Simulation Makes Vehicles Real
Advances in simulation software include integration with other CAx systems, simulations of more domains, and stunning virtual reality.
Simulation software doesn't have a C-acronym that neatly fits into CAx (computer-aided everything). And yet, simulation is very much a part of computer-aided design (CAD), computer-aided engineering (CAE), and so on. This brings up the proverbial chicken-and-egg problem: Which comes first—simulation or design, engineering, and analysis? In an ideal world, all of these disciplines should play off each other to come up with an optimize design for a final product. Enhancements to simulation software continue to do just that through interoperability, expanding the simulation problem set, and increasingly realistic simulations.
Interoperability and depth of simulation
Comsol Multiphysics from Comsol (www.comsol.com
) is a multiphysics modeler and simulator. The latest version adds support for Parasolid from Siemens PLM Software (www.siemens.com/plm
); a new bidirectional, fully associative Autodesk Inventor (www.autodesk.com
) interface (one already exists for SolidWorks; www.solidworks.com
); and a CAD Import Module that runs on the Apple Macintosh (www.apple.com
). The Parasolid support lets users repair or defeature individual parts in an assembly, which cuts the time spent meshing Parasolid geometry directly. The Inventor (and SolidWorks) interface lets users wrap any parametric sweep around any solver, including time-dependent, stationary, or eigenvalue solvers. A new AC/DC module can create geometries of printed circuit board (PCB) designs imported from ODB++ files and GDS files; NETEX-G can be used to create geometries from Gerber/drill file formats.
New model libraries in this version cover electromagnetic fields, acoustics, chemical engineering, heat transfer, viscoelasticity, and multijet reactor polymerization. The piezoelectric simulation can include structural damping, dielectric, and coupling losses. This release can also simulate viscoelastic material models and large deformations. A new time-dependent segregated solver makes this version faster than the previous one when solving for time-dependent structural mechanics, electromagnetic, acoustics, and fluid-flow simulations—three times faster for large flow models, say company officials.
Postprocessing also got enhanced. GIF and animated GIF formats are now supported. Users can customize color maps and create personalized color scales. Plus, users can now monitor solver progress and both update settings and restart the solvers as necessary.
The software sells for $8,995 and runs on Windows, Linux, Solaris, and Macintosh workstations.
Depth of automotive simulation
Cars are complex, multi-domain, linear and non-linear environments. So it's no surprise that vehicle handling is worth its own simulation tools. Imagine.Lab Vehicle Dynamics from LMS (www.lmsinternational.com
) is a set of simu-lation tools for analyzing vehicle ride, handling, and comfort. This analysis can occur during the conceptual stages of functional specification and design, well before detailed CAD or 3D models become available. As design details gel, Virtual.Lab Vehicle Motion can then be used to create detailed 3D models and simulations of vehicle handling. To help create those models, the Vehicle Motion module comes with subsystem templates for suspensions, steering, braking systems, and the driveline. The Vehicle Dynamics Control module covers individual chassis subsystems and actuators; such models can then be integrated with a single model to validate an entire chassis control design. Detailed simulations can show the real-life interactions of sensors, actuators, and active control systems with chassis and suspension systems. An interface to Mathworks' Simulink/RTW (www.themathworks.com
) is available for real-time control simulations on detailed vehicle models and to test safety-related electronic control units.
In February, LMS introduced Imagine.Lab Hybrid Vehicle, which works on the LMS Imagine.Lab AMESim multi-domain simulation system. This module lets automakers design conventional propulsion systems with on-board rechargeable energy storage systems using multi-domain libraries (IFP-Drive, IFP-Engine, Electric Motors and Drives, Powertrain). Both at the component and the entire system levels, automakers can analyze power management, electric systems, and engine sizing to determine the best architecture for hybrid power-train systems, while accounting for vehicle thermal management.
The PSA Peugeot Citroën Virtual Reality Center (www.psa-peugeot-citroen.com/en/hp1.php
) shows just how immersive and lifelike simulations can be. The center uses three types of systems to display life-sized 3D projections. First, the "CAVE" is a room surrounded by five vertical and horizontal screens stretching from floor to ceiling. Sensors on users and the stereoscopic glasses they're wearing direct projected images in real time according to the users' gaze. Inside the CAVE is a "sitting buck" for completing the impression of being inside a car. The car's interior details are displayed—in life size—all around the seat, and functional dashboard, HVAC, and entertainment controls operate, albeit in a virtual sense. Users can also be covered with movement sensors to drive a "virtual dummy"—a lifelike animation of people within a digitized, virtualized production line projected on the wall. Users can "perform" assembly operations in the virtualized environment to evaluate workstation ergonomics, worker operations, and kinematics.
Second, the "CADwall" consists of a large screen for showing life-sized models of cars and to show aerodynamic simulations. Force feedback devices involving a network of wires and motors, coupled with the CADwall, complete the sensory immersion. Users can manipulate objects in the virtual world and both see and feel other project team members. Last, the "Holobench" is a small-scale CAVE con-sisting of two perpendicular screens plus movement and force feed-back sensors for simulating assembly operations.
The primary products used in this center include 3DVIA Virtools Software Suite from Dassault Systèmes (/a2.media.3ds.com/products/3dvia/3dvia-virtools/
) for display, design reviews, assembly/disassembly applications, collaborative project reviews, and so on, and the I-Space Multi-walled stereoscopic room from Barco (www.barco.com