This paper focuses on the problem of force-feedback for the human-operator hand when manipulating virtual objects. We propose a method for the computation of feedback-forces that have to be applied on each individual phalanx and nger of the human hand in order to display pertinent, kinesthetic information about static or dynamic characteristics of objects present in the virtual scene. External ...

Abstract. In previous papers, we introduced the idea of a Virtual Sensor, which is a mathematical model trained to learn the potentially nonlinear relationships between spectra for a given image scene for the purpose of predicting values of a subset of those spectra when only partial measurements have been taken. These nonlinear relationships are induced by the physical characteristics of the i...

In previous papers, we introduced the idea of a Virtual Sensor, which is a mathematical model trained to learn the potentially nonlinear relationships between spectra for a given image scene for the purpose of predicting values of a subset of those spectra when only partial measurements have been taken. Such models can be created for a variety of disciplines including the Earth and Space Scienc...

A new method for the control reconfiguration of stable Hammerstein systems after actuator faults is described. The class of Hammerstein systems contains input-saturated systems, which are ubiquitous in practice. The new reconfiguration approach uses a virtual actuator that permits to keep the nominal controller in the loop. The concept of virtual actuators is extended to reflect the nonlinear p...

This paper introduces a methodology for differential nonlinear stability analysis using contraction theory (Lohmiller and Slotine, 1998). The methodology includes four distinct steps: the descriptions of two systems to be compared (the plant and the observer in the case of observer convergence analysis, the plant and the controller in the case of tracking controller analysis), the definition of...

stretching process of sheet metals in both cases of axisymmetric and non-axisymmetric is analyzed. a rigid-plastic, normal anisotrop material is assumed and large strain formulation is applied. triangular elements are used and stiffness equations of elements are obtained from virtual work principle. these nonlinear equations are linearized by newton-raphsons method and are solved by gaussian el...

We have developed a technique for authoring a nonlinear plot and for managing a story according to the plot in an interactive story-based virtual reality application. The technique exploits Petri Nets that alter reactive plans controlling individual actors. Its main advantage is that it allows for iterative design and copes with large virtual worlds inhabited with tens of actors. In this paper,...