Lag

About: Lag is a based out in . It is known for research contribution in the topics: Tokamak & Haptic technology. The organization has 4 authors who have published 4 publications receiving 37 citations.

Foldable carriage rack

Abstract: A carriage rack has two posts, two swivel arms, two elastic elements, a luggage holding rod, a bracket, and casters. The two posts are spaced in a parallel manner and provided with pivoting portion. Each of swivel arms is composed of a cylindrical portion and inner and outer lugs extending rearwards from the cylindrical portion, which is provided with an opening. The inner lug is furnished with a recess, a slant, and a baffle. The swivel arm is fastened to the bottom end of the post by means of its cylindrical portion which receives the post in such a manner that the pivoting portion of the post extends out of the opening of the cylindrical portion so as to permit the positioning of the swivel angle of the swivel arm. The elastic elements are used to drive the two swivel arms to move. The luggage holding rod has two upright legs pivotally fastened to the pivoting portions of the posts in such a manner that they urge the slants of inner lugs of the swivel arms so as to enable the swivel arms to move outwards. The bracket is fastened to the luggage holding rod in such a way that it keeps the two upright legs of the luggage holding rod to remain perpendicular to ground surface at the time when the carriage rack is in use.

Model Based Diagnostic Module for a FCC Pilot Plant

Abstract: This paper presents a diagnostic module developed by IFP and tested off-line on a FCC (Fluid Catalytic Cracking) pilot plant. The method uses four successive complementary techniques. They enable to go step by step from the observations to a sentence in natural language describing the faults. First, a quantitative causal model is elaborated from a quantitative behavioural model. Causality is obtained from the structure of each equation. Then, global and local alarms are generated using residuals (differences between measures and outputs of the model) and fuzzy logic reasoning. Then, a hitting set algorithm is applied to determine sets of components or equipment which are suspected to have an abnormal behaviour. Finally, expert human operator knowledge about those components is used to identify the fault(s) and produce messages for the operators. This software is currently tested off-line on the FCC pilot plant at IFP. The performance of the diagnostic module is illustrated on four practical scenarios of abnormal behaviour. This work is conducted as part of the CHEM EC funding project.

Towards Control of Steady State Plasma on Tore Supra

Abstract: The Tore Supra tokamak is the largest superconducting magnetic fusion facility, has been devoted to long-duration high-performance discharge research. With a steady-state magnetic field and water cooled plasma facing components, discharges up to 6 minutes 24 seconds duration with injected / extracted energy up to 1 GJ have been performed. The Tore Supra real time measurements and control (RTMC) system has been upgraded to address schemes dedicated to long pulse operation with simultaneous control of an increasing number of plasma parameters. This includes plasma equilibrium control with possible self calibration during the discharge, plasma density control with possible pellet injection, current profile control to avoid magneto-hydrodynamic (MHD) instabilities and infrared monitoring of plasma facing components preventing overheating. Most of these improvements are relevant to the tokamaks operation in a fully steady state regime.

Dynamical issues in interactive representation of physical objects

Abstract: The quality of a simulator equipped with a haptic interface is given by the dynamical properties of its components: haptic interface, simulator and control system. Some application areas of such kind of simulator like musical synthesis, animation or more general, instrumental art have specific requirements as for the "haptic rendering" of small movements that go beyond the usual haptic interfaces allow. Object properties variability and different situations of object combination represent important aspects of such type of application which makes that the user can be interested as much in the restitution of certain global properties of an entire object domain as in the restitution of properties that are specific to an isolate object. In the traditional approaches, the usual criteria are founded on the paradigm of transparency and are related to the impedance error introduced by the technical aspects of the system. As a general aim, rather than to minimize these effects, we look to characterize them by physical metaphors conferring to haptic medium the role of a tool. This positioning leads to firstly analyze the natural human object interaction as a simplified evolutive system and then considers its synthesis in the case of the interactive physical simulation. By means of a frequential method, this approach is presented for some elementary configurations of the simulator