1,721,068 research outputs found
New Optimal Approach for the Identification of Takagi-Sugeno Fuzzy Model
Get PDFA novel optimal method is developed to improve the identification and estimation of Takagi-Sugeno (TS) fuzzy model. The idea comes from the fact that the main drawback of T-S model is that it can not be applied when the membership functions are overlapped by pairs. This limits the application of the T-S model because this type of membership function has been widely used in the stability and controller design of fuzzy systems. It is also very popular in industrial control applications. The method presented here can be considered as a generalized version of T-S fuzzy model with optimized performance in approximating nonlinear functions. Various examples are chosen to show the high function approximation accuracy and fast convergence obtained by applying the proposed method in approximating nonlinear systems locally and globally in comparison with the original T-S model
Event-triggered Controlled Charger for Lithium Battery Packs
No full textEvent-triggered Control is a modification for digital based control systems that has gain popularity in recent years. This alteration in control algorithms offers advantages like reductions in computation times or even in the requirements of system's hardware bay reducing its processing and communications to the minimum required; allowing for less computation and communication time needed to perform control actions and making them relevant for environments with shared communication mediums or hardware handling multiple processes simultaneously. In this work, a comparison is presented between a classic control scheme and its event triggered counterpart when controlling a Power Source for a simple Lithium Battery Charger. The event triggered versions of the current programmed control and the voltage Proportional-Integral-Derivative controllers are designed to adhere to the maximum admissible errors of the system (voltage and current output ripple) and results are presented to show how the modifications manage to obtain equivalent results to thous of their classic continuous counterparts while minimizing control loop actuation and therefore improve computation and communications performance without hindering system efficiency. This results are specially relevant for such ubiquitous devices in complex systems like electric vehicles or portable consumer electronics, allowing for computation time to be dedicated to other tasks and freeing communication channels for other devices.Peer reviewe
IGBT Overcurrent Capabilities in Resonant Circuits
No full textThe control of IGBT (insulated gate bipolar transistor) and MOSFET (metal oxide semiconductor field effect transistor) is of great interest nowadays as they are widely used in electric vehicles, photovoltaic applications, and a multitude of systems. The field of power electronics and their correct activation ensures that the transistors are operated without being destroyed. In this work, a double resonant transformer was built and used to produce very high currents. These currents are switched by a full bridge of resonant IGBT transistors to demonstrate the feasibility of exceeding the maximum permissible transistor currents in a resonant system. The system is controlled by the feedback from two current sensors. In this case the currents exceed in a 170% the peak current of the transistor without problems. In this way, resonant circuits with IGBT transistors can be designed with currents lower than the maximum currents of the resonant circuit, therefore reducing the cost of the circuit and reducing the switching losses to nearly zero
An asinh-type regulator for robot manipulators with global asymptotic stability
Get PDFIn this paper, a new asinh-type control scheme with gravity compensation for the position control problem of robot manipulators in joint space is presented. The properties and characteristics
of the asinh control structure make the position error and the motion velocity asymptotically converge to the equilibrium point. A strict Lyapunov function to formally prove global
asymptotic stability is developed. The tuning of the control gains is obtained by PSO (Particle
Swarm Optimization) technique without saturating the servomotors. To illustrate the effectiveness and performance of the proposed scheme, an experimental comparative analysis between
the proportional-derivative (PD) and atanh controls against the proposed algorithm on a three
degrees of freedom direct-drive robot manipulator is carried out.The authors would like to thank the Benemérita Universidad Autonoma de Puebla, for its financial support with the project VIEP-100048866-2019 (Control de posición con
ganancias variables de robots manipuladores), which partially supported this work.Peer reviewe
Global Saturated Regulator with Variable Gains for Robot Manipulators
Get PDFIn this paper, we propose a set of saturated controllers with variable gains to solve the regulation problem for robot manipulators in joint space. These control schemes deliver torques inside the prescribed limits of servomotors. The gamma of variable gains is formed by continuous, smooth, and differentiable functions of the joint position error and velocity of the manipulator. A strict Lyapunov function is proposed to demonstrate globally asymptotic stability of the closed-loop equilibrium point. Finally, the functionality and performance of the proposal are illustrated via simulation results and comparative analysis against Proportional-Derivative (PD) control scheme on a two-degrees-freedom direct-drive robot manipulator
Algoritmo de control de un robot omnidireccional de tres ruedas
No full text(SPA)Este proyecto se centra en el desarrollo y la implementación de un algoritmo cinemático de control de un robot omnidireccional de tres ruedas. Para ello ha sido necesario el diseño, fabricación y montaje del robot, incluyendo tanto los componentes mecánicos como los electrónicos.
El robot móvil se compone de tres ruedas universales, dotadas con rodillos pasivos que permiten la movilidad del robot en todas las direcciones. Las ruedas se accionan mediante motores paso a paso, los cuales requieren del uso de controladores específicos. El funcionamiento está basado en un microcontrolador conectado a un ordenador de placa simple que se comunica con el ordenador principal para recibir las ordenes de dirección.
Para alcanzar los objetivos de este trabajo se han utilizado diversos paquetes de software, además de la instrumentación electrónica necesaria para comprobar el correcto funcionamiento de los circuitos electrónicos. También se han empleado tecnologías de fabricación innovadoras para la obtención de las diferentes partes de las que se compone el robot, como la impresión 3D y el corte láser.
Para finalizar, se ha realizado un estudio de movilidad en el que se ha verificado el funcionamiento del algoritmo implementado en la configuración seleccionada. Junto con este estudio se presenta la simulación del funcionamiento del algoritmo del robot en Matlab®, y los resultados obtenidos en las pruebas realizadas sobre el prototipo.(ENG)The project involves the development and implementation of a kinematic control algorithm for a three-wheeled-omnidirectional robot. Therefore, it is required the design, manufacturing and assembling of the robot, including its mechanical and electronical components.
The mobile robot has three Universal wheels, consisting of passive rollers which allows mobility in all directions. The wheels are moved by stepper motors, which are controlled by specific drivers. The functioning is based on a microcontroller connected to a simple-based computer which communicates with main computer to receive direction orders.
Achieving the aims of this project requires several software programs, also electronic instruments to check the correct functioning of electronic circuits. In addition, innovative manufacturing technologies were required to obtain the different parts which compose the robot, as 3D printing and laser cutting.
Finally, the mobility study carried out has verified the robot’s algorithm operation in selected configuration. Along with the study, the omnidirectional robot functioning algorithm was simulated in Matlab® and represented with results obtained in tests carried out on the prototype
Diseño e implementaciónn de una plataforma para teleoperación y control de sistemas dinámicos
No full text(SPA)En este trabajo, se presenta el desarrollo de una plataforma hardware, que puede funcionar como
una interfaz de control remoto y como un controlador del sistema. La implementación de esta idea da como resultado un mando en forma de guante que controla un sistema físico real, un dron con estabilización de orientación capaz de seguir la señal enviada desde el guante. El dron implementa un controlador PID en cascada y el filtro de cuaternios de Madgwick en el algoritmo de fusión de sensores para la orientación.
Comienza desde la teoría física y matemática que explica el comportamiento de estos sistemas, pasando por los dispositivos específicos disponibles con la tecnología actual hasta llegar a la lógica que hace que estos dispositivos actúen de la manera deseada. (ENG)In this work, the development of a hardware platform, that can work both as a remote control interface and as a controller of the system, is presented. The implementation of this idea results in a glove shaped remote that controls a real physical system, a drone with attitude stabilization able to follow the sent signal from the glove. The drone implements a cascade PID controller and the Madgwick quaternion filter in the attitude fusion sensor algorithm.
It starts from the physical and mathematical theory that explains the behaviour of these systems, going through the specific devices available with current technology until getting to the logic that makes these devices act in the desired manner
Design scheme of discrete time variable structure controllers applied to multi-input-multi-output linear systems with chattering elimination
No full textDesigning discrete time variable structure control with sliding mode (SM) schemes implies finding an asymptotically stable sliding surface with a control policy which assures the existence of a SM. Based on a recently innovative approach, where the authors developed a flexible design of sliding surfaces applied to discrete time linear multi-input multi-output (MIMO) systems, a novelty controller design strategy is proposed, where a switching surface parameter is used for the adjustment of the control signal limitations and for the improvement of the controlled system dynamics against model uncertainties. It is the first time that these drawbacks are solved modifying the switching surface values because it has been always resolved via control law adjustment. Moreover, a new chattering elimination method using adjustable sigmoid functions is also implemented in the controller. The main advantages of the proposed methodology are: firstly, it can be easily applied to high-order linear MIMO systems; secondly, system dynamics coordinates representation transformations are not needed and thirdly, the non-ideal SM dynamics is considered in the design procedure. Both the sliding surface and the control law specification are included in the proposed methodology. An illustrative example is included.Peer reviewe
Navigation of mobile robots using neural networks and genetic algorithms
No full textThe navigation of robots has been a subject of widespread interest over the last few decades. In the previous years, traditional methods based on mathematical equations were used, and there has been an evolution towards the use of methods based on artificial intelligence. Two of which have been used in this work: neural networks and genetic algorithms. Neural networks are used as a machine learning model to teach the robot to move from any starting point to a goal, avoiding obstacles along the way. However, this model needs an algorithm to learn how to carry out this activity, which is what the genetic algorithm will be used for. Furthermore, this method of navigation will be compared with the traditional method based on potential fields, where it can be observed how this new method based on artificial intelligence improves and solves some typical problems of the old methods, such as the tendency to get stuck in local minima.Peer reviewe
Cost-Effective Localization of Mobile Robots Using Ultrasound Beacons and Differential Time-of-Flight Measurement
No full textThis paper presents an innovative and cost-effective solution for the absolute localization of mobile robots using ultrasound beacons. The proposed system addresses the challenge of precise positioning within a controlled environment by employing Differential Time-of-Flight (ToF) measurements to determine the relative distances between the robot and optimally placed beacons. Unlike other ToF methods that require synchronization pulses, the proposed approach eliminates this requirement, significantly simplifying the setup and reducing system complexity. Furthermore, the system achieves a higher sampling rate than conventional synchronization-based systems, enhancing real-time performance. Detailed analysis and simulation demonstrate the system’s ability to provide accurate and reliable localization. The results highlight the potential for broad application in various robotic environments, offering a robust solution for absolute positioning without complex synchronization strategies. This work underscores the advantages of using ToF measurements with ultrasound beacons and contributes to the ongoing development of efficient and cost-effective robotic localization systems
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