EDSVS

Name	EDSVS (Engineering Dynamics Single Vehicle Simulator)
Description	EDSVS is a simulation of the response of a motor vehicle to driver braking and steering inputs. It is based on a program called TBST developed at the University of Michigan Transportation Research Institute. As a simulation, the user provides a set of initial conditions and a table of driver inputs. EDSVS determines how the vehicle responds to the inputs of generating the path, velocity, acceleration, tire forces and other data as a function of time. EDSVS is a 3-degree of freedom (yaw plane) analysis; suspension effects are ignored. Load transfers are calculated on a quasi-static basis. The program is particularly well suited to low-to-moderate road friction regimes. It also serves as an excellent first-order approximation for higher friction regimes. Accident investigators can use EDSVS to determine how a driver may have lost vehicular control. By repeated adjustments of the braking and steering input tables, the user will converge on those driver inputs which match accident site evidence. It can also be used to study the handling effects due to changes in vehicle weight distribution, wheel base, track width, CG height, tire friction, cornering stiffness, and other parameters.
Input	Title, Class, Configuration (tandems, duals, antilock), Initial Position (x, y, psi) and Velocity (forward, lateral, angular), Simulation Time, Vehicle Dimensions (inter-tandem, wheelbase, track width, CG longitudinal, lateral, and vertical location), Vehicle Inertia (weight and yaw moment), Payload Data (CG location, weight, yaw moment), Tire Data (peak/slide friction, slid at peak friction, cornering stiffness), Brake Force Table (each wheel), Steer Angle Table (front wheels). By selecting AUTOLOAD, the user can automatically load all of the required input data (except brake force and steer tables) for a given class vehicle. Various parameters can then be changed at the user's option prior to execution.
Output	Path (x, y, psi, turn radius, sideslip), Velocity (longitudinal, lateral, angular), Acceleration (U-dot, V-dot, longitudinal, lateral, angular), Tire Loads (FX, FY, FZ), Load Transfers (dFX, dFY), Tire Slip Angles, Brake Force, Steer Angle, Echo of Vehicle Data.
Graphics	Vehicle Trajectory (various formats include continuous, variable time increment, freeze and movie) with simultaneous display of key data; Plotting of output data vs. time.
Other Features	Input session logic checks data as it is entered; the user may change any data prior to execution; the user may request a detailed explanations of the required input, including answer format and sample answer; rerun and file-saving options. Output session uses a spread sheet format, allowing the user to manipulate each data column into the position desired for viewing and/or printing; variable time increment for output; file saving option.