Keyframe Multimedia, Inc.

For vehicle-involved accident recreation, we employ a physics-based software engine specifically designed to calculate the behavior of a vehicle based upon real world dynamics. This can give us a very reasonable idea of the outcome of how a vehicle may have performed in a single car incident or multi-vehicle incident. We can plot various speed targets along different parts of the vehicles' path in order to try to determine what veleocity a vehicle may have been going in order to flip, skid and lose control.

Factors Programmable Into Vehicle Simulation

Mass

• The weights of the basic individual components of the vehicle which include Body, Front Wheels, Rear Wheels, Engine and Center of Gravity. These settings describe the overall weighting of the vehicle.

Aerodynamics

• Drag Coefficient for the vehicle
• Downforce Coefficient on the Front
• Downforce Coefficient on the Rear

Braking

The effects of anti-lock braking can also be applied to the simulation or left out if desired. 

• Brake Torque Front
• Brake Torque Rear
• Handbrake Torque

Power Train

• Real-wheel drive
• Front-wheel drive
• Four-wheel drive
• Engine torque
• Gear Ratio - for up to 7 gears can be applied
• RPM-based automated gear shifting (both up and down)
• Traction control for wheel slippage can be adjusted as well as ABS braking slip ratio.

Chassis

Springs and Dampers are one unit and form together, commonly referred to as shock absorbers. These variables can be input and computed into the vehicle's overall performance.

• Spring Rate Front
• Spring Rate Rear
• Damper Rate Front
• Damper Rate Rear
• Pitch of Springs
• Camber

Speed Points

Speed points or targets can be placed all along the vehicle's path. These serve to tell the physics engine a goal speed at which the vehicle, with its current settings, should be traveling. It allows for a variety of experimentation to determine speed-related cause & effect. Since the physics software is based on real-world dynamics, it would be unrealistic to expect a 2,500 pound vehicle to meet a speed target of 60 mph within 20 feet from where it started. The purpose of the speed points is to tell the physics engine that we would like to attempt to have the vehicle moving at a particular speed at this point and place in time, although it may not always be physically possible to have that happen. If it is not physically possible, then the physics software will attempt to get as close to the target as it can.

The neat thing about this system is that if you try to make the target vehicle navigate a 90 degree turn at 50 mph, the laws of physics will kick in and cause loss of control, if not a rollover.