History of Mechanical Simulation

Mechanical Simulation Corporation was founded in 1996 to make simulation technology developed in the course of 30 years of research available to the automotive community.

Vehicle Dynamics

Starting in the late 1960's, the University of Michigan Transportation Research Institute (UMTRI) was a pioneer in developing knowledge about vehicle dynamic behavior and modeling. Knowledge about vehicle dynamics came from three activities:

1. experimental testing and analysis of results;
2. development of models and algorithms to try to duplicate the observed behavior; and
3. special laboratory tests and measurements to obtain the vehicle/tire properties needed to use the models.

The early research projects included many experimental tests, where modeling assumptions were validated by direct comparison with test data.

The modeling concepts and assumptions developed at UMTRI and elsewhere underlie the CarSim and TruckSim models. In addition to emphasizing the correctness of the math, we apply the research results to include vehicle properties that are both significant and measurable.

VehicleSim and our Math Models

In the late 1980's, one of the UMTRI scientists (Dr. Michael Sayers, a founder) developed the world's most advanced automated code generation capability for vehicles and other multibody systems. The code generator — AutoSim (the predecessor of VehicleSim)— was used at UMTRI to create new vehicle models with unparalleled computational efficiency.

In 2005, development began on a new simulation design called VehicleSim (VS) that combines the optimization methods from AutoSim with a new simulation architecture that allows users to extend models at run-time with a variety of methods. Completed in 2007, CarSim 7 is the first product to fully use the new VS technology.

Users can modify some of the model equations of motion, add new equations with the built-in VS command language, integrate with other software such as Simulink, LabView, and ETAS/ASCET, or add custom C code to work with the math model using the VS application program interface (API).

VehicleSim technology supports several characteristics of our software development:

1. We can create new models and extend existing models quickly. (All of the equations involving multibody dynamics are machine-generated with a symbolic multibody program called VehicleSim Lisp.)
2. Our models run fast, as required to support real-time and optimization applications.
3. We can support new interface and operating-system requirements rapidly by using the VS API.
4. If the API or the math model architecture does not work for some new application, we can extend VehicleSim Lisp or the VS API as needed.

Graphical User Interface

The main limitation to the use of vehicle dynamics simulation is the time needed to learn how to use the software (training and education).

Extensive development was done at UMTRI in the 1990's to create a database browser for simulations, now called the VS browser, and standard data files for simulation (ERD files) that are used in our products. Since 1996, the development has continued at Mechanical Simulation. Our vehicle dynamics simulation products have become the most popular in the world, in part because they are exceptionally easy to use.

Ongoing Development and Improvements

As the ease-of-use and efficiency of CarSim, BikeSim, and TruckSim make simulation accessible to more engineers, we are working to make the software more productive for existing users, and also to provide simulation to engineers and planners who have never considered the use of vehicle math models.

Although we continue to improve the math models, we are also working to extend (1) the ways that the models can be run and (2) the ways the associated data can be transferred and shared.