Letteratura scientifica selezionata sul tema "IOPID CONTROLLER"

Over two decades, the fractional (non-integer) order PID (FOPID or PIλDµ ) controller was introduced and demonstrated to perform the better responses in comparison with the conventional integer order PID (IOPID). In this paper, the design of an optimal FOPID controller for a DC motor speed control system by the flower pollination algorithm (FPA), oneof the most efficient population-based metaheuristic optimization searching techniques, is proposed. Based on the modern optimization framework, five parameters of the FOPID controller are optimized by the FPA to meet the response specifications of the DC motor speed control system and defined as constraint functions. Results obtained by the FOPID controller are compared with those obtained by the IOPID designed by the FPA. As the simulation results show, the FOPID can provide significantly superior speed responses to the IOPID.

In this paper, a new control method for large time delay system is proposed. Firstly, the decreasing time delay controller is used to remodel large delay time plant into small delay time plant. Then, a fractional robust proportional-integral controller (FOPI) is designed, using the phase margin and cut-off frequency at a specified point in the Bode plot of flat robust conditions, to guarantee the desired control performance and the robustness of the high order system to the gain order system. For comparison between the fractional order proportional integral controller and the traditional integer order PID (IOPID) controller, the IOPID controller is also designed following the same proposed tuning specifications. The simulation results indicates that the both designed controllers work efficiently. Furthermore, the FOPI controller makes the large time-delay system get better control effect, the system has high robustness, adaptive ability and anti-jamming ability.

Fractional order Controllers have been used in several industrial cases to achieve better performance of the systems. This paper proposes a Fractional Order Proportional Integral Derivative (FOPID) controller. It is synthesized using Oustaloup approximation, and its parameters are tuned using the Genetic Algorithm (GA) optimization method. The aim is to minimize the error, the energy and the startup torques using two objective functions to improve the control performances and the robustness. The validity of the proposed controller is shown via simulation by controlling a two-link exoskeleton for children's gait rehabilitation, and the results are compared to an Integer order PID (IOPID) controller. Simulation results clearly indicate the superiority of the optimized FOPID in terms of trajectory tracking and the used torques. Moreover, the FOPID controller is tested with parameter uncertainties. Its robustness is proven against thigh and shank masses variation. Both controllers are simulated under the same frequency conditions using Simulink MATLAB R2018a.

A fractional order PID (FOPID) controller, which is suitable for control system designing for being insensitive to the variation in system parameter, is proposed for hydroturbine governing system in the paper. The simultaneous optimization for several parameters of controller, that is,Ki,Kd,Kp,λ, andμ, is done by a recently developed metaheuristic nature-inspired algorithm, namely, the firefly algorithm (FA), for the first time, where the selecting, moving, attractiveness behavior between fireflies and updating of brightness, and decision range are studied in detail to simulate the optimization process. Investigation clearly reveals the advantages of the FOPID controller over the integer controllers in terms of reduced oscillations and settling time. The present work also explores the superiority of FA based optimization technique in finding optimal parameters of the controller. Further, convergence characteristics of the FA are compared with optimum integer order PID (IOPID) controller to justify its efficiency. What is more, analysis confirms the robustness of FOPID controller under isolated load operation conditions.

This article is based on the theory of fractional calculus control, and put forward a kind of fractional order PI controller design method for lateral attitude control system of unmanned aerial vehicle (UAV) model. And the unit step response of the control system is analyzed in the simulation to improve the UAV flight control system stability and robustness. Use the controller parameter tuning method and combined with fuzzy reasoning to design IOPID controller, FOPI controller and fuzzy fractional order PI controller. Then, by exploiting Matlab, the frequency domain response and unit step response characteristics of the different control systems can be plotted. The results verified that the designed fuzzy fractional order controller for the attitude control system is effective.

This paper presents an analytical design method for fractional order proportional integral (FOPI) controller for the spherical tank which is modelled as a first order plus dead time (FOPDT) process. The design is based on the Bode’s ideal transfer function and fractional calculus. By using frequency domain, the proposed FOPI tuning rules are directly derived for a generalized first order plus dead time process and then applied to the transfer functions obtained at various operating points of the spherical tank. The performance of the designed FOPI controller is compared with the conventional integer order proportional integral derivative (IOPID) controller in simulation.

Parameter adjustment is usually applied for designing the proportional-integral-differential (PID) controllers. However, the ability to improve control performance by adjusting parameters is limited. Hence, with the goal to achieve ideal closed-loop response, this paper takes advantage of a structural optimization method for modifying the controller model. A symbolic adaptation algorithm for fractional order PID (FOPID) controller is employed to obtain precise nonlinear controller model. Firstly, a modeling comparison for nonlinear duffing system is carried out to highlight the efficiency of the symbolic adaptation algorithm. The case study indicates the proposed algorithm can establish compact dynamic models by amending the shortcomings of symbolic regression. Secondly, the proposed controller is restructured with the linear FOPID controller and its nonlinearity is increased by adjusting controllers’ components in symbolic form. The proposed controllers are simulated in an unstable second-order system, a time-delay system and a nonlinear VanderPol system. Compared with the IOPID and the FOPID controller, the symbolic adaptation algorithm improves the structural flexibility of these linear controllers. Meanwhile, the system response can better approximate the desired response and the structural integrity of the nonlinear controller model is guaranteed simultaneously. Finally, the nonlinear FOPD controllers for trajectory tracking experiments are carried out on a rotary inverted pendulum control system.

In recent years, power quality has become almost as important in the renewable energy sector. Much of today's research is focused on resolving power quality issues. These issues are related to a voltage (sags, swells, distortions, and imbalances), system response speed, harmonics, ripples, and Electromagnetic Interference (EMI). Many researchers have recently been working on various controllers to address power quality issues. These articles primarily address power quality issues that arise as a result of system response time, harmonics, and torque ripples. This study will be used to improve the performance of a photovoltaic (PV) fed multilevel inverter. In the field of renewable energy systems, controllers have played a critical role. Proportional (P), Proportional-Integral (PI), and Proportional Integral Derivative (PID), Fractional Order PID (FOPID), and Integral Order PID (IOPID) controllers are used in renewable energy systems to improve power quality. In this study, the response of the PI controller will be measured, analyzed, and compared to the response of the PI hysteresis controller. Existing methods make use of a photovoltaic-fed multilevel inverter, a boost converter, a multilevel inverter, and a proportional-integral (PI) controller. As a load, a three-phase induction motor is used. A PI hysteresis controller is used in place of a traditional PI controller in the proposed system. For the PI Controller, the Experimental Hardware prototype model is designed and validated. Simulation designs for existing and proposed systems are carried out using MATLAB Simulink, and the results are noted and verified. Keywords: PI controller, Multilevel Inverter (MLI), boost converter, hysteresis controller, ripple reduction, Photovoltaic module.

This study mainly investigates the current and speed control strategies of a doubly-fed induction generator (DFIG), which is applied to a tidal stream turbine (TST). Indeed, DFIG using integer-order PI (IOPI) controller has been widely proposed in the applications with a similar system, especially in wind energy conversion system (WECS). However, these conventional controllers cannot deal with the problems caused by the parameter variations satisfactorily under complex and harsh operation conditions, and may even deteriorate the performance. As a result, a fractional-order PI (FOPI) controller is considered to improve the efficiency and performance of DFIG-based TST in this paper. The FOPI controller, developed from the traditional IOPI controller and the fractional calculus theory, has a lot of prominent merits in many aspects, such as robustness, stability, and dynamic performance. In this paper, the proposed control strategies are embedded into the whole TST model which contains the tidal stream turbine, and the generator. The obtained simulation results demonstrate the prominent effectiveness and advantages of the proposed strategies compared with the conventional IOPI controller in terms of overshoot, static error, adjustment time, and robustness. It implies that FOPI controller could be a good candidate in TST applications.

This research presents a fractional order integral controller strategy, which improves the steering angle for Autonomous Underwater Vehicles (AUVs). The AUV mathematical modeling is presented. A Fractional Order Proportional Integral (FOPI) control scheme is implemented to ensure the yaw angle stability of the AUV steering under system uncertainty. The FOPI controller is validated with MATLAB/Simulink and is compared to the conventional Integer Order PI (IOPI) controller to track the yaw angle of the structure. The simulation results show that the proposed FOPI controller outperforms the IOPI controller and improves the AUV system steering and the overall transient response while ensuring the system's stability with and without external disturbances such as underwater current and different loading conditions.

Process control in industry is improving gradually with the innovations and implementation of new technology. Different control techniques are being used for process control. Proportional Integral and Derivative (PID) controller is employed in every facet of industrial automation. In any of control application, controller design is the most important part. There are different types of controller architectures available in control literature. The applications of PID controller span from small industries to high technology industries. Designing a PID controller to meet gain and phase margin specifications is a well-known design technique. If the gain and phase margin are not specified carefully, then the design may not be optimum in the sense that a large phase margin (more robust) that could give better performance. This research outlines the development and design of an infrared radiation heating profile controller. An attempt has been made to theoretically analyze the system, design of the Controller, their simulation, and real-time implementation of an infrared ceramic heating profile controller. The Controller has been subjected to comparative testing with a proportional control model to observe its performance and validate its effectiveness. PID controllers of this nature that are commercially available either lack the functionality of this unit or are too expensive to implement for research purposes. This unit has been designed with cost-effectiveness in mind but still meets the standards required for an industrial controller. Heating profiles are necessary and useful tools for the proper processing of a host of materials. The Controller developed in this research is able to meet a level of a fair degree of accuracy and track a heating profile. The results confirm that this programmable control model will be advantageous and a valuable tool in temperature regulation. This means that intensive studies into the effects of infrared radiation on materials are now feasible. Research of this nature could possibly expand the application of infrared as a heating mechanism. Although tests were conducted on this Controller, they are not meant to serve as an exhaustive analysis. The conclusions of these simulations do reveal the benefit of such a v controller. More rigorous investigation is suggested as a subject for further study. System identification of this nonlinear process is done using black box model, which is identified to be nonlinear and approximated to be a First Order plus Dead Time (FOPDT) model. In order to obtain an accurate mathematical expression of the IR heater used in this research, a step response test of the IR heater has been completed. This method of testing has been done in accordance with the Ziegler-Nichols, Astrom Hügglund, and Cohen-Coon methods. Simulation of the obtained transfer function, using Mat Lab software, showed good agreement. Although the transfer function represented a first-order model with transportation lag, the simulated results reflected an acceptable accuracy. An exhaustive study has been done on different PID controller tuning techniques. The PID controller of the model has been designed using the classical method, and the results have been analyzed. A compromise has been made between robustness and tracking performance of the system in the presence of time delay. The results of the simulation indicate the validity of the study. Integer order PID controller (IOPID) based on Bode plot and Nyquist plot has been designed. The results illustrate that the IOPID controllers have the capability of minimizing the control objectives better than the previously designed controllers (Ziegler-Nichols, Astrom-Hügglund, and Cohen-Coon method-based Controller).With the change in temperature occurs, the oscillations of the controlled system outputs are eliminated and the output steady state errors become very small. The results demonstrate that the IOPID controller is stable and it suppresses the cost function (Maximum overshoot, Rise Time, Settling time and Peak time) even in case of significant disturbances. IOPID controller has also been designed using Bode plot and Nyquist plot for high gain system. The results have shown that the responses of Ceramic IR heater temperature profile have been reduced to very small value and prove that the IOPID controller is still stable and it suppresses the cost function even if significant disturbances have occurred. Fuzzy Logic controller-based model reference has been designed. Its implementation indicates that the proposed Controller suppresses the output of the controlled system. The results illustrate that the proposed Controller only slightly vi improves the performance of the cost function. The various AI techniques (GA) and Soft Computing (bio inspired) based algorithm (BFO, ACO) for PID controller offers several advantages. These methods can be used for higher order process models in complex problems. Approximations that are typical to classical tuning rules are not needed. Compared to conventionally tuned system, GA, PSO, BFO and ACO tuned system provides good steady state response and performance indices. The genetic approaches can achieve better temperature control with smaller settling time, overshoot and undershoot, and zero steady error. The control signal changes more frequently and with larger magnitude as the genetic algorithms are stochastic in nature. The PSO has an additional unique advantage that it adapts any change in system conditions, and obtains different system dynamics accurately in a short time period. It is a random search method but if combined with an artificial intelligence features, it tracks required system dynamics accurately in short time (small number of iterations). The BFO based Controller has the advantage of a better closed loop time constant, which enables the Controller to act faster with a balanced overshoot and settling time. The response of the conventional Controller is more sluggish than the BFO based Controller. Compared to conventionally tuned system, BFO tuned system has better steady state response and performance indices. Ant- Colony algorithm (ACO) has no special requirements on the characteristics of optimal designing problems, which has a fairly good universal adaptability and a reliable operation of program with ability of global convergence. Simulation results show the controlled system has satisfactory response and the proposed method has an effective tuning strategy. ACO shows better performance for PID controller parameter tuning of the considered control system. The simulation results show that the proposed method achieve minimum tracking error and estimate the parameter values with high accuracy. The work presents tuning method for fractional order proportional Integral and derivative controllers (FOPID) for the first order plus time delay (FOPTD) class of systems based on gain and phase margin. Techniques such as fractional order PID controller design and the results of their application to real-world system vii have been presented. A comparative study has been done using different control techniques to analyze the performance of different controllers. First, the conventional PID controller is implemented as primary Controller. The performance of PID, IOPID, Fuzzy Logic Controller, and Artificial Intelligence based PID, Bio inspired based PID controller and FOPID controllers have been examined. It has been concluded that the overall performance of the FOPID-based Controller is better than other controllers. In real-time implementation, the performance of the process control includes the time required by the heater to be settled on the initial set-up temperature. The rising of temperature is slow due to the resistance heating element used in ceramic infrared heaters. So the settling time is very high. The results obtained by simulation and real-time implementation with fractional order PID controller show overall better performance( rise time , settling time, peak time and peak overshoot) in comparison with other designed and implemented Controllers embedded with ceramic infrared systems. Further stability problems of fractional order system with leakage delay and distributed delay with hybrid feedback controller have been solved (with examples) using the Mittag-Leffler function and Lyapunov direct method and proved Global Mittag-Leffler stability of fractional order system of the proposed model which implies faster convergence rate of the network model which represents the stability of the system. This work performs a small-scale test measuring controller performance so that it serves as a platform for future research efforts leading to the real-life implementation of a Ceramic Infrared Heater Temperature control system.

Drone control systems are experiencing more and more challenges when integrating with more sensors. For example, the drone visual servoing systems often have a large sampling period due to limited on-board computing capability. Therefore, controllers that can tolerate a large sampling period are needed. Our previous work showed that a fractional order proportional-derivative controller (FOPD controller) can tolerate a larger sampling period than an integer order proportional-integralderivative controller (IOPID controller). In this paper, we verified this conclusion using control system stability criteria to estimate the largest sampling periods and time-domain simulation.

This paper considers the fractional order proportional derivative (FOPD) controller and fractional order [proportional derivative] (FO[PD]) controller for networked position servo systems. The systematic design schemes of the networked position servo system with a time delay are presented. It follows from the Bode plot of the FOPD system and the FO[PD] that the given gain crossover frequency and phase margin are fulfilled. Moreover, the phase derivative w.r.t. the frequency is zero, which means that the closed-loop system is robust to gain variations at the given gain crossover frequency. However, sometimes we can not get the controller parameters to meet our robustness requirement. In this paper, we have studied on this situation and presented the requirement of the gain cross frequency, and phase margin in the designing process. For the comparison of fractional order controllers with traditional integer order controller, the integer order proportional integral differential (IOPID) was also designed by using the same proposed method. The simulation results have verified that FOPD and FO[PD] are effective for networked position servo. The simulation results also reveal that both FOPD controller and FO[PD] controller outperform IO-PID controller for this type of system.

Abstract Ethernet Control Automation Technology (EtherCAT) applies distributed clock (DC) to realize synchronization among different slaves. Due to the influence of the crystal oscillator manufacturing process and environment, there is still synchronization error between reference clock and non-reference clock. To solve the clock synchronization problem, this paper proposes a clock drift compensation algorithm based on the idea of closed-loop control. By designing integer-order proportional integral (IOPI) and fractional-order proportional integral (FOPI) controllers, the synchronization error between slaves can be minimized. The IOPI and FOPI controllers designed in this paper are used to eliminate the drift error. This method improves the synchronization accuracy without bringing too much computational load. The results show that the proposed FOPI controller can effectively reduce the synchronization error with even better performance over the IOPI controller.