|
Digital simulation of reality
Written by: Dr. Yuri Iserlis
Clever Ace
Introduction. Every day new applications appear on the Market, and sometimes their authors or developing companies don’t call intelligent programs, but they are actually intelligent programs in their functions and content.
While in the last 2-3 decades, due to successes in the development of powerful computers and achievements in programming, technology of simulation of physical processes and behavior of complex systems in our reality has been undergoing substantial growth. There are several examples from our present life:
-
With this computerized system, surgeons can position new knees of patient with greater accuracy than ever. When patients have perfect knee alignment, they have an improved range of motion and shorter rehabilitation times.
-
Major metropolitan areas in the United States have Advanced traffic management systems (ATMS). The dispatcher monitors can show real images of vehicles and their positions on the roads and highways. Early warning of dangerous conditions is visually highlighted by signaling.
-
Marine simulation as well as military air forces and commercial airlines provide a safe and effective way of training pilots and other personnel in a given environment by fully simulating real equipment and real conditions.
In large manufacturing industries such as machinery, automotive and aircraft industries, product design and development are now done completely by the computers. Product designers and engineers use Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) systems to create three-dimensional geometrical objects that can be drawn, analyzed, tested and optimized. Manufacturing engineers use Computer-Aided Manufacturing (CAM) systems for process planning, control , tool design, etc.
If CAD/CAM systems were born 2-3 decades ago, CAE tools had the rapid growth and adoption at the period of the last decade. This type of tools has a number of applications in structural design, civil engineering, mechanical engineering, electrical engineering and so on. Now we can get CAE tools for simulation of solid, fluid, electromagnetic and other physical phenomena. This growth is propelled by market pressures that demand reduced time-to-market, increased productivity and enriched features for their products.
To build a model of either processes, or events, or processes with continuous or discrete events, there are needs to have the descriptions of all above by text, math formulas, any kinds of graphs, matched data, etc. and special methods of digital modeling (simulation) with help of different types of models (2D or 3 D), such as wireframe models, solid models, surfaces models, etc., plus special tricks, needed to graphically visualize, manipulate, and solve engineering, architectural, training and other problems. For more information see: Curt Franklin's article: How 3-D Graphics Work.
Traditional modeling paradigms started from mathematical description of processes, are now giving way to new modeling approaches and methods such as Object-Oriented Simulation, Neural Nets, Adaptive/Heuristic Simulation, Artificial Intelligence algorithms, 3D graphics, and so on. For systems, used in the area of water resources, ground fields, urban , etc., when looking back into the history of the numerical modeling it can be seen that the general trend of the modeling approach is moving from the periods of ‘function-centric’ where numerical models were self-contained and supported by their own data sets, towards ‘map-centric’ where models would be created and supported in Geographic Information Systems (GIS).
Universal simulation tools
Historically an any process simulation could be executed with help of methods of applying mathematics and special and universal computer languages. There exists several popular and very effective software tools such as MathCad 12, Matlab7, Maple 9.5, Mathematica, etc.
The Global Optimization Toolbox and the Database Integration Toolbox are products developed by Maplesoft Inc, which include kits for integration with major enterprise-class software systems, and engineering design applications.
Mathematica 5.0 (developing by Wolfram Research) is the complete environment for technical computing tasks, whether simple calculations or large-scale computations, visualizing or modeling data. Mathematica allows distributing also complex calculations across given clusters, multiprocessor machines, or computing grids.
Descreet, Inc. develops tools using for 3D animation (3ds max), media mastering, effects compositing, digital color grading, etc.
GoldSim Pro developed by GoldSim, is a general-purpose simulator suitable for modeling any type of business, scientific, and engineering system that can be expressed mathematically.
Special digital simulation tools (DST) are complexes of different types of simulation and computer based research applications for different cases.
Once constructed with help of DST , the model can run on a computer, and the results of the run may be used for different goals. The well done model could have an acceptable degree of accuracy of about 1-2 % and less. While computer simulations can perform many functions, two are especially important:
-
simulations can allow for designer, researcher or scientist to visualize and to measure the characteristics of many processes taking place inside of the real objects,
-
simulations can demonstrate possible relationships between variables and functions, between input and output data in dynamic as function of time , or function of environment parameters.
Such quality model maybe used with a high degree of confidence to make design, analysis and predictions with respect to the real-world reference system. These models and based on them simulation tools allow: saving development time and cost , testing and finding critical situation, optimizing parameters of systems and control.
Simulation tools widely use for these goals such methods as Finite Element (FE) and Discrete Element (DE) analysis technology (see: "FEA World" on the site of Altair Engineering).
One of the principal benefits of a digital model is that its development can begin with a simple approximation of a process, and subsequent to that gradually, via interactions refining this model for its improvement by accuracy, by interface, by the quality of the visualization. Interactive simulation, this “step-by-step refinement" enables a possibility to achieve good approximations of very complex problems pretty quickly. For these goals can be used also special formal methods and machine learning tools.
When some knowledge for modelling is missing or is fragmented and incomplete, for the goals of simulation can be utilized Hybrid simulation models. Usually it is a combination of physically based models and empirical models. For designing of empirical models there can be used methods such as Regression Analysis, Fuzzy Logic, Neutral Network, and so on.
Industrial DST are very often used together with CAD systems, such as Pro/ENGINEER, MicroStation, CATIA, etc.
At present, there are created and developed a number of powerful simulation tools for simulating many physical processes in different machines and industrial systems, for example the following processes:
-
Flow in Centrifugal Pumps
-
Processes in the Heating, Ventilation, Air Conditioning
-
Lubrication of Bearings
-
Flow in Pipes
-
etc.
These tools are used for different goals in the following industries: aerospace and defense, automotive, electronics, agricultural and environmental sciences, and so on. Some of these tools and their developers are described below. There are many applications not covered , and some developers could fit in multiple categories, but due to space limitations, they are only included in one. For example:
ANSYS , Inc. is developing simulation solutions — from mechanical to computational fluid dynamics (CFD). This company is focused on delivering a next-generation simulation system that encompasses multiple tools built to work together and be integrated into a customer’s development process, as well as is focused on delivering a modular simulation system that is easy to use and to extend to meet customer needs. One tool from product families - ANSYS® Multiphysics™ 8.1 provides the analysis industry's most comprehensive coupled physics tool combining structural, thermal, CFD, acoustic and electromagnetic simulation capabilities into a single software product.
Analytic Computational Research, Inc.(ACRi) is a leading high technology company specialized in CFD, software and consulting services. This company issued Integrated Development Environment (IDE) CFDStudio™, that supports the following tools:
- tool using to analyze problems such as low pressure film deposition, cooling of electronic components, automobile fluid dynamics, ventilation of tunnels, HVAC design optimization, analysis of process tanks, design of ramjets and aircraft engines, missile launch tube simulations, lubrication of bearings, and performance of high Mach number missiles.
PORFLOW™ - tool to accurately solve problems involving transient or steady state fluid flow, heat, salinity and mass transport in multi-phase, variably saturated, porous or fractured media with dynamic phase change.
ESI Group is a world leading provider of digital simulation software for prototyping and manufacturing processes that take into account the physics of materials. ESI Group has developed an entire suite of coherent, industry-oriented applications to realistically simulate a product's behavior during testing, to fine tune the manufacturing processes in synergy with the desired product performance, and to evaluate the environment's impact on product usage. Typical examples of the virtual test applications are crash test, drop test, stamping, casting, welding, aero-dynamics, aero-acoustics, electro-magnetics and bio-mechanics. ESI Group's product portfolio represents a unique collaborative, virtual engineering solution, known as the Virtual Try-Out Space (VTOS). By reducing costs and development lead times, VTOS solutions allow to eliminate the need for testing of physical prototypes.
Developed by Streamsim Technologies Streamline simulation is a powerful, complementary technique. The Streamline simulation is software tool that allows engineers to model fluid flows, whether in water, oil or gas reservoirs. In result, powerful visualization of flow behavior allow for rapid decision making with less uncertainty.
Maxwell 3D developed by Ansoft Corp. simulates frequency and time domain electromagnetic fields in complex-3D structures with unsurpassed accuracy and ease of use. Users, can quickly build virtual prototypes of complex 3D electromechanical components, high-power MRI coils and more.
Integrated simulation systems for physical processes and events
The simulation of complex systems requires methodologies capable of integrating models built on different paradigms.
The company Next Limit Technologies (Spain) is developing the following products: Realflow and Realwave. Realflow is a physically-based animation tool which enables the user not only to simulate wave propagation, objects floating and bobbing at a liquid’s surface, waves which break and generate spray following a collision but also to create effects based on complex interactions between particles and solid objects. Realwave simulates highly complex scenes at the resolution of the customer choice, ensuring that his creativity is never constrained. The integration and seamless interaction between Realflow and RealWave create a impressive capacity for solving different kind of engineering tasks.
Founded in 1981, EASi is a world-class provider of innovative Engineering, CAE and IT solutions for Fast-to-Market Product Development. EASi is a Tier-1 supplier to many of the largest automotive companies in the world, including BMW, DaimlerChrysler, Ford, etc. as well as over 65 automotive suppliers.
Since 1989, Visual Solutions has developed Windows-based software for the modeling and simulation of dynamic systems. VisSim™ products are used by companies worldwide to model, simulate and embed control, communication and signal processing systems. VisSim combines an intuitive drag & drop block diagram interface with a powerful simulation engine. The visual block diagram interface offers a simple method for constructing, modifying and maintaining complex system models. The simulation engine provides fast and accurate solutions for linear, nonlinear, continuous time, discrete time, time varying and hybrid system designs.
Once more the popular CAE tool, Working Model 2004 developing by MSC.Software is a conceptual design tool that allows creating simulations that replace vague, time consuming, inaccurate “back of the envelope" calculations. Working Model has been adopted by thousands of professional engineers to create and analyze real-life mechanical systems. MSC.visualNastran 4D (vN4D) takes mechanical simulation to the next dimension by merging CAD, motion, FEA, and controls technologies into a single functional modeling system. Users can import a CAD drawing from SolidWorks®, Solid EdgeTM, Mechanical Desktop®, Inventor®, and Pro/Engineer® perform motion and FEA simulations and link to a MATLAB®/Simulink® control system - all within a single program.
Simulation of behavior of real system in different environment
MÄK Technologies develops software to link, simulate and visualize the virtual world. This company created tools and toolkits for distributed simulations, develop PC-based military tactical trainers, craft custom solutions, and research and develop the latest simulation technologies.
The Multigen-Paradigm allows to find Flight, Ground, Marine, Urban solution , and 3D GIS-solutions for training personnel in different types of environments. Leaders in the airline transportation, aircraft manufacturing, space and defense industries utilize Vega's advanced simulation technology for critical operations such as pilot and gunner training, aircraft design, mission planning rehearsal and missile visualizations.
Distributed simulation
Simulation systems for modeling multi-object and multi- process systems can be the complex systems built on multiple computers, or processors.. They incorporate very specific I/O, sophisticated simulation algorithms as well as very precise timing and synchronization. Applications of distributed simulation have appeared in diverse industrial domains such as aerospace, emergency planning, manufacturing, maritime , supply chains, and so on. A common trend is development of simulations systems composed from models linked together over a network that can interoperate to support decision making and training.
AEgis Technologies utilizes its extensive HLA (High Level Architecture) and DIS (Distributed Interactive Simulation) experience to provide detailed integration support to a variety of distributed simulation programs. HLA and DIS are software architectures for the development and execution of distributed simulation applications, according to concept by the DARPA Simulation Networking (SIMMET) program.
Intelligent Automation, Inc. (IAI). develops the Agent technology that involves building complex applications from autonomous, interacting components. It is very effective approach for modeling, simulating, and analyzing complex systems, as well as improving and optimizing their behavior. Decomposing complex systems to agents along their physical and logical boundaries has many potential advantages. IAI has developed Cybele™, an agent infrastructure that provides network communication, event handling, concurrency management, as well as agent migration and load-balancing services. This company has also developed DIVA, a case tool for designing agent behavior following agent design methodology.
Simulation of behavior of the unreal system in the unreal situations - for games and films
NewTek's Emmy-winning LightWave 3D® is a key tool in visual effects field. Integration Production Suite VT[3] is providing live switching, real-time keying, titling, compositing, 2D video painting, 3D modeling and animation, with the highest-quality uncompressed component digital video output. NewTek products can be found in nearly every top Hollywood production studio, TV station and major motion picture company.
Academy Award® winning Maya® software developed by Alias Systems Corp is the powerfully integrated 3D modeling, animation, effects, and rendering solution. Many film and video artists, game developers, visualization professionals, Web and print designers turn to Maya to take their work to the next level. For those in scientific, educational, and military industries who need to accurately visualize real-world phenomena on their workstations, Maya® software brings data to life. Maya accurately imports and exports real-world data from a variety of sources including: CAD software, motion and structural-analysis systems, telemetry, and in-flight recorders.
Digital Simulation Labs, Inc. (DSL) is a newly formed company that creates and develops digital simulation tools. 3D graphic technology of this company provides solutions for the films, video, game development, interacted media, industry design and visualization market. Work of this company is being used in numerous Hollywood features.
Program-Ace is a game development company that can develop a wide range of PC games of any genre: Arcade, RTS, Action, Sport Simulator, etc.( 2D & 3D).
The Viewpoint Platform by Viewpoint Corp. is an application development and visualization platform that enables the creation of cutting-edge rich media and rich Internet applications and presentations that seamlessly intermix video, audio, 3-D and 2-D images as well as formats such as Flash, QuickTime and SVG. Leveraging the power of the Viewpoint Media Player and its client-side architecture and the reach of the Viewpoint Distribution Network, the Viewpoint Platform creates innovative, powerful content and applications of incomparable quality and impact.
3D graphics and Virtual Reality for America's Army
According to Don Brutzman, "Although most military organizations have been known to be strongly traditional and uninterested in change, recently the US military has been at the forefront in both funding and creating virtual reality and Web3D. No other organization in the world has been so eager to embrace these new technologies for training and simulation". The MOVES Institute's mission is research, application and education in the grand challenges of Modeling, Virtual Environments and Simulation (MOVES). They created Computer games for America's Army for recruitment and training. The US Army's Telemedicine & Advanced Technology Research Center (TARTRC) is at the forefront in medical modeling and simulation.
Web-based simulation
Web-based simulation represents an integration of digital simulation methodologies and applications within the World Wide Web. There are several advantages for web-based simulation:
-
can be accessed through Internet or Intranet using any web browser,
-
can be run on one or many computers, located anywhere,
-
for any web application, can provide the best achievements of digital simulation technology,
-
can be platform-independent and operating-system-independent.
For more information see :A Survey of Web-Based Simulation
Combined simulations is combining physical models and digital models for training, engineering, science and entertainment goals.
Realtime Technologies’ (RTI) off-road simulator is built for both training and research purposes. It is completely scalable using RTI’s SimCreator software. Systems can be configured with up to five visual channels. Each channel can be configured as front or rear projection, head mounted displays, or CAVE Automatic Virtual Environment systems. The off-road simulator includes a small six-degree-of-freedom motion base. This provides important cues such as orientation on off-road terrain as well as speed and roughness information not available in fixed base systems. In addition, a high-fidelity control loading system provides feedback on the steering wheel that is directly coupled with the vehicle dynamics. Important factors such as power steering boost curves, and tire aligning torque, are included in the steering model.
Canadian Aviation Electronics Ltd. (CAE) one from the world's largest independent provider of aviation training services, with more than 100 full-flight simulators installed in more than 20 locations on four continents. CAE's full flight simulator replicates in every detail the cockpit of the aircraft that it simulates. It also reproduces, with great accuracy and realism, the visual environment the aircraft appears to be flying in, including clouds, thunderstorms, and the landing approaches of airports around the world. In a military simulator, additional features such as aerial refueling or combat environments can also be simulated to reproduce authentic training exercises. CAE simulators also simulate sound and motion, including the banking and turning of the aircraft, accelerations, and the feel of tires as they roll across the bumps and cracks in the runway. Each simulator recreates the operational characteristics of a specific type of aircraft as well as the conditions, normal or abnormal, that a pilot may encounter, such as for example, a smoke in the cockpit.
For more information see: Web site www.cleverace.com |
