Showing papers on "Open-loop controller published in 2016"
TL;DR: In this paper, a maiden attempt has been made to apply a Proportional integral-Proportional derivative (PI-PD) cascade controller in automatic generation control (AGC) of an interconnected four area thermal system.
164 citations
TL;DR: The supremacy of the proposed LUS–TLBO algorithm optimized fuzzy-PID controller is proved for both the power systems (with and without HVDC link) by comparing the results with that of recently published article based on Differential Evolution algorithm optimized conventional PID controller.
162 citations
TL;DR: The superiority of the proposed FA optimized fuzzy PID controller has been demonstrated by comparing the results with some recently published approaches such as optimal control and Differential Evolution optimized PID controller for the identical interconnected power system.
160 citations
TL;DR: In this article, a quasi-proportional-resonant (quasi-PR) controller is applied to reduce the steady-state current tracking errors of the CGCI.
Abstract: The capacitive-coupling grid-connected inverter (CGCI) is coupled to the point of common coupling via a second-order LC branch. Its operational voltage is much lower than that of a conventional inductive-coupling grid-connected inverter (IGCI) when it serves as a multifunctional inverter to compensate reactive power and transfer active power simultaneously. It is a promising solution for microgrid and building-integrated distributed generator systems. A quasi-proportional-resonant (quasi-PR) controller is applied to reduce the steady-state current tracking errors of the CGCI in this paper. The quasi-PR controller generates the voltage reference for use of carrier-based pulse-width modulation, which can effectively reduce output current ripples. The second-order coupling impedance of the CGCI causes its modeling and controller design to differ from that of the conventional IGCI. A comprehensive design method for the quasi-PR controller in a CGCI is developed. The quasi-PR controller is also compared with a proportional-integration current controller. Simulation results are provided to verify the effectiveness of the quasi-PR controller and its design method in a CGCI. The current tracking errors are greatly reduced when the quasi-PR controller rather than the proportional-integration controller is applied. Experimental results are also provided to validate the CGCI as a multifunctional grid-connected inverter.
128 citations
TL;DR: A Fractional Order PID (FOPID) controller based on Gases Brownian Motion Optimization (GBMO) is used in order to mitigate frequency and exchanged power deviation in two-area power system with considering governor saturation limit.
Abstract: Load-frequency control is one of the most important issues in power system operation. In this paper, a Fractional Order PID (FOPID) controller based on Gases Brownian Motion Optimization (GBMO) is used in order to mitigate frequency and exchanged power deviation in two-area power system with considering governor saturation limit. In a FOPID controller derivative and integrator parts have non-integer orders which should be determined by designer. FOPID controller has more flexibility than PID controller. The GBMO algorithm is a recently introduced search method that has suitable accuracy and convergence rate. Thus, this paper uses the advantages of FOPID controller as well as GBMO algorithm to solve load-frequency control. However, computational load will higher than conventional controllers due to more complexity of design procedure. Also, a GBMO based fuzzy controller is designed and analyzed in detail. The performance of the proposed controller in time domain and its robustness are verified according to comparison with other controllers like GBMO based fuzzy controller and PI controller that used for load-frequency control system in confronting with model parameters variations.
112 citations
TL;DR: A fixed switching frequency scheme for finite-control-set model predictive control is presented to achieve an output waveform quality that compares well to that of a pulse-width-modulator-based linear controller, while retaining the benefits of model predictivecontrol.
Abstract: A fixed switching frequency scheme for finite-control-set model predictive control is presented to achieve an output waveform quality that compares well to that of a pulse-width-modulator-based linear controller, while retaining the benefits of model predictive control. The controller is divided into two parts: the offline calculation and storage of the coefficients of the prediction equations and the online evaluation of the controller. The controller is experimentally evaluated on a five-level flying-capacitor converter.
98 citations
TL;DR: The results demonstrate that the proposed controller has a better performance related to conventional sliding mode and proportional–integral controllers in terms of the settling time and robustness to the disturbances.
Abstract: In this study, a fast terminal sliding-mode control scheme is proposed as a new approach for the voltage tracking control of the DC-DC boost converter affected by disturbances, such as the variations in the input voltage and the load resistance. Some experiments are performed on a test bench to show the effectiveness of the proposed approach. The fast reference tracking capability with small overshoot and robustness to the disturbances of the designed controller is verified by the experimental results. Moreover, the results demonstrate that the proposed controller has a better performance related to conventional sliding mode and proportional-integral controllers in terms of the settling time and robustness to the disturbances.
91 citations
TL;DR: From the simulation test results, it is evident that bat optimized fuzzy proportional derivative controller has superior performance than the other controllers considered.
89 citations
TL;DR: An analysis of commonality of three lateral nonlinear adaptive controllers based on the immersion and invariance (I & I) principle is presented to highlight the advantages and drawbacks of each control approach in lateral tracking of a reference trajectory.
Abstract: This paper focuses on the lateral control of intelligent vehicles; the aim is to minimize the lateral displacement of the autonomous vehicle with respect to a given reference trajectory. The control input is the steering angle, and the output is the lateral error displacement. We present here an analysis of commonality of three lateral nonlinear adaptive controllers. The first controller is a higher order sliding-mode controller (SMC). The second controller is based on the immersion and invariance $(I \& I)$ principle. The design of this controller led us to prove a very strong stability criterion of the closed-loop system for all controller gains chosen to be positive. Thereafter, some interesting characteristics of passivity of the systems were proved following this development. Hence, the third controller is a passivity-based controller (PBC), an adaptive PI controller based on the feedback of a passive output. To validate our control laws, tests have been performed on SCANeR Studio, a driving simulation engine, according to several real driving scenarios. A comparison of these different controllers is made to highlight the advantages and drawbacks of each control approach in lateral tracking of a reference trajectory.
82 citations
TL;DR: In this paper, a fuzzy fractional order PI+I (FFOPI+I) controller for grid connected Variable Speed Wind Energy Conversion System (VS-WECS) is proposed.
75 citations
TL;DR: This study presents a comprehensive analytical study of a fuzzy proportional-integral-derivative (fuzzy-PID) controller with derivative filters for automatic generation control (AGC) in multi-area power system tuned by a novel hybrid local unimodal sampling-teaching learning based optimisation (LUS-TLBO) algorithm.
Abstract: This study presents a comprehensive analytical study of a fuzzy proportional-integral-derivative (fuzzy-PID) controller with derivative filter (fuzzy-PIDF) for automatic generation control (AGC) in multi-area power system tuned by a novel hybrid local unimodal sampling-teaching learning based optimisation (LUS-TLBO) algorithm. The relevant advantage of this recommended controller is its high sensitivity to load perturbation. Initially a two area non-reheat type thermal system is considered and the gains of PIDF controller are tuned employing hybrid LUS-TLBO algorithm. The supremacy of PIDF controller is shown by comparing the results with some recently published articles. The study is further extended to design fuzzy logic based PID controller with derivative filter (fuzzy-PIDF) for AGC of the same power system employing hybrid LUS-TLBO algorithm. Supremacy of the proposed approach is shown by comparing the results with another recently published article. In addition, the work is also extended to deal with AGC issues in two area multi source hydro thermal power system using the proposed controller. Finally, it is seen that fuzzy-PIDF controller retains its supremacy over PID/PIDF/fuzzy-PID controllers. In addition to it, robustness analysis is carried out for the non-reheat two area thermal power systems by varying different parameters within the range of ±50%.
TL;DR: Optimal pole-zero approximation method in discrete form is proposed for realization of digital fractional order controller and shows better speed control of separately excited DC motor with the realized digital FO-PID controller than that of the integer order PID controller.
Abstract: The aim of paper is to employ digital fractional order proportional integral derivative (FO-PID) controller for speed control of buck converter fed DC motor. Optimal pole-zero approximation method in discrete form is proposed for realization of digital fractional order controller. The stand-alone controller is implemented on embedded platform using digital signal processor TMS320F28027. The five tuning parameters of controller enhance the performance of control scheme. For tuning of the controller parameters, dynamic particle swarm optimization technique is employed. The proposed control scheme is simulated on MATLAB and verified by experimental results. Performance comparison shows better speed control of separately excited DC motor with the realized digital FO-PID controller than that of the integer order PID controller.
TL;DR: An energy-saving controller that is capable of shaping the light output of an LED lighting system autonomously based on data received from sensors is presented, and an optimized smart algorithm on a controller to process the sensor feedback and employ pulse width modulation dimming to vary the brightness of the luminaire is implemented.
TL;DR: In this article, an adaptive second-order sliding mode output feedback controller is developed to deal with the case that the bound of the uncertainty/perturbation is unknown, and adaptive gain laws are provided to increase the controller and the observer gains until the closed loop has been stabilized.
Abstract: An adaptive second-order sliding mode output feedback controller is developed to deal with the case that the bound of the uncertainty/perturbation is unknown. The control structure consists in a twisting controller and a super-twisting observer to estimate the unmeasured variable. The gains of the controller and observer are parametrized in terms of a scalar gain, such that increasing these two gains, it is always possible to find values to finite-time stabilize the closed loop system. Finally, adaptive gain laws are provided to increase the controller and the observer gains until the closed loop has been stabilized. The main technical contribution of the paper is to give a sound and non-trivial Lyapunov analysis of this otherwise intuitively simple idea. We illustrate the performance of the proposed controller by means of experimental results in a laboratory setup. Copyright © 2016 John Wiley & Sons, Ltd.
TL;DR: In this article, a new optimal hybrid control approach called Optimal General Type II Fuzzy Sliding Mode (OGT2FSM) is presented, which not only warranties the constancy and hardiness against uncertainties of the lumped resulted by external disturbances and unmodeled dynamics, but also considerably decreases the control chattering inherent in traditional sliding mode control.
Abstract: In current study, in order to find the control of general uncertain nonlinear systems, a new optimal hybrid control approach called Optimal General Type II Fuzzy Sliding Mode (OGT2FSM) is presented. In order to estimate unknown nonlinear activities in monitoring dynamic uncertainties, the benefits of general type-2 fuzzy logic systems (GT2FLS) is utilized by the suggested controller. The suggested controller not only warranties the constancy and hardiness against uncertainties of the lumped resulted by external disturbances and un-modeled dynamics, but also considerably decreases the control chattering inherent in traditional sliding mode control. Moreover, the Modified Backtracking Search Algorithm (MBSA), which is a new heuristic algorithm, is used in the offered controller. A comparison is performed between the results of current study and the results of some of the most recent studies on the same topic, which are an Adaptive Interval Type-2 Fuzzy Logic Controller (AGT2FLC) and Conventional Sliding Mode Controller (CSMC), to assess the efficiency of the suggested controller. The suggested control scheme is finally used to the Electric Vehicles type as a case study. Results of simulation confirm the good performance the suggested controller.
TL;DR: In this article, a robust controller is presented that compensates for both types of uncertainties; the full mechanical and electrical dynamics of the turbine are considered These dynamics require acceleration of the rotor to provide feedback information which is not available in sufficiently accurate form during practice.
Abstract: This study exhibits the automatic generation control (AGC) of an unequal three-area thermal system having single reheat turbine, generation rate constraint, and governor dead band, in all areas. A three-degree-of-freedom proportional-integral-derivative (3DOF-PID) controller is used as secondary controller in all the areas and its dynamic performance is compared with that of classical PI, ID, and PID controllers. The controller parameters are simultaneously optimised using biogeography-based optimisation (BBO) technique, where 3DOF-PID controller outperforms the other. A hybrid pattern search BBO (hPS-BBO) technique is applied for the first time in AGC, to simultaneously optimise 3DOF-PID controller parameters. Comparison of dynamic responses corresponding to BBO and hPS-BBO optimised 3DOF-PID controller gives better performance of the latter. This is also validated with random disturbance. The considered system is checked for optimal location of interline power flow controller (IPFC) using BBO optimised 3DOF-PID controller. Observations reveal that IPFC placed between Line1 and Line3 is the optimal location. A comparatively better response is observed with hPS-BBO optimised 3DOF-PID controller parameters, having IPFC placed in its optimal location. Sensitivity analysis of the hPS-BBO optimised 3DOF-PID controller parameters is tested and found satisfactory for variations in system loading and inertia constant H
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TL;DR: An effective model free controller which is called Extended State Observer - based intelligent Proportional Integral (ESO-based iPI) controller is designed and this proposed method is composed mainly of the referred ESO observer, and a time delay estimation based iPI controller.
Abstract: In this paper modeling and common-rail pressure control of high pressure common rail injection system (HPCRIS) is presented. The proposed mathematical model of high pressure common rail injection system which contains three sub-systems: high pressure pump sub-model, common rail sub-model and injector sub-model is a relative complicated nonlinear system. The mathematical model is validated by the software Matlab and a virtual detailed simulation environment. For the considered HPCRIS, an effective model free controller which is called Extended State Observer - based intelligent Proportional Integral (ESO-based iPI) controller is designed. And this proposed method is composed mainly of the referred ESO observer, and a time delay estimation based iPI controller. Finally, to demonstrate the performances of the proposed controller, the proposed ESO-based iPI controller is compared with a conventional PID controller and ADRC.
TL;DR: In this paper, a super twisting sliding mode controller for a quadrotor Unmanned Aerial Vehicle (UAV) was proposed by utilising a cascaded inner outer loop structure.
TL;DR: General type-2 fuzzy logic sets and the modified harmony search algorithm techniques for adaptive tuning of the most popular existing proportional–integral (PI) controller is integrated in order to address uncertainties in the control of electrical vehicles.
Abstract: The control of electrical vehicles (EVs) should be designed robustly and adaptively to improve the system on both dynamic and steady-state performances, because EV systems are basically time variant (e.g. the operation parameters of EV and the road condition are always varying) that make the operation of controlling an EV difficult. In this study, general type-2 fuzzy logic sets and the modified harmony search algorithm techniques for adaptive tuning of the most popular existing proportional–integral (PI) controller is integrated in order to address these uncertainties. Although it is computationally expensive to carry out general type-2 fuzzy systems, it can be examined as a composition of several interval type-2 fuzzy logic systems with a corresponding level of α for each by using a new plan which is presented, general type-2 fuzzy set. The controller uses the linguistic rules directly. The achieved results are compared with optimal fuzzy-PI controller and optimal interval type-2 fuzzy-PI controller results which are the most recent researches into in the present issue to evaluate the proficiency of the proposed controller. The simulation results demonstrate the successfulness and effectiveness of the proposed controller.
TL;DR: In this article, a new observer-based adaptive fuzzy integral sliding mode controller is proposed based on the Lyapunov stability theorem for a real-time mechanical vibrating system.
TL;DR: An improved tuning methodology of PID controller for standard second order plus time delay systems (SOPTD) is developed using the approach of Linear Quadratic Regulator (LQR) and pole placement technique to obtain the desired performance measures.
Abstract: An improved tuning methodology of PID controller for standard second order plus time delay systems (SOPTD) is developed using the approach of Linear Quadratic Regulator (LQR) and pole placement technique to obtain the desired performance measures. The pole placement method together with LQR is ingeniously used for SOPTD systems where the time delay part is handled in the controller output equation instead of characteristic equation. The effectiveness of the proposed methodology has been demonstrated via simulation of stable open loop oscillatory, over damped, critical damped and unstable open loop systems. Results show improved closed loop time response over the existing LQR based PI/PID tuning methods with less control effort. The effect of non-dominant pole on the stability and robustness of the controller has also been discussed.
01 Oct 2016
TL;DR: Two-layered fractional order fuzzy logic controller (TL-FOFLC) scheme for a two-link planar rigid robotic manipulator with payload for trajectory tracking task outperforms its integer order design, conventional FLC and PID controller.
Abstract: Two-layered fractional order fuzzy logic controller (TL-FOFLC) is implemented for robotic manipulator.The optimal controller parameters are obtained with cuckoo search algorithm.Robustness analysis of proposed scheme is done with its integer order design, conventional FLC and PID controllers.The proposed scheme outperforms its integer order design, conventional FLC and PID controller. The robotic manipulators are highly coupled and nonlinear systems wherein the time-varying parameters and uncertainties adversely affect the characteristics and response of these systems. Hence, these systems require an effective and robust controller to handle such complexities which is a difficult challenge for control engineers. This paper presents two-layered fractional order fuzzy logic controller (TL-FOFLC) scheme for a two-link planar rigid robotic manipulator with payload for trajectory tracking task. For the optimal design, the controller parameters of the proposed scheme are obtained with potential meta-heuristic technique named as cuckoo search algorithm (CSA). In order to ensure effectiveness, the performance of proposed TL-FOFLC is compared with that of its integer order design approach, i.e., two-layered FLC (TL-FLC), single-layered FLC (SL-FLC), and the conventional proportional-integral-derivative (PID) controllers. Further, the robustness testing is carried out for parameter variations and external disturbance rejection.
TL;DR: In this article, a proportional integral derivative controller and a fuzzy logic controller are compared for a single-axis solar tracking system using an Atmel microcontroller, where a solar panel is oriented to the side where light intensity is greatest by being designed for the related supervisory controllers.
Abstract: Proportional integral derivative controllers are widely used in industrial processes because of their simplicity and effectiveness for linear and nonlinear systems. The fuzzy controller is the most suitable for the human decision-making mechanism, providing the operation of an electronic system with decisions of experts. In addition, using the fuzzy controller for a nonlinear system allows for a reduction of uncertain effects in the system control. In this study, a proportional integral derivative controller and a fuzzy logic controller are designed and compared for a single-axis solar tracking system using an Atmel microcontroller. According to the angle of solar energy, a solar panel is oriented to the side where light intensity is greatest by being designed for the related supervisory controllers. Thus, the aim is to increase the energy obtained from solar panels by providing the specular reflection of the sun’s rays to a solar panel. At the same time, a maximum efficient processing system has been determined by taking account of two controllers for the designed system.
TL;DR: This paper presents the implementation of a vision-based position control for planar cable-driven parallel robots using four-bar linkage kinematic concept, which could be used in online control approaches for real-time purposes.
TL;DR: This study presents the control and modelling of modular multilevel converter (MMC) with grid-connected photovoltaic system and designs and implements the fuzzy tuned PI controller, designed and implemented to overcome poor tuning of controller gain values.
Abstract: This study presents the control and modelling of modular multilevel converter (MMC) with grid-connected photovoltaic system. Synchronisation is an important issue in grid-connected system. Even though conventional proportional–integral (PI) controller used for synchronisation provides adequate performance, it yields poor transient response of the system because of poor tuning of controller gain values. In this study, the fuzzy tuned PI controller is designed and implemented to overcome this problem. The fuzzy logic controller refrains the controller gains based on the operating point of the system. The improved performance parameters such as faster transient response, tracking of the reference current with low overshoot and short settling time with system parameter changes under partial shading of the proposed controller are validated. The results are compared with conventional PI controlled grid-connected MMC with various PI gains. The developed controller algorithm is implemented through TMS320F28335 digital signal processor.
TL;DR: In this paper, the authors presented the automatic generation control of an unequal four-area thermal system with appropriate generation rate constraint and governor dead band (GDB) and compared the performance of several classical controllers, such as single degree-of-freedom proportional-integral-derivative (PID), 2DOF-PID, and three degree of freedom PID as secondary controllers.
Abstract: This study presents the automatic generation control of an unequal four-area thermal system with appropriate generation rate constraint and governor dead band (GDB). Performances of several classical controllers, such as single degree-of-freedom proportional–integral–derivative (PID), two degree-of-freedom PID (2DOF-PID) and three degree-of-freedom PID (3DOF-PID) as secondary controllers are evaluated separately in the system. An attempt is made to apply the successful evolutionary optimisation technique named as biogeography-based optimisation technique for simultaneous optimisation of several variables, such as controller gains, setpoint weights and so on. Comparison of dynamic responses corresponding to PID, 2DOF-PID and 3DOF-PID reveals that 3DOF-PID controller outperforms the others. Sensitivity analysis reveals that the optimum gains and other parameters of the optimal controller obtained at nominal conditions are robust and need not be reset for wide changes in system condition like system loading, system parameters such as inertia constant (H), synchronising coefficient (Tij ) and GDB. The performance of 3DOF-PID controller is also studied with different step-load perturbations (SLPs) and random-load perturbations (RLPs). Analysis proves that 3DOF-PID controller performs better than 2DOF-PID at different SLPs and RLPs.
TL;DR: In this article, the basic PID tuning method (Ziegler-Nichols) and its modification (Chien-Hrones-Reswick) are discussed, and the speed control DC motor response is analyzed using the PID controller parameters that result from the tuning methods mentioned earlier.
Abstract: The traditional PID controllers are used for a long time to control the DC motor for many industrial processes, that because of the simplicity, flexibility, and satisfactory performance of this type of controller. This paper discusses the basic PID tuning method (Ziegler-Nichols) and its modification (Chien-Hrones-Reswick). Also, analysis the speed control DC motor response using the PID controller parameters that result from the tuning methods mentioned earlier. Moreover, explain the advantage and disadvantage of each formula of these methods. GUL/MATLAB windows used to implementing both methods to create more comfortable and friendly environment for better understanding of the PID controller tuning methods formula for engineering students and practicing engineers.
TL;DR: In this paper, an integral sliding mode controller with a new anti-windup was proposed, which has low overshoot and no steady-state error, and an approach using a switching sigmoid function was presented.
Abstract: This work presents a sliding mode controller, applied to the three-phase induction motor using indirect field-oriented control technique. A possible approach for chattering reduction with high degree of robustness is based on the switching saturation function, although it presents steady-state error. This paper, therefore, proposes an integral sliding mode controller with a new anti-windup, which has low overshoot and no steady-state error. In addition, an approach using a switching sigmoid function is presented. The motor performance is verified by means of numeric simulations and experimental tests with load disturbances. The proposed controller presents better results when compared to other conventional sliding mode controllers and a tuned PI controller.
TL;DR: In this article, a PLC based PID controller is developed and its open loop responses are identified and simulation studies are carried out in the MATLAB/SIMULINK platform to ensure the performance of the controller.