Percorrer por autor "Ferreira, N. M. Fonseca"
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- Analysis and control of a dragonfly-inspired robotPublication . Couceiro, Micael S.; Ferreira, N. M. Fonseca; Tenreiro Machado, J. A.Dragonflies demonstrate unique and superior flight performances than most of the other insect species and birds. They are equipped with two pairs of independently controlled wings granting an unmatchable flying performance and robustness. In this paper it is studied the dynamics of a dragonfly-inspired robot. The system performance is analyzed in terms of time response and robustness. The development of computational simulation based on the dynamics of the robotic dragonfly allows the test of different control algorithms. We study different movement, the dynamics and the level of dexterity in wing motion of the dragonfly. The results are positive for the construction of flying platforms that effectively mimic the kinematics and dynamics of dragonflies and potentially exhibit superior flight performance than existing flying platforms.
- Analysis of Two Arms Working in CooperationPublication . Ferreira, N. M. Fonseca; Machado, J. A. Tenreiro; Cunha, J. BoaventuraThis paper analyzes the performance of two cooperative robot manipulators. In order to capture the working performancewe formulated several performance indices that measure the manipulability, the effort reduction and the equilibrium between the two robots. In this perspective the proposed indices we determined the optimal values for the system parameters. Furthermore, it is studied the implementation of fractional-order algorithms in the position/force control of two cooperative robotic manipulators holding an object.
- Aplication of fractional algoritms in the control of an helicopter systemPublication . Coelho, J.; Neto, R. Matos; Lebres, C.; Fachada, H.; Ferreira, N. M. Fonseca; Pires, E. J. Solteiro; Tenreiro Machado, J. A.This paper compares the application of fractional and integer order controllers for a laboratory helicopter twin rotor MIMO system using the MatLab package.
- Application of fractional algorithms in the control of a twin rotor multiple input-multiple output systemPublication . Coelho, J.; Neto, R. Matos; Lebres, C.; Santos, Victor; Ferreira, N. M. Fonseca; Pires, E. J. Solteiro; Tenreiro Machado, J. A.This paper presents the modelling and control of a laboratory helicopter twin rotor MIMO system using the MatLab package. Firstly, we provide an overview of the system model, secondly, we compare the behaviour of fractional and integer order controllers used a PSO algorithm for the controller optimization in order to obtain the minimum error. Finally, we analyse the system performance and the results obtained with the real helicopter show that fractional algorithms are smoother than conventional PID. Both controllers reveal good output responses but the PID needs more energy to perform the same task.
- Application of Fractional Calculus in the Dynamical Analysis and Control of Mechanical ManipulatorsPublication . Ferreira, N. M. Fonseca; Duarte, Fernando B.; Lima, Miguel F. M.; Marcos, Maria G.; Tenreiro Machado, J. A.Mathematics Subject Classification: 26A33, 93C83, 93C85, 68T40Fractional 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. In the field of dynamical systems theory some work has been carried out but the proposed models and algorithms are still in a preliminary stage of establishment. This article illustrates several applications of fractional calculus in robot manipulator path planning and control.
- Applications of fractional calculus in electrical and computer engineeringPublication . Tenreiro Machado, J. A.; Silva, Manuel; Barbosa, Ramiro; Jesus, Isabel S.; Reis, Cecília; Marcos, Maria da Graça; M. Afonso, Luís; Lima, Miguel F. M.; Pires, E. J. Solteiro; Ferreira, N. M. FonsecaFractional 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, due to the progress in the area of chaos that revealed subtle relationships with the FC concepts. In the field of dynamical systems theory some work has been carried out but the proposed models and algorithms are still in a preliminary stage of establishment. Having these ideas in mind, the paper discusses a FC perspective in the study of the dynamics and control of several systems. This article illustrates several applications of fractional calculus in science and engineering. It has been recognized the advantageous use of this mathematical tool in the modeling and control of many dynamical systems. In this perspective, this paper investigates the use of FC in the fields of controller tuning, electrical systems, digital circuit synthesis, evolutionary computing, redundant robots, legged robots, robotic manipulators, nonlinear friction and financial modeling.
- Automated Synthesis Procedure of RF Discrete Tuning Differential Capacitance CircuitsPublication . Mendes, Luís; Pires, E. J. Solteiro; Vaz, João C.; Rosário, Maria J.; Oliveira, P. B. de Moura; Machado, J. A. Tenreiro; Ferreira, N. M. FonsecaThe paper presents a RFDSCA automated synthesis procedure. This algorithm determines several RFDSCA circuits from the top-level system specifications all with the same maximum performance. The genetic synthesis tool optimizes a fitness function proportional to the RFDSCA quality factor and uses the epsiv-concept and maximin sorting scheme to achieve a set of solutions well distributed along a non-dominated front. To confirm the results of the algorithm, three RFDSCAs were simulated in SpectreRF and one of them was implemented and tested. The design used a 0.25 mum BiCMOS process. All the results (synthesized, simulated and measured) are very close, which indicate that the genetic synthesis method is a very useful tool to design optimum performance RFDSCAs.
- Biological inspired flying robotPublication . Couceiro, Micael S.; Ferreira, N. M. Fonseca; Figueiredo, Carlos M.; Tenreiro Machado, J. A.This paper presents the development of computational simulation based on the dynamics of a robotic bird. The study analyze the wing angle of attack and the velocity of the bird, the tail influence, the gliding flight and the flapping flight with different strategies and algorithms of control. The results are positive for the construction of flying robots. Some highlights are given about the fist implemented architecture of the structure of a robotic bird. This platform consists on a body, wings and tail with actuators independently controlled though a microcontroller; a radio transmission system and batteries are used in order to avoid wired connections between the computer and the robot.
- Control optimization of a robotic birdPublication . Couceiro, M. S.; Ferreira, N. M. Fonseca; Mendes, R.; Pires, E. J. Solteiro; Machado, J. A. TenreiroIn this paper it is studied the modeling and control of a robotic bird. The results are positive for the design and construction of flying robots and a new generation of airplanes developed to the similarity of flying animals. Once implemented the dynamic models studied, we will study different movement planning routines and the dynamic stability to adopt, the development of computational simulation based on the dynamic of the robotic bird should allow testing strategies and different kind of control such as integer and fractional controllers. It is studied different kindo of optimization algorithms in order to achieve the best algorithm of control to use in our model. We compare the Gradient Descent optimization method to the PSO algorithm presenting somo time response parameters of our system under the action of different controllers. Firstly, we provide an overview of the system model; secondly, we compare the behaviour of fractional and integer order controllers using different algorithm for the controller optimization in order to obtain the menium error.
- Cooperative Transportation of an Object based on Fractional Order ControllersPublication . Figueiredo, Carlos M.; Couceiro, Micael S.; Ferreira, N. M. Fonseca; Tenreiro Machado, J. A.Advanced control techniques have been used in simulations to overcome nonlinear phenomena in order to describe the performance of robots with two rotational (RR) degrees-of-freedom (dof). Given the current state-of-the-art, fractional order algorithms lead to better performance when compared to integer order controllers. Also, the development of simulation platforms allows evaluating the best control methodology. In this context, the use of RR robots attached to mobile platforms, denoted in this paper as RR mobile robots, demonstrates a remarkable ability in manipulating and transporting objects. The present work aims to study two cooperative RR mobile robots by analyzing the manipulator’s trajectory and the forces applied to the common load. Are considered two robotic platforms based on an 8-bit microcontroller with inverse kinematics based on the Denavit-Hartenberg formulation and fractional order PID controllers inspired in the Grünwald-Letnikov definition.