstract: The great developments in applied mathematics and computational capabilities facilitate the design and implementation of robust control. In addition, the huge developments in nanotechnology and its availability in civilian level with less cost, size and weight attract many of the researchers all over the world towards embedded systems especially the embedded flight control. Among the real applications are the guided missiles especially the antitank guided missile systems which are commanded to the line of sight (CLOS) against ground and short-range targets. The present work is concerned with improving the performance of an antitank guided missile system belonging to the first generation via robust synthesis of guidance systems. The selection of nominal model is required to design the guidance computer for the system. This paper is devoted to the quantitative analysis to select a nominal plant which used to design a guidance computer that has a successful flight path trajectory against different types of uncertainties. The design and analysis necessitates somehow accurate model with different uncertainties for the system. The flight path is evaluated considering the HIL environment.
Keywords: Missile; Command guidance systems; Robust control; Guidance; nominal model; Autopilot design.
Intelligent Proportional-Integral Sliding Mode Control of Wind Turbine Systems Based Particle Swarm Optimization
by Salma Aboulem, El-mahjoub Boufounas, Ismail Boumhidi
Abstract: This paper presents a robust intelligent proportional-integral sliding mode controller for a variable speed wind turbine (VSWT). The main objective of the controller is to optimize the energy captured from the wind, and minimize the mechanical stress in the system. In order to guarantee the wind power capture optimization without any chattering problems, this study propose to combine the sliding mode control (SMC), proportional integral (PI) control and particle swarm optimization (PSO) algorithm. The PSO technique with efficient global search is used to optimize the PI and SMC parameters simultaneously to control the system trajectories to a sliding manifold that determines the system performance. The stability of the system using this controller is shown by the Lyapunov theory. The simulation results of the proposed PSO-PI based SMC (PSOPISMC) method are compared with the PSO-I based SMC (PSO-ISMC) and the conventional PSO based SMC (PSO-SMC). The comparison results reveal that the proposed controller is more effective in reducing the tracking error and chattering. In addition, the controller shows more robustness against uncertainties and faster transient response of the system with reduced steady state error.
Keywords: sliding mode control; PI sliding surface; particle swarm optimization; variable-speed wind turbine.
A new three-dimensional chaotic system: Its adaptive control and circuit design
by Sundarapandian Vaidyanathan, Oumate Alhadji Abba, Gambo Betchewe, Mohamadou Alidou
Abstract: A new three-dimensional chaotic system with two nonlinearities is proposed in
this research work. Specifically, the two nonlinearities considered in the construction of the new chaotic system are a quadratic nonlinearity and a quartic nonlinearity. A systematic study of the three-dimensional chaotic system has been made including phase portraits, dissipativity, rest points and their stability, Lyapunov chaos exponents, Kaplan-Yorke fractal dimension, etc. As main control results, we design feedback control laws using adaptive control theory to achieve global stabilisation of the new chaotic system and also global synchronisation of identical chaotic systems with unknown parameters. Finally, an electronic circuit design of the new chaotic system using Electronic Work Bench (EWB) is described in detail to confirm the feasibility of the theoretical chaotic model.
Keywords: Chaos; chaos control; chaos synchronisation; adaptive control; circuit design.
Robust Observer-based Synchronization of Chaotic Oscillators with Structural Perturbations and Input Nonlinearity
by KAMMOGNE SOUP TEWA Alain, Ahmad Taher Azar, Hilaire Bertrand Fotsin, Romanic Kengne
Abstract: This paper presents a generalized robust adaptive chaotic synchronization method for chaotic systems with structural perturbations. One control input is used to synchronize both systems exponentially fast based on Lyapunov theory. This approach can not only make the outputs of both master and slave systems reach synchronization with the passage of time between both systems but it can also reduce the effect of external perturbations and input nonlinearities. By assuming bounded solutions of the nominal uncoupled systems, sufficient conditions have been derived for boundedness of the solutions of two different class of chaotic systems with input nonlinearity affected by structural perturbations. The propose approach offers a systematic design procedure for robust adaptive synchronization of a large class of chaotic systems in the chaos research literature. As an illustration of the effectiveness and robustness of the proposed strategy, synchronization problem of a master system consists of a perturbed modified Colpitts oscillator and an observer consisting of a Chua oscillator. It was found that the controller maintains robust stable synchronization in the presence of exoteric perturbations and structural uncertainties.
Keywords: Chaos synchronization; Adaptive observer; Lyapunov theory; synchronization; input nonlinearity.
An optimized 2-DOF IMC-PID based Control Scheme for Real-time Magnetic Levitation System
by Avadh Pati, Richa Negi
Abstract: This paper addresses an optimized 2-DOF internal model based PID controller for unstable magnetic levitation system. Here, the proposed controller is realized using IMC control theory and its parameter are calculated using Maclaurin series expansion. Particle Swarm Optimization (PSO) algorithm is used for obtaining an optimized 2-DOF IMC-PID controller. The proposed method is simpler to use due to its explicit tuning method as compared to other frequency response methods. The real-time experimental results are given, illustrating the effectiveness of proposed controller. The suggested controller not only improves the transient and tracking response but also maintains the robustness of maglev system under various disturbance environments. The performance of the proposed controller is compared with conventional PID controller.
Keywords: Maglev System; Internal Model Control; PID controller; Particle Swarm Optimization; 2-DOF IMC PID Controller; Stability Analysis; Robustness; Disturbance Rejection.
Adaptive Wavelet Network Controller design for Nonlinear Time Delay Systems in the presence of Actuator Failure
by Mahshid Rahimifard, Marzieh Kamali, Maryam Zekri
Abstract: This paper presents an adaptive wavelet network controller for a class of strict-feedback uncertain nonlinear systems with unknown time delays and in the presence of external disturbances and actuator failure. The type of considered actuator failure is loss of effectiveness, in which the system input may lose unknown fraction of its effectiveness during the system operation. Wavelet networks are utilized to approximate unknown nonlinear functions and the proposed adaptive-neural controller is constructed based on dynamic surface control (DSC) design method. By applying the appropriate LyapunovKrasovskii functionals, the boundedness of all the closed-loop signals is guaranteed and the tracking error is proved to converge to a small neighborhood of the origin. The performance of the proposed adaptive-neural control approach is illustrated by applying a theoretical system and a chemical reactor system. The simulation results indicate the effective capabilities of the proposed control algorithm.
Keywords: Adaptive neural control; Wavelet networks; Nonlinear time delay systems; DSC.
NONLINEAR MULTIVARIABLE TRACKING CONTROL: APPLICATION TO AN ETHANOL PROCESS
by María Cecilia Fernández, María Nadia Pantano, Ricardo F. A. Machado, Oscar Alberto Ortiz, Gustavo Scaglia
Abstract: In this paper, a controller based on linear algebra for a fed-batch ethanol production process is proposed. It involves finding feed rate profiles (control actions obtained as a linear equations system solution) in order to make the system follow predefined concentration profiles. A Monte Carlo experiment is used for controller tuning. Moreover, several tests (adding parametric uncertainty, perturbations in the control action and in the initial conditions) are carried out so as to evaluate the controller performance. A comparison with other controller is made and the demonstration of the error convergence is included.
Keywords: fed-batch bioprocess; ethanol production; nonlinear model control; profile tracking control; numeric methods/linear algebra.
Real-Time Implementation of Nonlinear State and Disturbance Observer Based Controller for Twin Rotor Control System
by Bhanu Pratap, Shubhi Purwar
Abstract: A nonlinear state observer based controller for the twin rotor control system (TRCS) with actuator saturation is developed in this paper. The TRCS exemplifies a higher order multiple-input-multiple-output (MIMO) system having nonlinear dynamics with significant cross couplings. A nonlinear local state observer for TRCS is implemented by coordinate transformation that transforms the plant model in an approximate normal form. On the basis of proposed observer, a feedback controller for TRCS is implemented in real-time. To tackle the external disturbances and friction on the rotor shaft, a nonlinear disturbance and friction observer (NDFO) has been employed. To take into account control input within practical range, a compensator using Chebyshev neural network (CNN) is augmented to the proposed control scheme. The simulation and experimental results are highlight that the controlled response has fast convergence, high degree of tracking with small errors, bounded control effort under the effect of friction and disturbance.
Keywords: Chebyshev neural network; nonlinear coupled system; nonlinear friction; observer based control; twin rotor control system.
Nonlinear control scheme based on a second order sliding mode: application to DFIG supplied by five-level PWM inverter
by Ahmed Benzouaoui, Zoubir Ahmed-foitih, Mohamed Faycal Khelfi
Abstract: Adaptive control is a set of approaches used for the automatic adjustment of the controller parameters in order to achieve or maintain a certain level of performance when the parameters of the control process vary over time or unknown. The parameters of the controller are adapted to ensure also that there is no overestimation of the gain with real a priori unknown value of uncertainties. The proposed control approach consists in using second-order sliding mode with a dynamically adapted control gain that guarantees the stability and robustness of the control law even with the presence of uncertainties and perturbation of the system. The control is applied by simulation (Matlab-Simulink) on a doubly fed induction generator (DFIG) integrated into a variable speed wind turbine and controlled by super twisting sliding mode control. The simulations indicate the efficiency of the proposed approach especially in the case of change of the reference speed and/or the parameters variation.
Keywords: Adaptive second order sliding mode control; chattering; doubly fed induction generator; five-level inverter; wind energy.
H Control of Asynchronous Networked Control Systems with Markov Time Delays
by Xiaoqiang Sun, Weijie Mao
Abstract: In this paper, the solutions to the H∞ synthesis problems of stochastic asynchronous discrete-time (DT) networked control systems (NCSs) with random communication time delays are proposed according to the following steps. Firstly, a new Lyapunov-Krasovskii functional is explicitly constructed to analyze the stochastic stability of the systems. Both sensor-to-controller (S-C) and controller-to-actuator (C-A) random networked-induced delays, which are two Markov chains, are considered in the analysis. Moreover, the stochastic sampling of S-C and holding of C-A are also considered in the analysis. Secondly, based on a specified definition of the state with delay and a more rigorous inequality, sufficient delay-dependent stability conditions can be transformed into the form of linear matrix inequalities (LMIs) by slack matrix method and the lemma of Schur complement. The LMIs are less conservative and have fewer tuning parameters and lower dimensions. Therefore, the LMIs can be conveniently solved by LMI tools. Finally, the proposed theory is validated by a simulation example.
Keywords: H∞ synthesis; DT asynchronous system; random delay; Markov chain; stochastic sampling and holding; delay-dependent LMIs.
LQG Controller Design for a Quadrotor UAV Based on Particle Swarm Optimization
by Rabii Fessi, Soufiene Bouallègue
Abstract: This paper deals with the modelling and the Linear Quadratic Gaussian
(LQG) control design of a quadrotor Unmanned Aerial Vehicle (UAV)
using different Particle Swarm Optimization (PSO) variants. Such a
PSO-designed LQG controller is optimized in order to stabilize the
position and the heading of the studied Vertical Take-Off and Landing
(VTOL) quadrotor. Both canonical and recent variants of PSO algorithm, with linearly decreasing of inertia weight~(PSO-In) and perturbed updating strategy~(PSO-gbest), are considered for the systematically design and tuning of the LQG weighting matrices. These effective control parameters of the LQG approach
represent the decision variables of the PSO-based LQG optimization
problem. Such an optimization problem is formulated to minimize
various performance time-domain criteria, like the Integral of
Absolute Error (IAE) and the Maximum Overshoot (MO) index, under
nonlinear constraints related to the step responses of the
closed-loop quadrotor dynamics. All proposed PSO algorithms are
compared with each other and with the well known Harmonic Search Algorithm~(HSA) and Water Cycle Algorithm~(WCA) metaheuristics for the stabilization problem of the position and heading dynamics of the VTOL drone. Demonstrative simulation results are carried out in order to show the effectiveness of the proposed
PSO variants-tuned LQG control approach.
Keywords: Quadrotor UAV; modelling; position and heading stabilization,
LQG weighting matrices tuning; Particle Swarm Optimization.
PLC-Based implementation of Supervisory Control for Flexible Manufacturing Systems using Theory of Regions
by Sadok Rezig, Chekib Ghorbel, Zied Achour, Nidhal Rezg
Abstract: The supervisory control is a common theory for the synthesis of Petri net (PN) supervisors for discrete event systems given a PN model and a control specification for the maximum permissive behaviour. The theory of regions asrnone of control synthesis method generates a PN controller to satisfy the control specification. Though the theory of regions has for over a decade received a considerable attention in academy, still very few applications exist. The real cause of this seems to be a contradiction between the abstract controller and its physical implementation. This is evident in particular when the implementation is supposed to be based on a Programmable Logic Controllers (PLC), as is the case for flexible manufacturing systems. Indeed, since the synchronous PLC is based on signals, the PN supervisor remains asynchronous; this explains its implementation difficulty. In this paper, we propose a synthesis method of PN monitor using a Java application implemented on PLCs of a Flexible Manufacturing System (FMS) installed in our research laboratory in the University of Lorraine in Metz, FRANCE.
Keywords: Petri nets; Theory of regions; Program Logic controller; Supervisory control; Flexible Manufacturing System.
Design and simulation of self-tuning Fractional Order Fuzzy PID controller for robotic manipulator
by Reza Rouhi Ardeshiri, Hoda Nikkhah Kashani, Atikeh Reza-Ahrabi
Abstract: Two-link robotic manipulator system is completely non-linear and time-varying multiinput- multiple output. Therefore designing a controller that has high accuracy and good performance is the researchers' attention. In this paper, the Fractional Order Fuzzy PID (FOFPID) controller is proposed in order to control the robotic manipulator position. This controller has been designed by a fuzzy system and a fractional order PID controller. Fractional order PID (FOPID) controller, can be more flexible than classic PID controller function. Since real control systems are generally non-linear systems, therefore, better control of these systems requires the usage of an adaptive or non-linear controller. Therefore, in this work we applied a fuzzy system in order to determine the coefficients of a fractional order PID controller based on particle swarm optimization (PSO) evolutionary algorithm to determine the fractional order operators. In definition of fitness function for the optimization problem, we considered Integral of Absolute Error (IAE) and Integral of Absolute Change in Controller Output (IACCO). Finally, in order to compare the proposed controller with the conventional controller (FPID), numerical simulations were performed on the robotic manipulator. The results clearly demonstrate that the overshoot of FOFPID controller is less than FPID. In addition the proposed controller has less oscillations amplitude and has a high robustness against noise which improves the performance of trajectory tracking system.
Keywords: Robotic manipulator; Fractional calculus; FOFPID controller; Fuzzy logic controller; PSO algorithm.
Synthesize of MPC Controller for Uncertain Systems subject to Input and Output Constraints: Application to Anthropomorphic Robot Arm
by Imen Dakhli, Elyes Maherzi, Mongi Besbes
Abstract: This paper proposes a synthesis of a dynamic controller under constraints. It is based on Model Predictive Control (MPC) approach and resolution of a convex optimization problem with Linear Matrix Inequalities (LMI). The controller guarantees the closed-loop stability for polytopic time-varying uncertain systems. Conditions are provided for the controller design based on the parameter dependent Lyapunov functions (PDLF). A new demonstration is developed based on the relaxation technique, to include a slack variables Gi. The new LMI's formulation offers an additional degree of freedom for the controller design. Input and output constraints are also taken into account during the design of the controller. This approach allows varying and adjusting the dynamic of system by taking into account input/output constraints.
Keywords: Model Predictive Control (MPC); Dynamic controller; Linear matrix inequality (LMI); Parameter dependent Lyapunov functions (PDLF); Input / Output Constraint.
Hybrid intelligent controller design for an unstable Electromagnetic Levitation System: A fuzzy interpolative controller approach
by Ravi Gandhi, Dipak Adhyaru
Abstract: This article presents the design and implementation of hybrid
intelligent controller for the dynamically nonlinear and unstable Electro-
Magnetic Levitation System (EMLS). The hybrid design is having the
intelligence of the Fuzzy Interpolative Controller (FIC) with estimation ability
and noise immunity achieved by means of the Kalman filter. The Fuzzy
Inference System (FIS) is replaced by fuzzy linear interpolation networks based
on look-up table to form the fuzzy rule base in ordered to reduce the
computational complexity and to boost up the execution speed of the control
approach as compared to conventional Mamdani or Sugeno type FIS toolkits.
The proposed design stabilizes the EMLS under wide initial and assorted
operating conditions. Further, the proposed controller maintains the
performance robustness under 0-25% of vertical payload disturbance by
holding the steel ball within the safe limits. Simulation results are presented to
validate the novelty and effectiveness of the proposed approach for EMLS.
Keywords: Fuzzy Interpolative Controller (FIC); Kalman filter; hybrid
intelligent control; Electromagnetic Levitation System; set-point filter;
Optimal Preview Control Design of Pneumatic Servo System: A Comparative Analysis
by Randeep Kaur, Jyoti Ohri
Abstract: This paper describes the development of a preview controller based on optimal control theory for positioning control of a pneumatic servo system. The preview theory of tracking control using the future information has been studied extensively but did not get enough applications in the field of servo control systems, used in modern industrial processing, that will increase the accuracy and efficiency of the industrial product. In the pneumatic servo system, the position of pneumatic cylinder is the command input and its future information can be known a priori. The proposed control system is composed of feedback from the state of the plant and feed-forward from the reference signal by using future information. The validity of the proposed control system is confirmed by simulation and comparative analysis is done with optimal control. Simulation results imply that good performance and good phase characteristics can be obtained using optimal preview controller.
Keywords: Pneumatic Servosystem; Preview Control; Optimal Control; Algebraic Riccati Equation; Performance Index; Tracking.
Stabilisation of a rotary inverted pendulum system with double-PID and LQR control: Experimental verification
by Teng Fong Tang, Shin Horng Chong, Kee Kiat Pang
Abstract: Rotary inverted pendulum (RIP) system is an under-actuated system. The RIP system consists of a pendulum, which is rotating freely in the vertical plane. A swing-up action using a pivot arm in the horizontal plane would then result in the pendulum to achieve upright equilibrium point. This paper describes the design of a double Proportional-Integral-Derivative (PID) controls with a Linear Quadratic Regulator (LQR) controller for the stabilisation control of a RIP system. The dynamic model of the RIP system is described too. The LQR controller was tuned using Taguchi method. The double-PID controller was designed using Ziegler-Nichols method, which the LQR controller is embedded in the RIP system to improve the stabilisation performance. The effectiveness of the double-PID and LQR controller is clarified with a RIP experimentally. The proposed controller has demonstrated succeed stable the pendulum within 0.5 degrees in 3 seconds and the rotary arm within 22.5 degrees.
Keywords: rotary inverted pendulum; mathematical modelling; linear quadratic regulator; proportional-integral-derivative; Taguchi method; Ziegler-Nichols method.
Encoder-less Field Oriented Control of Permanent Magnet Synchronous Motor by using a Full Order Adaptive State Observer.
by Sudhanwa Kelkar, Bharat Sharma
Abstract: This paper proposes a full order adaptive state observer, for the
field oriented control of a permanent magnet synchronous motor (PMSM),
without using a speed sensor. The observer is designed in the estimated fieldsynchronous
coordinate system. The rotor speed is treated as an unknown
parameter. The adaptive law for speed is derived by using Lyapunovs stability
theorem. Since control algorithms and models are processed in micro computers,
the proposed observer has been discretized by Eulers method. To make the
observer dynamically faster than the motor dynamics, observer poles are fixed
proportionally to those of the motor by using pole placement technique. The
simplifying assumptions used to discretize the observer, along with the stator
current harmonics, introduce ripples in the estimated rotor speed. To mitigate this
effect, various counter-measures are explored. The validity of proposed scheme
is verified through MATLAB simulink.
Keywords: Encoder-less ; Permanent Magnet Synchronous Motor (PMSM) ; adaptive state observer ; pole placement ; Lyapunov’s stability theorem ; Euler’s discretization.
A Distributive Approach for Position Control of Clamps in a Reconfigurable Assembly Fixture
by Olayinka Olabanji, Khumbulani Mpofu, Olga Battaia
Abstract: Hydraulic actuator is a type of clamp used in a reconfigurable assembly fixture for exact positioning and effective immobilization of workpiece during the assembly process. However, due to their non-linearity, there is a need to design a control system for their effective performance. This study presents a distributive approach to mathematical modelling and position control of multiple hydraulic actuators used as a clamping system in a reconfigurable assembly fixture. The electrohydraulic system is verified experimentally in order to observe the synchronisation of the hydraulic actuators. The mathematical model of the system is developed in the Simulink environment. A Simulink model of the system is developed from the mathematical model and simulated with a Fuzzy-PID controller in order to obtain the response of all the actuators and other operating characteristics of the system. Simulation results are shown graphically in order to verify the theoretical development.
Keywords: Electrohydraulic system; Position control; Fuzzy-PID controller; Hydraulic actuator; Reconfigurable Assembly Fixture; Distributive modelling.
Stability Analysis and Robust Synchronization of Fractional-Order Modified Colpitts Oscillators
by Kammogne Soup Tewa Alain, Ahmad Taher Azar, Kengne Romanic, Fotsin Hilaire Bertrand
Abstract: Based on the stability theory of the fractional order system, the dynamic behaviours of the uncertain Colpitts oscillator with fractional order-derivative is studied. Furthermore, based on the extended bounded real lemma, the robust controller is obtained using the drive-response synchronization concept together with the Lyapunov stability theory formulated using the fractional Lyapunov direct method where the fractional-order q belongs to . In order to bring out the dynamic behaviour of this system, their phase portraits, the bifurcation diagrams and the Lyapunov exponent are simulated. Moreover, in this work, an approximated solution for both systems to show that the solution of such a system can be represented as a simple power-series function is provided. This study equally provides a systematic procedure to highlight the simplicity and flexibility of the suggested control approach. Simulations with both parameters uncertainty and external disturbance show the applicability and the efficiency of the proposed scheme.
Keywords: Lyapunov exponent; Bifurcation diagram; Chaos; fractional modified Colpitts Oscillator; synchronization; robust controller.
Novel Robust Stability Condition for Uncertain Systems with Interval Time-varying Delay and Nonlinear Perturbations
by Yubin Wu
Abstract: In this paper, the problem of robust stability analysis for a class of uncertain systems with interval time-varying delay and nonlinear perturbations is studied. In order to develop a less conservative stability condition, a LyapunovKrasovskii functional (LKF) comprising quadruple-integral term is introduced. A novel delay dependent stability criterion in terms of linear matrix inequalities (LMIs) is given by using a new delay-partitioning approach and reciprocally convex combination technique, which is derived by integral inequality approach (IIA). Compared with the existing literature, this criterion can greatly reduce the complexity of theoretical derivation and computation. Finally, three well-known numerical comparative examples are given to verify the superiority of the proposed approach in reducing the conservation of conclusion.
Keywords: Interval time-varying delay; Delay-partitioning; Robust stability; Reciprocally convex combination; Lyapunov–Krasovskii functional (LKF); Quadruple-integral term.
Adaptive fuzzy control for the stabilization of chaotic systems
by Hanene Medhaffar, Moez Feki, Nabil Derbel
Abstract: In this paper, we investigate the stabilization of unstable periodic orbits
of continuous time chaotic systems using adaptive fuzzy controllers. For this aim,
we present a control method that can achieve the stabilization of an unstable
periodic orbit (UPO) without any knowledge of the system model. Thus, a fuzzy
adaptive linear controller is proposed based on time-delay feedback approach
to obtain one that achieves UPO stabilization. Finally, we use reduced order
sliding observer to estimate the necessary state for the controller construction.
The efficiency of proposed methods is demonstrated using numerical simulations
applied to Chuas system.
Keywords: Chaos control; Fuzzy adaptive systems; Time-delayed state feedback,
Sliding mode observer.
Processor-in-the-Loop Co-Simulations and Control System Design for a Scaled Autonomous Multi-Wheeled Combat Vehicle
by Amr Mohamed, A.N. Ouda, Jing Ren, Moustafa El-Gindy
Abstract: This paper describes the design and implementation of PID and fuzzy logic controllers for tracking the desired heading angle for a scaled Autonomous Multi-Wheeled Combat Vehicle (AMWCV). The challenge of designing these control systems is to control the steering of the front four wheels individually in order to obtain the correct heading angle of the vehicle. The performance of the developed controllers is validated in the presence of noise and disturbance in order to evaluate their robustness. A Processor-In-The-Loop (PIL) co-simulation is conducted to permit and achieve a more realistic situation where the developed control algorithms are evaluated while running on a dedicated processor. The obtained results from both simulation and PIL are compared. This comparison will demonstrate the controller effectiveness in tracking the desired heading angles.
Keywords: Autonomous vehicle; multi-wheeled combat vehicle; heading control; fuzzy logic; classical control; processor-in-the-loop.
A Two-Phase Approach for the Design of Two-Degree of- Freedom of Robust Controller for Higher Order Interval System
by Mangipudi Siva Kumar, Danaboyina Srinivasa Rao, Manyala Ramalinga Raju
Abstract: This paper proposes a novel method for the design of the robust controller to retain both the robust stability and performance of the higher order interval system via reduced order model using the differential evolution (DE) algorithm. A stable reduced interval model is generated from a higher order interval system using DE in order to minimize the cost and reduce the complexity of the system. The reduced order interval numerator and denominator polynomials are determined by minimizing the Integral Squared error (ISE) using the DE. From reduced order interval model, a robust PI controller is designed based on the new stability conditions of interval system. The designed robust controller from the reduced order interval model will be attributed to the higher order interval system. The designed PI controller from the proposed method not only stabilizes reduced order model but also stabilizes the original higher order system. Finally, with the help of frequency domain method a pre-filter is constructed to improve the performance of interval system. The viability of the proposed methodology is illustrated through a numerical example for its successful implementation.
Keywords: Interval system; Kharitonov’s theorem; Robust controller; model order reduction,Differential Evolutionary algorithm.
Online Sensor Aging Detection using a Modified Adaptive Filter
by AQEEL MADHAG, Guoming Zhu
Abstract: Modern control systems heavily rely on sensors signals for feedback control, and therefore, sensor performance and fault diagnostics are essential. Degradation of sensor performance due to sensor aging affects the closed-loop system performance, reliability, and even stability. Sensor aging can be characterized by the gradual-variation of the sensor measurement noise covariance. This paper proposes a fault detection algorithm to detect online sensor performance degradation and failure due to sensor aging, where the sensor faults due to aging are characterized by slow variations of the sensor measurement noise covariance matrix. To be specific, the key feature of the proposed algorithm is online detecting gradual sensor performance degradation due to sensor aging by estimating the slowly-varying sensor measurement noise covariance matrix.rnThe proposed algorithm utilizes the information about the quality of weighted innovation sequence to estimate the slowly-varying sensor noise covariance. The iterative manner of the proposed algorithm leads to significant reduction of the computational load, reduced sensitivity to initial conditions and improved estimation accuracy, making it suitable for online applications. Simulation results show that the proposed algorithm is capable of estimating the slowly-varying sensor noise covariance for multiple-input and multiple-output systems with noise covariance varying linearly, exponentially, or linearly with sinusoid fluctuation. Furthermore, the proposed estimation algorithm shows a reasonable rate of convergence, better estimation accuracy and less computation load in contrast to published literature.
Keywords: Sensor aging noise; covariance identification; Kalman filter; covariance matching; discrete time-varying system.
An analytical approach to optimal control of nonlinear systems with input constraints
by Mehdi Mirzaei, Reza Mojed Gharamaleki, Sadra Rafatnia, Behrooz Alizadeh
Abstract: In this paper, a novel optimal control method with the analytical solution strategy is developed for a wide class of nonlinear systems with input constraints. First, an equivalent constrained optimization problem is formulated by performing a quadratic performance index including the control inputs and the predicted tracking errors. Then, the problem is analytically solved by using the Kerush-Kuhn-Tucker (KKT) theorem to find the optimal control law. For comparison, a computational technique based on calling the genetic algorithm (GA) is also provided to online solving the developed optimization problem. The proposed control method with two solutions is applied on a mathematical example and a chemical reactor which is a multi-input multi-output (MIMO) system. The results show that the proposed KKT-based predictive controller is effective from different aspects. Importantly, it is very fast, easy to solve and suitable for online implementation compared with the conventional nonlinear model predictive control (NMPC) method.
Keywords: Constrained optimal control; Nonlinear systems; Prediction; Optimization; Analytical solution.
Robust cooperative adaptive cruise control design and implementation for connected vehicles
by Mark Trudgen, Rebecca Miller, Javad Mohammadpour Velni
Abstract: Cooperative adaptive cruise control (CACC) is a developing technology that achieves reduced inter-vehicle distance following in order to increase roadway capacity. CACC provides much lower headway values than adaptive cruise control (ACC) or human drivers can; however, this relies on real-time acceleration data, which inherently has inexact timing. In order to implement a string stable CACC platoon following scheme, meaning that disturbances are attenuated down the stream of the platoon of vehicles, while also overcoming the inherent challenges of wireless communication and uncertain internal model parameters, we design an H∞ controller that is robust to all aforementioned uncertainties. We implement this controller on a laboratory-scale test bed with an anti-windup compensation scheme and particularly show that the controller design is able to account for communication shortcomings.
Keywords: cooperative adaptive cruise control; CACC; robust H∞ control; anti windup; loop shaping; platoon following; wireless communication; cyber physical systems; CPSs.
A new approach in three-axis satellite stabilisation using redundant thruster in elliptical orbit
by M. Fakoor, A. Sattarzadeh, M. Bakhtiari
Abstract: Three-axis attitude stabilisation of a satellite in a LEO elliptical orbit, with respect to the effects of applied disturbances such as eccentricity, gravity gradient, solar radiation pressure and aerodynamic loads is presented by applying three reaction wheel actuators. A new attitude stabilisation method is investigated by considering failure in one or more reaction wheels. If any failure happens in reaction wheels, redundant thruster will be added to the system by gimbal mechanism as an input controlling actuator. Control algorithm based on dynamic and kinematic equations of the satellite's motion is developed. Considering the variable satellite model in different situations, neuro-fuzzy controller is employed. For training the intelligent neuro-fuzzy controller, PID controller is utilised. Numerical simulations show that the recommend control method has acceptable results and supplementing of a thruster actuator as redundancy, could increase the space mission reliability.
Keywords: satellite; attitude control subsystem; ACS; neuro-fuzzy; PID controller; reaction wheel; elliptical orbit.
Extension of operating air-gap in electromagnetic levitation system by using intelligent controllers
by Subrata Banerjee
Abstract: Electromagnetic levitation system (EMLS) is inherently unstable and strongly nonlinear in nature. The parameters of EMLS undergo considerable variation with change in air-gap. This makes the design and implementation of robust controllers difficult. This paper deals with intelligent controllers utilising gravitational search algorithm (GSA) based piecewise linear control and GSA based fuzzy control scheme to extend the range of operating air-gap for an EMLS. Extensive simulation has been carried out for the tuning of controller parameters and it is found the GSA based technique produces improved performance. Robust design of controllers for different zones is confirmed by Kharitonov/Nyquist enclosure. The controllers are tested in a small-scale system in the laboratory confirming the usefulness of the proposed technique. Such systems are useful for magnetic levitation (maglev) based applications those need to operate in a large operating air-gap.
Keywords: electromagnetic levitation; DC-DC power converters; PWM; fuzzy control; gravitational search algorithm; GSA; piecewise linear control; robust control.
Literature survey for autonomous vehicles: sensor fusion, computer vision, system identification and fault tolerance
by Amr Mohamed, Jing Ren, Moustafa El-Gindy, Haoxiang Lang, A.N. Ouda
Abstract: Autonomous vehicle technologies are receiving great attention with increasing demands for autonomy for both civilian and military purposes. In previous work (Mohamed et al., 2016), the recent developments in autonomous vehicles in the fields of advanced control, perception and motion planning techniques is surveyed. In this paper, the state of research w.r.t. autonomous vehicles from different perspectives will be described. The capability to integrate data and knowledge from different sensors are essential. In addition, advanced perception techniques and the capability to locate obstacles and targets are necessary to properly operate autonomous systems. Moreover, achieve reliable levels of performance by determining the faults and enabling the system to operate with these faults in mind. Fault tolerance is required to analysing the measured input/output signals of the system. This paper will briefly survey the recent developments in the field of autonomous vehicles from the perspectives of sensor fusion, computer vision, system identification and fault tolerance.
Keywords: autonomous vehicles; sensor fusion; computer vision; system identification; fault tolerance.
PSO based parameter estimation and PID controller tuning for 2-DOF nonlinear twin rotor MIMO system
by Roshni Maiti, Kaushik Das Sharma, Gautam Sarkar
Abstract: The present paper proposes a control methodology for a nonlinear multi-input multi-output (MIMO) system that combines a stochastic optimisation and proportional-integral-differential (PID) control scheme. This methodology is demonstrated through a laboratory scale helicopter setup commonly known as the twin rotor MIMO system (TRMS). The objective is to design a stochastically optimal/near optimal control law that can simultaneously stabilise the TRMS with considerable cross-couplings and provide satisfactory tracking performance to reach a desired position. The proposed control methodology utilises two PID controllers independently employed for the two rotors of TRMS. A PSO based parameter estimation technique has been utilised in this paper to estimate the parameters of the nonlinear TRMS laboratory setup. The nonlinear TRMS model with estimated parameters is employed to tune the PID gains by means of PSO in an offline manner and then implemented in real-life experimentations. The proposed realisation of PID control strategy is implemented for both simulation and real-life experimentations and their results demonstrate the usefulness of the proposed methodology.
Keywords: multi-input multi-output system; MIMO; twin rotor MIMO system; TRMS; proportional-integral-derivative controller; PID; parameter estimation.
Special Issue on: Sliding Mode Control and Its Engineering Applications
Adaptive Terminal Sliding Mode Control of High- Order Nonlinear Systems
by Pooyan Alinaghi Hoseinabadi, Ali Soltani Sharif Abadi
Abstract: In recent decades, controller design has been attracted a great deal of interest of many researchers in control community which can make the job of many other researchers in different area of research easier. The present study aims to design a finite time adaptive control input for a high-order nonlinear system in presence of a variety of mismatched uncertainties and external disturbances. Adaptive Terminal Sliding Mode Control (ATSMC) method is used to design robust controller in a finite time. Also, adaptive concept is employed in ATSMC to estimate the upper bound of mismatched uncertainties and external disturbances and their estimations are used in control input. The finite time stability proof is performed by defining a proper candidate Lyapunov function. Numerical simulation results are carried out in Simulink/MATLAB to reveal the correctness of proposed design in this research. Finally, the performance criterion, Integral of the Square Value (ISV), is defined to provide a numerical comparison between the proposed adaptive controller and non-adaptive controller.
Keywords: Adaptive; Finite Time; SMC; High order; Terminal.
Chaos control of a four-dimensional fundamental power system using pole placement based proportional integral sliding mode control
by Manish Kumar, PIYUSH PRATAP SINGH
Abstract: In this paper, the problem of chaos control for a four-dimensional fundamental power system (FDFPS) model is investigated. Pole placement based proportional integral sliding mode control (PISMC) is designed to control the chaos present in the system. Proportional integral sliding mode control law is derived by placing the poles at appropriate location to control the chaotic behaviour in four-dimensional fundamental power systems. The sufficient condition is derived for the asymptotic stability of the sliding manifold using Lyapunov stability theory. The proposed controller reduces the chattering, simplifies the design of power system stabilizer. Further the proposed pole placement based PISMC is compared with conventional SMC approach. MATLAB is used for simulation. Simulation results show the effectiveness of proposed PISMC scheme.
Keywords: Chaotic system; Chaos control; SMIB power system; Proportional-Integral Sliding mode control; Lyapunov stability theory.
Hybrid petri network super twisting sliding mode control of wind turbine for maximum power point tracking
by Aghiles Ardjal, Rachid Mansouri, Maamar Bettayeb
Abstract: This paper deals with a hybrid sliding mode control and super twisting algorithm second order sliding mode control with Petri network (HSMC-STA) applied to reach the maximum power point tracking (MPPT) of a variable speed wind energy conversion system. It is aimed to solve the main and major undesired phenomenon faced by conventional sliding mode control, the high frequency oscillations (chattering), and to reduce the transient response (rise time) of super twisting algorithm second order sliding mode control systems. The design of a hybrid controller based on switching Petri network sliding mode control (PNSMC) is proposed, wherein a Petri network is used to supervise and switch between the classical sliding mode control law and the super twisting control law. The new hybrid controller is tested in a Simulink/Matlab environment. Simulation results of the proposed control scheme present good dynamic and steady-state performance compared to the classical SMC and high order sliding mode with respect to the reduction of the chattering phenomenon and transient response.
Keywords: Sliding mode super-twisting; Robust control; Petri network; Wind turbine; MPPT.
A memristor-based system with hidden hyperchaotic attractors, its circuit design, synchronisation via integral sliding mode control and an application to voice encryption
by Sundarapandian Vaidyanathan, Ahmad Taher Azar, Akif Akgul, Chang-Hua Lien, Sezgin Kacar, Unal Cavusoglu
Abstract: A memristor-based system with hyperchaos and hidden attractors is introduced
in this research work. The proposed four-dimensional memristor-based system exhibits
both line equilibrium and no-equilibrium for different choice of parameters. An
experimental emulation of the memristor-based system is carried out by an electronic
circuit. An adaptive integral sliding mode controller is designed for globally synchronising
a pair of memristor-based hyperchaotic systems with unknown parameters. As another
application, the memristive system with hyperchaos is applied for voice encryption, which
has potential applications in cryptosystems, computing and secure communication.
Keywords: Hyperchaos; hyperchaotic systems; circuit design; sliding mode control; memristors; hidden attractors; voice encryption.