The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The paper considers a reference-based control system for heaving wave energy converters. The proposed controller comprises two parts: lower level part (LLP) and higher level part (HLP). The HPL generates the buoy's velocity reference with the objective to maximize the power absorption with the constraints in the maximum control force and the power take-off device's utilization index. The index is...
This paper deals with the experimental results of implementing a fault tolerant control (FTC) in a classical ball-on-plate control framework. The work builds on the fact that a robust nominal controller is found to be insufficient in accommodating a sensor fault generated by the presence of a second ball. Invariant sets are used to monitor and detect occurrence of faults in the system and a switching...
This paper proposes a DC link controller based on H∞ method for robust and reliable operation of a single-phase grid-connected inverter with an LCL-filter in photovoltaic (PV) applications. The H∞ DC link controller minimizes the bus voltage fluctuations caused by the power variations of PV system. Also, the controller ensures system robustness against such power variations, which conventional controllers...
A design of a feed-forward-based fractional-order model reference adaptive control (FO-MRAC) compensator using a modified MIT rule to control a DC-DC boost converter is presented in this work. As the plant is non-minimum phase, an implementation of the so-called parallel feed-forward configuration is required to make the plant satisfy ASPR (almost strictly positive real) conditions that in turn, allows...
Because of nonlinear and strong coupling features, control system of permanent magnet synchronous motor usually requires high robustness, which can be achieved by fractional-order controller with strong ability against disturbances. A tuning approach based on D-decomposition method and maximum sensitivity is proposed to design fractional-order PIλ controller for permanent magnet synchronous motor...
The purpose of his paper is to offer a numerical strategy in order to control the thermal processes with distributed parameters. Designing the control system for processes of this kind is usually difficult, mostly because of their non-standard dynamic model representation. Using energy balance equations for the process-a heat exchanger, the model is obtained. The proposed solution is to design a polynomial...
Active rectifier topologies are used for different purposes, especially widespread in renewable generation and distributed energy sources. The most common configuration for active rectifiers is the back-to-back converter. In this article, a back-to-back structure for connecting a variable frequency source to the utility grid is observed and a control algorithm, robust to grid impedance values, is...
Aiming at multiple-input multiple-output (MIMO) systems with multiple time delays in the process industry, all-pole approximation is proposed for different time delays in this paper. What is more, in order to reinforce the tracking performance and controller robustness in the case of uncertainty and disturbance, loop transfer recovery method at output side is proposed to realize the multiple-loops...
The paper present an architecture multi-controller based in conventional PID controller and robust Fractional PID controller (FOPID) using PSO algorithm to optimize the parameters of PID and FOPID, and improved the robustness. This approach applied to control robotics wrist (Robot RX-90 Staübli). A brief overview of the process with a non-linear and linear mathematical modeling of the process. Principle...
For three-phase voltage-sourced PWM rectifier, a novel double closed loop control method was proposed in this paper, based on the mathematical model in synchronous rotating coordinate system. Considering the coupling characteristics, the current inner loop developed a practical hybrid control method, consisting of inverted decoupling and internal model control (IMC), which could realize the complete...
This paper studies the performance of a fractional-order proportional integral derivative (FOPID) controller designed for parabolic distributed solar collectors. The control problem addressed in concentrated solar collectors aims at forcing the produced heat to follow a desired reference despite the unevenly varying solar irradiance. In addition to the unpredictable variations of the energy source,...
In this paper, an enhanced form of modified Smith predictor (EMSP) is designed for the control of higher order stable systems. The higher order process, whose controller design is practically difficult, is reduced into first order plus delay (FOPDT) and second order plus delay (SOPDT) and thereby designing controllers capable to control servo and regulatory problems of its original higher order process...
This paper proposes a novel robust cascade structure which has better performance when the transmission line undergoes a perturbation. Cascade control structure is normally used when the control procedure can be split into two (or more) cascaded parts. Compared with the conventional cascade control structure which has a limited ability to handle the perturbation in the plant model, the novel structure...
We treat the design problem of second-degree IIR digital differentiators. The design problem (cost function) is formulated in the quadratic form without any frequency sampling. Since the cost function is the quadratic form, the solution is unique and the optimization scheme does not require any recursive optimization. Hence, the procedure of the design for the second-degree differentiators is very...
This paper presents a controller design methodology for linear dynamic systems with interval parameters. In order to overcome the conservatism of classical Interval Analysis methods applied to this class of uncertain systems, the paper proposes a solution for the problem of multi-incidences of model parameters when the controller design is based on interval Diophantine equations. The paper includes...
By using the vector control for direct-drive permanent magnet synchronous motor (DD-PMSM), the current static decoupling between d-axis and q-axis is realized, however, there still exists the dynamic coupling relationship. The d-q currents cannot be decoupled by the tradition PI method, and although the decoupling is accomplished to some extent by the internal model decoupling control method, the...
In this paper, we present a robust pole placement control scheme that can be used to control a wide class of linear and time invariant systems with unknown parameters, including nonminimum phase systems, using only plant input and output signals. We assume that the unknown plant parameters has known bounds, i.e., the control scheme is designed for an interval plant whose coefficients are closed intervals...
An active disturbance rejection controller (ADRC) is designed and originally implemented on a real torsional plant. The torsional plant resembles the dynamics of a rotational system. Due to mass imbalance, centrifugal imbalance, and the non-coincidence between the principal and geometric axes of a rotating disc, the system parameters of this torsional plant are varying constantly. In addition, an...
This paper presents an analytical decoupling approach to designing a velocity and altitude tracking autopilot for a generic hypersonic vehicle (GHV). Different from other decoupling control methods which need to design a decoupler and a controller, the adopted design method only needs to design one controller to satisfy both set-point tracking and decoupling requirements simultaneously. Besides, the...
This paper deals with the robust control problem for linear systems with both gain and time constants variations under fractional order PIλDμ controller. A robustness specification to the parameters variations is proposed. For those systems with more than one uncertain time constant, the robustness specifications are analyzed and simplified. To minimize the phase offset nearby the crossover frequency,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.