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Este trabajo presenta el desarrollo y control de un péndulo invertido rotacional (péndulo de Furuta) mediante controladores en el espacio de estados, control óptimo y lógica difusa. Este tipo de sistemas son las aeronaves, vehículos espaciales, vehículos submarinos, barcos, satélites y robots, construidos por barras y uniones articuladas, pasivas y activas. Estos sistemas generalmente están desafiando a la gravedad y deben mantenerse en equilibrio, por lo tanto, las plantas de estos sistemas son no lineales y se hace necesario controlarlo mediante leyes de control no lineales; sin embargo, debido al aparecimiento de la lógica difusa,este tipo de control tiene una gran ventaja que radica en que no es necesario saber con exactitud las características de la planta; el control puede ser adaptado para sistemas SISO y MIMO; la clave del control difuso radica especialmente en el conocimiento que debe tener el experto para plantear los rangos de las funciones de inferencia y su tipo de funciones, además, plantear el método de inferencia de la máquina de inferencia; por lo tanto, para este tipo de control se debe hacer varias pruebas hasta conseguir los objetivos planteados en el sistema de control.

The paper presents four solutions to the voltage source inverter (VSI) control system with existing delays in the measurement channels and the middle switching frequency (25,600 Hz): Single-Input Single-Output Coefficient Diagram Method (SISO-CDM), Multi-Input Multi-Output Passivity-Based Control (MISO-PBC), Multi-Input Multi-Output One-Sample-Ahead Preview Controller (MISO-OSAP), and MISO-OSAP with Luenberger Observer (MISO-OSAP-LO). The theory, including adjustments to controller gains or to the coefficients of the characteristic equation of the closed-loop system, is presented. Simulations of the VSI operation with these control systems for the nonlinear load and the dynamic resistive load (per the requirements of the EN 62040-3 standard) are presented. The SISO-CDM and MISO-PBC are finally selected for experimental verification of the simulations. The results of the tests enable the selection of the control type for a particular VSI design based on its cost and an estimation of the advantages of the more expensive solution. The paper should help in engineering design according to the remarks in the paper.

Soft robotics is an attractive and rapidly emerging field, in which actuation is coupled with the elastic response of the robot's structure to achieve complex deformation patterns. A crucial challenge is the need for multiple control inputs, which adds significant complication to the system. A novel concept of single‐input control of an actuator is proposed, which composes of interconnected bistable elements. Dynamic response of the actuator and predesigned differences between the elements are exploited to facilitate any desired multistate transition using a single dynamic input. Formulation and analysis of the control system's dynamics and pre‐design of its multiple equilibrium states, as well as their stability, are shown. Then, fabrication and demonstration are done experimentally on single‐input control of two‐ and four‐element actuators, where the latter can achieve transitions between up to 48 desired states. This work paves the way for next‐generation soft robotic actuators with minimal actuation and maximal dexterity. A concept for reducing the number of control inputs to one in a system with N degrees of freedom, is presented. Incorporating structural instabilities, cleverly, enables choosing any desired trajectory out of (N!)2 with only one input. The concept is demonstrated experimentally, along with analytical insights and numerical simulations. Such actuation ability will enable simpler, smaller, and cheaper robots.

This study addresses two major single-input single-output control problems involving both feedback and feedforward actions: (i) the model matching in reference tracking and (ii) the rejection of measurable disturbances. Its aim is to overcome the limitations of inversion-based feedforward design methods when system uncertainty is considered, and to find a control engineering solution based on the quantitative feedback theory (QFT). The proposed methodology leads to minimum cost of feedback by limiting the feedback action to the strictly necessary amount that enables the use of a feedforward controller. Although the model matching problem had drawn some attention of the QFT community in the last few years, the measurable disturbance rejection problem remained unaddressed. This study provides a novel solution for both of them in which the need for feedback is linked to the existence of a common feedforward solution for all plants within the model uncertainty. This work also deals with the generation of the corresponding quadratic inequalities and new QFT bounds for the mentioned feedback demand. A practical and well-known benchmark example illustrates the main details and advantages of the new methodology.

The high-order fully actuated system (HOFAS) approach has recently been proposed, aiming at establishing a unified architecture for control of general nonlinear systems. Its core idea is to firstly obtain a HOFAS model for a dynamical system, and then to cancel the nonlinearity using the full-actuation property. Based on this, the control problem of both linear and many types of nonlinear systems is finally turned into a specific eigenstructure assignment problem of a particular matrix pair. Because of this, the specific eigenstructure assignment problem is considered as the fundamental problem of the HOFAS approach, and is investigated in detail in this paper. A general parametric solution is established in an iterative form with all the degrees of freedom provided, and special solutions for some commonly used cases are also given. These form a database for various design problems and provide some ready-to-use results. Finally, illustrative examples demonstrate the usage of the database.

The present paper studies the formation flight of four nanosatellites forming a tetrahedron. The main goal of this research is to find the relative orbits of these satellites that, at least in the linear Hill–Clohessy–Wiltshire model, ensure finite relative motion and keep the volume and shape of the tetrahedron configuration. Since real motions of these satellites will differ from the linear ones, especially under the influence of the J2\\(J_2\\) perturbation, active control is necessary. In addition, the limited size of the satellites does not allow us to use a complex 3-axis attitude control system. In the present paper we consider the passive magnetic attitude control system and suppose that the thrust direction is always aligned with the local geomagnetic field. In order to increase mission lifetime the control algorithm that minimizes the propellant consumption and keeps the tetrahedron volume and shape is investigated.

In this study, the authors address the design of the multi-loop controllers for multi-input and multi-output (MIMO) processes for disturbance rejection. Three types of disturbance rejection are analysed, and they demonstrate that those disturbance responses are directly related to the integral terms of the controllers. A concept of non-parametric effective model is introduced here to decompose a MIMO control system into several equivalent single-input and single-output control systems. Based on the effective model in each loop, a non-convex optimisation problem is established to obtain the optimal controller parameters with certain robustness indices. Considering the drawbacks of using random search algorithm, they develop a numerical algorithm to solve this non-convex optimisation problem. Simulation studies demonstrate that the proposed method improves the disturbance rejection compared with other decentralised controllers.

In this study, a design method for single Input interval type-2 fuzzy PID controller has been developed. The most important feature of the proposed type-2 fuzzy controller is its simple structure consisting of a single input variable. The presented simple structure gives an opportunity to the designer to form the type-2 fuzzy controller output in closed form formulation for the first time in literature. This formulation cannot be achieved with present type-2 fuzzy PID controller structures which have employed the Karnik-Mendel type reduction. The closed form solution is derived in terms of the tuning parameters which are chosen as the heights of lower membership functions of the antecedent interval type-2 fuzzy sets. Elaborations are done on the derived closed form output and a simple strategy is presented for a single input type-2 fuzzy PID controller design. The presented interval type-2 fuzzy controller structure still keeps the most preferred features of the PID controller such as simplicity and easy design. We will illustrate how the extra degrees of freedom provided by the antecedent interval type-2 fuzzy sets can be used to enhance the control performance on linear and nonlinear benchmark systems by simulations. Moreover, the type-2 fuzzy controller structure has been implemented on experimental pH neutralization. The simulation and experimental results will illustrate that the proposed type-2 fuzzy controller produces superior control performance and can handle nonlinear dynamics, parameter uncertainties, noise and disturbances better in comparison with the standard PID controllers. Hence, the results and analyses of this study will give the control engineers an opportunity to draw a bridge and connect the type-2 fuzzy logic and control theory.

This paper describes a control scheme that provides an efficient way to design a Fuzzy Logic Controller (FLC) for the unmanned underwater vehicle (UUV). The proposed method, known as the Single Input Fuzzy Logic Controller (SIFLC), reduces the conventional two-input FLC (CFLC) to a single input single output (SISO) controller. The SIFLC offers significant reduction in rule inferences and simplify the tuning of control parameters. Practically it can be easily implemented by a look-up table using a low cost microprocessor due its piecewise linear control surface. To verify its effectiveness, the control algorithm is simulated using the Marine Systems Simulator (MSS) on the Matlab/Simulink® platform. The result indicates that both the SIFLC and CFLC give identical response to the same input sets. However SIFLC requires very minimum tuning effort and its execution time is in the orders of two magnitudes less than CFLC.

This article introduces a human–robot interaction controller toward the lower extremity exoskeleton whose aim is to improve the tracking performance and drive the exoskeleton to shadow the wearer with less interaction force. To acquire the motion intention of the wearer, two subsystems are designed: the first is to infer the wearer is in which phase based on floor reaction force detected by a multi-sensor system installed in the sole, and the second is to infer the motion velocity based on the multi-axis force sensor and admittance model. An improved single-input fuzzy sliding mode controller is designed, and the adaptive switching controller is combined to promote the tracking performance considering system uncertainties. Adaptation laws are designed based on the Lyapunov stability theorem. Therefore, the stability of the single-input adaptive fuzzy sliding mode control can be guaranteed. Finally, the proposed methods are applied to the lower extremity exoskeleton, especially in the swing phase. Its effectiveness is validated by comparative experiments.