Modeling and simulation

About: Modeling and simulation is a research topic. Over the lifetime, 10273 publications have been published within this topic receiving 111550 citations.

CAD tools for data converter design: an overview

Abstract: This paper presents an overview of the recent advances in modeling, simulation and structured synthesis that are pushing ahead the capabilities and efficiency of CAD tools for integrated data converter design. First, a hierarchical design methodology and a common framework with standardized interfaces are shown to be essential to create a design environment that is flexible enough to cover a wide range of specifications and applications. The different approaches for data converter modeling and simulation are then reviewed and compared, ranging from purely electrical simulators to state-of-the-art behavioral analog-digital simulators. In particular, it is shown how behavioral models of data converters are emerging as a powerful solution for complex system simulations with highly reduced computational requirements. Next, the key steps in the automatic synthesis of data converters are discussed, and state-of-the-art synthesis systems are compared and illustrated with some practical design examples. Finally, the progress in tools for testing and design for testability of data converters is described.

Modeling and Simulation of a Flexible Manufacturing System—A Basic Component of Industry 4.0

Abstract: The field of Flexible Manufacturing Systems (FMS) has seen in recent years a dynamic development trend and can now be considered an integral part of intelligent manufacturing systems and a basis for digital manufacturing. Developing the factory of the future in an increasingly competitive industrial environment involves the study and analysis of some FMS key elements and managerial, technical, and innovative efforts. Using a new approach, thus paper presents a material flow design methodology for flexible manufacturing systems in order to establish the optimal architecture of the analyzed system. The research offers a solution for modeling and optimizing material flows in advanced manufacturing systems. By using a dedicated analysis and simulation software, the structure of the system can be established and specific technical and economic parameters can be determined for each processing and transport capacity. Different processing scenarios will be evaluated through virtual modeling and simulations in order to increase the performance and efficiency of the system. Thus, an interactive tool useful in the design and management of flexible manufacturing lines will be developed for companies operating in the industrial sector. The application of this paper is mainly in the field of development of intelligent manufacturing systems, where the control system will make and use simulations in order to analyze current parameters and to predict the future.

High-Fidelity Multi-Rotor Unmanned Aircraft System Simulation Development for Trajectory Prediction Under Off-Nominal Flight Dynamics

Abstract: The NASA Unmanned Aircraft System (UAS) Traffic Management (UTM) project is conducting research to enable civilian low-altitude airspace and UAS operations. A goal of this project is to develop probabilistic methods to quantify risk during failures and off nominal flight conditions. An important part of this effort is the reliable prediction of feasible trajectories during off-nominal events such as control failure, atmospheric upsets, or navigation anomalies that can cause large deviations from the intended flight path or extreme vehicle upsets beyond the normal flight envelope. Few examples of high-fidelity modeling and prediction of off-nominal behavior for small UAS (sUAS) vehicles exist, and modeling requirements for accurately predicting flight dynamics for out-of-envelope or failure conditions are essentially undefined. In addition, the broad range of sUAS aircraft configurations already being fielded presents a significant modeling challenge, as these vehicles are often very different from one another and are likely to possess dramatically different flight dynamics and resultant trajectories and may require different modeling approaches to capture off-nominal behavior. NASA has undertaken an extensive research effort to define sUAS flight dynamics modeling requirements and develop preliminary high fidelity six degree-of-freedom (6-DOF) simulations capable of more closely predicting off-nominal flight dynamics and trajectories. This research has included a literature review of existing sUAS modeling and simulation work as well as development of experimental testing methods to measure and model key components of propulsion, airframe and control characteristics. The ultimate objective of these efforts is to develop tools to support UTM risk analyses and for the real-time prediction of off-nominal trajectories for use in the UTM Risk Assessment Framework (URAF). This paper focuses on modeling and simulation efforts for a generic quad-rotor configuration typical of many commercial vehicles in use today. An overview of relevant off-nominal multi-rotor behaviors will be presented to define modeling goals and to identify the prediction capability lacking in simplified models of multi-rotor performance. A description of recent NASA wind tunnel testing of multi-rotor propulsion and airframe components will be presented illustrating important experimental and data acquisition methods, and a description of preliminary propulsion and airframe models will be presented. Lastly, examples of predicted off-nominal flight dynamics and trajectories from the simulation will be presented.

Modeling and Simulation in Scilab

Abstract: One of the fundamental problems in many areas of science and engineering is the problem of modeling and simulation. Scilab provides a large array of tools for developing and simulating models of several types. For several of these tools it is possible to use them with abbreviated commands and default values of some parameters. However, to know how to choose the appropriate tools and how to get the kind of answers desired, it is often necessary to know something about how the algorithms are set up and what to do if there are difficulties.

Modeling and simulation methods for plasma processing

Abstract: Methods used for the modeling and numerical simulation of the plasma processes used in semiconductor integrated-circuit fabrication are reviewed. In the first part of the paper, we review continuum and kinetic methods. A model based on the drift-diffusion equations is presented as an example of a continuum model; the model and associated numerical solutions are discussed. The most widely used simulation method for kinetic modeling is the Particle-ln-Cell/Monte-Carlo-Collision (PIC/MCC) method, in which the plasma is modeled by a system of charged superparticles (each of which represents a collection of a large number of ions or electrons) that move in self-consistent electromagnetic fields and collide via given collision cross sections. In the second part of the paper, we review the modeling and simulation of the evolution of surface topography in plasma etching and deposition.