Carsim
Encyclopedia
CarSim is a commercial software package that predicts the performance of vehicles in response to driver controls (steering, throttle, brakes, clutch, and shifting) in a given environment (road geometry, coefficients of friction, wind). CarSim is produced and distributed by an American company, Mechanical Simulation Corporation, using technology that originated at The University of Michigan
Transportation Research Institute (UMTRI) in Ann Arbor, Michigan.
The software is used by over 30 automotive manufacturers (General Motors
, Toyota, Honda
, Ford, etc.), over 60 suppliers, and over 150 research labs and universities. The math models simulate physical tests to allow engineers to view results that are similar to test results, but which can be obtained repeatably, safely, and much quicker than is possible with physical testing. The simulation models are often used to evaluate vehicle designs that have not yet been built. Results are visualized via animation, plotted for analysis, or exported to other software for analysis using the same methods that are applied to physical test data.
The math models replicate system-level behavior with high fidelity. They contain the major effects that determine how the tire contacts the road, and how forces from the tire/road interface are transferred through the suspension to the chassis. However, they do not have details of linkage connections or structure compliance. The models have been validated repeatedly by manufacturers for reproducing overall vehicle motions needed to evaluate handling, directional and roll stability, braking, and acceleration. On the other hand, they do not include component details needed to determine durability, fatigue, or high-frequency vibrations.
The math models are generated with a symbolic multibody code generator called VehicleSim Lisp (originally named AutoSim) that was developed by one of the company founders at UMTRI. The machine-generated code is highly optimized to achieve fast computation, such that the math models run much faster than real time. Starting in 1998, real-time versions of CarSim have been available for testing hardware in the loop (HIL). The math models are used directly in over 350 driving simulator
s to provide physics models that have been validated over most conditions of interest.
The main applications of the CarSim software are:
The same technology is used in BikeSim, a program for simulating motorcycle and scooter dynamics, and TruckSim, used to simulate dynamics of commercial vehicles with dual tires, trailers, and more than two axles per unit.
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
Transportation Research Institute (UMTRI) in Ann Arbor, Michigan.
The software is used by over 30 automotive manufacturers (General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
, Toyota, Honda
Honda
is a Japanese public multinational corporation primarily known as a manufacturer of automobiles and motorcycles.Honda has been the world's largest motorcycle manufacturer since 1959, as well as the world's largest manufacturer of internal combustion engines measured by volume, producing more than...
, Ford, etc.), over 60 suppliers, and over 150 research labs and universities. The math models simulate physical tests to allow engineers to view results that are similar to test results, but which can be obtained repeatably, safely, and much quicker than is possible with physical testing. The simulation models are often used to evaluate vehicle designs that have not yet been built. Results are visualized via animation, plotted for analysis, or exported to other software for analysis using the same methods that are applied to physical test data.
The math models replicate system-level behavior with high fidelity. They contain the major effects that determine how the tire contacts the road, and how forces from the tire/road interface are transferred through the suspension to the chassis. However, they do not have details of linkage connections or structure compliance. The models have been validated repeatedly by manufacturers for reproducing overall vehicle motions needed to evaluate handling, directional and roll stability, braking, and acceleration. On the other hand, they do not include component details needed to determine durability, fatigue, or high-frequency vibrations.
The math models are generated with a symbolic multibody code generator called VehicleSim Lisp (originally named AutoSim) that was developed by one of the company founders at UMTRI. The machine-generated code is highly optimized to achieve fast computation, such that the math models run much faster than real time. Starting in 1998, real-time versions of CarSim have been available for testing hardware in the loop (HIL). The math models are used directly in over 350 driving simulator
Driving simulator
Driving simulators are used for entertainment as well as in training of driver's education courses taught in educational institutions and private businesses...
s to provide physics models that have been validated over most conditions of interest.
The main applications of the CarSim software are:
- Test engineers simulate hundreds of tests ahead of time to identify problems or clear designs that show no problems.
- Developers of advanced controls (brakes, stability, traction, etc.) test their simulated control designs with the simulated vehicle. In these applications, CarSim simulates the basic vehicle dynamic behavior as a plug-in to controller design software such as SimulinkSimulinkSimulink, developed by MathWorks, is a commercial tool for modeling, simulating and analyzing multidomain dynamic systems. Its primary interface is a graphical block diagramming tool and a customizable set of block libraries. It offers tight integration with the rest of the MATLAB environment and...
(from Mathworks), LabVIEWLabVIEWLabVIEW is a system design platform and development environment for a visual programming language from National Instruments. LabVIEW provides engineers and scientists with the tools needed to create and deploy measurement and control systems.The graphical language is named "G"...
(from National InstrumentsNational InstrumentsNational Instruments Corporation, or NI , is an American company with over 5,000 employees and direct operations in 41 countries. Headquartered in Austin, Texas, it is a producer of automated test equipment and virtual instrumentation software...
), or custom code (MATLABMATLABMATLAB is a numerical computing environment and fourth-generation programming language. Developed by MathWorks, MATLAB allows matrix manipulations, plotting of functions and data, implementation of algorithms, creation of user interfaces, and interfacing with programs written in other languages,...
, Visual Basic, C/C++, etc.) - Car manufacturers and suppliers test actual controller hardware using real-time HIL systems.,
- Researchers and others use the CarSim math models in driving simulatorDriving simulatorDriving simulators are used for entertainment as well as in training of driver's education courses taught in educational institutions and private businesses...
s, ranging from low-cost systems using game controller up to full-scale large motion simulators such as the Toyota simulator.
The same technology is used in BikeSim, a program for simulating motorcycle and scooter dynamics, and TruckSim, used to simulate dynamics of commercial vehicles with dual tires, trailers, and more than two axles per unit.