Oscar Barambones
University of the Basque Country
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Publication
Featured researches published by Oscar Barambones.
Automatica | 2002
Oscar Barambones; V. Etxebarria
A robust neural control scheme for mechanical manipulators is presented. The design basically consists of an adaptive neural controller which implements a feedback linearization control law for a generic manipulator with unknown parameters, and a sliding-mode control which robustifies the design and compensates for the neural approximation errors. It is proved that the resulting closed-loop system is stable and that the trajectory-tracking control objective is achieved. Some simulation results are also provided to evaluate the design.
IEEE Transactions on Industrial Electronics | 2014
Oscar Barambones; Patxi Alkorta
An adaptive robust position control for real-time high-performance applications of induction motors is developed in this work. The proposed sliding-mode controller provides a global asymptotic position tracking in the presence of model uncertainties and load torque variations. The proposed control scheme incorporates an adaptation law for the switching gain, so that the controller can calculate the switching gain value that is necessary to overcome the existing system uncertainties. The design also incorporates a sliding-mode-based load torque and rotor flux observers in order to improve the control performance without using sensors that increase cost and reduce reliability. The proposed design does not present a high computational cost and, therefore, can be easily implemented in real-time applications. Simulated and experimental results show that this scheme provide high-performance dynamic characteristics, and that it is robust with respect to plant parameter variations and external load disturbances.
Journal of The Franklin Institute-engineering and Applied Mathematics | 2011
Oscar Barambones; Patxi Alkorta
Abstract A novel adaptive sliding-mode control system is proposed in order to control the speed of an induction motor drive. This design employs the so-called vector (or field oriented) control theory for the induction motor drives. The sliding-mode control is insensitive to uncertainties and presents an adaptive switching gain to relax the requirement for the bound of these uncertainties. The switching gain is adapted using a simple algorithm which does not imply a high computational load. Stability analysis based on Lyapunov theory is also performed in order to guarantee the closed loop stability. Finally, simulation results show not only that the proposed controller provides high-performance dynamic characteristics, but also that this scheme is robust with respect to plant parameter variations and external load disturbances.
International Journal of Control | 2002
Oscar Barambones; V. Etxebarria
In this paper a terminal sliding-mode adaptive control scheme for robotic manipulators designed following an energybased approach is presented. The control comprises two basic terms: a composite adaptive term which implements a feedback law for compensating the modelled dynamics and a non-linear sliding-mode term for overcoming the unmodelled dynamics and perturbations. The resulting closed-loop system is proved to be stable and it is also shown that the trajectory-tracking error converges to zero in finite time. Moreover, an upper bound of this error convergence time is calculated. Finally, the design is evaluated by means of simulations.
IEEE Transactions on Industrial Electronics | 2014
Patxi Alkorta; Oscar Barambones; José Antonio Cortajarena; Asier Zubizarrreta
This paper presents the design and the experimental validation of a new linear multivariable generalized predictive control for speed and rotor flux of induction motor. This control approach has been designed in the d-q rotating reference frame, and the indirect vector control has been employed. Load and flux observers, as well as the possibility of including a model-reference-adaptive-system speed estimator, have been considered in the implementation. The proposed controller not only provides enhanced dynamic performance but also guarantees compliance with physical voltage and current constraints. Hence, it ensures that the space vector pulsewidth modulation (SVPWM) always operates in the linear area and that the stator windings are not damaged due to overcurrent. Moreover, the controller includes a novel torque current tracker that allows obtaining an effective electromagnetic torque without a chattering phenomenon. Several simulation and experimental tests have been carried out, both in suitable and adverse conditions, even at zero speed zone, demonstrating that the proposed controller provides an efficient speed tracking and suggesting its use in industry.
Mathematical Problems in Engineering | 2013
Izaskun Garrido; Aitor J. Garrido; Mikel Alberdi; Modesto Amundarain; Oscar Barambones
The 2009/28/EC Directive requires Member States of the European Union to adopt a National Action Plan for Renewable Energy. In this context, the Basque Energy Board, EVE, is committed to research activities such as the Mutriku Oscillating Water Column plant, OWC. This is an experimental facility whose concept consists of a turbine located in a pneumatic energy collection chamber and a doubly fed induction generator that converts energy extracted by the turbine into a form that can be returned to the network. The turbo-generator control requires a precise knowledge of system parameters and of the rotor angular velocity in particular. Thus, to remove the rotor speed sensor implies a simplification of the hardware that is always convenient in rough working conditions. In this particular case, a Luenberger based observer is considered and the effectiveness of the proposed control is shown by numerical simulations. Comparing these results with those obtained using a traditional speed sensor, it is shown that the proposed solution provides better performance since it increases power extraction in the sense that it allows a more reliable and robust performance of the plant, which is even more relevant in a hostile environment as the ocean.
Mathematical Problems in Engineering | 2015
Izaskun Garrido; Aitor J. Garrido; Jesús Romero; Edorta Carrascal; Goretti Sevillano-Berasategui; Oscar Barambones
One of the main problems of fusion energy is to achieve longer pulse duration by avoiding the premature reaction decay due to plasma instabilities. The control of the plasma inductance arises as an essential tool for the successful operation of tokamak fusion reactors in order to overcome stability issues as well as the new challenges specific to advanced scenarios operation. In this sense, given that advanced tokamaks will suffer from limited power available from noninductive current drive actuators, the transformer primary coil could assist in reducing the power requirements of the noninductive current drive sources needed for current profile control. Therefore, tokamak operation may benefit from advanced control laws beyond the traditionally used PID schemes by reducing instabilities while guaranteeing the tokamak integrity. In this paper, a novel model predictive control (MPC) scheme has been developed and successfully employed to optimize both current and internal inductance of the plasma, which influences the L-H transition timing, the density peaking, and pedestal pressure. Results show that the internal inductance and current profiles can be adequately controlled while maintaining the minimal control action required in tokamak operation.
international conference on engineering of complex computer systems | 2010
Enrique Kremers; Pablo Viejo; Oscar Barambones; Jose Maria Gonzalez de Durana
The structure and behaviour of Electrical Grids share many of the properties of Complex Computer Systems, with microgrids and other decentralised electrical systems attached to them, so they can be interpreted as Systems of Systems. Furthermore, the evolution of future electrical systems will bring a higher degree of decentralisation, especially concerning production and control. To deal with this paradigm change, new models and tools are necessary. In this paper a model of an electrical microgrid is presented. The approach used in the development of the model is agent-based in combination with system dynamics modelling. By mixing these approaches the different entities of the electrical system (production, demand, storage, etc.) have been represented. Through the individual behaviour of the agents it is possible to reproduce the complex behaviour of the system as a whole. This can produce expected and unexpected emergent effects on the interconnected system that are analysed through the simulation. A case study is presented to analyse the capabilities of such models. The example shows the simulation of an integrated microgrid system, where different components such as renewable energy sources and storage have been implemented. The simulation results of this case study are discussed.
international conference on control applications | 2006
Oscar Barambones; A.J. Garrido; F.J. Maseda; Patxi Alkorta
In this paper, an indirect field-oriented induction motor drive with a sliding-mode controller is presented. The proposed sliding-mode control law incorporates an adaptive switching gain that avoid calculating an upper limit of the system uncertainties. The design also includes rotor speed computation from measured stator terminal voltages and currents. The calculated speed is used as feedback in an indirect vector control system achieving the speed control without the use of shaft mounted transducers. Stability analysis based on Lyapunov theory is also presented, to guarantee the closed loop stability. Finally simulated results show on the one hand that the proposed controller with the proposed estimator provides high-performance dynamic characteristics, and on the other hand that this scheme is robust with respect to plant parameter variations and external load disturbances
international symposium on industrial electronics | 2007
Patxi Alkorta; Oscar Barambones; Aitor J. Garrido; Izaskun Garrido
This paper presents a new proposal of speed vector control of induction motors based on robust adaptive VSC (variable structure control) law and its experimental validation. The presented control scheme incorporates the SVPWM (space vector pulse width modulation) instead of the traditional current hysteresis comparator. The SVPWM improves the quality of the stator currents, reducing the harmonics, while maintains the main characteristics that is usual in this kind of algorithm, like the fast response and good rejection to uncertainties and measurement noises. This regulator is also compared with the PI (proportional integral) controller designed in the frequency domain, in order to prove the good performance of the proposed controller. The two controllers have been tested using various simulation and real experiments, taking into account the parameter uncertainties and measurement noise in the loop signal, in the rotor speed and in the stator current. This work shows that the VSC regulator is more efficient than the traditional PI controller in both adverse conditions and suitable conditions. Finally, some practical recommendations for real experiment implementations are also given.