In this paper, we propose a passivity monitor which evaluates stability of a system based on the concept of passivity, and a software limiter which turns the system stable if it is originally unstable. It is shown that asymptotic stability will be guaranteed for arbitrary robots with arbitrary control schemes and environments, even if their properties are unknown. The validity of the passivity ...

Abstract Sedimentation and erosion processes in sedimentary basins can be modeled by a parabolic equation with a limiter on the fluxes and a constraint on the time variation. This limiter happens to satisfy a stationary scalar hyperbolic inequality, within a constraint, for which we prove the existence and the uniqueness of the solution. Actually, this solution is shown to be the maximal elemen...

A weighted essential non-oscillatory reconstruction scheme based on Hermite polynomials is developed and applied as a limiter for a discontinuous Galerkin finite element method on unstructured grids. The solution polynomials are reconstructed using a WENO scheme by taking advantage of handily available and yet valuable information, namely the derivatives, in the context of the discontinuous Gal...

In this paper, we develop discontinuous Galerkin (DG) methods to solve ideal special relativistic hydrodynamics (RHD). In RHD, the density and pressure are positive. Units are normalized so that the speed of light is c = 1. Therefore, the velocity of the fluid has magnitude less than 1. To construct physically relevant numerical approximations, we develop a bound-preserving limiter to the schem...

An all-optical plasmonic limiter based on a nonlinear slow light waveguide is proposed and numerically investigated for the first time. The results reveal that the slowdown factor can be tuned by the intensities of incident surface plasmon waves. In addition, the nonlinear slow light waveguide can be operated as a limiter, in which surface plasmon waves with low incident power intensities can t...

In this paper, we investigate a simple limiter using weighted essentially non-oscillatory (WENO) methodology for the Runge-Kutta discontinuous Galerkin (RKDG) methods solving conservation laws, with the goal of obtaining a robust and high order limiting procedure to simultaneously achieve uniform high order accuracy and sharp, non-oscillatory shock transitions. The idea of this limiter is to re...

In order to reduce the total harmonic distortion (THD) of a bandpass-based oscillator, instead of using a conventional hard limiter, a multilevel hard limiter (MHL) is proposed which inherently removes the third and the fifth-order harmonics from the frequency spectrum of its output signal. The input–output characteristic of the proposed MHL contains slope values of only zero and infinity, maki...

A parameter-free limiting technique is developed for high-order unstructured-grid methods to capture discontinuities when solving hyperbolic conservation laws. The technique is based on a “troubled-cell” approach, in which cells requiring limiting are first marked, and then a limiter is applied to these marked cells. A parameter-free accuracypreserving TVD marker based on the cell-averaged solu...

The two-dimensional multifluid code TECXY has been used to model the biasing (with respect to the first wall) of the toroidal belt limiter ALT-II on the tokamak TEXTOR-94 and of the new toroidal pump limiter being installed on Tore Supra tokamak in the framework of the CIEL project. It is well known that the edge flow pattern can be influenced by the poloidal electric drifts from imposing radia...

Measurements of fast phenomena in the vicinity of a limiter inserted into a linear plasma column are shown in this work. The results were conducted at the plasma generator PSI-2 (Humboldt Universitaet zu Berlin, Germany) which provides a stationary plasma produced in a DC arc discharge. The plasma near a tungsten limiter was imaged on a photomultiplier tube equipped with 16 anodes. The photomul...