The brake drift maneuver was first implemented to address brake pull and drift pull issues. The simulation allowed the modeler to vary side to side brake split, road crown, and various alignment settings to investigate the issue. As the vehicle dynamic process became more of an up-front tool for vehicle design, the simulation has been used to not only address the drift issues, but also to evaluate other braking performance characteristics.

The brake drift maneuver is a full-vehicle simulation which begins with the vehicle traveling straight ahead at 55 mph (or a user specified speed). At time 0.2 seconds, the traction controller is turned off, which is quickly followed by brake controller activation. The vehicle is then slowed at a constant 0.5g deceleration to five mph when a flag indicates the simulation should be stopped. Throughout the maneuver, the steering wheel is held fixed.

When Adams/Chassis is called to build a brake drift simulation, the user must define several variables specific to this type of simulation. A listing of the Adams/Chassis requested variables are as follows, with the default values in parentheses:

Brake Drift Simulation Default settings: Steering wheel motion fixed at 0.00 Traction controller off time is 0.2 sec Braking controller on time is 0.2 sec

Braking Control Options Enter braking deceleration (g's) [0.500000]: .5 [ 0.50] selected. Enter brake proportioning (% front) [0.700000]: .7 [ 0.70] selected. Enter front brake split (% left) [0.500000]: .5 [ 0.50] selected.

Once you select these variables, Adams/Chassis modifies the generic model in three ways, SPLINE/61, SPLINE/71 and DIF/60. SPLINE/61 is the brake deceleration spline which specifies the decelerations g's at specific times during the simulation. SPLINE/71 specifies the brake proportioning front to rear and DIF/60 identifies the id of the brake deceleration spline, in this case, 61.