The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform

Hubert Westermayr - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear control of a turbocharged diesel engine using singular perturbation methods
    2007 European Control Conference (ECC), 2007
    Co-Authors: Hannes Seyrkammer, Kurt Schlacher, Hubert Westermayr
    Abstract:

    This contribution is concerned with a nonlinear control design for diesel engines equipped with a variable geometry turbocharger and an exhaust gas recirculation valve. The control objective is to supply an amount of fresh air and to achieve a Desired Pressure in the intake manifold for the actual operating point of the engine. The well known differential equations describing such a system are split into parts with a slow, and a fast transient response and transformed into the standard form for singular perturbed systems. For the proposed controller, the slow part is extended with two integrating states and asymptotic stability of the closed loop system in the sense of Lyapunov is guaranteed using singular perturbation methods. Finally, the performance of the controller is demonstrated by simulation results.

Hannes Seyrkammer - One of the best experts on this subject based on the ideXlab platform.

  • Control and stability analysis of a turbocharged Diesel engine using singular perturbation methods
    PAMM, 2007
    Co-Authors: Hannes Seyrkammer, Kurt Schlacher
    Abstract:

    The control of the air path of a diesel engine with a variable geometry turbocharger and exhaust gas recirculation can be improved significantly by nonlinear methods. The control objective is to supply an amount of fresh air by the compressor and to achieve a Desired Pressure in the intake manifold in the neighborhood of an operating point of the engine. The mathematical model of the air path is split into a slow and a fast part. For the proposed controller, asymptotic stability of the closed loop system in the sense of Lyapunov is guaranteed by the use of singular perturbation methods. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

  • Nonlinear control of a turbocharged diesel engine using singular perturbation methods
    2007 European Control Conference (ECC), 2007
    Co-Authors: Hannes Seyrkammer, Kurt Schlacher, Hubert Westermayr
    Abstract:

    This contribution is concerned with a nonlinear control design for diesel engines equipped with a variable geometry turbocharger and an exhaust gas recirculation valve. The control objective is to supply an amount of fresh air and to achieve a Desired Pressure in the intake manifold for the actual operating point of the engine. The well known differential equations describing such a system are split into parts with a slow, and a fast transient response and transformed into the standard form for singular perturbed systems. For the proposed controller, the slow part is extended with two integrating states and asymptotic stability of the closed loop system in the sense of Lyapunov is guaranteed using singular perturbation methods. Finally, the performance of the controller is demonstrated by simulation results.

Kurt Schlacher - One of the best experts on this subject based on the ideXlab platform.

  • Control and stability analysis of a turbocharged Diesel engine using singular perturbation methods
    PAMM, 2007
    Co-Authors: Hannes Seyrkammer, Kurt Schlacher
    Abstract:

    The control of the air path of a diesel engine with a variable geometry turbocharger and exhaust gas recirculation can be improved significantly by nonlinear methods. The control objective is to supply an amount of fresh air by the compressor and to achieve a Desired Pressure in the intake manifold in the neighborhood of an operating point of the engine. The mathematical model of the air path is split into a slow and a fast part. For the proposed controller, asymptotic stability of the closed loop system in the sense of Lyapunov is guaranteed by the use of singular perturbation methods. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

  • Nonlinear control of a turbocharged diesel engine using singular perturbation methods
    2007 European Control Conference (ECC), 2007
    Co-Authors: Hannes Seyrkammer, Kurt Schlacher, Hubert Westermayr
    Abstract:

    This contribution is concerned with a nonlinear control design for diesel engines equipped with a variable geometry turbocharger and an exhaust gas recirculation valve. The control objective is to supply an amount of fresh air and to achieve a Desired Pressure in the intake manifold for the actual operating point of the engine. The well known differential equations describing such a system are split into parts with a slow, and a fast transient response and transformed into the standard form for singular perturbed systems. For the proposed controller, the slow part is extended with two integrating states and asymptotic stability of the closed loop system in the sense of Lyapunov is guaranteed using singular perturbation methods. Finally, the performance of the controller is demonstrated by simulation results.

Linus Wunderlich - One of the best experts on this subject based on the ideXlab platform.

  • Isogeometric shape optimization for nonlinear ultrasound focusing
    Evolution Equations & Control Theory, 2019
    Co-Authors: Markus Muhr, Vanja Nikolić, Barbara Wohlmuth, Linus Wunderlich
    Abstract:

    The goal of this work is to improve focusing of high-intensity ultrasound by modifying the geometry of acoustic lenses through shape optimization. We formulate the shape optimization problem by introducing a tracking-type cost functional to match a Desired Pressure distribution in the focal region. Westervelt's equation, a nonlinear acoustic wave equation, is used to model the Pressure field. We apply the optimize first, then discretize approach, where we first rigorously compute the shape derivative of our cost functional. A gradient-based optimization algorithm is then developed within the concept of isogeometric analysis, where the geometry is exactly represented by splines at every gradient step and the same basis is used to approximate the equations. Numerical experiments in a \begin{document}$ 2 $\end{document} D setting illustrate our findings.

  • Isogeometric shape optimization for nonlinear ultrasound focusing
    arXiv: Optimization and Control, 2017
    Co-Authors: Markus Muhr, Vanja Nikolić, Barbara Wohlmuth, Linus Wunderlich
    Abstract:

    The goal of this work is to improve focusing of high-intensity ultrasound by modifying the geometry of acoustic lenses through shape optimization. The shape optimization problem is formulated by introducing a tracking-type cost functional to match a Desired Pressure distribution in the focal region. Westervelt's equation, a nonlinear acoustic wave equation, is used to model the Pressure field. We apply the optimize first, then discretize approach, where we first rigorously compute the shape derivative of our cost functional. A gradient-based optimization algorithm is then developed within the concept of isogeometric analysis, where the geometry is exactly represented by splines at every gradient step and the same basis is used to approximate the equations. Numerical experiments in a 2D setting illustrate our findings.

R. J. Zieve - One of the best experts on this subject based on the ideXlab platform.

  • a manganin foil sensor for small uniaxial stress
    arXiv: Instrumentation and Detectors, 2017
    Co-Authors: M. K. Frampton, N. Mclaughlin, Hu Jin, R. J. Zieve
    Abstract:

    We describe a simple manganin foil resistance manometer for uniaxial stress measurements. The manometer functions at low Pressures and over a range of temperatures. In this design no temperature seasoning is necessary, although the manometer must be prestressed to the upper end of the Desired Pressure range. The prestress Pressure cannot be increased arbitrarily; irreversibility arising from shear stress limits its range. Attempting larger Pressures yields irreproducible resistance measurements.

  • Note: Manganin foil sensor for small uniaxial stress
    The Review of scientific instruments, 2017
    Co-Authors: M. K. Frampton, N. Mclaughlin, Hu Jin, R. J. Zieve
    Abstract:

    We describe a simple manganin foil resistance manometer for uniaxial stress measurements. The manometer functions at low Pressures and over a range of temperatures. In this design, no temperature seasoning is necessary although the manometer must be prestressed to the upper end of the Desired Pressure range. The prestress Pressure cannot be increased arbitrarily; irreversibility arising from shear stress limits its range. Attempting larger Pressures yields irreproducible resistance measurements.