27 documents found, page 1 of 3
Limit Cycle Prediction of Systems with Fractional Controllers and Backlash
Barbosa, Ramiro S.; Machado, J. A. TenreiroThis article investigates the limit cycle (LC) prediction of systems with backlash by means of the describing function (DF) when using discrete fractional-order (FO) algorithms. The DF is an approximate method that gives good estimates of LCs. The implementation of FO controllers requires the use of rational approximations, but such realizations produce distinct dynamic types of behavior. This study analyzes th...
Neural control of an autonomous robot
Pinto, Adriano; Barbosa, Ramiro S.; Silva, Manuel SantosThis article aims to apply the concepts associated with artificial neural networks (ANN) in the control of an autonomous robot system that is intended to be used in competitions of robots. The robot was tested in several arbitrary paths in order to verify its effectiveness. The results show that the robot performed the tasks with success. Moreover, in the case of arbitrary paths the ANN control outperforms othe...
Traveled Distance Estimation Algorithm for Indoor Localization
Terra, Rui; Figueiredo, Lino; Barbosa, Ramiro S.; Anacleto, RicardoThis paper presents an ankle mounted Inertial Navigation System (INS) used to estimate the distance traveled by a pedestrian. This distance is estimated by the number of steps given by the user. The proposed method is based on force sensors to enhance the results obtained from an INS. Experimental results have shown that, depending on the step frequency, the traveled distance error varies between 2.7% and 5.6%.
Realization of Fractional-Order Controllers: Analysis, Synthesis and Applicatio...
Barbosa, Ramiro S.; Jesus, Isabel S.; Silva, Manuel S.; Machado, J. A. TenreiroThe synthesis and application of fractional-order controllers is now an active research field. This article investigates the use of fractional-order PID controllers in the velocity control of an experimental modular servo system. The system consists of a digital servomechanism and open-architecture software environment for real-time control experiments using MATLAB/Simulink. Different tuning methods will be emp...
Application of fractional calculus in engineering
Machado, J. A. Tenreiro; Jesus, Isabel S.; Barbosa, Ramiro S.; Silva, Manuel F.; Reis, CecíliaFractional Calculus (FC) goes back to the beginning of the theory of differential calculus. Nevertheless, the application of FC just emerged in the last two decades. It has been recognized the advantageous use of this mathematical tool in the modelling and control of many dynamical systems. Having these ideas in mind, this paper discusses a FC perspective in the study of the dynamics and control of several syst...
Fractional Control of Dynamic Systems
Barbosa, Ramiro S.; Machado, J. A. TenreiroThe concepts involved with fractional calculus (FC) theory are applied in almost all areas of science and engineering. Its ability to yield superior modeling and control in many dynamical systems is well recognized. In this article, we will introduce the fundamental aspects associated with the application os FC to the control of dynamic systems.
Fractional control of dynamic systems
Barbosa, Ramiro S.; Machado, J. A. TenreiroThe concepts involved with fractional calculus (FC) theory are applied in almost all areas of science and engineering. Its ability to yield superior modeling and control in many dynamical systems is well recognized. In this article, we will introduce the fundamental aspects associated with the application of FC to the control of dynamic systems.
Realization of fractional-order controllers: analysis, synthesis and applicatio...
Barbosa, Ramiro S.; Jesus, Isabel S.; Silva, Manuel F.; Machado, J. A. TenreiroThe synthesis and application of fractional-order controllers is now an active research field. This article investigates the use of fractional-order PID controllers in the velocity control of an experimental modular servo system. The systern consists of a digital servomechanism and open-architecture software environment for real-time control experiments using MATLAB/Simulink. Different tuning methods will be em...
Application of genetic algorithms in the design of an electrical potential of f...
Jesus, Isabel S.; Machado, J. A. Tenreiro; Barbosa, Ramiro S.Fractional calculus (FC) is currently being applied in many areas of science and technology. In fact, this mathematical concept helps the researches to have a deeper insight about several phenomena that integer order models overlook. Genetic algorithms (GA) are an important tool to solve optimization problems that occur in engineering. This methodology applies the concepts that describe biological evolution to ...
Effect of fractional orders in the velocity control of a servo system
Barbosa, Ramiro S.; Machado, J. A. Tenreiro; Jesus, Isabel S.The application of fractional-order PID controllers is now an active field of research. This article investigates the effect of fractional (derivative and integral) orders upon system's performance in the velocity control of a servo system. The servo system consists of a digital servomechanism and an open-architecture software environment for real-time control experiments using MATLAB/Simulink tools. Experiment...