MRA Vehicle Dynamics Simulation (VDS) is a comprehensive vehicle model of the automobile, suitable for generating transient responses (time histories) for a wide range of maneuvers over a varying terrain. The simulation is conducted through a time-based numerical integration of a lumped-parameter vehicle model with 16 degrees of freedom.

The degrees of freedom are: 6 chassis, 4 vertical unsprung, 4 rotational unsprung and 2 steering (rear wheel steering is modeled and is an option). The equations of motion are descended from those derived by the Vehicle Dynamics Group at Cornell Aeronautical Laboratories in the late 1960's. Predecessors to VDMS include DK-4 and HVOSM.

Inputs to the program are via ASCII data files which are compatible, with small exceptions, with MMM and LTS. Numerous modeling choices (input descriptions) are available for various vehicle subsystems. Steering wheel input can be open loop or via a "Preview-Predictor" model. VDS contains a highly detailed steering system model including the steering column, power steering unit and steering/suspension geometry.

VDS runs in a Windows DOS-box. At each integration time step nearly 220 output variables are recorded. These are readily graphed using the included Windows GUI plotter.

Purchase of a VDS license includes the program, sample data files, a full day of training at MRA, a 150 page User's Manual and support by MRA. MRA's intent is to ensure that the purchaser can take full advantage of the simulation.

While MMM gives the "big picture", VDS is useful for addressing specific areas of vehicle dynamics analysis and problem solving. Follow the links below to take a tour of VDS.

VDS TOUR

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