3,345 research outputs found
A novel technique for load frequency control of multi-area power systems
In this paper, an adaptive type-2 fuzzy controller is proposed to control the load frequency of a two-area power system based on descending gradient training and error back-propagation. The dynamics of the system are completely uncertain. The multilayer perceptron (MLP) artificial neural network structure is used to extract Jacobian and estimate the system model, and then, the estimated model is applied to the controller, online. A proportional–derivative (PD) controller is added to the type-2 fuzzy controller, which increases the stability and robustness of the system against disturbances. The adaptation, being real-time and independency of the system parameters are new features of the proposed controller. Carrying out simulations on New England 39-bus power system, the performance of the proposed controller is compared with the conventional PI, PID and internal model control based on PID (IMC-PID) controllers. Simulation results indicate that our proposed controller method outperforms the conventional controllers in terms of transient response and stability
Extruder for food product (otak–otak) with heater and roll cutter
Food extrusion is a form of extrusion used in food industries. It is a process by which a set of mixed ingredients are forced through an opening in a perforated plate or die with a design specific to the food, and is then cut to a specified size by blades [1]. Summary of the invention principal objects of the present invention are to provide a machine capable of continuously producing food products having an’ extruded filler material of meat or similarity and an extruded outer covering of a moldable food product, such as otak-otak, that completely envelopes the filler material
A survey of fuzzy control for stabilized platforms
This paper focusses on the application of fuzzy control techniques (fuzzy
type-1 and type-2) and their hybrid forms (Hybrid adaptive fuzzy controller and
fuzzy-PID controller) in the area of stabilized platforms. It represents an
attempt to cover the basic principles and concepts of fuzzy control in
stabilization and position control, with an outline of a number of recent
applications used in advanced control of stabilized platform. Overall, in this
survey we will make some comparisons with the classical control techniques such
us PID control to demonstrate the advantages and disadvantages of the
application of fuzzy control techniques
A robust PID autotuning method for steam/water loop in large scale ships
During the voyage of the ship, disturbances from the sea dynamics are frequently changing, and the ship's operation mode is also varied. Hence, it is necessary to have a good controller for steam/water loop, as the control task is becoming more challenging in large scale ships. In this paper, a robust proportional-integral-derivative (PID) autotuning method is presented and applied to the steam/water loop based on single sine tests for every sub-loop in the steam/water loop. The controller is obtained during which the user-defined robustness margins are guaranteed. Its performance is compared against other PID autotuners, and results indicate its superiority
The application of a new PID autotuning method for the steam/water loop in large scale ships
In large scale ships, the most used controllers for the steam/water loop are still the proportional-integral-derivative (PID) controllers. However, the tuning rules for the PID parameters are based on empirical knowledge and the performance for the loops is not satisfying. In order to improve the control performance of the steam/water loop, the application of a recently developed PID autotuning method is studied. Firstly, a 'forbidden region' on the Nyquist plane can be obtained based on user-defined performance requirements such as robustness or gain margin and phase margin. Secondly, the dynamic of the system can be obtained with a sine test around the operation point. Finally, the PID controller's parameters can be obtained by locating the frequency response of the controlled system at the edge of the 'forbidden region'. To verify the effectiveness of the new PID autotuning method, comparisons are presented with other PID autotuning methods, as well as the model predictive control. The results show the superiority of the new PID autotuning method
DEVELOPMENT & PERFORMANCE EVALUATION OF HYBRID NN – PID CONTROLLER FOR DC SERVOMOTOR
The project focuses on position control of the DC Servo Motor MS150 Servomotor
Modular. The objectives of the project is to design and develop an advanced control
strategy for the use in the servomotor as well as to observe, evaluate and compare the
controller performances of a proposed advanced controller – Artificial Neural
Network (ANN) with the conventional controller that is Proportional – Integral –
Derivative (PID) Control. This approach is selected to investigate and evaluate the
conventional method in controlling the position of DC servomotor due to the
advantage of cost reduction, simplicity, flexibility and also provides better
performance. Based on the information obtained from servomotor modular, the
controllers are designed and simulated using MATLAB/SIMULINK to analyze their
initial performance. Finally, the performance of the controllers are compared and
evaluated and the validation is done in terms of time response, overshoot response
and steady – state error
Robust data assimilation in river flow and stage estimation based on multiple imputation particle filter
In this paper, new method is proposed for a more robust Data Assimilation (DA) design of the
river flow and stage estimation. By using the new sets of data that are derived from the incorporated Multi
Imputation Particle Filter (MIPF) in the DA structure, the proposed method is found to have overcome the
issue of missing observation data and contributed to a better estimation process. The convergence analysis
of the MIPF is discussed and shows that the number of the particles and imputation influence the ability of
this method to perform estimation. The simulation results of the MIPF demonstrated the superiority of the
proposed approach when being compared to the Extended Kalman Filter (EKF) and Particle Filter (PF)
Novel strategies for process control based on hybrid semi-parametric mathematical systems
Tese de doutoramento. Engenharia QuĂmica. Universidade do Porto. Faculdade de Engenharia. 201
State of the art of control schemes for smart systems featuring magneto-rheological materials
This review presents various control strategies for application systems utilizing smart magneto-rheological fluid (MRF) and magneto-rheological elastomers (MRE). It is well known that both MRF and MRE are actively studied and applied to many practical systems such as vehicle dampers. The mandatory requirements for successful applications of MRF and MRE include several factors: advanced material properties, optimal mechanisms, suitable modeling, and appropriate control schemes. Among these requirements, the use of an appropriate control scheme is a crucial factor since it is the final action stage of the application systems to achieve the desired output responses. There are numerous different control strategies which have been applied to many different application systems of MRF and MRE, summarized in this review. In the literature review, advantages and disadvantages of each control scheme are discussed so that potential researchers can develop more effective strategies to achieve higher control performance of many application systems utilizing magneto-rheological materials
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