Manuel J Lopez

• PhD
• Professor (Associate) at Universidad de Cádiz

In this paper, it is proposed a method for controlling chaotic systems; where the main goal is to obtain a periodic behaviour for a chaotic system. In our approach, the system to control is considered as a black-box, and therefore it is not necessary to know a mathematical model of the system, only experimental measurements are used. Our method emp...

In this work we use computer simulations to test a method for controlling heart rhythm behavior based on the electrocardiogram (ECG) signal tracking. The proposed control algorithm is based on two parameters, the controller proportional gain and the norm of tracking error signal. The objective is to take out the heart rhythm dynamics from a non des...

In this paper we propose a control system design methodology which has two main objectives: the first one is to achieve control system specifications for a local H∞ controller designed for a given operation condition, and the second objective is to provide a procedure for bumpless transfer (BLT) when the controller is switched to another one, due t...

In this paper we propose a general purpose hardware/software environment for hard real time simulation of dynamical systems in the context of control engineering. With this system, realistic analysis and tests can be carried out for controller algorithms characterized by time determinism with strict restrictions, multiple inputs and multiple output...

Este libro pretende ser una puesta al día sobre el control de sistemas en los que no se conoce con precisión su dinámica. Para ello se aborda el problema desde dos puntos de vista diferentes, como son las técnicas de Control Adaptativo y las metodologías de diseño de Controladores Robustos. A lo largo del libro se procede a describir ambos enfoques...

This paper deals with the inherent instability observed in the speed of a planing type craft. In the case of displacement craft, the systems governing the speed are stable hence closed-loop control is trivial. In the case of planing craft, however, there may exist instability in their speed. By using the Qualitative Theory of Dynamical Systems (QTD...

This paper is centered on the guidance systems used to increase the autonomy of unmanned surface vehicles (USVs). The new Robust Reactive Static Obstacle Avoidance System (RRSOAS) has been specifically designed for USVs. This algorithm is easily applicable, since previous knowledge of the USV mathematical model and its controllers is not needed. In...

This work is focused on reactive Static Obstacle Avoidance (SOA) methods used to increase the autonomy of Unmanned Surface Vehicles (USVs). Currently, there are multiple approaches to avoid obstacles, which can be applied to different types of USV. In order to assist in the choice of the SOA method for a particular vessel and to accelerate the pret...

In this work, a new pre-tuning multivariable PID (Proportional Integral Derivative) controllers method for quadrotors is put forward. A procedure based on LQR/LQG (Linear Quadratic Regulator/Gaussian) theory is proposed for attitude and altitude control, which suposes a considerable simplification of the design problem due to only one pretuning par...

In this work, a new pre-tuning multivariable PID (Proportional Integral Derivative) controllers method for quadrotors is put forward. A procedure based on LQR/LQG (Linear Quadratic Regulator/Gaussian) theory is proposed for attitude and altitude control, which suposes a considerable simplification of the design problem due to only one pretuning par...

This work is located in a growing sector within the field of renewable energies, wave energy converters (WECs). Specifically, it focuses on one of the point absorber waves (PAWs) of the hybrid platform W2POWER.With the aim of maximizing the mechanical power extracted from the waves by these WECs and reducing their mechanical fatigue, the design of...

This work is located in a growing sector within the field of renewable energies, wave energy converters (WECs). Specifically, it focuses on one of the point absorber waves (PAWs) of the hybrid platform W2POWER.With the aim of maximizing the mechanical power extracted from the waves by these WECs and reducing their mechanical fatigue, the design of...

In this work a new pre-tuning multivariable PID controllers method for quadrotors is put forward. A procedure based on LQR/LQG theory is proposed for attitude and altitude control. With the aim of analyzing performance and robustness of the proposed method, a non-linear mathematical model of the DJI-F450 quadrotor is employed, where rotors dynamics...

This work is located in a growing sector within the field of renewable energies, wave energy converters (WECs). Specifically, it focuses on one of the point absorber waves (PAWs) of the hybrid platform W2POWER. With the aim of maximizing the mechanical power extracted from the waves by these WECs and reducing their mechanical fatigue, the design of...

This work is located in a growing sector within the field of renewable energies, wave energy converters (WECs). Specifically, it focuses on one of the point absorbers wave (PAWs) of the hybrid platform W2POWER. With the aim of maximising the mechanical power extracted from the waves by these WECs and reduce their mechanical fatigue, the design of f...

In this work, a control system is proposed as an equivalent numerical procedure whose aim is to obtain the natural equilibrium points of a dynamical system. These equilibrium points may be employed later as setpoint signal for different control techniques. The proposed procedure is based on the adaptive synchronization between an oscillator and a r...

En este trabajo se propone un sistema de control equivalente a un método numérico para el cálculo de los puntos de equilibrio de sistemas dinámicos, donde dichos equilibrios pueden ser empleados como señal de referencia en diversas técnicas de control. El procedimiento propuesto está basado en la sincronización adaptativa entre un oscilador y un mo...

The ship roll stabilization by active anti-heeling tanks operated by pressurized air is considered in this book. Assuming that there exist uncertain parameters and uncertain external perturbation in the ship roll model, a backstepping structure with robust control algorithm for ship roll stabilization system is designed . A roll equation consisting...

This paper proposes a new synthesis method and tuning procedure for a variable structure H∞ multivariable controller for fixed wing aircrafts attitude control, which consists in switching from one-degree of freedom controller (1-DOF) to two degrees of freedom controller (2-DOF), and vice versa, with a method for bump-less transfer in switching tran...

The search for alternatives to traditional energy sources is an important issue nowadays. Renewable energies are difficult to use because, among other factors, the uncertainty about their availability. One option to address this problem are hybrid systems, where different primary energy sources and storage systems are used. A hybrid system contains...

The aim of this paper is to present several applications used in Microcontrollers practical sessions of the Degree in Radioelectronics Engineering of the University of Cadiz. Block diagrams prove to be a suitable visual tool in programming especially in academic degrees where computer programming is not provided with a relevant specific weight. Thi...

This paper presents the control of the list angle of a ship in still water based on the utilisation of anti-heeling tanks oper-ated by pressurized air. The proposed and practical objective attempts to regulate the list angle to a prescribed value, nor-mally zero, during the loading process of a container ship. A nonlinear adaptive controller based...

This paper shows an experimental hybrid technique with several variants for controlling chaotic systems tested with two electronic circuits implemented using comercial components: The Chua circuit and the Gonzalez circuit. The control methods are based on variable event condition automatically adjunsted to system dynamics without mathematical model...

In this paper, an adaptive hybrid control method is proposed, which stabilizes chaotic systems in the neighborhood of unstable periodic orbits embedded in the chaotic dynamics of the process to control. The method is based on the joint action of two controllers (a continuous time controller and a discrete time controller) as well as on the phenomen...

A pulsed control algorithm is proposed to control chaotic oscillations that may occur in a continuous cutting process. The objective of our algorithm is to transform the chaotic oscillation into a periodic behavior. It is not necessary to know any mathematical model of the process. Only the measured data are used to adjust the control pulses to the...

This paper proposes an adaptive control method which lets to stabilize the chaotic oscillations that can occur in continuous cutting processes at a limit cycle. The method is based on the synchronization between a system model driven by the state variables measurements of the cutting process and the real process or plant. Synchronization analysis i...

In this paper we propose a new control method which stabilizes chaotic systems in the neighborhood of unstable periodic orbits (UPO) embedded in a strange attractor. It is used for that a piecewise continuous signal generated by means of two controllers, one analogic and other digital. The hybrid control method is synthesized in an algorithm which...

En este trabajo se presenta un méetodo pŕactico para control de sistemas caóticos por medio de pulsos, que utiliza una condición de evento ajustada a la dinámica del proceso. Se muestran resultados de simulación para tres sistemas caóticos usando para ello dos algoritmos de control (unipolar y bipolar). No se requiere conocimiento de un modelo mate...

In this work, a method for controlling chaotic systems by means of pulses, with four variants, is presented, and its real time application to a particular electronic chaotic circuit (Kiers-Schmidt-Sprott, KSS) is analyzed. Periodic behavior (periodic orbit, PO) is obtained from chaotic dynamics, with a control law depending on a variable event cond...

In this paper we propose a control system design methodology which has two main objectives: the first one is to achieve control system specifications for a local H∞ controller designed for a given operation condition, and the second objective is to provide a procedure for bumpless transfer (BLT) when the controller is switched to another one, due t...

A method for controller design and switching controller without bump effect has been proposed for a marine propulsion system with diesel engine used as propeller prime-mover. Due to different regimens operation of ship propulsion, it is common practice to design more than one linear controller, each at a different operating point, and to switch bet...

In this work we propose a method for chaos control of systems which have a mathematical model such as Lorenz system, Chen system and Lu system. The control system is composed by nonlinear state vector feedback and linear H ∞ controller. The nonlinear feedback linearizes system model and robust H ∞ controller is designed in order to achieve local in...

In this paper we propose a general purpose hardware/software environment for hard real time simulation of dynamical systems in the context of control engineering. With this system, realistic analysis and tests can be carried out for controller algorithms characterized by time determinism with strict restrictions, multiple inputs and multiple output...

A new control method for SISO and MIMO chaotic systems is described in this work, and a physical interpretation of the method is given for obtaining periodic orbits and unstable periodic orbits associated to the system dynamics. The mathematical notation, the physical interpretation and the phylosophy pointed out in this work will be adopted in nex...

In this paper, a method for controlling chaotic systems, such as Lorenz system, Chen system and Lu system is described; which is composed by a nonlinear state vector feedback and a linear H1 controller. With this method the objective is to stabilize chaotic oscillations to a steady state, as well as tracking a desired trajectory. In order to physic...

This paper presents a new flexible software and a complementary hardware system for process identification, controller design, analysis and evaluation. Controller implementation and closed loop plant simulations are carried out in hard real time, for which a suitable hardware based on PC architecture is proposed. Controllers are designed based on H...

This paper presents a novel and flexible software environment for data acquisition and system identification in real time, oriented to process control. Our application implements PID, H2 and Hinfin tuning methods for systems whose process reaction curve may be considered that belongs to some of the considered response patrons. A novel procedure for...

This paper presents a novel and flexible software environment for data acquisition and system identification in real time, oriented to process control. Our application implements PID, H2 and Hinfin tuning methods for systems whose process reaction curve may be considered that belongs to some of the considered response patrons. A novel procedure for...

In this paper we propose a new hardware/software environment for designing and testing control systems based on H2 and H∞ methods, where an innovative procedure is used for controller tuning. Model identification and controller design are carried out by means of a new software ControlAvH, which makes transparent for the user the mathematical comple...

In this paper a systematic design method for H2 and H∞ controller synthesis is proposed, combined with a procedure for incipient faults detection based on plant model (MB-FDI system). Controller is tuning in order to satisfy time domain specifications for step changes in set-point; where rise time, overshoot and stationary error are considered in a...

This paper describes a new procedure to design robust H1 controller with time domain specifications and a fault detection method for MIMO system. Controller design parameters and fault detection method are calculated solving multi-objective optimization problems which are based on genetic algorithms. Simulations tests are carried out to evaluate ou...

In this paper it is described the main-characteristics of a novel design methodology for H2 and H∞ controllers for process control, which is carried out with a new software application named ControlAvH. ControlAvH has been developed for data acquisition, system identification, controller design and control system evaluation, applied to processes co...

This paper presents a method for tuning Linear Quadratic Gaussian/Loop-Transfer Recovery (LQG/LTR) controller combined with a fault detection and isolation (FDI) filter design, which is applied and tested for F-16 aircraft by simulation. LQG/LTR controller is adjusted for design specifications, aided with a procedure where genetic algorithms are us...

This paper presents a method for tuning Linear Quadratic Gaussian/Loop-Transfer Recovery (LQG/LTR) controller combined with a fault detection and isolation (FDI) filter design, which is applied and tested for F-16 aircraft by simulation. LQG/LTR controller is adjusted for design specifications, aided with a procedure where genetic algorithms are us...

In this paper the architecture and functionalities of ControlAvH Tune software application is described. ControlAvH Tune has been developed for data acquisition, system identification, controller design and evaluation, applied to processes control in real time. It implements identification methods for obtaining mathematical models of the process to...

Resumen En este artículo se describe el diseño de un sistema de detección y aislamiento de fallos (FDI) aplicado a la dinámica lateral de un avión F-16. El sistema FDI se realiza mediante un generador de residuos robusto vía optimización multi-objetivo y algoritmos genéticos (MOO-GA). También se dan las especificaciones de un banco de pruebas de la...

In this paper the architecture of Control Av program is described. Control Av software has been designed for identification and control of industrial processes in real time. It implements identification methods for obtaining mathematical models of the process to control, which can be used for PID or H∞

This paper presents a fault detection and isolation (FDI) filter design for a lateral dynamics of a F-16 aircraft. The FDI filter is based on robust residual generator design via multi-objective optimisation and genetic algorithms (MOO-GA). In our case the fault detection filter is sensitive to roll and sideslip sensors. The FDI filter is implement...

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In this paper we propose a method for tuning output feedback multivariable Hinf controller based on standard theory and on genetic algorithms. Problem design considers time domain specifications such as overshoot, rising time and stationary error for MIMO systems, as well as robustness properties based on multiplicative stability margins for plant...

In this work a computer based environment for symbolic calculation applied to nonlinear L 2 control is described. A very practical design and analysis methodology for nonlinear H ∞ control is presented. Starting from a model of the plant in affine form, and a state feedback controller (or state estimated feedback controller), a design procedure is...

In this work a design procedure for course-changing control and path tracking control is presented, which is based on nonlinear L2 control theory. The proposed method uses a nonlinear model of the ship and obtains a non-linear suboptimal H∞ controller (state feedback version or state estimated approach with a non-linear observer). A symbolic comput...

In this paper we propose a method for tuning Linear Quadratic Gaussian/Loop-Transfer Recovery (LQG/LTR) controller based on genetic algorithms. Suitable time responses as well as satisfactory robustness properties are obtained using two optimisation loops, where genetic algorithms are employed to satisfy design specifications for a flight control s...

An automatic procedure for H-infinity regulator tuning is proposed. Design parameters are calculated based on a few parameters of a simple plant model, which are obtained by an identification method. With this approach adequate performance and robustness are guaranteed, and it is available an automaticH1 design method for the user. A fine-tuning of...

n this work we present a method for tuning Hinfinity controllers for ship autopilots. Weighting transfer functions are calculated by means aof ship mathematical model parameters, and these parameters are experimentally obtained using the turning circle test. Simulation results are presented for different ship types. Controller fine tuning depends o...

n this work we present a method for tuning Hinfinity controllers for ship autopilots. Weighting transfer functions are calculated by means aof ship mathematical model parameters, and these parameters are experimentally obtained using the turning circle test. Simulation results are presented for different ship types. Controller fine tuning depends o...

In this work we present a study carried out for a ship of Ferry type. An H∞ regulator is developed to keep a fixed course of the ship, and another H∞ controller is designed for course changing operation. Both designs have into account the physical limitations of the rudder servosystem. and uncertainties in ship dynamics. The objective of the contro...