The Experts below are selected from a list of 40470 Experts worldwide ranked by ideXlab platform

Yingning Peng - One of the best experts on this subject based on the ideXlab platform.

  • super resolution time Delay Estimation in multipath environments
    2007
    Co-Authors: Dongxu Shen, Yingning Peng
    Abstract:

    The super-resolution time Delay Estimation in multipath environment is very important for many applications. Conventional super-resolution approaches can only deal with signals with wideband and flat spectra. In this paper, we propose a novel super-resolution time Delay Estimation method that can treat signals with narrowband spectra. In our method, the time Delay Estimation is first transformed into the frequency domain, in which the problem is converted into the parameter Estimation of sinusoidal signals with lowpass envelopes. Then a MUSIC-type algorithm taking account of the envelope variation is applied to achieve the super-resolution Estimation. Time Delay Estimation in active and passive systems are considered. Simulation results confirm that the proposed estimators provide better performance than the classical correlation approach and the conventional MUSIC algorithm for separating closely spaced signals with narrowband spectra.

  • super resolution time Delay Estimation in multipath environments
    2004
    Co-Authors: Dongxu Shen, Yingning Peng
    Abstract:

    The problem of super-resolution time Delay Estimation in multipath environments is addressed in this paper. Two cases, active and passive systems, are considered. The time Delay Estimation is first converted into a sinusoidal parameter Estimation problem. Then the sinusoidal parameters are estimated by generalizing the multiple signal classification (MUSIC) algorithm for single-experiment data. The proposed method, referred to as the MUSIC-type algorithm, approximates the Cramer-Rao bound (CRB) in terms of the mean square errors (MSKs) for different signal-to-noise ratios (SNRs) and separations of multipath components. Simulation results show that the MUSIC-type algorithm performs better than the classical correlation approach and the conventional MUSIC method for the closely spaced components in multipath environments.

Khalid Benjelloun - One of the best experts on this subject based on the ideXlab platform.

  • current control of a six phase induction machine drive based on discrete time sliding mode with time Delay Estimation
    2019
    Co-Authors: Yassine Kali, Jorge Rodas, Magno Ayala, Maarouf Saad, Raul Gregor, Jesus Dovalgandoy, Khalid Benjelloun
    Abstract:

    This paper proposes a robust nonlinear current controller that deals with the problem of the stator current control of a six-phase induction motor drive. The current control is performed by using a state-space representation of the system, explicitly considering the unmeasurable states, uncertainties and external disturbances. To estimate these latter effectively, a time Delay Estimation technique is used. The proposed control architecture consists of inner and outer loops. The inner current control loop is based on a robust discrete-time sliding mode controller combined with a time Delay Estimation method. As said before, the objective of the time Delay Estimation is to reconstruct the unmeasurable states and uncertainties, while the sliding mode aims is to suppress the Estimation error, to ensure robustness and finite-time convergence of the stator currents to their desired references. The outer loop is based on a proportional-integral controller to control the speed. The stability of the current closed-loop system is proven by establishing sufficient conditions on the switching gains. Experimental work has been conducted to verify the performance and the effectiveness of the proposed robust control scheme for a six-phase induction motor drive. The results obtained have shown that the proposed method allows good performances in terms of current tracking, in their corresponding planes.

  • discrete time sliding mode with time Delay Estimation of a six phase induction motor drive
    2018
    Co-Authors: Yassine Kali, Jorge Rodas, Magno Ayala, Maarouf Saad, Raul Gregor, Khalid Benjelloun, Jesus Dovalgandoy, Graham C Goodwin
    Abstract:

    This paper investigates the problem of stator current control in presence of uncertainties and unmeasurable rotor current for a six-phase induction motor drive. An inner control loop based on a robust discrete-time sliding mode with time Delay Estimation method is proposed to ensure the finite-time convergence of the stator currents to their desired references while the proportional-integral controller is used for the outer speed control. Sufficient conditions are established to ensure the stability of the closed-loop system. Simulation results were carried out to verify the performance of the proposed robust control strategy for a six-phase induction motor drive.

  • super twisting algorithm with time Delay Estimation for uncertain robot manipulators
    2018
    Co-Authors: Yassine Kali, Maarouf Saad, Khalid Benjelloun, Charles Khairallah
    Abstract:

    This paper proposes a super-twisting algorithm (STA) with time Delay Estimation (TDE) for the problem of high-accuracy tracking trajectory of robotic manipulators in the presence of uncertainties and unexpected disturbances. The TDE method is known for it capability to estimate uncertainties simply without an exact knowledge of the system dynamics. Using the estimated uncertainties, the control law is then designed based on STA to ensure robustness, finite-time convergence and chattering reduction. The stability analysis of the closed-loop system and the finite-time convergence are proved using Lyapunov theory. In order to show the effectiveness of the proposed method, simulations and experimental results were carried out on a 2-DOF rigid robot manipulator and on the 7-DOF ANAT robot arm, respectively.

  • current control based on super twisting algorithm with time Delay Estimation for a five phase induction motor drive
    2017
    Co-Authors: Yassine Kali, Jorge Rodas, Maarouf Saad, Raul Gregor, Khalid Benjelloun, Jesus Dovalgandoy
    Abstract:

    Multiphase induction motor drives have gained popularity due to their fault tolerance and better power/current distribution per phase which are very attractive for industrial applications. Current control strategies with the Estimation of unmeasurable variables (typically rotor variables) has been recently proposed for multiphase induction drive. This paper proposes a novel current control based on super-twisting algorithm with time Delay Estimation for a five-phase induction motor drives. This method considers the Estimation of rotor variables and disturbances, and also ensures the stability by using Lyapunov theory. Simulation results are provided to show the effectiveness of the proposed method and also to compare with other controllers such as a proportional-integral and a model-based predictive controllers.

Yassine Kali - One of the best experts on this subject based on the ideXlab platform.

  • current control of a six phase induction machine drive based on discrete time sliding mode with time Delay Estimation
    2019
    Co-Authors: Yassine Kali, Jorge Rodas, Magno Ayala, Maarouf Saad, Raul Gregor, Jesus Dovalgandoy, Khalid Benjelloun
    Abstract:

    This paper proposes a robust nonlinear current controller that deals with the problem of the stator current control of a six-phase induction motor drive. The current control is performed by using a state-space representation of the system, explicitly considering the unmeasurable states, uncertainties and external disturbances. To estimate these latter effectively, a time Delay Estimation technique is used. The proposed control architecture consists of inner and outer loops. The inner current control loop is based on a robust discrete-time sliding mode controller combined with a time Delay Estimation method. As said before, the objective of the time Delay Estimation is to reconstruct the unmeasurable states and uncertainties, while the sliding mode aims is to suppress the Estimation error, to ensure robustness and finite-time convergence of the stator currents to their desired references. The outer loop is based on a proportional-integral controller to control the speed. The stability of the current closed-loop system is proven by establishing sufficient conditions on the switching gains. Experimental work has been conducted to verify the performance and the effectiveness of the proposed robust control scheme for a six-phase induction motor drive. The results obtained have shown that the proposed method allows good performances in terms of current tracking, in their corresponding planes.

  • discrete time sliding mode with time Delay Estimation of a six phase induction motor drive
    2018
    Co-Authors: Yassine Kali, Jorge Rodas, Magno Ayala, Maarouf Saad, Raul Gregor, Khalid Benjelloun, Jesus Dovalgandoy, Graham C Goodwin
    Abstract:

    This paper investigates the problem of stator current control in presence of uncertainties and unmeasurable rotor current for a six-phase induction motor drive. An inner control loop based on a robust discrete-time sliding mode with time Delay Estimation method is proposed to ensure the finite-time convergence of the stator currents to their desired references while the proportional-integral controller is used for the outer speed control. Sufficient conditions are established to ensure the stability of the closed-loop system. Simulation results were carried out to verify the performance of the proposed robust control strategy for a six-phase induction motor drive.

  • super twisting algorithm with time Delay Estimation for uncertain robot manipulators
    2018
    Co-Authors: Yassine Kali, Maarouf Saad, Khalid Benjelloun, Charles Khairallah
    Abstract:

    This paper proposes a super-twisting algorithm (STA) with time Delay Estimation (TDE) for the problem of high-accuracy tracking trajectory of robotic manipulators in the presence of uncertainties and unexpected disturbances. The TDE method is known for it capability to estimate uncertainties simply without an exact knowledge of the system dynamics. Using the estimated uncertainties, the control law is then designed based on STA to ensure robustness, finite-time convergence and chattering reduction. The stability analysis of the closed-loop system and the finite-time convergence are proved using Lyapunov theory. In order to show the effectiveness of the proposed method, simulations and experimental results were carried out on a 2-DOF rigid robot manipulator and on the 7-DOF ANAT robot arm, respectively.

  • current control based on super twisting algorithm with time Delay Estimation for a five phase induction motor drive
    2017
    Co-Authors: Yassine Kali, Jorge Rodas, Maarouf Saad, Raul Gregor, Khalid Benjelloun, Jesus Dovalgandoy
    Abstract:

    Multiphase induction motor drives have gained popularity due to their fault tolerance and better power/current distribution per phase which are very attractive for industrial applications. Current control strategies with the Estimation of unmeasurable variables (typically rotor variables) has been recently proposed for multiphase induction drive. This paper proposes a novel current control based on super-twisting algorithm with time Delay Estimation for a five-phase induction motor drives. This method considers the Estimation of rotor variables and disturbances, and also ensures the stability by using Lyapunov theory. Simulation results are provided to show the effectiveness of the proposed method and also to compare with other controllers such as a proportional-integral and a model-based predictive controllers.

Dongxu Shen - One of the best experts on this subject based on the ideXlab platform.

  • super resolution time Delay Estimation in multipath environments
    2007
    Co-Authors: Dongxu Shen, Yingning Peng
    Abstract:

    The super-resolution time Delay Estimation in multipath environment is very important for many applications. Conventional super-resolution approaches can only deal with signals with wideband and flat spectra. In this paper, we propose a novel super-resolution time Delay Estimation method that can treat signals with narrowband spectra. In our method, the time Delay Estimation is first transformed into the frequency domain, in which the problem is converted into the parameter Estimation of sinusoidal signals with lowpass envelopes. Then a MUSIC-type algorithm taking account of the envelope variation is applied to achieve the super-resolution Estimation. Time Delay Estimation in active and passive systems are considered. Simulation results confirm that the proposed estimators provide better performance than the classical correlation approach and the conventional MUSIC algorithm for separating closely spaced signals with narrowband spectra.

  • super resolution time Delay Estimation in multipath environments
    2004
    Co-Authors: Dongxu Shen, Yingning Peng
    Abstract:

    The problem of super-resolution time Delay Estimation in multipath environments is addressed in this paper. Two cases, active and passive systems, are considered. The time Delay Estimation is first converted into a sinusoidal parameter Estimation problem. Then the sinusoidal parameters are estimated by generalizing the multiple signal classification (MUSIC) algorithm for single-experiment data. The proposed method, referred to as the MUSIC-type algorithm, approximates the Cramer-Rao bound (CRB) in terms of the mean square errors (MSKs) for different signal-to-noise ratios (SNRs) and separations of multipath components. Simulation results show that the MUSIC-type algorithm performs better than the classical correlation approach and the conventional MUSIC method for the closely spaced components in multipath environments.

Umberto Spagnolini - One of the best experts on this subject based on the ideXlab platform.

  • angle and Delay Estimation of space time channels for td cdma systems
    2004
    Co-Authors: José Picheral, Umberto Spagnolini
    Abstract:

    In mobile communications the antenna arrays make it possible to estimate the path Delay, angle of arrival (or angle), and amplitude for the multipath propagation channel. This paper considers the problem of joint angle and Delay Estimation (JADE) in a time-division code-division multiple access system. The angle/Delay Estimation is made from multiple slots by exploiting the angle/Delay invariance of the channel regardless of the fast faded amplitude variation (i.e., angle/Delay is assumed quasistatic). JADE can be approximated by methods that estimate the frequencies of the two-dimensional complex sinusoids where the faded amplitudes act as sources. The shift invariance method (JADE-ESPRIT) is chosen for its capacity to pair Delay and angle for each path and each user. The consistency of JADE-ESPRIT for a large enough number of slots guarantees the feasibility of the method for spatially correlated noise. The performance of the JADE method for channel Estimation is evaluated analytically and numerically in propagation environments with increasing complexity.

  • shift invariance algorithms for the angle Delay Estimation of multipath space time channel
    2001
    Co-Authors: José Picheral, Umberto Spagnolini
    Abstract:

    In time-division CDMA systems the angle/Delay of the multipath propagation channel can be estimated jointly by exploiting the invariance of angles/Delays across multiple slots regardless of fast-variation in faded amplitudes. The joint angle/Delay Estimation (JADE) is reduced to the Estimation of frequency of 2D sinusoids, here the shift-invariance method (2D-ESPRIT) is used. Application of JADE to 3/sup rd/ generation mobile communication system (TDD-UTRA standard) and to realistic propagation environments demonstrates the advantage of the proposed method. Linear multiuser detection that exploits angle/Delay estimates shows a meaningful improvement (approx. 2/spl divide/4 dB in signal to noise ratio) with respect to the conventional least square estimate.